Comparison of 5.5 MM versus 3.5 MM scleral flaps in combined phacoemulsification and trabeculectomy with mitomycin C

Purpose: To determine if there is a difference in complications and results between a 5.5 mm vs. 3.5 mm scleral flap in fornix based combined phacoemulsification and trabeculectomy with MMC. Methods: A prospective study of consecutive patients undergoing a fornix based conjunctival flap combined procedure on a glaucoma service was designed to look at pre and post-op visual acuity, intraocular pressure control, and complication rates. 18 patients had 5.5 mm scleral flaps with the placement of a PMMA posterior chamber IOL and 13 patients had 3.5 mm scleral flaps with placement of a foldable lens. The rest of the operative procedure was the same for both groups. Results: There were no differences in pre-operative characteristics of the two groups. There were no statistically significant differences in the postoperative visual acuities or the intraocular pressures at 1 day, 1 week, 1 month, 3 months, and 6 months. The 5.5 mm scleral flaps were more likely to have laser suture lysis and more sutures required cutting (p = 0.0015). Two wound leaks occurred in the 3.5 mm group (NS). 23% of 3.5 mm eyes required supplemental 5FU, compared to 33% of 5.5 mm eyes (NS). Conclusion: There were no significant differences in postoperative complications, visual acuities, and intraocular pressure control between the 5.5 mm scleral flap with a PMMA lens vs. a 3.5 mm scleral flap with a foldable lens in up to six months of follow up. However, the larger scleral flap group required more laser suture lysis.