134022_isi Laporan.docx

CHAPTER I INTRODUCTION

1.1 Background Sensory and Integumentum System is the 16th block on semester 5 of Kurikulum Berbasis Kompetensi (KBK) system in Medical Faculty of Muhammadiyah Palembang University. One of the strategy from these curriculum is Problem Based Learning (PBL). Case tutorial is one of the implementation of this PBL methode. In this section, Students are divided into small groups and every groups will be guided by a mentor or a lecturer as a facilitator who will guide the students to solve the case. Tutorial process is a part of student’s evaluation exactly as a formative evaluation. These evaluation helps the students to reach the aim of study. Tutorial process is also requirment for students to join the block’s exam called OSOCA (Objective Structure Oral Case Analysis) which is included in summative evaluation. The aim of summative evaluation is assesing the student’s achievement in order to determine the competencies that have been achieved. Summative assessment is done by referring to the learning taxonomy proposed by Bloom that consist of cognitive, psychomotor, and affective assessment.

1.2 Purpose and Objectives The purpose and objectives of this case study tutorial, namely: 1. As a report task group tutorial that is part of KBK learning system at the Faculty of Medicine, Muhammadiyah Palembang University. 2. Can solve the case given in the scenario with the method of analysis and learning group discussion. 3. Achieving the objectives of the tutorial learning method.

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CHAPTER II DISCUSSION 2.1 Tutorial’s Data Tutor

: dr.

Moderator

:

Secretary

:

Notulis

:

Date and Time

: 1. Tuesday, November 27th 2018 Time : 08.00 to 10.30 a.m 2. Thursday, November 29st 2018 Time : 08.00 to 10.30 a.m

Rules

: 1. Everyone in the group should express their opinion 2. Gadget should be in silent mode. 3. Ask for permission if want to go outside. 4. Eating and drinking are not allowed in the room.

2.2 Case Scenario “My Eyes” Mr. Santo, 22 years old, as a “Hojex” driver, came to “Puskemas” with blurred vision in left eye since 2 days ago. Since 10 days ago, he complained left eyes of redness, pain, and yellowish white thick discharge. He didn’t come to doctor and only used eyes drop from market. He used minus glasses since 7 years ago. His friend complain about the same symptom. Physical Examination General Examination: Compos mentis Vital sign: Blood Pressure: 120/80 mmHg, Pulse Rate: 92x/minute, Respiratory Rate: 18x/minute, Temperature: 36,7oC.

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Spesific Examination Eyes: OS: VOS 4/60, pinhole insignificantly improve vision, mixed injection, yellowish white thick discharge, blepharospasm, infiltrate punctate form. OD: VOD 6/60, with correction: Spheris-2.00 become 6/6.

2.3 Clarification of Terms

Table 1. Clarification of Terms No 1.

Terms

Clarifications

Yellowish white thick Excretion from caruncula lacrimale that discharge

2.

Blepharospasm

3.

Blurred vision

4.

Redness

5.

Pinhole in signification

6.

Mixed injection

7.

Infiltrate

contained bacterial & mucous. Sudden contraction involunter muscle of eyelid. The lost of sharpness of eye sight making object appear out of focus and hazy. Excessive of blood in an eye that doe to local of general relaxtation of arteriole. An effort from someone to improve sharpness of eyesight shringking. Combination of two injections ciliary and conjunctiva injection. Infiltrating substante or a number of infiltration cell in punctate lacrimale. Lens range in frame as aid to vision -

9.

Minus glasses

Ciliary: Vasodilataton of ciliary of artery

-

Conjunctiva: Vasodilataton of ciliary posterior conjunctiva artery.

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2.4 Identification of Problems 1.

Mr.

2.

He

3.

Specific Examination Eyes: OS: VOS 4/60, pinhole insignificantly improve vision, mixed injection, yellowish white thick discharge, blepharospasm, infiltrate punctate form. OD: VOD 6/60, with correction: Spheris-2.00 become 6/6.

2.5 Analysis dan Synthesis of Problem 1.

Mr.. a. What are organs involve in this case? Answer: The organ involve in this case is Eyes.

b. How is the anatomy, physiology, and histology that involved in this case ? Answer: Anatomy - Palpebra Palpebra is in front of eyes, protect eyes from injury or trauma and excessive light. Palpebra superior is bigger and easier to move than palpebra inferior. Both of palpebra meet each other in medial angle and lateral. Fissura palpebra is a hole that has elips shape between palpebra superior and inferior, it is a place to entry saccus conjunctivae. If eyes is closed, palpebra superior will close cornea perfectly. If eyes is open and staring straight ahead , palpebra superior just close upper edge of cornea. Palpebra inferior is in the right below of cornea if eyes is open and will up just a bit if eyes is closed (Snell, 2011: 614).

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In superficial surface of palpebra is cover by skin and inner surface is contains of membrana mucosa that called conjuntivae. cilia, short and curved is in freely edge of palpebra that composed by two or three lines at the limit of mucocutaneus. There is sebacea gland, ciliaris gland and also tarsalis gland (Snell, 2011: 614).

Figure 1.1 Anatomy of Palpebra Source: Sobotta, 2006: 352

Lateral angle fissura of palpebra is more shar than medial and the location is connected with eyeball. Medial angle is globular and separated by narrow cavity that called lacus lacrimalis. In the middle of this cavity there is a small bulge that has reddish yellow that called plica seminularis is in lateral caruncula (Snell, 2011: 614). Near medial angle of eyes, cilia and tarsalis gland suddenly stopped and there is a small bulge that called papilla lacrimalis. Apex of papilla there is a small hole, punctum lacrimale, that connected with canaliculus lacrimalis. Papilla lacrimalis sticking into lacus, punctum and canaliculus will wetting tears into nose (Snell, 2011: 614).

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Figure 1.2 Palpebra and conjunctiva Source: Sobotta, 2006: 352

- Conjunctiva The conjunctiva is a thin, transparent mucous membrane overlying the anterior-most portion of the sclera and lining the inner surfaces of the eyelids. The conjunctiva is divided into the limbal, bulbar, forniceal, and palpebral regions. Associated with the conjunctiva are goblet cells, which produce mucus and eccrine glands: the conjunctival glands (of Krause) and the accessory lacrimal glands (of Wolfring). The conjunctival glands (of Krause) are concentrated in the upper fornix, whereas the accessory lacrimal glands (of Wolfring) are associated with the tarsus (Snell, 2011: 614). Conjuntiva is thin membrana mucosa that covered palpebra. Conjuntiva consists of : -

Tunica conjuntiva bulbi

-

Tunica conjuntiva palpebrum

-

Plica semilunaris

-

Fornix conjuntivae

- Lacrimal Gland and the Nasolacrimal System The lacrimal gland is nestled within the fossa of the frontal bone located in the anterior superotemporal quadrant of the orbit. The gland is divided into the orbital lobe and the palpebral lobe by the tendon of the levator palpebrae superioris. Ducts from both lobes traverse through the palpebral lobe and empty into the conjunctival

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fornix temporally. Lacrimal fluid is collected by 2 lacrimal canaliculi, which drain into the lacrimal sac at the medial canthus of the eye. These tears then drain into the inferior nasal meatus via the nasolacrimal duct (Snell, 2011: 614).

Figure 1.3 Lacrimal Apparatus Source: Sobotta, 2006: 357

Lacrimal gland consists of big pars orbitalis and small pars palpebralis. Both of that connected each other of the end lateral aponeurosis M. Levator palpebrae superior. This gland is above eyeball, anterior and superior orbita, posterior of septum orbitale. It is about 12 duct out from botton surface of gland and will boils down lateral fornix superior conjuntiva. Tears will flow and wetting cornea and will gather in lacus lacrimalis. From here, tears will enter to canaliculi lacrimales by puncta lacrimalia. Canaliculi lacrimalis walk to medial and boils down into saccus lacrimalis is in lacrimalis path behind ligamentum palpebra medial and it is the block upper edge from nasolacrimalis duct (Snell, 2011: 614). Lacrimalis duct has lenght is about 1,3 cm and out from the botton edge saccus lacrimalis. Duct will walk to botton, behind and lateral

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in canalis osseosa and will boils down to meatus nasi inferior. This estuary will protect membrana mucosa layer that called plica lacrimalis. This layer prevent the air enter by duct to saccus lacrimalis at the time of snot (Snell, 2011: 614).

