Asymmetric Pigmentary Glaucoma Resulting From Cataract Formation Robert Ritch, M.D., Teekhasaenee Chaiwat, M.D., and Thomas S. Harbin, Jr., M.D. Pigment dispersion syndrome usually man- ifests bilaterally, and asymmetric involve- ment is unusual. When asymmetry is present, the eye with greater involvement may have an additional exacerbating condition or the eye with less involvement may be protected. Analysis of such cases should further eluci- date the mechanism of the disorder and its development and regression. We examined four patients in whom unilateral cataract for- mation or extraction was associated with re- duced clinical signs of pigment dispersion syndrome in the affected eye. Cataract forma- tion, by inducing relative pupillary block, appears to decrease or prevent the manifesta- tion of pigment liberation. 1 IGMENT DISPERSION SYNDROME is characterized clinically by slitlike radial transillumination defects in the midperipheral iris and dispersion of pigment granules on the cornea (Krukenberg spindle), trabecular meshwork, zonules, lens, and anterior iris surface. 16 The loss of pigment from the iris results from friction between the posterior iris surface and the zonules during normal physiologic movement. 7 Intraocular pressures may be normal or increased. Pigment dispersion syndrome appears to be inherited through an autosomal dominant gene. 8,9 Both eyes are usually affected. 1 ' 4 When the severity of phenotypic expression differs between the two eyes, an explanation should be sought. The analysis of asymmetric cases may provide additional information regarding the Accepted for publication July 24, 1992. From the Department of Ophthalmology, New York Eye and Ear Infirmary, New York, New York (Drs. Ritch and Chaiwat); and Department of Ophthalmology, Pied- mont Hospital, Atlanta, Georgia (Dr. Harbin). This study was supported in part by the Glaucoma Foundation, New York, New York. Reprint requests to Robert Ritch, M.D., Glaucoma Service, New York Eye and Ear Infirmary, 310 E. 14th St., New York, NY 10003. pathophysiologic mechanism involved or serve as a clue for the existence of additional disease. We examined four patients with unilateral or asymmetric pigmentary glaucoma resulting from unilateral cataract formation or extrac- tion. Case Reports Case 1 A 58-year-old white man had had glaucoma diagnosed seven years previously at the time of retinal detachment repair. He had undergone laser treatment for a retinal tear in the right eye after initiation of miotic therapy. He was using 0.5% timolol in both eyes twice daily when first seen. His best-corrected visual acuity was R.E.: 20/20 with -7.00 sphere and L.E.: 20/200 with -10.00 sphere. He had a dense Krukenberg spindle and marked radial, slitlike, midperiph- eral, iris transillumination defects in the right eye only. Intraocular pressures were 18 mm Hg in the right eye and 15 mm Hg in the left eye. The angles were wide open with moderate pig- mentation of the trabecular meshwork in the right eye and light pigmentation in the left eye for 360 degrees. There was early nuclear sclero- sis in the right eye and a brunescent cataract in the left eye. The central anterior chamber in the left eye was shallower than that in the right. The cup/disk ratio by contour in the right eye was 0.8, while that in the left eye was 0.3. Goldmann visual fields were normal in both eyes. Case 2 A 57-year-old white man had a nine-year history of glaucoma in both eyes. He was using a combination of 1% epinephrine and 4% pilo- carpine in both eyes four times daily when first seen. A maternal uncle had had glaucoma. His best-corrected visual acuity was R.E.: 20/25 with -5.00 sphere +1.00 cylinder x 5 484 ©AMERICAN JOURNAL OF OPHTHALMOLOGY 114:484-488, OCTOBER, 1992