Long-Term Evaluation of Specular Microscopic Changes Following Nd: YAG Iridotomy in Chronic Primary Angle-Closure Glaucoma Eyes.

Aim

The aim of this study was to evaluate specular microscopy of chronic primary angle-closure glaucoma (CPACG) eyes at least 1 year after Nd:YAG iridotomy, and compare them with CPACG eyes without an iridotomy and age-matched, normal eyes.

Patients and method: Consecutive patients of CPACG at the Glaucoma service were screened. All patients underwent slit-lamp biomicroscopy, +90 D examination, and applanation tonometry. A total of 100 eyes of 100 consecutive patients of CPACG with an Nd:YAG iridotomy performed ≥1 year before, who met all inclusion/exclusion criteria, 60 consecutive CPACG eyes without an iridotomy, and 60 age and refraction-matched control eyes were enrolled. A specular microscopy was performed in one eye of each patient by an observer masked to diagnosis.

Results

CPACG patients had a mean age of 62±8 years, a mean intraocular pressure of 18±5.3 mm Hg, a mean specular count of 2536±224 cells/mm, and mean duration after iridotomy of 3.2±2 years. There was a significant correlation of specular endothelial counts with age (r=-0.39; P<0.001) and interval after iridotomy (r=-0.25; P=0.01). CPACG eyes without an iridotomy had a mean age of 62±5 years and a mean specular count of 2469±199 cells/mm. Normal control eyes with a mean age of 61±6 years had a mean specular count of 2729±299 cells/mm. There was no significant difference in specular count between CPACG eyes with or without an iridotomy (P=0.19); however, both CPACG groups had a specular count significantly lower than controls (P=0.01 and 0.02, respectively). There was no statistically significant difference seen in polymegathism (coefficient of variation) and pleomorphism (% of hexagonal cells) in endothelial cells among the 3 groups.

Conclusions

An Nd:YAG iridotomy in CPACG eyes did not lead to any significant changes in central corneal specular microscopy in the long term as compared with patients who did not undergo iridotomy. Eyes with CPACG, without and after an iridotomy, had a lower specular count compared with age-matched controls.