Corneal thickness and corneal endothelium in normotensive subjects with unilateral exfoliation syndrome

Purpose: To examine the central corneal thickness (CCT) and corneal endothe lium in both eyes of patients with unilateral exfoliation syndrome (EXS). T o determine the effect of CCT on the measurement of intraocular pressure (I OP). Methods: In this cross-sectional clinical study, comparisons were made of C CT (Humphrey Ultrasonic Pachometer), corneal endothelial cells (Keeler-Kona n contact specular microscope) and IOP (Goldmann applanation tonometer) bet ween the exfoliative (E) and fellow non-exfoliative (NE) eyes in 40 normote nsive patients with unilateral EXS. The CCT was used to obtain a corrected value for the IOP. Results: The E eyes had significantly higher values for CCT (0.528+/-0.030 vs 0.523+/-0.032 mm, P<0.01) and IOP (15.7+/-3.6 vs 14.4 +/-2.9 mmHg, P<0.001) than the fellow NE eyes. The paired E and NE eyes did not differ in endothelial cell density (2779+/-540 vs 2870+/-386 cells/mm( 2)), in the coefficient of variation of cell size (0.25+/-0.03 vs 0.26+/-0. 03) or in the frequency of hexagonal cells (80.5+/-6.5 vs 82.0+/-5.0%). Aft er correcting IOP for CCT, the E eyes still had significantly higher IOP th an the NE eyes (15.1+/-4.4 vs 14.2+/-3.7 mmHg, P<0.05). Conclusion: Normotensive eyes with early EXS did not have quantitative (cel l density) or qualitative (variation in cell size, frequency of hexagonal c ells) morphological changes in corneal endothelium, but had higher values f or IOP and CCT. After correcting IOP for CCT, the E eyes still had signific antly higher IOP than the fellow NE eyes.