Intraocular pressure control and visual field changes in primary angle closure disease: the CUHK PACG Longitudinal (CUPAL) study

To determine the relationship of intraocular pressure (IOP) control with subsequent visual field (VF) deterioration in patients with primary angle closure disease (PACD).419 PACD eyes from 240 Chinese patients were included. Mean IOP and IOP fluctuation were calculated as the average and SD divided by mean IOP, respectively, of all the IOP measured in the initial 18 months for assessment of IOP control. The relationship between IOP control and subsequent VF parameters over time was examined using linear mixed models. VF deterioration was defined as IOP control associated with decreased VF parameters over time with a p value <0.05. We calculated the average of the mean IOPs and IOP fluctuations in the cohort and used these two average values as a cut-off point to define high-threshold (≥average value) or low-threshold (