Bio Microscopy Guide

Slit Lamp Biomicroscopy Part One

Slit Lamp Illumination Types Associated Ocular Conditions And Slit Lamp Examination Procedures Direct Illuminations: 1.) Diffuse: Diffuse illumination or "wide beam" illumination deserves a short separate discussion from the other types of illuminations. The term diffuse has been carried over from earlier writings when slit lamps had either diffusing filters or independent racking microscopes. This allowed each to be independently focus on different structures. Most of todays slit lamp biomicroscopes have their light sources and microscope coincident to one another and are focused on the same structure at the same time. Diffusing filters are still found in some slit lamps and are used in photographing the anterior segment of the eye. "Wide beam" illumination is the only type that has the light source set wide open. Its main purpose is to illuminate as much of the eye and its adnexia at once for general observation. A wide, un-narrowed, beam of light is directed at the cornea from an angle of approximately 45 degrees. Position the microscope directly in front of the patient's eye and focus on the anterior of the cornea. Low to medium magnification (7 - 16x) should be used which allows the observer to view as many of the structures as possible. When viewing the eye with achromatic light one should note, on gross inspection, any corneal scars, irregularities of the lids, tear debris, irregularities of Descemet's membrane or pigmentary changes found in the epithelial layer, etc. These findings are investigated more thoroughly with other types of illumination. With the aid of the cobalt blue filter and either fluorescein sodium or Fluoresoft® permit the evaluation of bearing, movement, positioning of contact lenses. Using the cobalt blue filter and fluorescein sodium this is a reasonable illumination for assessing a patient's tear break up time (TBUT), dark drying areas of the epithelium. Staining of the cornea and conjunctiva can also be assessed. Fluorescein sodium dye will stain the cornea and conjunctiva any time the epithelium is compromised. Fluorescein dye does not stain epithelial cells themselves, but pools within the intercellular defects thus highlighting the damaged area. Fluorescein staining is relatively nonspecific, occurring with any http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (1 of 15)6/18/2006 1:14:56 AM

Slit Lamp Biomicroscopy Part One

condition affecting epithelial integrity. Do not confuse "negative staining" for true TBUT. Negative staining, often seen when checking TBUT or evaluating an area that has stained in the past. "Negative staining" results because of irregularities in the corneal epithelium. These dark areas are where the tears separate quickly rather than stain tissue. Examples: Map and dot dystrophies, micro-cystic edema, healing but still rough and not smoothly healed abrasions, etc. The cobalt blue filter is also helpful in detecting Fleischer's Ring or Line in keratoconus and Hudson Stahli's Line in older patients.

Using Rose Bengal and no filters will show a pink staining of epithelial cell damaged tissue as in cases of keratoconjunctivitis Sicca, herpatic lesions of the lids and cornea and other ulcer margins. Other types of illumination are better for evaluating the degree and depth of any staining. See color plates in Dr. Casser's book. Diffuse, wide-beam, illumination together with the red free (green) filter is helpful when viewing the bulbar conjunctiva, and episcleral blood vessels. With the aid of the red free filter small hemorrhages, aneurysms and engorged vessels stand out. It is not difficult to differentiate between conjunctival, episcleral, and scleral injection. Conjunctival vessels are obviously fairly superficial and are movable upon friction from the eyelid, whereas less superficial and deep vessels show minimal to no movement with the overlying conjunctiva. Deeper episcleral injection may also appear somewhat darker and give an overall purplish hue. (Abelson et al) proposed a standardized grading system for judging the different types of injection.

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (2 of 15)6/18/2006 1:14:56 AM

Slit Lamp Biomicroscopy Part One

A) Ciliary Injection B) Episcleral Injection C) Conjunctival Injection Grade Severity 0 White and Quiet 1/2 Slight, Usually Normal 1 to 1+ Mild 2 to 2+ Moderate 3 to 3+ Severe Adapted and modified from Abelson, M. et al. 2.)Direct Focal a.) Optic Section: Optic section is used primarily to determining the depth or elevation of a defect of the cornea, conjunctiva or locating the depth of an opacity within the lens of the eye. With the optic section as mentioned above, it is possible to detect changes in corneal and conjunctival thicknesses, to assess depths of foreign bodies, scars and opacities, to estimate the anterior chamber depth and to identify the anatomical location of cataracts within the crystalline lens. The biomicroscope should be directly in front of the patient's eye, the illumination source at about 45 degrees and the illumination mirror in "click" position. The slit width is almost closed (0.5 - 1.0 mm wide by 7 - 9 mm high). Set the magnification on low to medium (7 - 10 X) and focused on the patient's closed lid. The thickness of the eye lid (about 1 mm) means focusing on the cornea is accomplished with only slight movement of the joy stick. With eyes open, give the patient a point of fixation such as the fixation light, part of the biomicroscope, or the top of the examiner's opposite ear. Once the cornea is in sharp focus, scan the cornea from temporal limbus to nasal limbus. To maintain a clear, distortion-free view, the

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (3 of 15)6/18/2006 1:14:56 AM

