What is glaucoma?

group of disorders characterized by increased IOP and the consequences of elevated pressure, optic nerve atrophy, and peripheral visual field loss.

Usually due to imbalance between the aqueous humor production and the drainage/reabsorption.

Two types of glaucoma

1. Open-angle - most common, drainage channels become clogged.  Develops slowly, w/o symptoms.  Eventually becomes "tunnel vision".  Usually bilaterally
2. Angle-closure - reduction in the outflow of aqueous humor, causes lens to bulge forward (due to aging process).  Symptoms = sudden pain around eye, N/V, colored halos around lights, blurred vision, and ocular redness. Usually one eye.

Diagnostic of glaucoma

IOP normal pressure is 10-21 mm Hg

Open-angle IOP is 22-32 mm Hg.  Optic disc cupping may be one of the first signs of chronic open-angle.

Closure-angle IOP is 50 mm Hg or higher

Collaborative care for glaucoma

Open-angle:

1. Betoptic - < production.  *Bradycardia, heart block, pulmonary distress.
2. Propine - < production.  *Ocular discomfort/redness, tachycardia, HTN
3. Isopto Carbachol - > outflow.  *H/A, blurred vision, dysrhythmias, vomiting, diarrhea, ...
4. Diamox - < production.  *tingling in extremities, tinnitus, loss of appetite.
5. Trabeculectomy or trabeculoplasty.

Closed-angle = ocular emergency

1. Isopto Carpine - > outflow.  *H/A, blurred vision, dysrhythmias, vomiting, diarrhea, ...
2. Laser peripheral iridotomy or surgical iridectomy is necessary for long-term treatment and prevention.

Cataract

cause

therapy

Opacity within the lens.

Cx: age related, UV light, maternal rubella, drugs (corticosteroids), ...

Tx: Surgical only = need to dialate eyes (mydriatic [phenylephrine] alpha-adrenergic) and anticholinergic agent that produces paralysis of accommodation.  Patch is usually removed w/in 24 hours.

Macular Degeneration

- manifestation

- prevention

Two forms: dry (nonexudative) and wet (exudative).

     Dry - close vision tasks are becoming more difficult.  Slowly progressive and painless vision loss.

     Wet - more severe.  Most become functionally blind.  Rapd onset.

     Blurred and darkened vision, scotomas (blind spots), and metamorphopsia (distortion of vision).  Straight lines will look bent, unable to complete pentagon drawing.

     Sun exposure, smoking, light color eyes, dietary supplements of C, E, betacarotene and zinc.

Meniere's disease

- excessive accumulation of endolymph n the membranous labyrinth.

- characterized by symptoms caused by inner ear disease, including episodic, vertigo, tinnitus, fluctuating sensorineural hearing loss, and aural fullness.

- sudden severe attacks of vertigo with N/V, sweating, and pallor.

Meniere's disease treatment

• Acute attack - antihistamines (Benadryl), anticholinergics (atropine), and benzodiazepines (Ativan).
• Acute vertigo - bed rest, sedation, and antiemetics (Compazine) or antivertigo (Antivert).
• Low sodium diet, low sugar diet.
• Must learn to live with the unpredictability of the attacks and the loss of hearing.
• Shunts can be put in ear to reduce the pressure
• Still no relief vestibular nerce resection may be performed.

Detached retina

- manifestation

separation of the sensory retina and the underlying pigment epithelium.

• photopsia (light flashes), floaters, and a "cobweb", "hairnet", or ring in the field of vision.
• Painless loss of peripheral or central vision.

Treatment for a detached retina:

• often will be watched and refer to retinal specialist.
• Surgery to seal any retinal breaks and to relieve inward traction on the retina.

After eye surgery

1. Proper hygiene and eye care.
2. Signs and symptoms of infection.
3. Importance of complying with postoperative restrictions on head positioning, bending, coughing, and Valsalva maneuver.
4. How to instill eye medication.
5. Pain management.
6. Importance of follow up.

Myopia

- nearsightedness

- causes light rays to be focused in front of the retina

Hyperopia

- farsightedness

- causes light rays to be focused behind the retina

Presbyopia

- loss of accomodation associated with age.  Lens becomes larger, firmer, and less elastic.

- near objects

Astigmatism

- caused by irregular corneal curvature.

- causes light rays to bend unequally and does not focus at one spot.

Aphakia

- absence of a lens

Total blindness

- no light and no usable vision

Functional blindness

- receives light, but has no usable vision.

Legal blindness

1. Central vision acuity for distance of 20/200 or worse.
2. Visual field no greater than 20 degrees in its widest diameter.

Nursing care for the blind

• still humans!  Hello, goodbye, ...
• Active listening.
• Making eye contact.
• Orient client to environment.
• Serve as a sight guide, walk slightly ahead as they hold the back of your arm.
• Use the clock when giving directions.