Abstract
Purpose :
To identify risk factors associated with clinical hypotony after trabeculectomy
Methods :
This is a retrospective, observational clinical study of patients who underwent trabeculectomy with MMC at Jules Stein Eye Institute between 2014 and 2023. We explored risk factors for developing clinical hypotony and numerical hypotony. We defined Numerical hypotony as intraocular pressure (IOP) of ≤5 mmHg in 2 or more consecutive visits, ≥6 weeks after surgery. Clinical hypotony was defined by the presence of choroidals, hypotony keratopathy, maculopathy, flat or shallow anterior chamber at 6 weeks and later after surgery. Baseline characteristics that were evaluated as potential risk factors included demographics, medical history, glaucoma type, history of previous ocular lasers and surgeries, coexistent ocular conditions including significant myopia, lens status, number of glaucoma medications, IOP and visual acuity. Intraoperative variables including surgeon, MMC time and dose were included. Univariate and Multivariate analyses were conducted to assess the association between each characteristic and presence of numerical or clinical hypotony.
Results :
The study included 1,012 eyes from 805 patients, with a mean age of 73.9 years (SD 11.0) and mean follow-up of 4.2 years (SD 3.3). The most frequently used MMC doses were 0.3mg/dl (444 eyes) and 0.2mg/dl (254 eyes) administered for 1 minute during surgery. The mean final IOP was 11mmHg (SD 4.4). Among the included eyes, 170 met the criteria for numerical hypotony, and 71 for clinical hypotony. Of the 71 eyes with clinical hypotony, 38 did not meet the criteria for numerical hypotony. Of the 170 with numeric hypotony, only 33 showed clinical hypotony. During follow-up, 53 eyes underwent trabeculectomy revision due to hypotony. The most common clinical manifestations of hypotony were serous choroidals (n=40), hypotony maculopathy (n=21) and shallow anterior chamber (n=18). High preoperative IOP was found to be the only significant risk factor for clinical hypotony, showing a 3% increased risk per additional 1mmHg.
Conclusions :
19.4% of numeric hypotonies developed clinical manifestations. Increased preop IOP is a potential risk factor for clinical hypotony after trabeculectomy.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.