Anatomy of Eyeball The adult eyeball measures about 2.5 cm in diameter of its total area, and only the anterior one-sixth is exposed; the remainder is recessed and protected by the orbit, into which it fits. Anatomically, the wall of the eyeball consists of three layers: fibrous tunic, vascular tunic, and retina (Tortora&Derrickson, 2007: 582-3). - Fibrous Tunic The fibrous tunic is the superficial coat of the eyeball and consists of the anterior cornea and the posterior sclera. The cornea is a transparent coat that covers the colored iris. Because it is curved, the cornea helps focus light onto the retina. Its outer surface consists of nonkeratinized stratified squamous epithelium. The middle coat of the cornea consists of collagen fibers and fibroblasts, and the inner surface is simple squamous epithelium. Since the central part of the cornea receives oxygen from the outside air, contact lenses that worn for long periods of time must be permeable to permit oxygen to pass through them. The sclera, the “white” of the eye, is a layer of dense connective tissue made up mostly collagen fibers and fibroblasts. The sclera covers the entire eyeball except the cornea; it gives shape to the eyeball, makes it more rigid, and protecrs its inner parts. At the junction of the sclera and cornea is an opening known as the scleral venosus sinus (canal of Schlemm). A fluid called aqueous humor drains into the sinus (Tortora&Derrickson, 2007: 583).

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Figure 1.4 Structure of the Eyeball Source: Sobotta, 2006: 362 - Vascular Tunic The vascular tunic or uvea is the middle layer of the eyeball. It is composed of three parts: choroid, ciliary body, and iris. The highly vascularized choroid, which is the posterior portion of the vascular tunic, lines most of the internal surface of the sclera. Its numerous blood vessels provide nutrients to the posterior surface of the retina. The choroid also contains melanocytes that produce the pigment melanin, which cause this layer to appear dark brown in color. Melanin in the choroid absorbs stray light rays, which prevents reflection and scattering of light within the eyeball. As a result, the image cast on the retina by the cornea and lens remains sharp and clear (Tortora&Derrickson, 2007: 583). In the anterior portion of the vascular tunic, the choroid becomes the ciliary body. It extends from the ora serrata, the jagged anterior

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margin of the retina, to a point just posterior to the junction of the sclera and cornea. Like the choroid, the ciliary body appears dark brown in color because it contains melanin-producing melanocytes. In addition, the ciliary body consist of ciliary processes and ciliary muscle. The ciliary processes are protrusions or folds on the internal surface of the ciliary body. They contain blood capillaries that secrete aqueous humor. Extending from the ciliary process are zonular fibers (suspensory ligaments) that attach to the lens. The ciliary muscle is acircular band of smooth muscle. Contraction or relaxation of the ciliary muscle changes the tightness of the zonular fiber, which alters the shape of the lens, adapting it for near or far vision (Tortora&Derrickson, 2007: 583).

Figure 1.5 Iris Source: Sobotta, 2006: 364 The iris, the colored portion of the eyeball, is shaped like a flattened donut. It is suspended between the cornea and the lens and is attached at its outer margin to the ciliary processes. It consists of melanocytes and circular and radial smooth muscle fibers. The amount of melanin in the iris determines the eye color (Tortora&Derrickson, 2007: 583).

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A principal function of the iris is to regulate the amount of light entering the eyeball through the pupil, the hole in the center of the iris. The pupil appears black because, as you look through the lens, you see heavily pigmented back of the eye (choroid and retina). However, if bright light is directed into the pupil, the reflected light is red because of the blood vessles on the surface of the retina. It is for the reason that person’s eyes appear red in photograph (“red eye”) when a bright light is directed to the pupil. Autonomic reflexes regulate pupil diameter in response to light levels. When bright light stimulates the eye, parasympathetic fibers the occulomotor (III) nerve stimulate the circular muscles (sphincter pupillae) of the iris to contract, causing a decrease in the size of the pupil (constriction). In dim light, sympathetic neurons stimulate the radial muscles (dilator pupillae) of the iris to contract, causing an increase in the pupil’s size (dilatation) (Tortora&Derrickson, 2007: 583). - Retina The third and inner coat of eyeball, the retina, lines the posterior three-quarters of the eyeball and is the beginning of the visual pathway. The optic disc is the site where the optic (II) nerve exits the eyeball. Bundled together with the optic nerve are the central retinal artery, a branch of opthalmic artery, and the central retinal vein. Branches of the central retinal artery fan out to nourish the anterior surface of the retina; the central retinal vein drains blood from the retina through the optic disc. Also visible are the macula lutea and central fovea (Tortora&Derrickson, 2007: 583-4). The retina consists of a pigmented layer and a neural layer. The pigmented layer is a sheet of melanin-containing epithelial cells located between the choroid and the neural part of the retina. The melanin in the pigmented layer of the retina, like in the choroid, also helps to absord stray light rays. The neural layer of the retina is multilayered outgrowth of the brain that processes visual data

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extensively before sending nerve impulses into axons that form the optic nerve (Tortora&Derrickson, 2007: 855).

Figure 1.6 Optic Nerve Source: Sobotta, 2006: 368

Three distinct layers of retinal neurons: the photoreceptor layer, the bipolar cell layer, and the ganglion cell layer, are separated by two zones, the outer and inner synaptic layers, where synamptic contacts are made. Note that light passes through the ganglion and bipolar cell layer and both synaptic layers before it reaches the photoreceptor layer. Two other types of cell present in the bipolar cell layer of the retina are called horizontal cells and amacrine cells. These cells from laterally directed neural circuits that modify the signals being transmitted along the pathway from photoreceptor to bipolar cells to ganglion cells (Tortora&Derrickson, 2007: 855). The macula lutea is in the exact center of the posterior portion of the retina, at the visual axis of the eye. The central fovea, a small depression in the center of macula lutea, contains only cones cells. In addition, the layers of bipolar and ganglion cells, which scatter

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light to some extent, do not cover the cones here; these layers are displaced to the periphery of the central fovea. As a result, the central fovea is the area of highest visual acuity or resolution (Tortora&Derrickson, 2007: 855). - Lens Behind the pupil and iris, within the cavity of the eyeball, is the lens. Proteins calles crystallins, arranged like the layers of an onion, make up the lens, which normally is perfectly transparent and lacks blood vessles. It is enclosed by a clear connective tissue capsule and held in position by encircling zonular fibers, which attach to the ciliary processes. The lens helps focus images on the retina to facilitate clear vision (Tortora&Derrickson, 2007: 855).

Figure 1.7 Lens Source: Sobotta, 2006: 366 Interior of the Eyeball The lens divides the interior of the eyeball into two cavities: the anterior cavity and vitreous humor. The anterior cavity, the space anterior to the lens, consists of two chambers. The anterior chamber lies between the cornea and the iris. The posterior chamber lies behind the iris and in front of the zonular fibers and lens. Both chamber of the

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anterior cavity are filled with aqueous humor, a watery fluid that nourishes the lens and cornea. Aqueous humor continually filters out of blood capillaries in the ciliary processes and enters the posterior chamber. It then flows forward between the iris and the lens, through the pupil, and into the anterior chamber. From the anterior chamber, aqueous humor drains into the scleral venosus sinus (Canal of Schlemm) and then into the blood. Normally, aqueous humor is completely replaced every 90 minutes (Tortora&Derrickson, 2007: 855-6). The second, and larger, cavity of the eyeball is the vitreous chamber, which lies between the lens and the retina. Within the vitreous chamber is the vitreous body, a jellylike substance that holds the retina flush against the choroid, giving the retina an even surface for the reception of clear images. It is formed during embryonic life and consists of mostly water plus collagen fibers and hyalaronic acid. The vitreous body also contains phagocytic cells that remove debris, keeping this part of the eye clear for unobstructed vision (Tortora&Derrickson, 2007: 856).

Vascular Supply and Drainage of Eyes The arterial input to the eye is provided by several branches from the ophthalmic artery, which is derived from the internal carotid artery. These branches include the central retinal artery, the short and long posterior ciliary arteries, and the anterior ciliary arteries. Venous outflow from the eye is primarily via the vortex veins and the central retinal vein, which merge with the superior and inferior ophthalmic veins that drain into the cavernous sinus, the pterygoid venous plexus and the facial vein. In some species (e.g., rodents and lagomorphs), the orbital veins form a sinus (Kiel, 2011). The iris and ciliary body are supplied by the anterior ciliary arteries, the long posterior ciliary arteries and anatosmotic connections from the

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anterior choroid. The anterior ciliary arteries travel with the extraocular muscles and pierce the sclera near the limbus to join the major arterial circle of the iris. The long posterior ciliary arteries (usually two) pierce the sclera near the posterior pole, then travel anteriorly between the sclera and choroid to also join the major arterial circle of the iris. The major arterial circle of the iris gives off branches to the iris and ciliary body. Most of the venous drainage from the anterior segment is directed posteriorly into the choroid and thence into the vortex veins (Kiel, 2011).

