A Study Of Corneal Endothelial Changes In Patients Of Pseudoexfoliation Using Non Contact Specular Microscopy

The prevalence of Pseudoexfoliation Syndrome in India has been reported from 1.87% to 7.4%.The high rate of intraoperative and postoperative complications in these patients have been attributed to poorly dilating pupils and zonular instability.But the importance of evaluation of corneal endothelium pre operatively has not been emphasized. The aim of our study was to evaluate the changes in the corneal endothelial morphology in patients of pseudoexfoliation syndrome.

Pseudoexfoliation (PEX) is a common age-related disease that affects elderly people, who are also likely to undergo cataract surgery.

We conducted a study on 100 eyes with Pseudoexfoliation and compared it with 100 eyes of age and sex matched controls using non-contact specular microscopy. Corneal endothelial cell density, mean cell area with its standard deviation and coefficient of variation, percentage of hexagonality were studied.

This descriptive studywas carried out in 100 eyes of 80 patients with pseudoexfoliation. All patients with pseudoexfoliation were diagnosed on slit lamp examination. 100 eyes with pseudoexfoliation & 100 eyes of 100 age matched patients with IMSC were evaluated with specular microscopy.Computerized morphometry was used to evaluate the central corneal thickness, size, shape, cellular density, coefficient of variation and hexagonality of the endothelial cells by using a non contact specular microscope before and after laser capsulotomy.Data was analyzed using Z test and P values less than 0.05 were considered significant.

The endothelial cell density in eyes with pseudoexfoliation was 2120.80 +/- 310.33 cells/mm² & in the controls 2492.09 +/- 288.32 cells/mm² (p<0.05). There was significant difference in the two groups. The average cell size of cases was 481.40 ± 71.14 μm² & that of controls was 425.45± 74.39 μm² (p <0.05). There was a significant difference in the average cell size in the cases & control groups.Hexagonality of corneal cells in the cases varied from 11 % to 90 % with a mean of 47.34 %.  The controls had a mean of 61.01 % (p <0.05). There was a statistical difference in the hexagonality of the two groups.

Our study showed that corneal endothelium is damaged in pseudoexfoliation syndrome. Endothelial cell density and the percentage of hexagonal cells are reduced. An increase in the average cell size were also seen in patients.  Pseudoexfoliation affects the corneal endothelium and pre-operative evaluation of the corneal endothelium should be done routinely in all patients with pseudexfoliation syndrome likely to undergo intraocular surgeries. Also careful surgical techniques in terms of risk disclosure to patients, use of high viscosity viscoelastics and use of soft shell technique should be emphasized.