The Form and Ultrasound Biomicroscopic Findings of the Filtering Bleb after MMC/Trabeculectomy by Limbar Incision

Abstract

Abstract: : Purpose: To show that MMC/trabeculectomy by limber incision (LI) has a tendency to form flatter, more diffuse and vascularized filtering bleb by comparison with that by fornix incision (FI). Methods: Sixty nine eyes of 69 glaucomatous cases underwent MMC/trabeculectomy by LI (30 eyes of 30 cases) or FI (39 eyes of 39 cases). Postoperative intraocular pressure (IOP) was followed up for 24 months. In addition, slit lamp examination and ultrasound biomicroscopic (UBM) examination were performed between 6 and 12 month postoperative periods. Results: While postoperative IOP by LI was 9.00±3.58 mmHg at 6 months and 8.88±3.13 mmHg at 12 months, that by FI was 8.69±2.67 mmHg and 8.53±2.72 mmHg. Life table analysis by Kaplan-Meyer’s method showed probability of success (IOP< 21 mmHg and < preoperative IOP x -20 %) was 81.2% in LI and 93.6 in FI after 12 months of the surgery. Likewise that of IOP under 12 mmHg was 76.2 in FI and 84.8 in LI. Table 1 showed findings of the filtering bleb by slit lamp examination. Table 2 showed the UBM findings by classification of Yamamoto et al. (Ophthalmology 102: 1770-1776, 1995). Conclusions: MMC/trabeculectomy by LI has a tendency to form flatter, more diffuse filtering blebs than that by FI. In addition, capillaries on the surface of the bleb have not disappeared with LI completely. We may be able to prevent longstanding complications of filtering surgeries, such as button hole, bleb leak or postoperative infection by use of LI trabeculectomy. UBM findings  

Keywords: intraocular pressure • imaging methods (CT, FA, ICG, MRI, OCT, RTA, S • conjunctiva