Slit Lamp Biomicroscopy Part One

illumination source is always moved to the opposite side when crossing the mid-line of the cornea. With a clearly focused optic section slightly temporal to the center of the cornea, magnification increased to 16x then to 20x, and brightness increased note the following: 1) 2) 3) 4) 5)

The The The The The

Front Surface Bright Zone Is The Surface Of The Tears Next Dark Line Is The Epithelium Layer Next Brighter Thin Line Is Bowman's Membrane Gray Wider Granular Area Is The Stroma Zone Last Bright Inner Zone Is The Endothelium

To attain an optic section of the crystalline lens, the angular separation of the illumination source is reduced until the light beam just grazes the edge of the pupil and the vertical height is reduced to approximate the pupil size. This alignment can easily be accomplished from outside the biomicroscope. When the beam cuts just across the edge of the pupil, the crystalline lens will appear sectioned. By focusing the biomicroscopes joy stick with one hand and controlling the direction or angle of the light source with the other hand, the different layers of the lens can be brought into focus, hence, the anatomical location of any opacities can be determined. Furthermore, the degree of nuclear opalescence and color can be evaluated and graded via the, lens opacities classification system II (LOCS II)[Chylack, 1989]. Different magnifications may be used, but medium and high give the best detail. Van Herick's technique for grading the anterior chamber angles uses an optic section placed near the limbus with the light source always at 60 degrees. The biomicroscope is placed directly before the patient's eye. This technique only allows you to judge the temporal and nasal angles.

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (4 of 15)6/18/2006 1:14:56 AM

Slit Lamp Biomicroscopy Part One

Van Herick Angle Estimation Method

Angle Grades

Risk of Angle Closure

Cornea to Angle Ratio

4

Wide Open Angle; Incapable of Closure. Iris to Cornea Angular Separation Equals 35-450.

Anterior Chamber Depth (Shadow) is Equal to or Greater Than Corneal Thickness

3

Moderately Open Angle; Incapable Anterior Chamber Depth (Shadow) is of Closure. Iris to Corneal Angular Between 1/4 and 1/2 the Corneal Thickness Separation Equals 20-350

2

Moderately Narrow Angle; Closure Anterior Chamber Depth (Shadow) is Possible. Iris to Corneal Angular Equal to 1/4 the Corneal Thickness Separation Equals 200

1

Extremely Narrow Angle; Closure Probable. Iris to Corneal Angular Separation Equals 100

0

Basically Closed Angle; Closure is Anterior Chamber Depth (Shadow) is Only Most Emanate. Iris to Corneal a Very Narrow Slit; or no Anterior Chamber 0 Angle Angular Separation Equals 0

Anterior Chamber Depth (Shadow) is Equal to Less Than 1/4 the Corneal Thickness

Adapted from: Van Herick W, Shaffer RN, Schwartz A. Estimation of width of angle of anterior chamber. Am J Ophthalmol 1969;68:626-9.

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (5 of 15)6/18/2006 1:14:57 AM

Slit Lamp Biomicroscopy Part One

Optic section using the Van Herick Technique to grade the anterior chamber depth. This is a grade 1 or narrow angle. The "Split Limbal Technique" allows you to make an estimation of the superior and inferior angles. The slit lamp and illumination system are in click position aligned directly in front of the patient . The beam width is that of an optic section which is focused on the limbal cornea junction thus splitting the cornea and limbus. The doctor then views the arc of light through the cornea and that falling on the iris without the aid of the slit lamp. The angular separation seen at the limbus corneal junction is an estimation of the anterior chamber angle depth in degrees.

"Split Limbal Technique" Which Is Observed With The Naked Eye Grade Angle + 4 TO 4 ( 45 - 350 ) http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (6 of 15)6/18/2006 1:14:57 AM

Slit Lamp Biomicroscopy Part One

+ 3 TO 3 + 2 TO 2 1-0

( 35 - 200 ) < 20 BUT > 100) ( 100 OR LESS )

b.) Conical Beam: Examination of the anterior chamber for cells or flare must be performed before either dilation or applanation tonometry. Magnification 16 - 20x and illumination (high) or what the patient will tolerate. Dilation often results in an increase in the number of cells and fluorescein used in applanation tonometry causes an increase in flare [Schlaegel, 1982]. This type of illumination is used to detect floating aqueous cells and flare by the Tyndall effect (likened to dust floating in the air of a sun filled window) The traditional method of locating and grading cells and flare is to reduce the beam to a small circular pattern with the light source 45 to 60 degrees temporally and directed into the pupil. Position the biomicroscope directly in front of the patient's eye with as bright illumination as the patient will permit and high magnification. The examiner always allows themselves a period of time to dark adapt. The conical beam is focused between the cornea and the anterior lens surface and observation is concentrated on the dark zone between the out of focus cornea and lens. This zone is normally optically empty and appears totally black. Flare (protein escaping from dilated vessels) makes the normally optic empty zone appear gray or milky when compared to the uninvolved eye. Cells (white blood cells escaping from dilated vessels) will reflect the light and be seen as white dots. The techniques used may be either to oscillate the light source with the joy stick from left to right while focused in the anterior chamber or to focus from the posterior cornea to the anterior lens while oscillating the light source. The following is a less traditional technique, but one that works well clinically and is superior when grading the severity of inflammation. Use a parallelepiped approximately 2 mm wide and 4 mm high Focus on the iris then the pulled back the focus into the anterior chamber. The examiner waits and watches the zone between the out-of-focus cornea and the light passing through the pupil. The convection currents of the aqueous will move any protein or cells into this zone. Grading Cells and Flare

