Pseudoexfoliation syndrome may weaken critical corneal structures

Cornea. 2011;30(9):983-986.

Pseudoexfoliation syndrome may adversely affect corneal hysteresis and corneal resistance factor, key biomechanical properties of the cornea, a study found.

"PEX syndrome affects anterior segment structures, including the cornea, but it is not known whether this condition causes any change in the biomechanical tissue characteristics," the study authors said. "Therefore, the evaluation of these parameters might enlighten our understanding of eyes affected by PEX syndrome and will help us to see if there is any change in the biomechanical behavior of the cornea in this syndrome."

The study included 52 eyes of 52 patients with pseudoexfoliation (PEX) syndrome; the condition was unilateral in 27 patients and bilateral in 25 patients. Mean patient age was 68.98 years. A control group comprised 42 eyes of 42 age-matched subjects. Mean age in this group was 70.5 years.

The Ocular Response Analyzer (ORA, Reichert) was used to measure corneal biomechanical properties, corneal-compensated IOP and Goldmann-correlated IOP. The ORA-integrated handheld ultrasonic pachymeter was used to determine central corneal thickness. Snellen best corrected visual acuity, applanation tonometry and fundus images were also evaluated.

Study results showed that eyes with PEX syndrome had significantly lower corneal hysteresis and corneal resistance factor than normal control eyes (P < .05). However, both groups had similar corneal-compensated IOP and Goldmann-correlated IOP.

There were no significant differences in mean central corneal thickness, corneal hysteresis or corneal resistance factor between eyes with PEX syndrome and normal fellow eyes. However, eyes with PEX syndrome had significantly higher mean corneal-compensated IOP and Goldmann-correlated IOP than healthy fellow eyes (P < .05).

Results showed no difference in central corneal thickness between eyes with PEX syndrome and normal controls, the authors reported.