Patients With Vision And Eye Disorders

Assessment and Management of Patients with Eye and Vision Disorders Copyright © 2008 Lippincott Williams & Wilkins.

External Structures of the Eye

Copyright © 2008 Lippincott Williams & Wilkins.

Extraocular Muscles

Copyright © 2008 Lippincott Williams & Wilkins.

Visual Pathways

Copyright © 2008 Lippincott Williams & Wilkins.

Cross-Section of the Eye

Copyright © 2008 Lippincott Williams & Wilkins.

Internal Structures of the Eye

Copyright © 2008 Lippincott Williams & Wilkins.

Assessment and Evaluation of Vision • Ocular history: see Chart 58-1 • Visual acuity – Snellen chart  Record each eye  20/20 means the patient can read the “20” line at a distance of 20 feet • Finger count or hand motion Copyright © 2008 Lippincott Williams & Wilkins.

Examination of the External Structures • Note any evidence of irritation, inflammatory process, discharge, etc. • Assess eyelids and sclera • Assess pupils and pupillary response in a darkened room • Note gaze and position of eyes • Assess extraocular movements • Ptosis: drooping eyelid • Nystagmus: oscillating movement of eyeball Copyright © 2008 Lippincott Williams & Wilkins.

Diagnostic Evaluation • Ophthalmoscopy – Direct and indirect – Examines the cornea, lens, and retina • Slit-lamp examination • Color vision testing • Amsler grid • Ultrasonography • Fluorescein and indocyanine green angiography Copyright © 2008 Lippincott Williams & Wilkins.

Diagnostic Evaluation (cont.) • Tonometry – Measures intraocular pressure • Gonioscopy – Visualizes the angle of the anterior chamber • Perimetry testing – Evaluates field of vision – Scotomas: blind areas in the visual field Copyright © 2008 Lippincott Williams & Wilkins.

Impaired Vision • Refractive errors – Can be corrected by lenses that focus light rays on the retina • Emmetropia: normal vision • Myopia: nearsighted • Hyperopia: farsighted • Astigmatism: distortion due to irregularity of the cornea Copyright © 2008 Lippincott Williams & Wilkins.

Eyeball Shape Determines Visual Acuity in Refractive Errors

Copyright © 2008 Lippincott Williams & Wilkins.

Glaucoma • A group of ocular conditions in which damage to the optic nerve is related to increased intraocular pressure (IOP) caused by congestion of the aqueous humor • The leading cause of blindness in adults in the U.S.; incidence increases with age • Risk factors: see Chart 58-4

Copyright © 2008 Lippincott Williams & Wilkins.

Pathophysiology of Glaucoma • Normal outflow of aqueous humor

• In glaucoma, aqueous production and drainage are not in balance • When aqueous outflow is blocked, pressure builds up in the eye • Increased IOP causes irreversible mechanical and/or ischemic damage

See Chart 58-5 Copyright © 2008 Lippincott Williams & Wilkins.

Types of Glaucoma • Open-angle glaucoma – Chronic open-angle glaucoma – Normal-tension glaucoma – Ocular hypertension • Angle-closure (pupillary block) glaucoma – Acute angle-closure – Subacute angle-closure – Chronic angle-closure • Congenital glaucomas and glaucoma secondary to other conditions • See Table 58-3 Copyright © 2008 Lippincott Williams & Wilkins.

Clinical Manifestations • Called the “silent thief,” glaucoma renders the patient unaware of the condition until there is significant vision loss, including peripheral vision loss, blurring, halos, difficulty focusing, and difficulty adjusting eyes to low lighting • Patient may also experience aching or discomfort around the eyes or a headache

Copyright © 2008 Lippincott Williams & Wilkins.

Diagnostic Findings • Tonometry to assess IOP

• Progression of visual field defects

• Gonioscopy to assess the angle of the anterior chamber • Perimetry to assess vision loss

Copyright © 2008 Lippincott Williams & Wilkins.

