The outcome of Trabeculectomy with Mitomycin C at the Queen Elizabeth Hospital, Barbados

ABSTRACT

AIM: To evaluate the efficacy of trabeculectomy with mitomycin-c in a predominantly black population. METHOD: The records of 43 eyes with 34 patients (males 15, females 19; age range 22-87 years), who underwent trabeculectomies with mitomycin-c for uncontrolled glaucoma at the Queen Elizabeth Hospital were reviewed. Forty-three eyes (rt eyes 22, Lt eyes 21, unilateral 25, bilateral 9, combined procedure 4) had trabeculectomies. All surgeries were performed by six surgeons between July 1995 and October 1998. The concentration of mitomycin-c varied from 0.2 to 0.5 mg/ml and was applied over 2 to 5 minutes. RESULTS: We evaluated treatment outcome based on the following categories of surgical results for patients with a pre-operative IOP>21mmHg. 1. The operation was considered successful when the IOP was <21mmHg without any anti-glaucoma medications. 2. The operation was a failure when the IOP was raised >21mmHg and required anti-glaucoma medications to control the IOP. The mean preoperative IOP was 26mmHg and the mean postoperative IOP was reduced to 14mmHG. There was failure in 19 eyes where the IOP was raised over >21mmHg and required anti-glaucoma medications or control. Twenty-four eyes were still functional at 18 months with IOPs less than 21mmHg without any anti-glaucoma medications. Visual acuity (VA) in the functional 24 eyes the VA remained the same in 9 patients and the VA progressively deteriorated in the remaining 15 patients in spite of reduced IOP after mitomycin trabeculectomies. CONCLUSION: The most common cause of failure after trabeculectomy is scarring at the filtration site due to fibrosis or more appropriately normal healing by fibrosis - mitomycin simply delayed the normal healing. Eyes with pseudopakia are at higher risk for failure. Most of the studies in the past were done in the predominantly white population with a short follow-up period. In contrast, all the patients in this study were of African origin and had at least 18 months follow-up, with mean follow-up of 39 months. To our knowledge, this is one of the longest follow-up studies in a predominantly Black population and is the first in the Caribbean. (AU)