Pupil ruff atrophy correlations with intraocular pressure and cup-to-disc ratio in a glaucoma clinic population

Abstract

Purpose: To evaluate the correlations between pupil ruff changes and associated gonioscopy findings with intraocular pressure (IOP) and cup-to-disc ratio (CDR).

Design: Prospective, observational, comparative study.

Participants: A total of 103 patients from a glaucoma clinic population. Patients with pseudoexfoliation, previous intraocular surgery, and IOP-lowering medication were excluded.

Methods: Pupillary ruff and associated gonioscopy findings were graded from photographs based on the pupil ruff atrophy (PRA) grading system. Parameters evaluated include pupillary ruff absence and abnormality, pupil edge pigment, and trabecular meshwork pigment. Inter-eye differences were determined and analyzed for correlations with inter-eye differences in IOP and CDR based on Heidelberg Retinal Tomograph II imaging (Heidelberg Engineering, Dossenheim, Germany).

Main outcome measures: Correlations between inter-eye PRA grading differences and inter-eye IOP and CDR differences.

Results: A total of 103 patients were included, with a mean age of 64 years. The average amount of abnormal and missing ruff was 9.5 and 5 clock hours, respectively. Inter-eye IOP asymmetry was significantly associated with asymmetry of amount of abnormal ruff (P = 0.034) and amount of missing ruff (P = 0.022). Inter-eye CDR asymmetry was significantly associated with asymmetry of the amount of missing ruff (P = 0.001) and trabecular meshwork pigmentation (P = 0.006). The eye with the most pupillary ruff loss was 25% more likely to have the greater CDR.

Conclusions: Asymmetric pupillary ruff changes were associated with asymmetry in both IOP and CDR. However, the clinical significance of this finding requires further evaluation.