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (7 of 15)6/18/2006 1:14:57 AM

Slit Lamp Biomicroscopy Part One

Grade 0

1

2

Aqueous Cells None

2-5 Cells Seen in 45 Seconds or One Minute 5-10 Cell Seen at Once

3

Cells Scattered Through Out Beam 20 or More

4

Dense Cells in Beam, More Than You Can Count

Grade

Flare

0

Optically Empty Compared Bilaterally

1

Faint: Haze or Not Equal Bilaterally

2

Moderate: But Iris Detail Still Clear

3

Marked: Iris Details Becoming Hazy

4

Dense Haze: With Obvious Fibrin Collecting on Iris

READ VOL. 4 - CHAPTER 32 IN "DUANES' CLINICAL OPHTHALMOLOGY" Cells and flare in the anterior chamber represent a condition of great concern and are usually diagnostic of an inflammation. However, if cells or flare is not seen but an inflammation is suspected, use the "Consensual Pupillary Reflex" test "Henkind" test or "Consensual Pain Reflex" test, all the same, to help confirming an inflammatory diagnosis. The patient completely covers the eye in question so no light can enter. They are to report any discomfort when the slit lamp is focused on the "good eye" and the brightness is turned up. If he/ she reports discomfort, cells and flare may not be present, but there most likely is a smoldering inflammation that has not resolved or is about to develop [Au, 1981]. Grading the Consensual Pain Reflex Grade 1 To 1+ 2 To 2+ 3 To 3+ 4 To 4+

Patient Response Definite Pain Without Acute Distress Causes Wincing or Complaint of Pain Causes Withdrawal From the Light Severe Allows No Light in the Eye

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (8 of 15)6/18/2006 1:14:57 AM

Slit Lamp Biomicroscopy Part One

C.) Parallelepiped: A parallelepiped is one of most common types of illumination used. It is used in combination with a number of different types of illuminations. The biomicroscope should be directly in front of the patient's eye, the illumination source at about 45 degrees and the illumination mirror in "click," position. A parallelepiped is essentially an optic section, except the slit width is greater (2.0 - 4.0 mm) and the height may vary, providing a more three dimensional view of the cornea or crystalline lens. The three dimensional view permits observation of distinguishable details within the crystalline lenses "zones of discontinuity". As with the optic section, the angle between the illumination source and biomicroscope may be varied to expose more corneal epithelium, stroma and endothelium. The whole cornea should be scanned using a parallelepiped. When scanning the cornea, a clear undistorted view must be maintained by positioning the light source to the opposite side when crossing the mid-line of the cornea. Both normal and abnormal findings can be seen when scanning the cornea with varied levels of magnifications and brightness. Look for any of the following: Tear debris is usually benign and related to allergies or sinus conditions, but may correlate with bacterial infections. Corneal nerves are white thread-like structures that bifurcate and trifurcate and are located anywhere within the cornea. Blood filled vessels extend from the limbus onto or into the cornea, and are diagnostic of chronic or acute insult or inflammation. Ghost vessels extend from the limbus onto or into the cornea. They are empty of blood and diagnostic of some type of past corneal insult or inflammation. Corneal scars are white in color and diagnostic of some past corneal damage, ulcer, abrasion or foreign body. Corneal striae are white usually vertical thread-like twisting lines found in Descemet's membrane and posterior stroma. They are diagnostic of poor soft contact lens fitting, diabetes or metabolic changes as with the reduced number of endothelial cells of the elderly. They are the result of overall thickening of the entire cornea and buckling of the back surface. Grades of Cornea Striae Grade 0 1

Observed Number None Less Than Five

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (9 of 15)6/18/2006 1:14:57 AM

Slit Lamp Biomicroscopy Part One

2 3 4

Five To Ten Ten To Twenty More Than Twenty

Endothelial pigmentation when heavy and located vertically on the endothelium is known as "Krukenberg's Spindle", it may be diagnostic of iris atrophy and pigmentary glaucoma. Transillumination of the iris should be performed and any transillumination iris defects (TID's), holes in the iris, noted. Scant, very fine deposits are commonly seen and not pathological. 3.) Retro-Illumination: Usually uses a parallelepiped that bounces unfocused light off one structure while observing the back lighting of another. The alignment and angular separation of the biomicroscope to the illumination source will vary. The light source beam is reflected off another structure like the iris, crystalline lens or retina while the biomicroscope is focused on a more anterior structure. Retroillumination or transillumination the iris or crystalline lens uses low to medium magnification (7 - 10x). The slit width 1 - 2 mm wide and 4 - 5 mm high with the biomicroscope and light source placed in direct alignment with each other. They are both positioned directly in front of the eye to be examined. Focus the slit just off the edge of the iris and on the front of the lens. If there are defects or atrophy of the iris they will be seen as a retinal "orange" glow coming back through each defect or hole. Patients who have numerous endothelial pigment deposits must have their iris transilluminated. Remember the term transillumination iris defects or (TID's). See color plates in Dr. Casser's book. Furthermore, retroillumination of the crystalline lens is required to classify and grade both cortical and posterior subcapsular cataracts using LOCS II. The cornea is probably the most common structure viewed in retroillumination. Keratic precipitates (accumulation of white blood cells and fibrin) will appear white in direct illumination but dark by retroillumination. This technique is valuable for observation of deposits on the corneal endothelium and invading blood vessels. According to some authors this is the only way by which tiny rod-like fibrin flecks may be seen on the back of the cornea, warning the so-called "quiet iritis" is still active. Retro-illumination is regarded by most optometrist to be second in importance only to direct illumination.