Figure 1.8 Opthalmic Artery Source: Sobotta, 2006: 376

The arterial supply of the conjunctiva arteries from the two palpebras arches in eash eyelid and from anterior cilliary arteries. The palpebral arches are the large marginal and smaller peripheral, running respectively along the marginal and peripheral borders of the tarsal plates. The large marginal arch run 3mm from the free border of the eyeid between tarsal plate and the orbicularis is oculi muscle branches pass from one arch to the other in front and behind the tarsal plates. It is the arteries on the posterior surface of the tarsal plat that supply the palpebral cinjunctiva (Snell, 2011).

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Branches from the peripheral arch supply the supperiois and inferior conjunctival fornics. Many then run under; the bulbar conjunctiva, forming the posterior conjunctival arteries, to supply the bulbar conjunctiva; these arteries, the proceed toward the cornea. At the limbus they anatomose with the anterior conjunctival arteries, which are branches of the anterior cilliary arteries. The anterior cilliary arteries arise from th emuscular branches of the ophtalmis artery to the rectus muscles. Some person have no peripheral arterial arch to the lower lid. In these subjects the margial arch supplies the conjunctiva along with the anterior cilliary arteries (Snell, 2011).

Figure 1.9 Opthalmic Vein Source: Sobotta, 2006: 376

The conjunctival veins are more numerous that the arteries. They accompany the arteries and drain into the palperbral veins or directly into the superior and inferior ophtalmic nerve. The retina is supplied by the central retinal artery and the short posterior ciliary arteries. The central retinal artery travels in or beside the optic nerve as it pierces the sclera then branches to supply the layers of the inner retina (i.e., the layers closest to the vitreous compartment). There are marked species differences in the inner retinal vascularization, with primates having a complex 4-zone arrangement and an avascular zone at the fovea,

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lagomorphs having a rather simple narrow band of superficial vessels, rodents having a wagon-wheel spoke-like arrangement and guinea pigs having no inner retinal vessels. Retinal venules and veins coalesce into the central retinal vein, which exits the eye with the optic nerve parallel and counter-current to the central retinal artery (Snell, 2011). The short posterior ciliary arteries (typically 6-12) pierce the sclera around the optic nerve then arborize to form the arterioles of the dense outer layer of conduit vessels of the choroid. The arterioles the give off roughly perpendicular terminal arterioles that supply lobules of choriocapillaries

that

comprise

the

sheet-like

layer

of

the

choriocapillaris adjacent to Bruch’s membrane, the retinal pigment and the outer segments of the photoreceptors (Kiel, 2011). The vascular supply of the optic nerve is complex. The optic nerve has three zones referenced to the lamina cribosa, the connective tissue extension of the sclera through which the optic nerve axons and the central retinal artery and vein pass. The prelaminar (i.e., inside the eye relative to the lamina cribosa) optic nerve is supplied by collaterals from the choroid and retina circulations. The laminar zone is supplied by branches from the short posterior ciliary and pial arteries. The post laminar zone is supplied by the pial arteries. Venous drainage is via the central retinal vein and pial veins. For the optic nerve vessels, the laminar zone marks the transition from exposure to the IOP to the cerebral fluid pressure within the optic nerve sheath (Kiel, 2011).

Histology Fibrous Layer This layer includes two major regions, the posterior sclera and anterior cornea, joined at the limbus (Mescher, 2013). - Sclera

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The fibrous, external layer of the eyeball protects the more delicate internal structures and provides sites for muscle insertion. The white posterior five-sixths of this layer is the sclera, which encloses a portion of the eyeball about 22 mm in diameter in adults. The sclera averages 0.5 mm in thickness and consists mainly of dense connective tissue, with flat bundles of type I collagen parallel to the organ surface but intersecting in various directions; microvasculature is present near the outer surface. Tendons of the extraocular muscles which move the eyes insert into the anterior region of the sclera. Posteriorly the sclera thickens to approximately 1 mm and joins with the epineurium covering the optic nerve. Where it surrounds the choroid, the sclera includes an inner suprachoroid lamina, with less collagen, more fibroblasts, elastic fibers, and melanocytes (Mescher, 2013). - Cornea In contrast to the sclera, the anterior one-sixth of the eye—the cornea—is transparent and completely avascular. A section of the cornea shows five distinct layers according to Mescher (2013): - An external stratified squamous epithelium; - An anterior limiting membrane (Bowman’s membrane), which is the basement membrane of the external stratified epithelium; - The thick stroma; - A posterior limiting membrane (Descemet’s membrane), which is the basement membrane of the endothelium; and - An inner simple squamous endothelium. The stratified surface epithelium is nonkeratinized, five or six cell layers thick, and comprises about 10% of the corneal thickness. The basal cells have a high proliferative capacity important for renewal and repair of the corneal surface and emerge from stem cells in the corneoscleral limbus that encircles the cornea. The flattened surface

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cells have microvilli protruding into a protective tear film of lipid, glycoprotein, and water. As another protective adaptation, the corneal epithelium also has one of the richest sensory nerve supplies of any tissue. The basement membrane of this epithelium, often called Bowman’s membrane, is very thick (8-10 μm) and contributes to the stability and strength of the cornea, helping to protect against infection of the underlying stroma (Mescher, 2013).

Figure 1.10. Histology of Cornea Source: Mescher, 2013 The stroma, or substantia propria, makes up 90% of the cornea’s thickness and consists of approximately 60 layers of parallel collagen bundles aligned at approximately right angles to each other and extending almost the full diameter of the cornea. The uniform orthogonal array of collagen fibrils contributes to the transparency

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of this avascular tissue. Between the collagen lamellae are cytoplasmic extensions of flattened fibroblast-like cells called keratocytes). The ground substance around these cells contains proteoglycans such as lumican, with keratan sulfate and chondroitin sulfate, which help maintain the precise organization and spacing of the collagen fibrils (Mescher, 2013). The posterior surface of the stroma is bounded by another thick basement membrane, called Descemet’s membrane, which supports the

internal

simple

squamous

corneal

endothelium.

This

endothelium maintains Descemet’s membrane and includes the most metabolically active cells of the cornea. Na+/K+ ATPase pumps in the basolateral membranes of these cells are largely responsible for regulating the proper hydration state of the corneal stroma to provide maximal transparency and optimal light refraction (Mescher, 2013). - Limbus Encircling the cornea is the limbus, a transitional area where the transparent cornea merges with the opaque sclera. Here Bowman’s membrane ends and the surface epithelium becomes more stratified as the conjunctiva that covers the anterior part of the sclera (and lines the eyelids). As mentioned previously, epithelial stem cells located at the limbus surface give rise to rapidly dividing progenitor cells that move centripetally into the corneal epithelium. The stroma becomes vascular and less well-organized at the limbus, as the collagen bundles merge with those of the sclera (Mescher, 2013). Also at the limbus Descemet’s membrane and its simple endothelium are replaced with a system of irregular endotheliumlined channels called the trabecular meshwork. These penetrate the stroma at the corneoscleral junction and allow slow, continuous drainage of aqueous humor from the anterior chamber. This fluid moves from these channels into the adjacent larger space of the scleral venous sinus, or canal of Schlemm, which encircles the eye.

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From this sinus aqueous humor drains into small blood vessels (veins) of the sclera (Mescher, 2013).

