A condition of the eye characterized by intraocular pressure (i.e., the production of aqueous fluid by the ciliary body exceeds the drainage rate through the trabecular system and Canals of Schlemm).
Classification includes three basic types:
Primary Glaucoma Open-angle or simple glaucoma, the most common type, and closed-angle or acute/chronic type.
Congenital Glaucoma Buphthalmos or hydrophthalmos and juvenile types associated with congenital anomalies.
Secondary glaucoma Due to changes in the lens or uveal tract, trauma, rubeosis, surgical procedures, or topical corticosteroids.
Heredity seems to predispose individuals to glaucoma, although it may also be related to medications and/or surgical procedures in other parts of the eye. If untreated, the effects can cause damage to the optic disk, restricted visual fields, and corneal edema; cataracts also often develop. Complete blindness can result. When treated early, the condition can be successfully managed medically. Because its onset is so gradual, all adults should be checked regularly for glaucoma.
Glaucoma cannot be “cured” — only controlled. Miotics help to facilitate aqueous drainage, and other medications (also in eyedrop form) decrease aqueous production. When these measures do not halt the advancing damage to visual fields or optic nerve, surgery (to clear or enlarge the drainage system) is indicated; it is a procedure of last resort. Trabeculectomy and trabeculotomy are microsurgical techniques with high success rates.
There may be periods of fluctuating vision if medication level also fluctuates. Fatigue may be a factor in regulating assignments.
There is some evidence to suggest that stress tends to exacerbate glaucoma; therefore, emotional upset should be avoided. Excessive fatigue should also be avoided. Optical aids and illumination control (e.g., sunglasses) are recommended as needed, since photophobia and decreased visual acuity are symptoms of glaucoma. A unique characteristic of this disorder is the observation by the patient of halos around lights. Early identification and ongoing control are essential if visual function is to be maintained.
Genetic counseling may be indicated. Halos around lights may also be a sign of incipient cataracts.
Additional information is available in the Blind Children’s Center Pediatric Visual Diagnosis Fact Sheets.