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (10 of 15)6/18/2006 1:14:57 AM

Slit Lamp Biomicroscopy Part One

4.) Sclerotic Scatter: This illumination uses a parallelepiped at the limbus to scatter light internally throughout the cornea. Use low 6 10x magnification. In the case of central corneal clouding (CCC) the biomicroscope is not used. The pupil is observed with the naked eye from an angle directly opposite from the light source. 5.) Indirect-Lateral-Proximal: Place the biomicroscope directly in front of the patient's eye and the illumination light source at about 45 degrees. Make sure the illumination mirror is in "click" position. Use a parallelepiped beam sharply focused on a given structure like the cornea. The light passes through the cornea and falls out of focus on the iris. The dark area just lateral or proximal to the parallelepiped is the indirect or proximal zone of illumination. This is the area of the cornea which one surveys through the biomicroscope. This type of illumination is widely used for observation of the corneal epithelium and tears. Most helpful in detection of mycrocystic edema, faint corneal infiltrates and other types of irregularities of the epithelium and tears. Because it utilizes direct, indirect and retroillumination simultaneously, one should consider it to be as important as any other type of illumination.

Keratic precipitates on the endothelium of the cornea as seen in direct, indirect, and retroillumination using a parallelepiped.

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (11 of 15)6/18/2006 1:14:57 AM

Slit Lamp Biomicroscopy Part One

6.) Specular Refection: Again a parallelepiped is used. This is the only means by which one is able to view the endothelial cells of the cornea or the epithelial cells on the back of lens. The cells are seen only by one eye and they appear in the ocular opposite from the direction of the illumination light source. The basic requirements for specular reflection are as follows: 1) The angle between the illumination source and biomicroscope is approximately 60 degrees. 2) High magnification must be used. 3) High illumination is needed. 4) A parallelepiped beam of light is used. Place he biomicroscope directly in front of the patient's eye and the illumination light source at 45 - 60 degrees. Just off the limbus, obtain a sharply focused parallelepiped of the cornea. Slowly advanced it across the cornea until a dazzling reflection of the filament is seen within the biomicroscope. This reflection is only seen by one eye the other eye is not bothered. Keeping the reflected light within the biomicroscopes field of view, the focus is moved back toward the endothelial cells. There will be a point where two images of the filament are seen, one bright, and the other ghostlike or copper-yellow in color. Critically focus the biomicroscope on the latter until a mosaic of hexagonal cells are seen. It should be noted that even with 40x magnification the endothelial cells do not look as large as most texts show. They resemble the appearance of the dimpled surface of an orange peel or basketball. When the slit lamp's illumination system and the biomicroscope are at equal angles of incidence and reflection the cornea's endothelium is viewable. Both front and back surfaces of the crystalline lens can also be viewed using specular refection.

Positioning The Patient In The Slit Lamp

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (12 of 15)6/18/2006 1:14:57 AM

Slit Lamp Biomicroscopy Part One

1.) Procedure: Inform the patient what you are going to do and why. For Example: This is a slit lamp biomicroscope and I'll be examining the general health of your eye. I'll be checking for any signs of past or present infections that you may or may not be aware and any signs of cataracts. 2.) Head Position: A.) Tell the patient what you want them to do: chin in the chin rest and forehead up against the head rest. For professional and hygienic reasons always place a facial tissue on the slit lamp's chin rest. You should have already cleaned the head and chin rest with an alcohol swab. This is always done between every patient. This not only helps keep things more antiseptic, but also makes the slit lamp smell clean and more professional. B.) Make sure the patient not only looks comfortable but is comfortable. Their forehead tight against the head rest, chin firmly down on the chin rest and their outer canthus aligned with the black marker on the slit lamp post. At this point it is a good idea to reach around and gently pull their head slightly forward against the headrest. 3.) Fixation Instructions: The patient must be given fixation instructions, where you want them to look. This might be the fixation light, part of the slit lamp or just past your ear. 4.) Pre-Alignment And Focusing: Tell your patient to close their eyes and relax while you get things aligned. Turn the biomicroscope on and focus the light source on the patient's lid. The eye lid is only about 1 mm thick, therefore, when you instructed the patient to open their eyes you should almost be in focus on the tear film of the cornea. Suggested Slit Lamp Examination Procedure (1)

(2)

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (13 of 15)6/18/2006 1:14:57 AM

Slit Lamp Biomicroscopy Part One

Use Broad Beam or a 2 To 3 mm wide Parallelepiped Type Illumination, Magnification 10-16x, Illumination On Low @ 45 Degrees, Examine Both The Upper And Lower Lids And Lashes In A Arching Motion. The Patient's Eyes Are Open And The Illumination Source Is Moved At The Midline Of The Lid. (3)

Have The Patient Look To Their Right, Light Source To The Left At 45 Degrees The Microscope Is Set Straight Ahead. Scan And Examine The Nasal Bulbar Conjunctiva.