Vascular Layer The eye’s more vascular middle layer, known as the uvea, consists of three parts, from posterior to anterior: the choroid, the ciliary body, and the iris (Mescher, 2013). - Choroid Located in the posterior two-thirds of the eye, the choroid consists of loose, well vascularized connective tissue and contains numerous melanocytes. These form a characteristic black layer in the choroid and prevent light from entering the eye except through the pupil. Two layers make up the choroid according to Mescher (2013): - The inner choroido-capillary lamina has a rich microvasculature important for nutrition of the outer retinal layers. - Bruch’s membrane, a thin extracellular sheet, is composed of collagen

and

elastic

fibers

surrounding

the

adjacent

microvasculature and basal lamina of the retina’s pigmented layer. - Ciliary Body The ciliary body, the anterior expansion of the uvea that encircles the lens, lies posterior to the limbus. Like the choroid, most of the ciliary body rests on the sclera. Important structures associated with the ciliary body include the following according to Mescher (2013): - Ciliary muscle makes up most of the ciliary body’s stroma and consists of three groups of smooth muscle fibers. Contraction of these muscles affects the shape of the lens and is important in visual accommodation (see Lens). - Ciliary processes are a radially arranged series of about 75 ridges extending from the inner highly vascular region of the ciliary body. These provide a large surface area covered by a double

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layer of low columnar epithelial cells, the ciliary epithelium. The epithelial cells directly covering the stroma contain much melanin and correspond to the anterior projection of the pigmented retina epithelium. The surface layer of cells lacks melanin and is contiguous with the sensory layer of the retina. Cells of this dual epithelium have extensive basolateral folds with Na+/K+-ATPase activity and are specialized for secretion of aqueous humor. Fluid from the stromal microvasculature moves across this epithelium as aqueous humor, with an inorganic ion composition similar to that of plasma but almost no protein. Aqueous humor is secreted by ciliary processes into the posterior chamber, flows through the pupil into the anterior chamber, and drains at the angle formed by the cornea and the iris into the channels of the trabecular meshwork and the scleral venous sinus, from which it enters venules of the sclera. - The ciliary zonule is a system of many radially oriented fibers composed largely of fibrillin-1 and 2 produced by the nonpigmented epithelial cells on the ciliary processes. The fibers extend from grooves between the ciliary processes and attach to the surface of the lens, holding that structure in place. - Iris The iris is the most anterior extension of the middle uveal layer which covers part of the lens, leaving a round central pupil. The anterior surface of the iris, exposed to aqueous humor in the anterior chamber, consists of a dense layer of fibroblasts and melanocytes with interdigitating processes and is unusual for its lack of an epithelial covering (Mescher, 2013). Deeper in the iris, the stroma consists of loose connective tissue with melanocytes and sparse microvasculature. The posterior surface of the iris has a two-layered epithelium continuous with that covering the ciliary processes, but very heavily filled with melanin.

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The highly pigmented posterior epithelium of the iris blocks all light from entering the eye except that passing through the pupil. Myoepithelial cells form a partially pigmented epithelial layer and extend contractile processes radially as the very thin dilator pupillae muscle. Smooth muscle fibers form a circular bundle near the pupil as the sphincter pupillae muscle. The dilator and sphincter muscles of the iris have sympathetic and parasympathetic innervation, respectively, for enlarging and constricting the pupil (Mescher, 2013).

Figure 1.11 Aqueous Humor Source: Mescher, 2013 Melanocytes of the iris stroma provide the color of one’s eyes. In individuals with very few lightly pigmented cells in the stroma, light with a blue color is reflected back from the black pigmented epithelium on the posterior iris surface. As the number of melanocytes and density of melanin increase in the stroma, the iris color changes through various shades of green, gray, and brown. Individuals with albinism have almost no pigment and the pink color

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of their irises is due to the reflection of incident light from the blood vessels of the stroma (Mescher, 2013).

Lens The lens is a transparent biconvex structure suspended immediately behind the iris, which focuses light on the retina. Derived from an invagination of the embryonic surface ectoderm, the lens is a unique avascular tissue and is highly elastic, a property that normally decreases with age. The lens has three principal components according to Mescher (2013): - A thick (10-20 μm), homogeneous lens capsule composed of proteoglycans and type IV collagen surrounds the lens and provides the place of attachment for the fibers of the ciliary zonule. This layer originates as the basement membrane of the embryonic lens vesicle. - A subcapsular lens epithelium consists of a single layer of cuboidal cells present only on the anterior surface of the lens. The epithelial cells attach basally to the surrounding lens capsule and their apical surfaces bind to the internal lens fibers. At the posterior edge of this epithelium, near the equator of the lens, the epithelial cells divide to provide new cells that differentiate as lens fibers. This process allows for growth of the lens and continues at a slow, decreasing rate near the equator of the lens throughout adult life. - Lens fibers are highly elongated, terminally differentiated cells that appear as thin, flattened structures. Developing from cells in the lens epithelium, lens fibers typically become 7 to 10 mm long, with crosssection dimensions of only 2 by 8 μm. The cytoplasm becomes filled with a group of proteins called crystallins, and the organelles and nuclei undergo autophagy. Lens fibers are packed tightly together and form a perfectly transparent tissue highly specialized for light refraction.

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The lens is held in place by fibers of the ciliary zonule, which extend from the lens capsule to the ciliary body. Together with the ciliary muscles, this structure allows the process of visual accommodation, which permits focusing on near and far objects by changing the curvature of the lens. When the eye is at rest or gazing at distant objects, ciliary muscles relax and the resulting shape of the ciliary body puts tension on the zonule fibers, which pulls the lens into a flatter shape. To focus on a close object the ciliary muscles contract, causing forward displacement of the ciliary body, which relieves some of the tension on the zonule and allows the lens to return to a more rounded shape and keep the object in focus. In the fourth decade of life presbyopia (Gr. presbyter, elder + L. opticus, relating to eyes) normally causes the lenses to lose elasticity and their ability to undergo accommodation (Mescher, 2013).

Vitreous Body The vitreous body occupies the large vitreous chamber behind the lens. It consists of transparent, gel-like connective tissue that is 99% water (vitreous humor), with collagen fibrils and hyaluronate, contained within an external lamina called the vitreous membrane. The only cells in the vitreous body are a small mesenchymal population near the membrane called hyalocytes, which synthesize the hyaluronate and collagen, and a few macrophages (Mescher, 2013).

Retina The retina, the innermost tunic of the eye, develops with two fundamental sublayers from the inner and outer layers of embryonic optic cup according to Mescher (2013): - The outer pigmented layer is a simple cuboidal epithelium attached to Bruch’s membrane and the choroidocapillary lamina of the

25

choroid. This heavily pigmented layer forms the other part of the dual epithelium covering the ciliary body and posterior iris. - The inner retinal region, the neural layer, is thick and stratified with various neurons and photoreceptors. Although its neural structure and visual function extend anterior only as far as the ora serrata, this layer continues as part of the dual cuboidal epithelium that covers the surface of the ciliary body and posterior iris.

- Retina Pigmented Epithelium The pigmented epithelial layer consists of cuboidal or low columnar cells with basal nuclei and surrounds the neural layer of the retina. The cells have well-developed junctional complexes, gap junctions, and numerous invaginations of the basal membranes associated with mitochondria. The apical ends of the cells extend processes and sheath-like projections that surround the tips of the photoreceptors. Melanin granules are numerous in these extensions and in the apical cytoplasm. This cellular region also contains numerous

phagocytic

vacuoles

and

secondary

lysosomes,

peroxisomes, and abundant smooth ER (SER) specialized for retinal (vitamin A) isomerization. The diverse functions of the retinal pigmented epithelium include the following according to Mescher (2013): - The pigmented layer absorbs scattered light that passes through the neural layer, supplementing the choroid in this regard. - With many tight junctions, cells of the pigmented epithelium form an important part of the protective blood-retina barrier isolating retina photoreceptors from the highly vascular choroid and regulating ion transport between these compartments. - The cells play key roles in the visual cycle of retinal regeneration, having enzyme systems that isomerize all-trans-

26

retinal released from photoreceptors and produce 11-cis-retinal that is then transferred back to the photoreceptors. - Phagocytosis

of

shed

components

from

the

adjacent

photoreceptors and degradation of this material occurs in these epithelial cells. - Cells of pigmented epithelium remove free radicals by various protective antioxidant activities and support the neural retina by secretion of ATP, various polypeptide growth factors, and immunomodulatory factors.

Figure 1.12 Retina Source: Mescher, 2013 - Neural Retina True to its embryonic origin, the neural retina functions as an outpost of the CNS with glia and several interconnected neuronal subtypes in well-organized strata. Nine distinct layers comprise the neural retina, described here with their functional significance (Mescher, 2013).

27

Three major layers contain the nuclei of the interconnected neurons: - Near the pigmented epithelium, the outer nuclear layer (ONL) contains cell bodies of photoreceptors (the rod and cone cells). - The inner nuclear layer (INL) contains the nuclei of various neurons, notably the bipolar cells, amacrine cells, and horizontal cells, all of which make specific connections with other neurons and integrate signals from rods and cones over a wide area of the retina. - Near the vitreous, the ganglionic layer (GL) has neurons (ganglion cells) with much longer axons. These axons make up the nerve fiber layer (NFL) and converge to form the optic nerve which leaves the eye and passes to the brain. The GL is thickest near the central, macular region of the retina but it thins peripherally to only one layer of cells. Between the three layers with cell nuclei are two fibrous or “plexiform” regions containing only axons and dendrites connected by synapses: - The outer plexiform layer (OPL) includes axons of the photoreceptors and dendrites of association neurons in the INL. - The inner plexiform layer (IPL) consists of axons and dendrites connecting neurons of the INL with the ganglion cell. The rod and cone cells, named for the shape of their outer segments, are polarized neurons with their photosensitive portions aligned in the retina’s rod and cone layer (RCL) and their axons in the IPL. As shown schematically, both rod and cone cells have highly specialized outer and inner segments. All neurons of the retina are supported physically by glial cells called Müller cells. With their nuclei in the INL, Müller cells extend fine processes and branching lamellae that serve as a scaffold for the neurons and their fibers. Müller cells also organize two boundaries that appear as very thin layers within the retina according to Mescher (2013):

28

- The outer limiting layer (OLL) is a faint but well-defined series of tight and adherent junctions that form at the level of the rod and cone inner segments between the photoreceptors and Müller cell processes. The OLL forms one side of the compartment that encloses the rods and cones. - The inner limiting layer (ILL) consists of terminal expansions of other Müller cell processes that cover the collagenous membrane of the vitreous body.

