Longitudinal changes in optic disc topography of adult patients after trabeculectomy

Objective: To study longitudinal changes in optic disc topography after tra beculectomy in adult patients. Design: Prospective case series, Participants: Twenty-five eyes of 25 patients undergoing trabeculectomy wer e enrolled. Intervention: Images of the optic disc were obtained preoperatively and app roximately 2 weeks, 4 months, and 8 months after surgery by use of a confoc al scanning laser ophthalmoscope (Heidelberg Retina Tomograph). Main Outcome Measures: The topographic optic disc parameters (cup volume, c up area, rim volume, rim area, cup-disc area ratio, mean cup depth, maximum depth, cup shape, and height variation contour) were measured automaticall y for each image with the Heidelberg Retina Tomograph Software (version 1.1 1). Results: Approximately 2 weeks after surgery, the mean preoperative intraoc ular pressure (IOP) of 19.3 mmHg (SD, 6.4 mmHg) decreased to 6.0 mmHg (SD, 3.6 mmHg), cup volume and mean cup depth decreased, height variation contou r increased, and the cup shape parameter became more negative. Approximatel y 4 months after surgery, mean IOP was 9.7 mmHg (SD, 4.2 mmHg), and the onl y statistically significant change from preoperative values of optic disc p arameters was in the cup shape measure, Approximately 8 months after surger y, there was no statistically significant change in any of the optic disc p arameters compared with preoperative values, although IOP was 10.4 mmHg (SD , 5.9 mmHg). Conclusions: Changes in the optic disc that may be present 2 weeks after a trabeculectomy do not appear to persist 4 and 8 months later in eyes with a dvanced glaucomatous optic nerve damage, except for cup shape, which was di fferent from preoperative values at 4 months but not at 8 months.