(5)

Have The Patient Look Down, Retract The Upper Lid, Examine The Upper Bulbar Conjunctiva and Superior Cornea. The Light Source Should Be Moved Across To The Opposite Side At The Midline Of The Eye. Microscope Is Set Straight Ahead. (7)

Have The Patient Look To Their Left, Light Source To Your Left At Approximately 45 Degrees , The Microscope Is Set Straight Ahead. Scan And Examine The Temporal Bulbar Conjunctiva

(4)

Have The Patient Look UP, Retract The Lower Lid, Examine The Lower Bulbar, Lower Palpebral Conjunctiva and Inferior Cornea. The Light Source Should Be Moved Across To The Opposite Side At The Midline Of The Eye. Microscope Is Set Straight Ahead. (6)

Use A Parallelepiped, 16X Magnification, Light Source At 45 Degrees And The Microscope Set Straight Ahead. Scan And Examine The Cornea. The Light Source Should Be Moved Across At The Midline Of The Cornea. (8)

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (14 of 15)6/18/2006 1:14:57 AM

Slit Lamp Biomicroscopy Part One

Use A Full Length Optic Section, Magnification 16X, Light Source At 60 Degrees And The Microscope Set Straight Ahead. Evaluate And Grade The Temporal And Nasal Angles Using The Van Herick Technique

Use A Narrow Parallelepiped, 16X Magnification, Light Source At 45 Degrees And The Microscope Set Straight Ahead. Examine The Iris, Crystalline Lens And The Anterior Vitreous Body.

Important: Always, pull the slit lamp back, shut off the instrument, and lock it down at the end of any procedure. The above is only intended as a schematic and students are encouraged to develop any order with which they feel comfortable. It should be pointed out that all steps in the schematic are relevant and should be part of the procedure.

To View Part Two

Return To Home Page

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_part_one_slitlamp.html (15 of 15)6/18/2006 1:14:57 AM

Slit Lamp Biomicroscopy Part Two

Slit Lamp Examination Associated Ocular Conditions Part Two

Things You Must Know Tear Make Up

1.) Lipid: Meibomian Glands ( Outermost ) 2.) Serous: Lacrimal Gland 3.) Mucin: Goblet Cells ( Innermost, Nearest The Cornea) Tear Break Up Time And Contact Lens Success 1.) Equal To Or > 15 Sec.----Very Acceptable 2.) 10 - 14 Sec.-------------Is Questionable --Must Be Selective 3.) < 10 Sec.----------------Not Acceptable --"Dry Eye"

Types Of Corneal Opacities (Scars) Scar Types---------------------To Be Seen---------------Vision 1.) Nebular }(No) ----------Need Slit Lamp--------Vision Usually Okay 2.) Macular }(More) -------Need Slit Lamp--------Vision Can Be Affected 3.) Leukoma }(Light) -----Just Light------------Vision Greatly Reduced Anterior Uveitis "Signs And Symptoms" 1.) PAIN: Moderate To Severe 2.) PHOTOPHOBIA: Pain From Most Any Type Of Light, Consensual Pain Reflex Present 3.) INJECTION: Conjunctival And Or Limbal 4.) SMALL PUPIL: On The Affected Side 5.) MUDDY IRIS: Due To Swollen Vessels An Cellular & Protein Debris 6.) REDUCED VISION: Due To Tearing Or What Precipitated The Inflammation 7.) FLARE: Smoky-Appearing Precipitate Of Protein "Flare" 8.) CELLS: White Blood Cells 9.) POSTERIOR SYNECHIAE: Resulting From The Cells And Flare

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (1 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

10.) LOWERED INTRAOCULAR PRESSURE: Reduced Aqueous Production Secondary To The Inflammation. This is True in the Initial Stage of the Inflammation. In The Later Stages The Intraocular Pressure Will Rise If Treatment And Control Has Not Been Established. Homatropine (5%) is the drug of choice for dilation a patient with a anterior uveitis. Place one drop in the affected eye every 5 minutes (i gtt q 5 minutes) or until the pupil starts to dilate. It is very important to know the pupil is dilating before patching a patient. When prescribing homatropine for use at home, instruct the patient to place one drop in the affected eye, once in the morning and again before going to sleep until told to do otherwise. Every morning and at bedtime is abbreviated (qam & hs). Unique Properties of Homatropine and Why It Is Used 1.) PRODUCES CYCLOPLEGIA: Paralyzes The Ciliary Body Which Increases Patient Comfort and Reduces Pain. 2.) RESTORES NORMAL IRIS VASCULATURE: Reduces Release Of Cells And Protein 3.) PREVENTS POSTERIOR SYNECHIAE: Dilates the pupil Averting Secondary Glaucoma Upper Lid Eversion You must to be able to evert both the right and left upper lids with the patient behind the slit lamp. The technique described in Dr. Casser's book leaves out one very important step. Regardless, if a Q' tip or just fingers are used to evert the upper lid the lid must be totally everted. Evert the lid from the temporal side completely to the most nasal side.