Figure 1.13 Layers of Retina Source: Mescher, 2013 Rod Cells The human retina has on average 92 million rod cells. They are extremely sensitive to light, responding to a single photon, and allow some vision even with light low levels, such as at dusk or nighttime. Rod cells are thin, elongated cells (50 μm X 3 μm), composed of two functionally distinct segments. The outer segment is a modified primary

29

cilium, photosensitive and shaped like a short rod; the inner segment contains glycogen, mitochondria, and polyribosomes for the cell’s biosynthetic activity (Mescher, 2013). The rod-shaped segment consists mainly of 600 to 1000 flattened membranous discs stacked like coins and surrounded by the plasma membrane. Proteins on the cytoplasmic surface of each disc include abundant rhodopsin (or visual purple) which is bleached by light and initiates the visual stimulus. Between this outer segment and the cell’s inner segment is a constriction, the connecting stalk, which is part of the modified primary cilium arising from a basal body (Mescher, 2013). The membranous discs form by repetitive in-folding of the plasma membrane near the connecting stalk and insertion of rhodopsin and other proteins transported there from the inner segment. In rod cells the newly assembled discs detach from the plasma membrane and are displaced distally as new discs form. Eventually the discs arrive at the end of the rod, where they are shed, phagocytosed, and digested by the cells of the pigmented epithelium. Each day approximately 90 membranous discs are lost and replaced in each rod, with the process of assembly, distal movement, and apical shedding taking about 10 days (Mescher, 2013).

Cone Cells Less numerous and less light-sensitive than rods, the average 4.6 million cone cells in the human retina produce color vision in adequately bright light. There are three morphologically similar classes of cones, each containing one type of the visual pigment iodopsin (or photopsins). Each of the three iodopsins has maximal sensitivity to light of a different wavelength, in the red, blue, or green regions of the visible spectrum, respectively. By mixing neural input produced by these visual pigments, cones produce a color image (Mescher, 2013).

30

Like rods cone cells are elongated, with outer and inner segments, a modified cilium connecting stalk, and an accumulation of mitochondria and polyribosomes. The outer segments of cones differ from those of rods in their shorter, more conical form and in the structure of their stacked membranous discs, which in cones remain as continuous invaginations of the plasma membrane along one side. Also, newly synthesized iodopsins and other membrane proteins are distributed uniformly throughout the cone outer segment and, although iodopsin turns over, discs in cones are shed much less frequently than in rods (Mescher, 2013).

Figure 1.14 Rod and Cone Cells Source: Mescher, 2013 Accessory Structures of the Eye - Conjunctiva The conjunctiva is a thin, transparent mucosa that covers the exposed, anterior portion of the sclera and continues as the lining on the inner surface of the eyelids. It consists of a stratified columnar

31

epithelium, with numerous small goblet cells, supported by a thin lamina propria of loose vascular connective tissue. Mucous secretions from conjunctiva cells are added to the tear film that coats this epithelium and the cornea (Mescher, 2013). - Eyelids Eyelids are pliable structures containing skin, muscle, and conjunctiva that protect the eyes. The skin is loose and elastic, lacks fat, and has only very small hair follicles and fine hair, except at the distal edge, where large follicles with eyelashes are present. Associated with the follicles of eyelashes are sebaceous glands and modified apocrine sweat glands. Beneath the skin are striated fascicles of the orbicularis oculi and levator palpebrae muscles that fold the eyelids. Adjacent to the conjunctiva is a dense fibroelastic plate called the tarsus that supports the other tissues. The tarsus surrounds a series of 20 to 25 large sebaceous glands, each with many acini secreting into a long central duct that opens among the eyelashes. Oils in the sebum produced by these tarsal glands, also called Meibomian glands, form a surface layer on the tear film, reducing its rate of evaporation, and help lubricate the ocular surface (Mescher, 2013). - Lacrimal Glands The lacrimal glands produce fluid continuously for the tear film that moistens and lubricates the cornea and conjunctiva and supplies O2 to the corneal epithelial cells. Tear fluid also contains various metabolites, electrolytes, and proteins of innate immunity such as lysozyme. The main lacrimal glands are located in the upper temporal portion of the orbit and have several lobes that drain through individual excretory ducts into the superior fornix, the conjunctiva-lined recess between the eyelids and the eye. The lacrimal glands have acini composed of large serous cells filled with

32

lightly stained secretory granules and surrounded by well-developed myoepithelial cells and a sparse, vascular stroma (Mescher, 2013). Tear film moves across the ocular surface and collects in other parts of the bilateral lacrimal apparatus: flowing through two small round openings (0.5 mm in diameter) to canaliculi at the medial margins of the upper and lower eyelids, then passing into the lacrimal sac, and finally draining into the nasal cavity via the nasolacrimal duct. The canaliculi are lined by stratified squamous epithelium, but the more distal sac and duct are lined by pseudostratified ciliated epithelium like that of the nasal cavity (Mescher, 2013).

Physiology - Eyelashes and eyebrows The eyelashes, which project from the border of each eyelid, and the eyebrows, which arch transversely above the upper eyelids, help protect the eyeballs from foreign objects, perspiration, and the direct rays of the eyelashes, called sebaceous cilliary glands, release a lubricating fluid into the follicles (Tortora&Derrickson, 2007). - The Lacrimal Apparatus The lacrimal apparatus is a group of structures that produces and drains lacrimal fluid, or tears. The lacrimal glands, each about the size and shape of an almond. Secrete lacrimal fluid which drains into 6-12 excretory lacrimal ducts that empty tears onto the surface of conjunctiva of the upper lid. From here the tears pass medially over the anterior surface of the eyeball to enter two small openings called lacrimal puncta. Tears then pass into two ducts, the lacrimal canals, which lead into the lacrimal sac and then into the nasolacrimal duct. This duct carries the lacrimal fluid into the nasal cavity just inferior to the inferior nasal concha. An infection of the lacrimal sacs is called dacryoscystitis. It is usually caused by a bacterial infection

33

and results in blockage of the nasolacrimal ducts. The lacrimal glands are supplied by parasympathetic fibers of the facial (VII) nerves. The lacrimal fluid produced by these glands is a watery solution containing salts, some mucus, and lysozyme, a protective bactericidal enzyme. The fluid protects, clens, lubricates, and moistens the eyeball. After being secreted from the lacrimal gland, lacrimal fluid is spread medially over the surface of the eyeball by the blingking of the eyelids. Each gland produces about 1 mL of lacrimal fluid per day (Tortora&Derrickson, 2007). Normally, tears are cleared away as fast as they are produced, either by evaporation or by passing into the lacrimal canals and then into nasal cavity. If an iritating substance make contact with conjunctiva, however, the lacrimal glands are stimulated to oversecrete, and tears accumulate. Lacrimation is a protective mechanism, as the tears dilute and wash away the irritating substance (Tortora&Derrickson, 2007). - Phototransduction The stacked membranous discs of rod and cone outer segments are parallel with the retinal surface, which maximizes their exposure to light. The membranes are very densely packed with rhodopsin or one of the iodopsin proteins; one rod contains about a billion rhodopsin molecules. Each of these visual pigments contains a transmembrane protein, the opsin, with a small, light-sensitive chromophore molecule bound to it. The vitamin A derivative called retinal acts as the chromophore of rhodopsin in rods (Mescher, 2013). Phototransduction involves a cascade of changes in the cells triggered when light hits and activates the chromophore, a basically similar process in both rods and cones. As diagrammed for a rod, in darkness rhodopsin is not active and cation channels in the cell membrane are open. The cell is depolarized and continuously

34

releases neurotransmitter at the synapse with the bipolar neurons. When retinal on rhodopsin absorbs a photon of light, it isomerizes within one picosecond from 11-cis-retinal to all-trans--retinal. This causes a configuration change in the opsin, which in turn activates the

adjacent

membrane-associated

protein

transducin,

a

heterotrimeric G protein to which opsin is coupled (Mescher, 2013).

