Due to the widespread use of electronic medical records (EMRs), it is now possible to easily collect information from large-scale patient populations to better understand disease progression and treatment response. A new study in the American Journal of Ophthalmology is the first to use this big data approach to compare the rate of visual field (VF) loss in glaucoma patients with uveitis versus those with primary open-angle glaucoma. The study also examined whether the findings were associated with intraocular pressure (IOP).
Anonymous VF and IOP measurements were retrieved from an EMR in five different glaucoma clinic regions in England and included 205 eyes with uveitis plus glaucoma and 4,600 eyes with primary open-angle glaucoma only. Only one eye per patient was analyzed. Minimum inclusion criteria were four or more visits in 4 years. Median patient age was 64 years in the uveitis group and 70 years in the primary open-angle glaucoma group. Researchers used a mixed-effects model and pointwise VF progression analysis of pattern deviation to confirm differences between groups.
Regarding rate of VF loss, the uveitis group had 23 (11%) eyes and the primary open-angle glaucoma group had 331 (7%) eyes that progressed at ≥1.5 dB/year. The relative risk of a fast rate of progression for uveitis was 1.6 and age-adjusted was 1.9, meaning a patient in the uveitis group was 1.9 times more likely to be a fast progressor than patients in the primary open-angle glaucoma group.
Regarding IOP, a total of 143 eyes from the uveitis group and 3,386 eyes from the primary open-angle glaucoma group met the additional inclusion criteria for longitudinal IOP analysis. No statistically significant difference was found in mean IOP between groups. Mean difference in IOP between fast and non-fast progressors was within 1 mmHg.
Results showed that glaucoma patients with uveitis were more likely to be younger and have worse mean deviation at baseline than those with primary open-angle glaucoma. This finding is important because it suggests early VF loss in patients with uveitis may be undetected. However, despite patients with uveitis having a more rapid rate of vision loss, both groups monitored with VFs at the same intensity.
Patients with uveitis require closer attention for ruling out VF loss during treatment.
Rabiolo A, Caprioli J. Cataract surgery and rate of visual field progression in primary open-angle glaucoma [published online ahead of print June 2019]. Am J Ophthalmol. doi: 10.1016/j.ajo.2019.04.028.