Comprehensive Study Guide: Eye and Vision Disorders

Low Vision and Blindness Definitions

• Low Vision: This condition requires the use of devices and/or specific strategies in addition to standard corrective lenses. It is defined by a Best Correct Visual Acuity ($BCVA$) ranging from $20/70$ to $20/200$.

• Blindness: Defined by a $BCVA$ of $20/200$ or worse, or No Light Perception ($NLP$).

• Legal Blindness: This classification applies when the $BCVA$ is $20/200$ or worse, or if the widest visual field is restricted to $20\,deg$ or less in at least one eye.

• Visual Impairment: Characterized by slow visual orientation and the necessity for constant scanning of the environment. Individuals may still be able to explore surroundings without aids, a state referred to as "travel vision."

• Functional Impairment: This stage requires the use of mobility devices and assistive tools, such as a cane, guide dog, Braille, or various computer aids.

General Nursing Management and Hospital Accommodations

• Sensory Device Maintenance: Always ensure that the client's sensory devices (glasses, hearing aids) are with them or being worn.

• Coping Support: Actively promote coping mechanisms for clients experiencing new blindness.

• Environmental Adjustments:

  • Ensure the bedside table and call light are always within reach.

  • A unique intervention is to tape a cotton ball to the nurse call button to provide a tactile indicator.

  • Orient the client thoroughly to the layout of the hospital room.

• Mealtime Assistance:

  • Describe the food and its location on the plate (often using the clock method).

  • Set up the meal tray for the client.

• Communication: Always announce yourself when entering or leaving the room to prevent startling the client.

Glaucoma: Pathophysiology and Clinical Management

• Pathophysiology: Involves optic nerve damage often caused by increased ocular pressure, which eventually leads to blindness.

• Risk Factors:

  • Genetics and family history.

  • Hypertension ($HTN$) and Cardiovascular Disease.

  • History of migraines.

  • Nearsightedness (Myopia).

  • Eye trauma.

  • Prolonged use of topical or systemic steroids.

  • Age over $60$ years and individuals Assigned Male At Birth ($AMAB$).

• Clinical Manifestations: Known as the "silent thief of sight" because treatment is often sought too late. Symptoms include:

  • Blurred vision and halos around lights.

  • Difficulty focusing and difficulty seeing in low light.

  • Loss of peripheral vision (often the first significant sign of damage).

  • Physical symptoms such as eye pain or headache.

• Medical Management:

  • Lifelong Therapy: Required to manage the condition.

  • Medications: Timolol eye drops (a $\beta$-blocker) and Latanoprost eye drops (a prostaglandin).

  • Surgical Management: Aimed at increasing the drainage of aqueous humor.

• Nursing Interventions: Encourage regular visits to an ophthalmologist for prevention of progression. Emphasize medication compliance and scheduling. Assist the client in coping with potential blindness and maintaining self-care.

Cataracts: Pathophysiology and Postoperative Care

• Pathophysiology: The lens becomes cloudy. It is a leading cause of disability in older adults and the most frequent cause of treatable blindness.

• Risk Factors:

  • Aging (typically over $65$ years).

  • Toxic exposures/Medications: Steroids, cigarettes, and metal poisoning.

  • Physical factors: Poor nutrition, chronic dehydration, trauma, and sun damage (UV exposure).

• Clinical Manifestations: Painless, blurry vision. Vision may seem dimmer, with issues regarding glare and contrast. Visual acuity is reduced as the condition progresses.

• Medical Management: Surgery is the primary treatment (outpatient, usually less than $1\,hour$). Cataracts are treated one eye at a time. The clouded lens is removed (often using ultrasound) and replaced with an artificial lens.

• Nursing Interventions: Clients remain visually impaired until treatment; they must not drive at night and may be restricted from daytime driving based on progression.

• Postoperative Discharge Instructions:

  • Wear glasses or a metal eye shield as instructed.

  • Wash hands before touching or cleaning the eye.

