Common types of glaucoma:
- Open Angle Glaucoma is the most common type of glaucoma in the United States. Risk factors include race, family history, hypertension, diabetes, age and appearance of the optic nerve. Therapy usually includes eye drops but may also involve specialized glaucoma surgery, including laser. It is painless and there are usually no symptoms noted by the patient. Only an eye examination will determine if you have glaucoma.
- Narrow Angle Glaucoma is somewhat uncommon in the United States but is much more prevalent in Asian countries. (It may be precipitated by certain over-the-counter cold medicines). Patients can complain of eye pain, headache, halos around lights and nausea. Definitive laser treatment is usually helpful in this condition.
- Angle Recession Glaucoma is associated with severe blunt trauma. This type of glaucoma results in higher intraocular pressure due to damage to the drainage portion of the eye (the trabecular meshwork). Patients usually do not experience symptoms and it may take years for the glaucoma to develop.
- Other types of glaucoma include pigmentary dispersion, phacomorphic, phacolytic and uveitic. These types of glaucoma are less common, yet can be detected by thorough eye examination.
Treatment Options
Treatment requires monitoring eye pressure and measuring changes in the peripheral field. Control of glaucoma usually means that the eye pressure is at an acceptable level and that there has been little or no loss of the visual field as measured by a visual field analyzer. Although there are many risk factors for developing glaucoma, control of eye pressure is the mainstay of therapy.
Intraocular pressure may be controlled by a variety of ways:
- Topical drops are usually the first line of treatment. Taken on a daily basis, these usually are very effective in controlling eye pressure. Over time, these drops may become less effective and your doctor may elect to change your medications. Drops either decrease production of intraocular fluid or increase its absorption.
- Oral medications may also be effective but may have more systemic side effects. If tolerated, these can be useful adjuncts to other glaucoma treatments.
- Selective Laser Trabeculoplasty (SLT) is extremely successful in lowering eye pressure in certain types of glaucoma such as open angle glaucoma, pigment dispersion syndrome and pseudo-exfoliation. Treatment is focused on the trabecular meshwork (responsible for fluid drainage from the eye) to increase fluid outflow and thereby reduce eye pressure. This treatment may replace topical drops and can be repeated if necessary.
- Laser iridotomy involves the creation of a small hole in the iris (colored portion of eye) to permit an alternate channel or pathway for intraocular fluid to reach the trabecular meshwork and be drained from the eye. This procedure is usually indicated in narrow angle glaucoma.
- Trabeculectomy is a type of surgery whereby intraocular fluid (aqueous humor) is directed to the outside of the eye to increase its absorption. This is commonly performed when medications fail, although some practitioners may recommend this as initial treatment.
- Seton or shunt placement for glaucoma also involves the creation of an alternate pathway for to intraocular fluid be absorbed outside the eye. It, too, is not a first line of treatment and may be reserved for very difficult situations.