Alterations of Eyes: Glaucoma
Glaucoma is a condition in which an obstruction of outflow occurs within the trabecular meshwork and the canal of Schelmn leading to increased pressure within the eyeball.
- Being at the age of 40
- Diabetes mellitus
- Previous ocular injury
Two types of Glaucoma:
- Chronic glaucoma – open angle glaucoma; This happens bilaterally and destroys optic nerve function causing blindness.
- Acute glaucoma – closed angle glaucoma; This is sudden, complete, unilateral closure with dilation stimulated by dark environment, emotional stress or mydriatic drugs. This is a medical emergency and delay in immediate response may lead to blindness within days after the onset.
- Visual Acuity – The result is reduced visual acuity.
- Tonometry – A reading of 24 to 32 mmHg suggests glaucoma
- Opthalmoscopic Exam – shows the narrowing of small vessels
- Perimetry – Shows defects in visual fields
- Administration of medications:
- Miotics (Pilocarpine) – constricts the pupil and draws the smooth muscle of the iris away from the canal of Schlemn to permit aquoues humor to drain out
- Carbonic anhydrase inhibitors (Diamox) – restricts the action of enzyme necessary to produce aqueous humor
- Anticholinesterase (Humersol) – helps in outflow of aqueous humor
- Sympathomimetic drugs (Epinephrine) – reduces the rate of production of aqueous humor
- Hyperosmotic agents – increases blood osmolarity
- Beta adrenergic drugs (Timolol maleate) – reduce production of aqueous humor without changing pupil
- May perform surgical treatment:
- Peripheral iridectomy
- Cyclodiathermy or cyclotherapy
- Emphasize the importance of refraining from activities that increases intraocular pressure such as stooping, heavy lifting or pushing.
- Avoid emotional flare ups.
- Encourage exercise in moderation only.
- Maintain accurate intake and output.
- Use eyes in moderation when reading or watching TV.
Photo credits: www.healthguide.howstuffworks.com