Figure 1.15 Phototransduction Source: Mescher, 2013

Transducin activity then indirectly closes cGMP-gated Na+ channels, causing hyperpolarization which reduces the synaptic release of neurotransmitter. This change in turn depolarizes sets of bipolar neurons, which send action potentials to the ganglion cells of the optic nerve. causes the chromophore to dissociate from the opsin,

35

a process called bleaching. The free all-trans-retinal is transported from the rod into the adjacent pigmented epithelial cell where it is converted back to 11-cis-retinal, then transported back into a photoreceptor for reuse. This cycle of retinal regeneration and rhodopsin recovery from bleaching may take a minute or more and is part of the slow adaptation of the eyes that occurs when moving from bright to dim light (Mescher, 2013). - Specialized Areas of the Retina The blind spot of the retina, or optic disc, lacks photoreceptors and all conducting neurons. It occurs in the posterior area of the retina where axons in the NFL converge to produce the optic nerve which leaves the retina. The central artery and vein of the retina enter at the optic disc (Mescher, 2013). Near the optic disc, within the portion of retina directly opposite the pupil, lies a specialized area about 1.5 mm in diameter called the fovea centralis, where visual acuity or sharpness is maximal. The fovea (L. fovea, a small pit) is a shallow depression with only cone cells at its center; ganglion cells and other conducting neurons are located only at its periphery. Cone cells in the fovea are long, narrow, and closely packed. Blood vessels do not cross the fovea and light falls directly on its cones. The locations and structural adaptations of the fovea together account for the extremely precise visual acuity of this region (Mescher, 2013). Surrounding the fovea centralis is the macula lutea (L. macula, spot; lutea, yellow), or simply macula, 5 mm in diameter. Here all layers of the retina are present and the two plexiform layers are rich in various carotenoids, which give this area its yellowish color. The carotenoids have antioxidant properties and filter potentially damaging short-wavelength light, thus helping to protect the cone cells of the fovea (Mescher, 2013).

36

Within the GL of the entire retina a subset of ganglion cells serve as nonvisual photoreceptors. These neurons contain 11-cis-retinal bound to the protein melanopsin and serve to detect changes in light quantity and quality during each 24-hour dawn/dusk cycle. Signals from these cells pass via axons of the retinohypothalamic tract to the suprachiasmatic nuclei and the pineal gland, where they help establish the body’s physiologic circadian rhythms (Mescher, 2013).

c. What are the possible diseases with blurry vision with redness, pain, and yellowish white thick discharge? Answer: According to Alteveer (2012), the possible disease are: 1. Blurry vision with redness: - Keratoconjunctivitis - Keratitis - Uveitis - Endopthalmitis - Acute Glaukoma - Eye allergies, etc 2. Blurry vision with pain: - Keratoconjunctivitis - Optic neuritis - Blepharitis - Keratitis - Eye allergies, etc 3. Blurry vision with yellowish white thick discharge : - Keratokonjungtivitis - Conjunctivitis - Keratitis - Blepharitis - Eye allergies, etc

37

d. What is the relation between the age and gender and job with the complain in this case? Answer: There is no corelation between age and gender. Everyone and every age can suffer this complain. His job as hojex driver is risk factor. He often exposed by dust and discharge.

e. How is the mechanism of blurred vision and whole symptom in this case? Answer: The surface tissues of the eye and the ocular adnexa are colonized by

normal

flora

such

as streptococci, staphylococci,

and corynebacteria. Alterations in the host defense, in the bacterial titer, or in the species of bacteria can lead to clinical infection. Alteration in the flora can also result from external contamination (eg, contact lens wear, swimming, dust), the use of topical or systemic antibiotics, or spread from adjacent infectious sites (eg, rubbing of the eyes). In this case one of the risk factor from external contamination is dust and polution from vehicle. The primary defense against infection is the epithelial layer covering the conjunctiva. Disruption of this barrier can lead to infection. Secondary defenses include hematologic immune mechanisms carried by the conjunctival vasculature, tear film immunoglobulins, and lysozyme and the rinsing action of lacrimation and blinking (Yeung, 2017). Due to the infection, there will be inflammation reaction. Inflammation is a response of vascularized tissues to infections and tissue damage that brings cells and molecules of host defense from the circulation to the sites where they are needed, to eliminate the offending agents. The external manifestations of inflammation, often called its cardinal signs, are heat (calor in Latin), redness (rubor), swelling

38

(tumor), pain (dolor), and loss of function (functio laesa). After the microbe is recognized by the machropage, machropage will release some pro-inflammatory mediators such as TNF, IL-1, IL-2, IL-6, histamine, and prostaglandin that lead to the process of dilatation of small vessels, leading to increase in blood flow and emigration of the leukocytes from the microcirculation (Abbas, et al., 2015: 60). In this case, the artery that vasculate the conjunctiva that is posterior conjunctiva artery become dilate and show as redness in the eye (Abbas, et al., 2015: 60). In response to the tissue injury of the conjunctiva, it wil activate the peripheral pain receptors and their specific A delta and C sensory nerve fibers (nociceptors) through the sensory nerve of opthalmica division from trigeminus nerve. Then the pain fibers enter the spinal cord at the dorsal root ganglia and synapse in the dorsal horn. From there, fibers cross to the other side and travel up the lateral columns to the thalamus and then to the cerebral cortex, and this process manifest as pain in the eye (Sherwood, 2014). Emigration of the leukocytes from the microcirculation, their accumulation in the focus of injury, and their activation to eliminate the offending agent leading to the formation of discharge. In this case, the formation of yellowish white thick discharge is caused by the leukocytes which phagocytes the microbes (bacteria) (Abbas, et al., 2015: 60). During the infection, Mr.Santo didn’t get adequate treatment, leads to another infection of the eye structure that is cornea. The infection spread diffusely through the epithelial of conjuctiva bulbi to the epithelial of cornea. So the interruption of an intact corneal epithelium and/or abnormal tear film permits entrance of microorganisms into the corneal epithelium to cause infection. Virulence factors may initiate microbial invasion, or secondary effector molecules may assist the infective process. The inflammation of the cornea makes the cornea become cloudy and distrub the refraction function of the cornea. The

39

cornea can not refract incoming light rays to focus them on the retina and show as blurry vision (Deschenes, 2017).

f. What is the relation between Mr. Santo complained in 10 days ago and 2 days ago? Answer: Ten days ago Mr. Santo complained his left eyes red, pain, and have yellowish white thick discharge. Probably because of conjunctivitis due to bacterial infection but because of inadecuate treatment, the bacterial spread to deeper organ such as cornea and blurry vision since two days ago is a sign of infection in cornea (Deschenes, 2017).

2.

He didn’t come to doctor and only used eyes drop from market. He used minus glasses since 7 years ago. His friend complain about the same symptom. a. What is the meaning of he didn’t come to doctor and only used eyes drop from market? Answer: The meaning Mr. Santo didn’t come to doctor and only used eyes drop prom masket is to tell us that Mr. Santo never get doctor treatment before, and never get doctor treatment before can make bad progression like Mr. Santo complain 2 days ago.

b. How is the pharmacology of eyes drop? Answer: Frequently used eye drops contain Tetrahydrozoline Hydrochloride. Tetrahydrozoline is applied topically to the conjunctiva to temporarily relieve congestion, itching, and minor irritation, and to control hyperemia in patients with superficial corneal vascularity. Ocular decongestants

are

ineffective

in

the

treatment

of

delayed

hypersensitivity reactions such as contact dermatoconjunctivitis. The

40

vasoconstrictor effect of tetrahydrozoline may be used during some ocular diagnostic procedures (NCBI, 2017). The mechanism of action of tetrahydrozoline has not been conclusively determined. Most pharmacologists believe that the drug directly stimulates a-adrenergic receptors of the sympathetic nervous system and exerts little or no effect on beta-adrenergic receptors. Following topical application of tetrahydrozoline to the conjunctiva, small arterioles are constricted and conjunctival congestion is temporarily relieved, but reactive hyperemia may occur. The drug also may produce mydriasis when applied to the conjunctiva, but this effect is usually minimal with the concentrations used as ocular decongestants. Intranasal application of tetrahydrozoline results in constriction of dilated arterioles and reduction in nasal blood flow and congestion. In addition, obstructed eustachian ostia may be opened. Nasal ventilation and aeration are improved temporarily (NCBI, 2017). Following topical application of tetrahydrozoline hydrochloride solutions to the conjunctiva or nasal mucous membranes, local vasoconstriction usually occurs within a few minutes and may persist for 4-8 hours. Occasionally, enough tetrahydrozoline may be absorbed to produce systemic effects (NCBI, 2017).

