Risk Factors for Complications and Failure after Gonioscopy-Assisted Transluminal Trabeculotomy in a Young Cohort

To determine the risk factors for failures and complications of gonioscopy-assisted transluminal trabeculotomy (GATT) in a young cohort. Retrospective case series. Eyes that underwent GATT at Bascom Palmer Eye Institute. Preoperative and postoperative intraocular pressure (IOP), extent of angle treated, postoperative IOP spike, postoperative drop regimen, and postoperative failure were recorded. Failure was defined as (1) IOP of more than 21 mmHg or less than 5 mmHg after postoperative month 3, (2) absence of at least 20% reduction from the preoperative IOP baseline after postoperative month 3, or (3) performance of additional IOP-lowering surgery before postoperative month 3. Intraocular pressure spike complication was defined as an increase in IOP in the operated eye at any postoperative visit to higher than preoperative IOP within the first 3 months. Kaplan-Meier survival analysis and Cox proportional hazards regression were used to assess the time to events (failure and IOP spike). Risk of failure associated with any of the preoperative, intraoperative, or postoperative variables. A total of 102 eyes of 88 patients were included. The median follow-up time was 7.4 months, with an interquartile range of 3.3 to 13.1 months (standard deviation, 8.7 months). Patients who used corticosteroids after surgery were more likely to experience IOP spikes than those using nonsteroidal anti-inflammatory drugs (NSAIDs) alone (hazard ratio, 3.34; P = 0.042), and patients who underwent noncircumferential trabeculotomy were 2.56 times more likely to experience treatment failure (P = 0.002) compared with those who underwent circumferential surgery. Eyes that received postoperative corticosteroids were more likely to experience an IOP spike complication than those that received postoperative NSAIDs alone, which may suggest corticosteroid-mediated outflow obstruction distal to the trabecular meshwork. Achieving a circumferential trabeculotomy and using only NSAIDs may be more likely to result in surgical success when compared with noncircumferential trabeculotomy or using postoperative corticosteroids.