  • Clean the eye with a clean tissue, wiping from the inner canthus outward in a single gesture.

  • Bathe or shower carefully; shampoo hair with assistance.

  • Avoid lying on the side of the affected eye on the first night.

  • Keep activity light (walking, reading, TV) and avoid strenuous activity, sexual activity, or driving until cleared.

  • Weight Limitation: Do not lift, push, or pull objects heavier than $15\,lb$.

  • Avoid bending or stooping for extended periods.

Retinal Disorders: Detachment and Macular Degeneration

Retinal Detachment

• Pathophysiology: There are four types, the most common being Rhegmatogenous. Other types include Traction, Combination, and Exudative.

• Risk Factors: Nearsightedness, Aphakia (absence of lens after cataract surgery), trauma, and Diabetic Retinopathy (which creates scarring and tension).

• Clinical Manifestations: Sensation of a "curtain closing" across the vision, seeing cobwebs, bright flashing lights, and a sudden onset of large amounts of floaters. Notably, this condition is painless.

• Medical Management: Outpatient surgery to reattach the retina. Education is specific to the surgical procedure performed.

• Post-Surgical Care/Interventions: No heavy lifting or strenuous exercise. No reading (to prevent eye strain). Wear sunglasses during the day and an eyepatch while sleeping.

• Complications to Report: Sudden vision changes, fever, lid swelling, increased redness, pain, or bleeding.

Macular Degeneration (AMD)

• Pathophysiology: Age-Related Macular Degeneration ($AMD$) is the leading cause of irreversible vision loss (though usually not total blindness). It involves the development of yellow spots (drusen) under the retina and primarily affects central vision.

• Risk Factors: Age over $60$, smoking, $HTN$, genetics, thyroid hormone use, Hydrochlorothiazide ($HCTZ$) use, and arthritis.

• Types:

  • Dry Type: Common, nonexudative, and nonneovascular. Manifests as gradual, sporadic missing areas of vision.

  • Wet Type: Exudative and neovascular. Involves leaky vessels and bleeding, leading to rapid changes and loss of central vision.

• Management:

  • Monitoring: Use Amsler grids several times per week to monitor for sudden progression.

  • Nutrition: Supplemental Vitamin $B$, $C$, $E$, Zinc, Copper, and Lutein.

  • Medications/Treatment: Laser treatment (with risks of retinal damage). For Wet $AMD$, Verteporfin may be used (given IV), which causes photosensitivity, headache, and flu-like symptoms for $5-7\,days$.

Infectious and Inflammatory Eye Disorders

Conjunctivitis ("Pink Eye")

• Pathophysiology: Inflammation of the conjunctiva. Types include:

  • Bacterial: Acute/chronic, includes purulent discharge.

  • Viral: Acute/chronic, includes watery discharge.

  • Allergic: Acute, includes mucous discharge.

  • Toxic/Foreign Object: Acute onset.

• Clinical Manifestations: Pink/red eye, possible drainage, crusting, blurry vision, photophobia, and lymphadenopathy. Often starts unilaterally and spreads to the other eye.

• Management: Hand washing is the primary prevention. Treatment depends on type (antibiotic drops, ointments, or allergy meds).

Orbital Cellulitis

• Pathophysiology: Inflammation of the tissues surrounding the eye, typically bacterial, fungal, or viral in origin. Often spreads from the face or sinuses.

• Clinical Manifestations: Pain, lid swelling, conjunctival edema, and proptosis/exophthalmos (bulging of the eye).

• Management by Type:

  • Bacterial: Culture and sensitivity ($C\&S$) labs, broad-spectrum antibiotics, monitoring vision, surgical drainage if necessary. Involve an otolaryngologist if the sinus is affected.

  • Viral: Cold compresses; highly contagious—no social contact until symptoms resolve.

  • Allergic: Antihistamines, corticosteroids, topicals, and ice packs.

  • Toxic: Extensive irrigation.