Anterior Segment Optical Coherence Tomography Analysis of Clinically Unilateral Pseudoexfoliation Syndrome: Evidence of Bilateral Involvement and Morphologic Factors Related to Asymmetry

Abstract

To compare the morphology of the anterior chamber angle (ACA) and iris in eyes with pseudoexfoliation (PEX) syndrome to that of their clinically unaffected fellow eyes and normal control eyes. Forty-two patients with unilateral PEX syndrome and 42 normal subjects were studied. Eyes were separated into those with PEX, their clinically unaffected fellow eyes, and normal eyes. The dark-light changes of the ACA and iris were documented by anterior segment optical coherence tomography (AS-OCT) video recordings. The nasal ACA parameters including the angle opening distance at 500 μm (AOD500), the trabecular-iris space at 500 μm (TISA500), and the trabecular-iris angle at 500 μm (TIA500); anterior chamber depth (ACD); iris-lens contact distance (ILCD), and iris configuration were analyzed with the built-in software and a customized program. The ACA parameters were not significantly different among all three groups in the dark. The PEX eyes had significantly smaller ACA parameters than their fellow eyes and normal control eyes in the light. PEX eyes also had significantly shallower ACD, longer ILCD, and greater iris convexity (both in dark and light), and thinner iris (in dark) than their fellow eyes. The fellow eyes had significantly lower ACD both in the dark and light, and smaller angle opening distance at 500 μm and ILCD in the light than normal controls. There were no significant differences in the iris area among the three groups. Differences in the anterior segmental morphology are present between PEX and fellow eyes. These disparities may be related to the asymmetry in patients with the unilateral PEX syndrome.