Résumé
Purpose: To objectively evaluate surgically induced astigmatism (SIA) after phacotrabeculectomy using keratometry and topography and to compare the magnitude of SIA and the refractive outcomes of single-site and twin-site phacotrabeculectomies. Methods: Forty prospective subjects were enrolled in the study and were randomized into single-site and twin-site cohorts. SIA was objectively assessed using keratometry and Orbscan before and at three months after surgery. For both cohorts, the changes in SIA were assessed using power vector analysis compared at the third month after surgery. Results: Each cohort consisted of 20 eyes. The preoperative parameters and postoperative IOP were comparable and similar, respectively, in both the cohorts (P = 0.1). Majority of the patients in both the cohorts had preoperative against-the-rule (ATR) astigmatism. The median change in SIA at the three-month postoperative visit was similar in both the cohorts, with a small increase in ATR astigmatism. Although the SIA change measured by keratometry in the J0 component was similar in both the groups (P = 0.54), that of J45 was significantly different (P = 0.01). However, the median change in SIA was similar in both the groups for both the J0 (P = 0.52) and J45 components (P = 0.94) when measured by Orbscan. The SIA in both the groups measured with keratometry (P = 0.62) and topography (P = 0.52) were clinically and statistically similar. In both the groups, the refraction was similar at 1 month and 3 months. Conclusion: The SIA as measured with keratometry and topography was similar in the single-site and twin-site phacotrabeculectomy cohorts at the end of 3-months. The postoperative refraction was stabilized in 1-month in both the groups.
Résumé
Phacotrabeculectomy is the preferred surgical management of coexisting visually significant cataract and moderate to advanced glaucoma. We report the surgical technique of a new modified fornix-based separate-site phacotrabeculectomy, with mitomycin C (MMC) application, in both primary open angle and angle closure glaucoma. In this new separate-site technique, both phaco and filtration are accommodated superiorly, side by side, hence called twin-site. This was achieved in an efficacious and safe manner with sparing of limbal stem cells without compromising safety. It is not only MMC-compatible but also has a low incidence of wound leak. The technique has no adverse consequence on the survival of the bleb, and we achieved complete success in 79.2% and total success in 93.1% in 130 eyes of 117 patients, in the intermediate term. Furthermore, the time taken for this separate-site surgical technique is comparable to published one-site procedures.