c. What is the meaning of Mr. Santo used minus glasses since 7 years ago? Answer: It means that Mr.Santo has a refractive disorder, which is myopia. People with myopia will be corrected with spheris minus lens (Ilyass,2013). Synthesis: Myopia known as nearsightedness. Myopia occurs when the eye grows too long from front to back. Instead of focusing image on the retina-the light-sensitive tissue in the back of the eye- the lens of the

41

eye focuses in the image in front of the retina. Myopia also can be the result of a cornea-the eye’s outermost layer- that is too curved for the length of the eyeball or a lens that is to thick. The risk factor people with myopia are genetics factor and enviroment factor. The genetic factor is take the biggest role in the incident of myopia (Sherwood, 2013). Myopia occurs when the eyeball is too long, relative to the focusing power of the cornea and lens of the eye This causes light rays to focus at a point in front of the retina, rather than directly on its surface. Nearsightedness also can be caused by the cornea and/or lens being too curved for the length of the eyeball. In some cases, myopia is due to a combination of these factors (Sanjay, 2015).

d. What is the relation between used minus glasses since 7 years ago with Mr. Santo complain? Answer: In this case, there is no relation between used minus glasses since 7 years ago with Mr. Santo complain.

Synthesis: Risk factors that would have made patient susceptible to develop eyes infection such as keratitis according to Deschenes (2017), are: - Wearing contact lens - Trauma (including previous corneal surgery) - Use of contaminated ocular medications - Decreased immunologic defenses - Use of immunosuppresive agents such as steroid drops that may predispose to infection - Aqueous tear deficiencies - Structural alteration or malposition of the eyelids

42

So there’s no actual relation between Mr. Santo uses minus glasess (Miopia) with the main complain. The keratitis just makes Mr. santo’s visions become worse than before.

e. What is classification of refractive disorder? Answer: 1. Myopia Myopia known as nearsightedness. Myopia occurs when the eye grows too long from front to back. Instead of focusing image on the retina-the light-sensitive tissue in the back of the eye- the lens of the eye focuses in the image in front of the retina. Myopia also can be the result of a cornea-the eye’s outermost layer- that is too curved for the length of the eyeball or a lens that is to thick. The risk factor people with myopia are genetics factor and enviroment factor. The genetic factor is take the biggest role in the incident of myopia (Sherwood,2013).

Figure 2.1 Refraction in Myopia Source: Sherwood, 2013: 220

Myopia occurs when the eyeball is too long, relative to the focusing power of the cornea and lens of the eye This causes light rays to focus at a point in front of the retina, rather than directly on

43

its surface. Nearsightedness also can be caused by the cornea and/or lens being too curved for the length of the eyeball. In some cases, myopia is due to a combination of these factors (Sanjay, 2015). 2. Hyperopia Hyperopia also known as farsightedness, is a common type of refractive error where distant objects may be seen more clearly than objects that are near. Hyperopia develops in eyes that focus images behind retina instead of retina, which can result blurred vision. This occurs when the eyeball is too short, which prevents incoming light from focusing directly on the retina. It may also be caused by an abnormal shape of the cornea or lens. People whose parents have hyperopia may also be more likely to get the condition (Sherwood,2013).

Figure 2.2 Refraction in Hyperopia Source: Sherwood, 2013: 220

Farsightedness (Hyperopia) is the result of the visual image being focused behind the retina rather than directly on it. It is mainly cause by two reasons: - Low converging power of eye lensbecause of weak action of ciliary muscles.

44

- Eyeball being too short because of which the distance between eye lens and retina decreases. Farsightedness is often present from birth, but children have a veryflexible eye lens, which helps make up for the problem. As aging occurs, glasses or contact lenses may be required to correct the vision. Farsightedness is hereditary (Sanjay, 2015). 3. Astigmatism Astigmatism is a common type of refractive disoreder. It is conditio which the eye does not focus light evenly onto the retina. Astigmatism occurs when the light is bent differently depending on where it strikes the cornea and passes throught the eyeball. The cornea of normal eye is curved like a basketball, with the same degree of roundness in all areas. An eye with astigmatism has a cornea that is curved more like a football, with some areas that are steeper or more rounded than other. This can cause images to blurry and stecthed out (Sherwood,2013). Astigmatism is an optical condition in which the refracting power of lens is not same in all meridians. Astigmatism is a natural and commonly occurring cause of blurred or distorted vision that is usually associated with an imperfectly shaped cornea. The exact cause in not known. A person's eye is naturally shaped like a sphere. Under normal circumstances, when light enters the eye, it refracts, or bends evenly, creating a clear view of the object. However, the eye of a person with astigmatism is shaped more like a football or the back of a spoon. For this person, when light enters the eye it is refracted more in one direction than the other, allowing only part of the object to be in focus at one time. Objects at any distance can appear blurry and wavy (Sanjay, 2015).

Synthesis:

45

The normal eye, known as an emmetropic eye can sufficiently refract light rays from an object 6m (20 feet) away so that a clear image is foccused on the retina. Many people however, lack this ability beacuse of refraction abnormalities among these abnormalities are myopia or near sigthdness, which occurs when the eyeball is too long relative to the focusing power of the cornea and lens, or when the lens is thicker than normal, so an image converges in front of the retina. Myopic individuals can see close objects clearly, but not distant objects. In hypermetropia the eyeball length is short relative to the focusing power of the cornea and lens, or the lens is thinner then normal, so in image converges behind the retina. Hyepermetropia individuals can see distant objects clearly, but not close ones (Sherwood, 2013).

Figure 2.3 Emetropia Source: Sherwood, 2013: 220

Astigmatism in which either the cornea or the lens has an irregular curvature. With aging, the lens loses elasticity and thus its abillity to curve to focus on objects that are close. Therefore, older people cannot read print at the same close range as can young sters. This condition called presbyopia (Tortora&Derrickson, 2007).

f. What is the meaning his friend complain about same symptom? Answer:

46

The meaning is risk factor of conjunctivitis cause conjunctivitis spread through hand-to-eye contact by hands or objects that are contaminated (Vaughan, 2014).

3.

Specific Examination Eyes: OS: VOS 4/60, pinhole insignificantly improve vision, mixed injection, yellowish white thick discharge, blepharospasm, infiltrate punctate form. OD: VOD 6/60, with correction: Spheris-2.00 become 6/6. a. What is the interpretation of physical examination? Answer: Oculi Sinistra Table 2. Interpretation of Eyes Specific Examination Meaning

Examination VOS 4/60

Patient are only able to see as 4 meters on the snellen chart. While others are able to see as 60 meters on the snellen chart.

Pinhole

Patient has no refractive disorder.

insignificantly Mixed

Ciliary and conjunctival injection occurs indicate

injection

the vasodilatation of anterior ciliary artery and posterior conjunctival artery (Inflammation in cornea and conjunctiva).

Discharge

Mucopurulent (Indicate bacterial infection)

Infiltrate

Keratitis

punctate

Oculi Dextra

47

Table 3. Interpretation of Eyes Specific Examination Meaning

Examination VOD 6/60

Patient are only able to see as 6 meters on the snellen chart. While others are able to see as 60 meters on the snellen chart.

Spheris -2.00 Myopia

b. How the abnormal mechanism of physical examination? Answer: VOS 4/60 The transmition of this infection throught hand to eye from contaminated friend before. Which will lead to infection in Mr. Santo conjunctiva bulbi. After conjunctivitis that was not treat inadequate. The infection spread to cornea that infected the cornea also. The infection that happens in cornea will make the inflammation in cornea which make the cornea cloudy because of infiltrate punctate form in cornea. Cornea is one of the refractive media that has a main role in refractive which about 40 dioptri. It will make a symptom such as lowering the vision (Ilyas dan Yulianti, 2017).

Mixed injection The transmition of this infection throught hand to eye from contaminated friend before. Which will lead to infection in Mr. Santo conjunctiva bulbi. After conjunctivitis that was not treat inadequate. The infection spread to cornea that infected the cornea also. The infection that happens in both conjunctiva and cornea will make the vasodilation of artery conjunctiva posterior and artery cilliaris anterior That will manifestated as mixed injection (Ilyas dan Yulianti, 2017).

Infiltrate punctate form

48

The transmition of this infection throught hand to eye from contaminated friend before. Which will lead to infection in Mr. Santo conjunctiva bulbi. After conjunctivitisthat was not treat inadequate. The infection spread to cornea that infected the cornea also. When the infection come there will be an inflammation which make inflammation cell will be infiltrate in cornea (Ilyas dan Yulianti, 2017).