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (2 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

ONLY GRASP THE LASHES AND NOT THE SKIN OF THE UPPER LID BETWEEN THE THUMB AND INDEX FINGER.

THE INDEX FINGER MUST BE FREE TO REACH OVER AND EVERT THE INNER MOST PART OF THEIR LID.

The technique is to have the patient look down so your thumb is just under the upper lashes. Grasp only the lashes between your thumb and index finger. Pull down and out breaking the suction and forming a slight air pocket between lid and globe. Once the upper lid is everted use the thumb to firmly pin the outer lid margin and lashes against the temporal orbit. Freeing the index finger, reach it across and evert the nasal part of the lid too. It is important to give your patient good instructions. Do not overly alarm them just explain what you are going to do and why. The patient is told the procedure is slightly uncomfortable but not painful. Tell the patient to keep looking down at all times. This helps keep the cornea partly covered by the lower lid reducing tearing and drying. If the patient looks up most likely the lid will flip back down and the procedure will have to be started all over again. This will only add to the patient's anxiety and unwillingness to cooperate. "Be sure to check for false eyelashes before your start." There are many reasons for everting the upper lids, the following are just some of those reasons: 1.) All Prospective Contact Lens Patients 2.) Patients With Irritation And Seasonal Allergies 3.) Removal Of A Lost Or Possible Lost Contact Lens 4.) Searching For A Foreign Body 5.) Removal Of A Foreign Body From The Upper Lid 6.) Evaluating The Apex Of Internal And External Hordeolums 7.) Evaluating The Internal Apex Of Chalazions 8.) Grading And Evaluating The Presence Of Giant Papillary Conjunctivitis (GPC) 9.) Evaluate GPC With Fluorescein Sodium And Cobalt Blue Light 10.) Checking For Scaring Of The Lid Secondary To Previous GPC

Clinical Stages of Giant Papillary Conjunctivitis

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (3 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

Preclinical - Baseline Stage

Early Developmental Stage

Little Fluorescein Pooling

Increased Fluorescein Pooling

Clinically Significant Stage

Severe Clinical Stage

Marked Fluorescein Pooling

Extreme Fluorescein Pooling

Grading Giant Papillary Conjunctivitis Stage

Morning Discharge

Itching on Lens Size of Papillae Removal

1

Minimal Increase

Mild

2

Moderate Increase

Increased

Baseline Small Red Dot Papillae Areas Extending to Lid Margin

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (4 of 14)6/18/2006 1:16:05 AM

Method of Diagnosis Symptoms Only Slit Lamp Cobalt Filter and Fluorescein Dye that Pools Around Beginning Elevations

Slit Lamp Biomicroscopy Part Two

3

4

Moderate Heavy Heavy: Lids Stick Together and May Have to be Separated

Moderate to Severe

Increased Slit Lamp and Number and Size Occasionally the of Elevations Naked Eye

Moderate to Severe

Flattening of the Elevations and Progression of Stage Three

With the Naked Eye

Adapted and Modified from Allansmith et al. Cataracts Types 1.) 2.) 3.) 4.)

Developmental: Usually Congenital Pre-Senile & Senile: Age Related Cataracts Complicated: Secondary To Intraocular Inflammations Traumatic: Secondary To Eye Trauma Examples

I.) Congenital Cataract Types Coronary (Club Or Crown):-- Found in the far periphery of the lens and are seen only with dilation. They have a ball bat or bowling pin shape and may be single or numerous. They are found in about 25% of the population in some shape or form.

B. "Y" Suture (Stellate):-- Are opacities located in the fetal nucleus and can involve either the anterior or posterior "y" sutures or both and many times are bilateral. They do not cause a reduction in vision nor will they get any larger.

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (5 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

C. Anterior Polar (Pyramidal): -- Usually round, well defined, dense opacity on the anterior surface of the lens. Because of its shape, which might look similar to a pyramid, the name anterior pyramidal cataract is sometimes used. This opacity may have an effect on vision depending on its size and location, though this is rare.

D. Posterior Polar (Pyramidal): -- Again, this is usually a round, well defined, dense opacity, but located on the posterior surface of the lens. Because of its shape it may, also, be referred to as a posterior pyramidal cataract. Because this opacity is located on the posterior surface of the lens, closer to the retina, there is a greater chance that it will have an effect on vision depending on its size and location.