Treatment • Goal is to prevent further optic nerve damage • Maintain IOP within a range unlikely to cause damage • Pharmacologic therapy: see Table 58-4 • Surgery – Laser trabeculoplasty – Laser iridotomy – Filtering procedures – Trabeculectomy – Drainage implants or shunts Copyright © 2008 Lippincott Williams & Wilkins.

Nursing Management • Patient education: see Chart 58-6 • Focus on maintaining the therapeutic regimen for lifelong control of a chronic condition • Emphasize the need for adherence to therapy and continued care to prevent further vision loss • Provide education regarding use and effects of medications • Medications used for glaucoma may cause vision alterations and other side effects; the action and effects of medications need to be explained to promote compliance • Provide support and interventions to aid the patient in adjusting to vision loss/potential vision loss Copyright © 2008 Lippincott Williams & Wilkins.

Cataracts • An opacity or cloudiness of the lens • Increased incidence with aging; by age 80, more than half of all Americans have cataracts • A leading cause of disability in the U.S. • Risk factors: see Chart 58-7

Copyright © 2008 Lippincott Williams & Wilkins.

Cataracts (cont.)

Copyright © 2008 Lippincott Williams & Wilkins.

Clinical Manifestations • Painless, blurry vision • Sensitivity to glare • Reduced visual acuity • Other effects include myopic shift, astigmatism, diplopia (double vision), and color shifts including brunescent c. (color value shift to yellow-brown) • Diagnostic findings include decreased visual acuity and opacity of the lens by ophthalmoscope, slitlamp, or inspection Copyright © 2008 Lippincott Williams & Wilkins.

Surgical Management • If reduced vision does not interfere with normal activities, surgery is not needed • Surgery is performed on an outpatient basis with local anesthesia • Surgery usually takes less than 1 hour and patients are discharged soon afterward • Complications are rare but may be significant: see Table 58-5 Copyright © 2008 Lippincott Williams & Wilkins.

Types of Cataract Surgery • Intracapsular cataract extraction (ICCE): removes entire lens; rarely done today • Extracapsular cataract extraction (ECCE): maintains the posterior capsule of the lens, reducing potential postoperative complications • Phacoemulsification: an ECCE that uses an ultrasonic device to suction the lens out through a tube; incision is smaller than with standard ECCE • Lens replacement: after removal of the lens by ICCE or ECCE, the surgeon inserts an intraocular lens implant (IOL), which eliminates the need for aphakic lenses; however, the patient may still require glasses Copyright © 2008 Lippincott Williams & Wilkins.

Nursing Management • Preoperative care • Usual preoperative care for ambulatory surgery • Dilating eye drops or other medications as ordered • Postoperative care: see Appendix B (Clinical Pathway) • See Chart 58-8 (Patient Teaching) • Provide written and verbal instructions • Instruct patient to call physician immediately if: vision changes; continuous flashing lights appear; redness, swelling, or pain increase; type and amount of drainage increases; or significant pain is not relieved by acetaminophen Copyright © 2008 Lippincott Williams & Wilkins.

Corneal Disorders • Treatment of diseased corneal tissue – Phototherapeutic keratectomy – Keratoplasty – Use of donor tissue for transplant: see Chart 58-9 – Need for follow-up and support – Potential graft failure; teach signs and symptoms • Refractive surgery – Elective procedures to recontour corneal tissue and correct refractive errors – Patients need counseling regarding potential benefits, risks, and complications Copyright © 2008 Lippincott Williams & Wilkins.

LASIK

Copyright © 2008 Lippincott Williams & Wilkins.

Retinal Disorders • Retinal detachment • Retinal vascular disorders – Central retina vein occlusion – Branch retinal vein occlusion – Central retinal vein occlusion – Macular degeneration Copyright © 2008 Lippincott Williams & Wilkins.

Retinal Detachment • Separation of the sensory retina and the retinal pigment epithelium (RPE) • Manifestations: sensation of a shade or curtain coming across the vision of one eye, bright flashing lights, and sudden onset of floaters • Diagnostic findings: assess visual acuity; assess retina by indirect ophthalmoscope, slit-lamp, stereo fundus photography, and fluroescein angiography; tomography and ultrasound may also be used Copyright © 2008 Lippincott Williams & Wilkins.

