Electron Microscopic Investigation of the Lens Capsule and Conjunctival Tissues in Individuals with Clinically Unilateral Pseudoexfoliation Syndrome

Purpose: To determine the presence of pseudoexfoliative material in the unaffected eyes of patients with clinically unilateral pseudoexfoliation syndrome. Design: Prospective observational case series. Participants: Thirty-two consecutive patients with clinically unilateral pseudoexfoliation syndrome, undergoing routine cataract surgery. Methods: Transmission electron microscopy (TEM) was used to examine conjunctival and anterior lens capsule specimens in affected and unaffected eyes. Main Outcome Measure: Presence of characteristic pseudoexfoliation syndrome findings on TEM. Results: Transmission electron microscopy demonstrated pseudoexfoliative material on either the anterior capsule or conjunctival sample from the clinically unaffected eye in 26 of the 32 patients with clinically unilateral pseudoexfoliation syndrome (81%; 95% confidence interval, 64%-93%). Conclusion: The results suggest that the seemingly uninvolved eye in a patient with clinically unilateral pseudoexfoliation syndrome has an 81% likelihood of being affected ultrastructurally. Several population studies examining conversion rates from unilateral to bilateral disease have found a similar proportion of patients with bilateral pseudoexfoliation syndrome in the later decades of life.