Objective To compare the efficacy and survival of trabeculectomy with intraoperative application of mitomycin-C (MMC) in Asian Americans and Caucasians at the University Glaucoma clinic in a retrospective case-controlled comparison.
Methods Trabeculectomies performed between July 1997 and April 2003 (69 months) were reviewed retrospectively. Twenty-nine Asian Americans (29 eyes) older than 30 with at least one year of follow-up were case-matched with 29 Caucasians. Primary matching criteria included age, glaucoma subtype, and preoperative intraocular pressure (IOP). Secondary matching criteria included gender, surgeon who performed the operation, and ocular history. The two groups were compared for IOP control, visual outcome, complication rate, hypotony rate, surgical success rate, and survival. Criteria of success included: (1) IOP reduction at least 20% of the preoperative IOP, or final IOP equal 10 mmHg or less, (2) final IOP was greater than 5 mmHg and less then 22 mmHg, and (3) without additional glaucoma surgery, loss of light perception, or devastating complication.
Results Mean follow-up durations of Asian American and Caucasian group were 28.6± 16.9 months and 31.2± 14.6 months, respectively. (p=0.52). One year after trabeculectomy, IOP decreased from 18.7±6.1 mmHg to 10.9±3.9 mmHg (p≤0.0001) in the Asian American group, and 19.0± 5.5 mmHg to 10.6± 3.4 mmHg (p≤0.0001) in the Caucasian group. At the final visits, IOP decreased to 11.9± 4.6 mmHg in the Asian American group (p≤0.0001) and 11.0± 3.8 mmHg in the Caucasian group (p≤0.0001). There were no significant differences between the groups in postoperative IOP levels at 6 months, 1 year, and at the final follow-up visit, at a power of 90% and 80% to detect a difference of 3.2 mmHg and 2.8 mmHg, respectively, between the groups at an á = 0.05. The probability of trabeculectomy survival at 12 and 36 months was 75.9% and 54.8% in the Asian American group, and 75.9% and 70.8% in the Caucasian group (p = 0.54). There were no significant differences in the rates of surgical success, failure, complication, vision decrease, hypotony, and cataract development.
Conclusions In a case-controlled comparison of trabeculectomies, Asian Americans have a similar efficacy and survival probability as Caucasians.