Evaluation of Sudden Visual Loss and Central 10-Degree Visual Field Change Following Glaucoma Surgery in Severe and End-Stage Eyes

OBJECTIVES: The purpose of the study was to evaluate the sudden visual loss and central 10-degree visual field (VF) change following glaucoma surgery in eyes with severe and end-stage glaucoma. METHODS: This was a single-center retrospective study. The charts of patients with severe and end-stage glaucoma who had undergone trabeculectomy and Ahmed glaucoma valve (AGV) implantation surgery were reviewed. Patients who had 10-2 Humphrey VF automated (HVFA) at follow-up were included and classified into two following groups: With split fixation on 10-2 HVFA before surgery split fixation group (SFG) and those without split fixation (WSFG). RESULTS: The data of 37 patients in SFG and 28 patients in WSFG were reviewed. The mean follow-up duration was 2.06±0.24 years in SFG and 2±0.3 years in WSFG. 10-2 HVFA revealed that SFG had a mean MD –25.8±5.2 dB preoperatively and –25.2±1.1 dB (p=0.18) at last visit, WSFG had a mean MD −9.8±4.8 dB preoperatively and −10.8±1.5 dB at last visit (p=0.10). In SFG, the mean intraocular pressure (IOP) decreased from 30.1±9.5 mmHg to 12.3±0.62 mmHg (p<0.001), and in WSFG, the mean IOP decreased from 30±6.9 mmHg to 12.3±0.90 mmHg at last visit (p<0.001). There was no statistical difference for visual acuity of both the groups at the follow-up (p=0.30 and p=0.70). In SFG, one patient had wipe-out phenomenon who had undergone AGV surgery. CONCLUSION: Although wipe-out phenomenon was a rare complication, it can develop not only after trabeculectomy but also after AGV surgery, and patients with split fixation and severe and end-stage glaucoma were at risk for this phenomenon regardless of the type of surgery. Both trabeculectomy and AGV surgery appear to provide stability of the central 10° VF.