Intraocular Pressure Control Predicts Retinal Nerve Fiber Layer Thinning in Primary Angle Closure Disease: The CUPAL Study.

ABSTRACT Purpose To determine the relationship of intraocular pressure (IOP) control with subsequent retinal nerve fiber layer (RNFL) thinning in patients with primary angle closure disease (PACD). Design Prospective cohort study. Methods Five hundred and seventeen treated PACD eyes from 280 Chinese subjects were followed up at least 24 months. IOP was measured every 3-month using Goldmann applanation tonometry, and RNFL were measured by SD-OCT (Spectralis, Heidelberg Engineering, Germany) every 6-month. IOP mean and fluctuation were calculated as the average and the coefficient of variation (CoV) of IOP measurements during the first 18-month of study period. The relationship between IOP and subsequent RNFL changes over time was examined using multivariable linear mixed models. Intra-class correlations at the patient- and eye-levels were also controlled using nested random intercepts in the models. Results IOP mean (β=-1.20 micron/year per 1mmHg, p Conclusions In treated PACD eyes, large IOP fluctuation is an independent predictor for subsequent progressive RNFL thinning, in addition to high mean IOP during follow-up.