E. Zonular (Lamellar): -- Some authors feel these are among the most frequent types of congenital cataracts. They may vary in size which is dependent upon what time during the intrauterine stage of development the disruption occurred. They are oval in shape when viewed with an optic section and round when viewed in retoillumination through a dilated pupil. They surround a clear or almost clear central zone of the embryonic and fetal nucleus and contain a varying number of small grayish to white punctate shaped opacities. These opacities have a tendency to increase in density rather than size, becoming stationary in mid-life "35 to 55" years of age. Because they do increase in density, vision may become reduce to varying degrees.

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (6 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

F. Mittendorf`s Dot: -- This is a remnant of the hyaloid artery that has failed to dissolve and usually remains partly attached to the back surface of the lens or may be free floating just behind the lens. There may be a part of the hyaloid artery that trails off into the vitreous in a corkscrew-shape. Though many may think this is a relatively benign finding, "I can assure you vision can be reduced to 20/200 or worse."

G. Reduplicating Cataract: -- This is a anterior lens opacity. This condition shows that there has been an intrauterine or, more rarely, postnatal injury or defect of the anterior capsule. This process results in a localized opacity of the anterior capsule with similar opacities behind it, but separated from each other by normal lens tissue.

II. Pre-Senile & Senile Cataracts (Age Related) A. Cortical (Spoke - Cuneiform): -- These start in the periphery of the lens and progress toward the pupillary area. They may start in any quadrant, however, the inferior nasal area seems to be more prevalent. They start out as lamellar separations as the lens takes on water and progress to waterclefts as the lamellar fibers are torn apart. These areas rapidly fill with fluid and appear as optically empty spaces when viewed with an optic section. These fluid filled spaces http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (7 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

progressively become more opaque until they finally form a fully developed cuneiform cataract.

Using Retroillumination Of The Lens And Locs II

If the spoke opacities do not invade the pupil and are only seen during dilation you should only grade them as grade 1/2. It is conceivable that one might have one sector extending into the pupil while another sector is only seen when the pupil is dilated, this should be graded as 1 and 1/2 or better yet as a (1+) cortical cataract. It should be kept in mind that these opacities may occur in either the anterior or posterior part of the lens and a cross section drawing should be made to indicate their true location. They are usually slow progressing opacities, however, like any cataract one cannot predict how fast they will progress. B. Posterior Subcapsular ( Cupuliform - PSC ): -- The typical appearance of this opacity is vacuolated and granular in nature. It is a thin area of dense opacification located in the most posterior layers of the lens cortex and usually along visual axis region. Patients past forty (40) it may take on a yellow hue secondary to nuclear sclerosis. Because of its position and granular nature it may cause marked reduction in vision while the remainder of the lens may be very clear. Causative factors may be, age - related, secondary to steroid therapy, trauma, or secondary to a long standing chronic uveitis. The last of these may take on a notable color play for it is a form of complicated cataract. Posterior subcapsular cataracts (PSC) are one of the fastest progressing age-related lens changes and need to be closely monitored. http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (8 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

Using Retroillumination Of The Lens

C. Nuclear Sclerosis ( NS ): -- It begins soon after the age of 40, as a simple sclerosis of the older central part of the lens. There is ultimately a change in the refractive index of the lens over time in the direction of myopia sometimes referred to as "second sight". In the advancing stages the nucleus will take on a round "oil droplet" like shadow appearance. This is very noticeable when viewed in retroillumination with the direct ophthalmoscope at a distal distance or reto-illumination with the slit lamp, both with the pupil dilated. Using An Optic Section

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (9 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

The Color Change, "Yellowing" Of The Lens, Plus The Overall Central Haziness Is What Determines The Stage Or Grade.

Grading Based On Lens Color Grade 1/2 1 2 3 4

Color Slight-Yellowing Definitely-Yellowing Very-Very-Yellow Yellow-Orange Orange-Brown (Brunescent)

There have been attempts to correlate the different and varying grades of color change with visual acuity. This in my opinion does not work out very consistently. It is not uncommon to have all types of these age related cataracts present at the same time and they will have an additive reduction on vision. Their location within the undilated pupil is the most important factor related to reduced vision. III.) Complicated Cataracts: -- This type of cataract is usually reserved for opacities developing within the lens secondary to an ocular disease or some other atypical type of ocular condition. Causative factors may include, high myopia, retinal detachment, chronic uveitis, retinitis pigmentosa, ocular tumor, etc. Complicated cataracts begin with a change in the posterior lens capsule, notably the lens shagreen, taking on a play of colors "not" seen in senile (agehttp://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (10 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

related) lens changes. In the later stages the posterior subcapsular part of the cortex becomes involved. There are two main features that help distinguish it from other forms of cataracts. 1.) Definite multicolored luster appearance, in the early stages, of the posterior lens capsule. 2.) The opacities are not clearly separated from the other lens structures, but rather are surrounded by a cloudy haze. IV.) Traumatic Cataracts A. Vossius Ring: -- There is an ongoing controversy over whether or not the anterior subepithelium of the lens tissue is effected. It is agreed that it only occurs in the young and is a pigment ring corresponding to the pupil margin of the iris following a contusion to the eye. Also, that the pigment is brown and in many cases the pigment may disappear completely. The controversy may be link to other lens findings following a contusion which may be related to hyphema (blood) in the anterior chamber. The hemosiderin (iron) from the blood is deposited within the lens surface epithelium. Questionable theory, but one that has been proposed. B.) Rosette Cataract: -- This opacity may occur under the anterior or posterior capsule or both and may be complete or sectored with a flower peddle or feather shape. One can get a very close estimation as to when the injury occurred by viewing the lens with an optic section and determining at which nucleus it appears. Like any other cataract the effect that it has on vision depends on its location and density.

