Outcome of repeat trabeculectomy with mitomycin C in isolati
Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...
Trabeculectomy is the most commonly used surgical intervention for the management of glaucoma. The most common cause of surgical failure is subconjunctival and episcleral fibrosis. The progressive fibrosis of subconjunctival and episcleral tissues has been attributed to the increase in subepithelial conjunctival fibroblasts stimulated after any surgery on the conjunctiva. Although previous filtration surgery is a known risk factor for trabeculectomy failure, repeat trabeculectomy is performed frequently in cases of initial trabeculectomy failure refractory to medical treatment.

There are a few reports in the literature describing the outcome of repeat trabeculectomy where success rates had been noted to be between 30 and 80% with reasonable qualified success and few complications. Repeat trabeculectomy has been noted to produce similar IOP reduction to non-valved shunt surgery in the Tube versus Trabeculectomy study, with higher rates of reoperation in the trabeculectomy group. However, there is no detailed analysis of success rates in different types of glaucoma or comparison between repeat trabeculectomy and phaco trabeculectomy. Since cataract progression is common after a trabeculectomy, many eyes would need cataract surgery along with repeat trabeculectomy.

A study was conducted to evaluate the effectiveness of repeat trabeculectomy with Mitomycin C (MMC) in isolation or combined with phacoemulsification and to identify risk factors for failure over 1 year. Retrospective review of 113 eyes of 113 patients (49 primary open-angle, 27 primary angle closure, 37 secondary glaucomas) who underwent repeat trabeculectomy with MMC. The primary outcome measure was intraocular pressure (IOP) at 1-year follow-up.

Mean IOP decreased from 24.5 ± 8.8 mmHg to 16.4 ± 7.6 mmHg 1 year after repeat trabeculectomy. The mean number of medications reduced from 2.9 ± 1.0 to 0.6 ± 1.0. Complete success with trabeculectomy versus phacotrabeculectomy for criterion A was 60% vs 55.3%, criterion B 54.7% vs 50.0% and criterion C 40.0% vs 28.9%. IOP equal to or less than 14 mmHg was more likely with trabeculectomy than phacotrabeculectomy. On regression analysis, duration between surgeries equal to or less than4 years and secondary glaucoma were identified as risk factors for surgical failure with criterion A. Younger age, fornix based flap, and phacotrabeculectomy for criterion C.

In Conclusion, repeat trabeculectomy with MMC is successful at lowering IOP and decreasing the number of antiglaucoma medications. Low IOP levels are less likely with phacotrabeculectomy.