Visual Field Progression After Glaucoma Surgery in Pseudoexfoliation versus Primary Glaucoma

PURPOSE: To compare visual field progression in severity-matched pseudoexfoliation glaucoma (XFG) and primary glaucoma after intraocular pressure (IOP) reduction by filtering surgery. METHODS: Patients with XFG (n=32), primary open-angle glaucoma (POAG, n=33) or primary angle closure glaucoma (PACG, n=28) that underwent routine cataract and glaucoma filtering surgery by the same surgeon (APR) between May 2017 and September 2021, were included for this prospective study. Rate of progression (ROP) was determined using guided progression analysis and compared between XFG and primary glaucoma. Multivariate regression was done to analyse the factors responsible for progression in each group. RESULTS: Visual field progression after surgery was noted in 48 eyes (n=11 XFG, 18 POAG and 19 PACG eyes) at a mean follow-up of 10±5.6 months after surgery with RVI seen in 18 of 48 eyes. The final IOP (p=0.8) and mean ROP (p=0.09) were not significantly different between XFG and primary glaucoma. The XFG eyes had a greater number of eyes (36%) showing an ROP worse than −5dB/yr, with 45% of eyes showing an IOP spike >5mm Hg, and a higher mean IOP spike between visits. The ROP in eyes with RVO and >5mm Hg IOP spikes was greater in XFG than in POAG or PACG. In the multivariate analysis, higher IOP fluctuations >5mm Hg, and associated retinal vein occlusions (RVO) were significant factors for visual progression greater than −5dB/year (R(2)=53.5%) in POAG and XFG eyes. Age, gender, baseline MD, and number of medications before surgery or at final follow-up did not influence visual progression rates in either group. CONCLUSION: A higher IOP fluctuation >5mm Hg and associated RVO were the significant factors predicting visual field progression after filtering surgery in XFG and POAG eyes. Control of both IOP-dependent and -independent mechanisms of VF progression is therefore essential in these eyes.