Identification of glaucomatous optic nerve head changes in Indian donor eyes without clinical history

Abstract

Purpose: The purpose of this study is to develop methods to identify glaucoma by examining the optic nerve head (ONH) of donor's eyes when information on the preexisting ocular disease is unavailable. Materials and Methods: The ONH of the donor's eyes was evaluated under a stereomicroscope for the cup-disc ratio (CDR) and focal retinal rim thinning. The vertical diameter of the cup and disc was also measured using a precalibrated eyepiece micrometer. The suspect eyes were subjected to histological analysis to confirm the presence of specific glaucomatous changes. Results: A total of 202 eyes from 119 donors (68 males and 51 females, aged 42-96) were evaluated for glaucoma. Among them, 190 (94%) eyes showing vertical CDR in the of 0.0-0.6 range were considered nonglaucomatous and the remaining eyes with >0.6 as glaucoma suspect. The calculated mean CDR of the two groups (0.3 +- 0.16, 0.62 +- 0.27) was highly significant (P = 0.0003). Of 12 eyes suspected of glaucoma, 7 eyes from 5 donors showed specific glaucomatous changes by histology. The prevalence of glaucoma was 4.2% among the donors studied. Conclusions: A simple method of screening fresh donor eyes for selecting those with glaucoma features using CDR and histological analysis was reported. This method helps to obtain biologically active human ocular tissue for glaucoma research on gene expression, ultrastructural/proteome changes, and outflow mechanism.