Long‐term effects of trabeculectomy on visual field progression across two centres in the United Kingdom: A 10 year follow‐up

Abstract

PurposeTrabeculectomy is the most commonly performed surgical procedure for the treatment of glaucoma in the UK. The overarching aim is to achieve good IOP control, and thereby halt or slow further visual field loss. We aim to analyse whether trabeculectomy is successful in achieving long‐term visual field stability.MethodsA retrospective analysis was performed on consecutive patients who underwent a trabeculectomy between 2001 and 2010 at the Queen Alexandra Hospital in Portsmouth and the Queen Elizabeth hospital, Birmingham under the care of two specialists (JK and PS). Only eyes with at least five years of follow‐up post‐operatively, as well as visual fields before surgery and at least 5 years after were included. Patient demographics and comorbidities, intraocular pressures before and after surgery, visual field information prior to surgery and at the most recent follow‐up were collated and analysed.Results146 eyes of 110 patients met the eligibility criteria. Median follow‐up time was 10.0 years (range 5–17.5 years) and median visual field progression per year was −0.12 dB. 69% (n = 101) achieved stable visual fields post op (MD loss/year < 0.3 dB), 14% (n = 20) showed borderline/minimal progression (0.3–0.5 dB MD loss/year), 13% (n = 19) had moderate progression (0.5–1 dB loss/year), and 4% (n = 6) showed rapid progression (MD loss >1 dB/year). Median IOP reduction at final follow‐up compared to before surgery was 47% (median final IOP was 11 mmHg). Eyes that achieved good IOP control (<12 mmHg at final review, n = 96) had a median visual field progression of −0.08 dB/year. All six cases of rapid deterioration were confounded by concurrent severe systemic diseases (two cases of metastatic cancer, one case each of infective endocarditis and severe hypotension) and non‐glaucoma ocular conditions (one case each of diabetic maculopathy and advanced age‐related macular degeneration) during the follow‐up period.ConclusionsIn the majority of these cases (83%, n = 121), trabeculectomy resulted in visual field stability. Its positive effect on visual field stability is enhanced when the final IOP is less than 12 mmHg.