Comparative Outcomes of Primary Trabeculectomy with Mitomycin C in Patients of Hispanic vs. European Descent

Abstract

Purpose : To compare intermediate-term outcomes after initial trabeculectomy with Mitomycin C (MMC) in subjects of Hispanic descent (HD) to those of European descent (ED) and assess risk factors for failure.

Methods : One hundred three eyes from 88 HD glaucoma patients were matched to 103 eyes from 100 ED patients by surgeon, baseline age (±5 years), lens status, and surgery year (±1 year). Three sets of criteria (A through C) defined success as final intraocular pressure (IOP) ≤18, ≤15, and ≤12 mmHg, along with either ≥20%, ≥25%, and ≥30% reduction of baseline IOP or reduction of ≥2 medications, respectively. Primary outcomes of interest were qualified success rates (with or without medication). Kaplan-Meier survival curves were compared, and Cox’s proportional hazard models were used to identify prognostic factors for failure.

Results : The average (SD) total follow-up length was 5.1 (4.1) years for HD and 6.1 (5.0) years for ED patients. The mean (SD) age, IOP, and visual field mean deviation at baseline were 68.8 (10.0) and 69.0 (9.5) years, 18.7 (7.3) vs. 19.8 (7.7) mmHg, and -11.8 (9.1) and -9.0 (8.5) dB, respectively. Success rates at five years for criteria A, B, and C were 45%, 37%, and 26% in HD patients and 61%, 55%, and 41% in ED patients (p =0.1, 0.03, and 0.009, respectively; log-rank test). On multivariate Cox’s regression analyses, lower baseline visual field mean deviation was associated with a higher failure rate with criteria A-C (HR=1.07, 1.08, and 1.07/dB; p=0.04, =0.01, and =0.02). Also, higher MMC concentrations were associated with a higher failure rate with criteria A and B (HR=1.88 and 1.87 per 0.1 mg; p=0.02 and =0.03). HD patients required more additional glaucoma surgeries than ED patients (39 vs. 29, p=0.18).

Conclusions : Patients of Hispanic descent experience higher failure rates after initial trabeculectomy with MMC compared to subjects of European descent. These findings need to be carefully considered when surgical treatment of glaucoma is contemplated in HD patients. A low target pressure is harder to achieve with trabeculectomy in HD patients.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Kaplan-Meier Survival Analysis (Criteria B, log-rank p-value=0.03) for Qualified Success for Eyes of Patients of Hispanic vs. European Descent.

 

Kaplan-Meier Survival Analysis (Criteria C, log-rank p-value=0.009) for Qualified Success for Eyes of Patients of Hispanic vs. European Descent.