Retinal Detachment (cont.)

Copyright © 2008 Lippincott Williams & Wilkins.

Surgical Treatment • Scleral buckle • Pars plana vitrectomy – Removal of the vitreous, locating the incisions at the pars plana – Frequently used in combination with other procedures • Pneumatic retinopexy – Injected gas bubble, liquid, or oil is used to flatten the sensory retina against the RPE – Postoperative positioning is critical Copyright © 2008 Lippincott Williams & Wilkins.

Scleral Buckle

Copyright © 2008 Lippincott Williams & Wilkins.

Nursing Management • Patient teaching – Eye surgery is most often done as an outpatient procedure, so patient education is vital • Teach the signs and symptoms of complications, especially increased IOP and infection • Promote comfort • Patient may need to lie in a special position with pneumatic retinopexy Copyright © 2008 Lippincott Williams & Wilkins.

Retinal Vein or Artery Occlusion • Loss of vision can occur from retinal vein or artery occlusion • Occlusions may result from atherosclerosis, cardiac valvular disease, venous stasis, hypertension, and increased blood viscosity; associated risk factors are diabetes mellitus, glaucoma, and aging • Patients may report decreased visual acuity or sudden loss of vision

Copyright © 2008 Lippincott Williams & Wilkins.

Macular Degeneration • Age-related macular degeneration (AMD) • The most common cause of vision loss in persons older than age 60 • Types – Dry or nonexudative type is most common, 85%-90%  Slow breakdown of the layers of the retina with the appearance of drusen – Wet type  May have abrupt onset  Proliferation of abnormal blood vessels growing under the retinachoroidal revascularization (CNV) Copyright © 2008 Lippincott Williams & Wilkins.

Vision Loss Associated With Macular Degeneration

Copyright © 2008 Lippincott Williams & Wilkins.

Retina Showing Drusen and AMD

Copyright © 2008 Lippincott Williams & Wilkins.

Progression of AMD—Pathways to Vision Loss

Copyright © 2008 Lippincott Williams & Wilkins.

Photodynamic Therapy for Slowing Progression of AMD • Light-sensitive verteporfin

dye is injected into vessels; a laser then activates the dye, shutting down the vessels without damaging the retina

• The result is to slow or stabilize vision loss • Patient must avoid exposure to sunlight or bright light for 5 days after treatment to avoid activation of dye in vessels near the surface of the skin Copyright © 2008 Lippincott Williams & Wilkins.

Nursing Management • Patient teaching • Supportive care • Safety promotion • Recommendations include improving lighting, getting magnification devices, and referring patient to vision center to improve/promote function Copyright © 2008 Lippincott Williams & Wilkins.

Trauma • Prevention of injury: see Chart 58-10 • Patient and public education • Emergency treatment – Flush chemical injuries – Do not remove foreign objects – Protect using metal shield or paper cup • Potential exists for sympathetic ophthalmia, causing blindness in the uninjured eye with some injuries Copyright © 2008 Lippincott Williams & Wilkins.

Protective Eye Patches

Copyright © 2008 Lippincott Williams & Wilkins.

Infectious and Inflammatory Disorders • Dry eye syndrome • Conjunctivitis (“pink eye”) – Classified by cause: bacterial, viral, fungal, parasitic, allergic, and toxic – Viral conjunctivitis is contagious: see Chart 58-11 • Uveitis • Orbital cellulitis • See Table 58-6 Copyright © 2008 Lippincott Williams & Wilkins.

Hyperemia in Viral Conjunctivitis

Copyright © 2008 Lippincott Williams & Wilkins.

Ocular Consequences of Systemic Disease • Diabetic retinopathy – Diabetes is a leading cause of blindness in people age 20 to 74 • Ophthalmic complications associated with AIDS • Eye changes associated with hypertension

Copyright © 2008 Lippincott Williams & Wilkins.

