Abstract
Purpose:
Needling of a scarred trabeculectomy is often performed in the office using a slit lamp microscope as an alternative to additional surgery to lower intraocular pressure (IOP). However, the success rate in an office setting is relatively low (31% after 6 months in one study). The authors used a modified bleb revision technique in the operating room, providing control and immediate feedback. To our knowledge, the success rate of this technique has not previously been described. The purpose of this study is to perform a retrospective chart review to determine the success rate of this procedure.
Methods:
The modified technique involves placing a 25 gauge infusion cannula in the anterior chamber. As fibrotic adhesions within the bleb are lysed with a 25 gauge needle, the continuous infusion of balanced salt solution from the anterior chamber provides immediate bleb elevation, indicating flow. A subconjunctival injection of 5-fluorouracil is given at the conclusion of each case. A retrospective chart review was performed for patients undergoing the intraoperative modified bleb revision technique in the setting of a failed trabeculectomy due to scarring at the Wilmer Eye Institute at Johns Hopkins University between 8/1/10 and 2/28/12. Data was collected and analyzed from the three clinic visits prior to the procedure, as well as data from post-operative day 1, week 1, month 1, month 3, month 6, and month 12.
Results:
25 eyes of 22 patients were identified. The mean IOP at the visit prior to the procedure was 21.72 +/- 6.52 and subjects were using an average of 2.1 +/- 1.4 medication classes. The mean IOP reduction at each time point was 8.58 +/- 8.14, 7.96 +/- 9.51, 9.24 +/- 7.33, 7.83 +/- 6.87, 5.86 +/- 8.08, and 6.26 +/- 5.82 respectively. The % reduction in IOP at the post-operative time points was 40.6 +/- 35.4, 36.8 +/- 39.6, 38.8 +/- 26.7, 32.8 +/- 22.2, 25.6 +/- 36.7 and 30.1 +/- 27.8. At day 1, no subjects were taking glaucoma medications. At subsequent time points, the reduction in medication classes was 1.4, 1.0, 1.0, 1.5 and 0.8 respectively. Of the 24 patients that had an IOP target set pre-operatively, 60.9%, 56.5%, 60.0%, 45.5%, and 63.2% were within the target IOP at the respective time points.
Conclusions:
The modified technique of bleb needling may provide a successful method to lower IOP in the setting of a previous trabeculectomy, thus preventing additional surgery and preserving conjunctiva.
Keywords: 568 intraocular pressure •
474 conjunctiva •
462 clinical (human) or epidemiologic studies: outcomes/complications