There are a great number of other forms of cataracts that have not been discussed and you should review. DR. FREDERICK C. CORDES' MANUAL CATARACT TYPES: ON RESERVE IN THE LIBRARY. Cataract Patient Referrals Doctors must decided when to refer a patient for cataract surgery. It

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (11 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

is most important that the patient's retina can still be evaluated by the surgeon. "The general rule of thumb for referring is as follows: when the patient's visual acuity has dropped to 20/80 in dim illumination or when the cataract starts to have an effect on their ability to perform their normal daily tasks". You cannot predict how fast a patient's cataracts will progress, however, patients are going to ask you how soon it will be before they will need surgery. The best policy is to monitor these patients on a four (4) to six (6) month bases or sooner if the patient becomes concerned because of a noticeable visual change. Vitreous Evaluation A.) Normal Vitreous: -- The anterior vitreous is adhered to the back of the lens in an area approximately 9mm in circular diameter and is known as the "Ligament Of Wieger." Within this area is an optically empty retrolental space known as "Berger's Space." The anterior vitreous of the young individual is grayish in color with optically empty spaces between the collagen fibers. Small white dots (nodosities ) may be seen where fibers cross one another and this is normal. B.) Aging Vitreous: -- With increasing maturity (aging) the collagen fibers lose their fluid binding ability and the fibers and fluid start to separate. The collagen fibers start to clump together forming an increase in the so-called vitreous floaters, noticed by the patient and the doctor. Further aging plus shirking and liquefaction of the vitreous the fluid may escape through the hyaloid membrane causing the vitreous body to pull and separate from its posterior attachment to the optic nerve. The posterior vitreous detachment (PVD) may be seen, at a distal distance with the direct ophthalmoscope, as a annular ring in retro-illumination and dilated pupil. Other reasons for floaters are vessels that fill the eye in the fetal state do not totally dissolve and remnants remain in the vitreous body. Also, myopic individual's cystoidal areas near the ora rupture easier allowing their fluid to be released into the vitreous causing somewhat of a earlier aging effect.

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (12 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

C.) Asteroid Hyalosis: -- This condition was once thought to be secondary to an ocular inflammation, which it is not. It is usually diagnosed in patients in their sixties or later and is considered to be an aging vitreous condition of unknown etiology. It is thought to occur more frequently in males than females. The condition is usually unilateral, but may be bilateral. These round spherical opacities (containing calcium soaps) within the vitreous are attached to the vitreous collagen fibers and will move with the vitreous like floaters which always return to their original position. They are disturbing to patients like floaters, but to a much greater degree for they have a disorientating effect. When viewed in direct illumination with either the slit lamp or direct ophthalmoscope they appear as bright yellow opacities. This is secondary to the nuclear sclerosis of the lens. These opacities are really white in color.

D. ) Synchisis Scintillans: -- Is a condition of a younger vitreous and is either secondary to an injury or inflammation that has involved the vitreous cavity. This is considered to be a rather rare condition which is usually bilateral. Unlike asteroid hyalosis the opacities are free floating in the vitreous, not attached to the collagen fibers, controlled by gravity and seeking the lowest point within the vitreous cavity. The opacities are cholesterol crystals and are truly yellow in color in direct illumination.

E.) Shafer's Sign: -- The presence of pigment granules suspended in the anterior vitreous or floating in Berger's space, sometimes termed "tobacco dust," can be very significant clues to a retinal break or detachment. Hamilton and Taylor found that 98% of patients in their

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (13 of 14)6/18/2006 1:16:05 AM

Slit Lamp Biomicroscopy Part Two

clinical review with this sign had retinal detachments and 60% had flat retinal holes. The source of the pigment granules is not known, though is suspected to arise from the retinal pigment epithelium (RPE). There are a large number of patients with retinal detachments that are totally asymptomatic an simply checking the retrolental (Berger's Space) & anterior vitreous for cells is important. The failure to check for this sign on a symptomatic patient could be considered gross negligence ( symptoms being flashes of lights in their peripheral fields and or an increase in the number of floaters). Red blood cells, secondary to a vitreous hemorrhage, may be difficult to differentiate from the pigment granules. However, when a red free filter (green) is introduced the red blood cells will appear black and not be seen while the pigment granules will. The pigment granules will not absorb the red-free light and will still be seen. If the vitreous cells are white in color, they are most likely inflammatory white blood cells. Their presence usually indicates a posterior segment inflammation; although, an anterior uveitis may cause cells in the anterior vitreous also.

Return To Lecture Notes

Return To Home Page

http://www.opt.indiana.edu/riley/HomePage/newslitlamp/1_Part_two_Slitlamp.html (14 of 14)6/18/2006 1:16:05 AM