SIGNS AND SYMPTOMS
Patients with pseudoexfoliation syndrome remain asymptomatic until an advanced glaucoma develops. The condition is most common in the sixth to eighth decade, with actual glaucoma developing later in this age range. There is no racial, sexual or geographic predilection. Typically, pseudoexfoliation syndrome begins unilaterally, but becomes bilateral within about seven years.
The patient presents with a fine, flaky material on the anterior lens capsule at the pupillary margin. Over time, this coalesces into a characteristic "bulls-eye" pattern seen in pseudoexfoliation. There is often increased transillumination of the iris at the pupillary margin and there may be pigment granules on the endothelium and iris surface. Within the angle, there may be observable pigment or clear flaky material. Initially, intraocular pressure is unaffected; however, elevated IOP develops in up to 80 percent of patients. In these cases, glaucomatous cupping and visual field loss may ensue.
Due to accumulation of abnormal basement membrane material at the pupillary margin, there is increased apposition with the iris and subsequent erosion of iris pigment as the pupil dilates and constricts. This leads to increased iris transillumination and deposition of pigment granules on the endothelium, iris surface and trabecular meshwork similar to pigment dispersion syndrome. Because this condition involves deposition of material on the anterior lens capsule, and not flaking-off of the lens capsule, lensectomy is not a remedy. In fact, some have observed exfoliative material deposits on intraocular lens implants.
The development of glaucoma typically occurs due to a buildup within the trabecular meshwork of pigment granules and pseudoexfoliative material. Patients develop a secondary open angle glaucoma. However, studies have identified patients with increased IOP but no decrease in aqueous outflow. In these cases, the glaucomatous mechanism is unknown.
Pseudoexfoliation syndrome without a pressure rise requires only periodic monitoring of IOPs, discs and visual fields. When first diagnosing pseudoexfoliation syndrome, perform automated visual fields to look for preexisting field loss since pseudoexfoliative glaucoma undergoes periods of exacerbation and remission.
Treat pseudoexfoliative glaucoma in the same manner as primary open angle glaucoma. Use topical beta-blockers, topical carbonic anhydrase inhibitors, prostaglandin analogs and alpha adrenergic agonists if not systemically contraindicated. However, the IOP level in pseudoexfoliative glaucoma is typically higher than in POAG and is more difficult to temporize. Laser trabeculoplasty and filtration surgery are often employed earlier than in POAG.
An initially normal IOP measurement does not preclude prior IOP elevation with subsequent field loss and disc damage. Remember that pseudoexfoliative glaucoma undergoes periods of exacerbation and remission. Serial photographs and automated visual fields are more appropriate for managing this condition than IOP measurements, since the patient may experience progression yet manifest normal IOP if measured during remission.
Argon laser trabeculoplasty and filtration surgery are more effective in controlling IOP in cases of pseudoexfoliative syndrome than in POAG.