Ophthalmic Medications • Ability of the eye to absorb medication is limited • Barriers to absorption include the size of the conjunctival sac; corneal membrane barriers; blood–ocular barriers; and tearing, blinking, and drainage • Intraocular injection or systemic medication may be needed to treat some eye structures or to provide high concentrations of medication • Topical medications (drops and ointments) are most frequently used because they are least invasive, have fewest side effects, and permit self-administration Copyright © 2008 Lippincott Williams & Wilkins.

Ophthalmic Medications (cont.) • Topical anesthetics • Mydriatics (dilate) and cycloplegics (paralyze): see Table 58-7 – Contraindicated with narrow angles or shallow anterior chambers and for inpatients on monoamine oxidase inhibitors or tricyclic antidepressants – May cause CNS symptoms and increased BP especially in children and the elderly • Anti-infective medications – Antibiotic, antifungal, and antiviral products Copyright © 2008 Lippincott Williams & Wilkins.

Ophthalmic Medications (cont.) • Medications used for glaucoma – Increase aqueous outflow or decrease aqueous production – May constrict the pupil and affect ability to focus the lens of the eye; affects vision – May also may produce systemic effects • Anti-inflammatory drugs; corticosteroid suspensions – Side effects of long-term topical steroids include glaucoma, cataracts, and increased risk of infection; to avoid these effects, oral NSAID therapy may be used as an alternate to steroid use Copyright © 2008 Lippincott Williams & Wilkins.

Low Vision and Blindness • Low vision – Visional impairment that requires devices and strategies in addition to corrective lenses – Best corrected visual acuity (BCVA) of 20/70 to 20/200 • Blindness – BCVA of 20/400 to no light perception – Legal blindness is BCVA that does not exceed 20/200 in better eye, or widest field of vision is 20 degrees or less • Impaired vision often is accompanied by functional impairment Copyright © 2008 Lippincott Williams & Wilkins.

Assessment of Low Vision • History • Examination of distance and near visual acuity, visual field, contrast sensitivity, glare, color perception, and refraction • Special charts may be used for low vision • Nursing assessment must include assessment of functional ability and coping and adaptation in emotional, physical, and social areas Copyright © 2008 Lippincott Williams & Wilkins.

Management • Support coping strategies, grief processes, and acceptance of visual loss • Strategies for adaptation to the environment – Placement of items in room – “Clock method” for trays • Communication strategies: see Chart 58-3 • Collaboration with low vision specialist, occupational therapy, or other resources • Braille or other methods for reading/communication • Use of service animals Copyright © 2008 Lippincott Williams & Wilkins.

Guidelines for Instilling Eye Medications •

Shake suspensions or “milky” solutions to obtain the desired medication level.

•

Wash hands thoroughly before and after the procedure.

•

Ensure adequate lighting.

•

Read the label of the eye medication to make sure it is the correct medication.

•

Assume a comfortable position.

•

Do not touch the tip of the medication container to any part of eye or face.

•

Hold the lower lid down; do not press on the eyeball. Apply gentle pressure to the cheek bone to anchor the finger holding the lid.

Copyright © 2008 Lippincott Williams & Wilkins.

Guidelines for Instilling Eye Medications (cont.) • Instill eye drops before applying ointments. • Apply a ½-inch ribbon of ointment to the lower conjunctival sac.

Copyright © 2008 Lippincott Williams & Wilkins.

Guidelines for Instilling Eye Medications (cont.) •

Keep the eyelids closed, and apply gentle pressure on the inner canthus (punctal occlusion) near the bridge of the nose for 1 or 2 minutes immediately after instilling eyedrops.

•

Using a clean tissue, gently pat skin to absorb excess eyedrops that run onto the cheeks.

•

Wait 5 to 10 minutes before instilling another eye medication.

Copyright © 2008 Lippincott Williams & Wilkins.

Safety Measures and Teaching • Patient teaching is a vital nursing intervention for patients with eye and vision disorders • Prevention of eye injuries; education • Provide safety strategies for patients with low vision in the hospital and home setting • Patient teaching after eye surgery or trauma – Potential complications – Loss of binocular vision with patch or vision impairment of one eye; safety – Use of eye patch and shield Copyright © 2008 Lippincott Williams & Wilkins.