Yellowish thick discharge and blepharospasm The transmition of this infection throught hand-to eye from contaminated friend before. Which will lead to infection in Mr. Santo conjunctiva bulbi. Goblet cell in caranculu lacrimales will excrete mucous that contains microorganism. It makes the discharge mukopurulen(yellowish thick discharge) and will be blepharospasm (Ilyas dan Yulianti, 2017).

c. What is the classification of glasses for refractive disorder? Answer: - Myopia : Concave lens - Hyperopia : Convex lens - Astigmatism : Hard contact lens if epitel is not fragile or soft contact lens if causes by infection, trauma and distrofi to give an irregular effect in surface. - Presbyopia : Convex lens

d. How to perform spesific examination object? Answer: Pinhole test This test perform to to determine whether a decrease in vision occurs due to refractive disorder or organic abnormalities in eyes. First asked patient to remove their glasses or contact lenses and stand or sit 20 feet (6 meters) from snellen chart. Cover one eyes with the occuler lenses.

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After that patient asked to read the snellen chart from the biggest letter until the smallest letter thet can be read cleary,with that we can also determine patient’s visus. Put the pinhole in front of patient eyes if the pinhole significantly improve the vision so that means patient have a refractive disorder but if not probably patient have organic abnormality (Ilyas dan Yulianti, 2017).

e. What is the classification of injection? Answer: 1. Conjunctiva Injetion Conjunctiva injection is the dilatation posterior conjunctiva artery. The etiology of conjunctiva injection usually caused by alergy,

conjunctiva

infection

and

mecanical

factor.

The

characteristic of conjunctia infection according to Ilyas and Yulianti (2017), are: - Fotofobia (-) - Normal pupil - Normal refraction - Fresh red color 2. Ciliary Injection Ciliary injecton is the dilatation of anterior cilliary artery. Usually, ciliar injection caused by keratitis, uveitis, glucoma. The characteristic according to Ilyas and Yulianti (2017), are: - Red colour - Pupil irregular - Fotofobia - Small size beside cornea

f. What are the possible causes of injection?

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Answer: The possible causes of injection according to Ilyas and Yulianti (2017) are: 1. Conjunctival injection usually caused by mechanical influences, allergic, infection of the conjunctival tissue. 2. Ciliary injection usually caused by inflammation of the cornea (keratitis), corneal ulcer, a foreign object in the cornea, inflammation of uvea (uveitis), glaucoma, endoftalmitis.

4.

What disturbances might happen in this case? Answer: Based on the analysis above, the disturbances that might be happen in this case, are: - Keratoconjunctivitis - Anterior uveitis - Acute glaucoma

5.

What investigations are needed to diagnose this case? Answer: - Slit Lamp Slit lamp photography can be useful to document the progression of the keratitis, and, in cases where the specific etiology is in doubt, it is used to obtain additional opinions, particularly in indolent and chronic cases not responding to antimicrobial therapy (Ilyas dan Yulianti, 2017). - Bacterial Culture Though pathogens can be identified within 12-15 hours of inoculation, most aerobic bacteria in microbial keratitis appear only within 48 hours on standard culture media. The plates should be examined on daily basis and liquid media observed for turbidity. Blood agar is best for isolation of aerobic bacteria. Anaerobes are slow

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growing; therefore, cultures should be incubated for at least 10 days. The most common combination found in polymicrobial keratitis is aerobic Gram-positive coccus plus Gram-negative rod, followed by fungus plus bacteria. There are no established criteria for true diagnosis of corneal infections. One of the authentic criteria was put forward by Jones which includes clinical signs of infection and isolation of ten or more colonies of bacteria on one solid medium and one additional medium in presence of a positive smear (Al-Mujaini, 2009).

6.

What disturbances are most likely to occur in this case? Answer: Keratokonjunctivitis sinistra and myopia oculi dextra.

7.

What is the etiology of keratitis? Jawab:

8.

-

Bacterial infection

-

Fungal infection

-

Viral infection

-

Allergies

How does the comprehensive management for this case? Answer: Pharmacology If it caused by bacterial infection: chloramfenicol drop as much as 1 drop 6x/day or eye ointment 3x/day for 3 days. Non-pharmacology - Before and after use ointment patient have to wash their hand - Ask patient to keep personal hygiene and environment - Don’t use the same towel or duster

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9.

What will happen if these circumstances are not manage comprehensively? Answer: - Cornea Ulcer - Blepharitis

10. Is this disorder can be overcome thoroughly, how the odds? Answer: - Quo ad Vitam: bonam - Quo ad Fungsionam: bonam - Quo ad Sanationam: bonam

11. How does the competence of general practitioner for this case? Answer: The competence of general practitioner for Keratitis is 3A and Conjunctivitis is 4A (KKI, 2012).

Synthesis: 3A. Non-emergency case General practitioner are able to make clinical diagnoses and provide preliminary therapy in non-emergency cases, to determine the most appropriate referral for the next patient's treatment and also able to follow up after returning from referrals (KKI, 2012). 4A.General practitioner are able to make clinical diagnoses and treatments independently and throughtly (KKI, 2012)

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12. How does the Islamic point of view of this case? Answer: Q.s Al-Mu’minun (23:78)

“And it is He who produced for you hearing, vision, and heart, little are you grateful”.

2.6 Conclusion Mr. Santo, 22 years old complained with blurred vision, eyes of redness, pain & yellowish white thick discharge due to keratoconjunctivitis oculi sinistra with myopia oculi dextra.

2.7 Conceptual Framework 1.

Keratoconjunctivitis concept

Risk Factor (Contact from contaminated friend

Injection in the conjunctiva bulbi

Eye redness Pain

Inadequate treatment

Conjunctivitis Discharge Infection spread to cornea

Keratoconjunctivitis

Blurry vision

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2.

Myopia concept

-

Length of eye ball its to long Cornea is to corved

The light fall in the front of the retina

Myopia Dextra

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REFERENCES

Abbas, A.K., Aster, J.C., dan Kumar, V. 2017. Robbins Basic Pathology. Tenth Edition. Singapura: Elsevier Saunders. page 60. Al-Mujaini, A, et al. 2009. Bacterial Keratitis: Perspective on Epidemiology, Clinico-Pathogenesis, Diagnosis and Treatment. SQU Med Journal, 9(2), 184-195. Alteveer, G Janet and Kathryn M.McCans. 2012. The Red Eye, The swollen Eye, and Acute Vision Loss. New Jersey: Emergency Medicine. Volume 4, Number 6 : 2-3. Al-quran Surah Q.s Al-Mu’minun (23:78) Deschenes, Jean. 2017. Bacterial Keratitis. E-Medicine: Medscape Reference, (online https://emedicine.medscape.com/article/1194028-overview#showall accessed on December 20th, 2017). Ilyas, Sidarta and Yulianti, Sri R. 2017. Ilmu Penyakit Mata. Edisi 5. Jakarta: Fakultas Kedokteran Universitas Indonesia. page: 113. 114. 27,59,60, 72,109, 75-84, 122, 100-105. Indonesia medical council. 2012. Standar Kompetensi Dokter Indonesia. Jakarta: KKI. page: 32. 37. Kiel, JW. 2011. The Occular Circulation. California: Morgan and Claypool Life Sciences. Maggs D.J., Miller P.E and Ofri R. 2013. Slatter’s fundamentals of veterinary ophthalmology 5th edn. Missouri : Elsevier. Mescher, Anthony L. 2013. Junqueira’s Basic Histology Text and Atlas. 13th Edition. United States of America: Mc-Graw Hill Education. National Center for Biotechnology Information. PubChem Compound Database; CID=10648,

(online

https://pubchem.ncbi.nlm.nih.gov/compound/10648

accessed on December 21, 2017). Scholete T, dkk. 2006. Pocket atlas of ophtalmology. New York: Thieme. Sherwood. 2013. Fisiologi dari Sel ke Sistem. Jakarta: EGC. page. 218-220.

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Snell, Richard S. 2011. Anatomi Klinik Berdasarkan Sistem. EGC: Jakarta. Page 612-25. Tortora, Gerard J and Derrickson, Bryan. 2007. Principles of Anatomy and Physiology. 11th edition. United States of America: John Wiley & Sons, Inc. page 582-6. Vaughan D, Riordan-Eva P. 2014. Konjungtivitis. In: General Ophtalmology. Edisi 14. Jakarta: Widya Medika. page 97. Yeung, Karen K. 2017. Bacterial Conjunctivitis (Pink Eye). E-Medicine: Medscape Reference,

(online

https://emedicine.medscape.com/article/1191730-

overview#showall accessed on December 20th, 2017).

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