Chapter 58: Eye and Visual Disorders

Vocabulary practice flashcards covering nursing care, pathophysiology, clinical manifestations, pharmacology, and emergency management of eye and visual disorders.

Snellen test

A visual screening assessment used to evaluate distance visual acuity separately for each eye.

Tonometry

An ocular diagnostic test used to measure intraocular pressure (IOP), which normally ranges around $10\text{--}21\,\text{mmHg}$.

Amsler grid

A diagnostic screening tool evaluated one eye at a time to detect macular distortion, such as wavy or missing lines.

Sighted-guide technique

A mobility assistance method where the nurse offers their arm above the elbow, walks slightly ahead of the visually impaired patient, and announces turns, steps, doors, and hazards.

Clock method (meal setup)

A strategy for orienting visually impaired individuals to meal trays by describing food locations according to clock positions (such as meat at 6 o'clock) to encourage eating independence.

Age-related macular degeneration (AMD)

An ocular disorder characterized by the deterioration of the macula, resulting in the loss of central vision and difficulty reading or recognizing faces, while peripheral vision is often spared.

Glaucoma

An eye disease marked by progressive optic nerve damage and early peripheral visual field loss, with elevated intraocular pressure serving as a primary modifiable risk factor.

Diabetic retinopathy

Microvascular retinal damage stemming from diabetes that is a leading cause of vision loss in working-age adults (especially age $40+$), progressing from nonproliferative microaneurysms to proliferative neovascularization.

Cataract

An opacity or clouding of the crystalline lens that scatters light before reaching the retina, resulting in painless, slowly progressive dimming or blurring of vision, glare, and faded colors.

Punctal occlusion

The technique of applying gentle pressure at the inner canthus for $1\text{--}2\,\text{minutes}$ following ophthalmic drop instillation to minimize systemic medication absorption.

Open-angle glaucoma

A chronic, painless form of glaucoma known as the 'silent thief' that leads to gradual peripheral visual field loss, reduced night adaptation, and late tunnel vision.

Acute angle-closure glaucoma

An immediate ocular emergency caused by rapid drainage-angle obstruction, presenting with severe eye pain or headache, red eye, blurred vision, halos, nausea, vomiting, and occasionally a mid-dilated pupil.

Latanoprost

A prostaglandin analog ophthalmic medication prescribed in glaucoma that reduces intraocular pressure by increasing aqueous humor outflow.

Topical timolol

A beta-blocker eye drop that decreases aqueous humor production, which carries risks of systemic side effects like bradycardia and bronchospasm in patients with asthma, COPD, or cardiac disease.

Metamorphopsia

The visual distortion of straight lines appearing bent or wavy, commonly noted in macular degeneration.

Dry (nonexudative) AMD

The form of age-related macular degeneration characterized by the accumulation of drusen deposits and gradual macular atrophy.

Wet (neovascular) AMD

An advanced form of age-related macular degeneration involving fragile abnormal blood vessels that leak or bleed beneath the retina, causing accelerated vision decline.

Retinal detachment

The separation of the neurosensory retina from the retinal pigment epithelium, classically presenting painlessly with sudden bright flashes, a new shower of floaters, and a dark shade or curtain across the visual field.

Chemical splash (ocular)

An urgent ocular event requiring immediate, copious irrigation with water or saline without stopping to take a history or check visual acuity, continued until ocular pH normalizes.

Penetrating eye injury / Open globe

An ocular emergency requiring application of a rigid shield without pressure, keeping the patient NPO, giving antiemetics, and strictly avoiding eye drops, irrigation, patching, or foreign object removal.