Abstract
Purpose:
To investigate the long term clinical outcomes of surgical revision of failed trabeculectomy using a limbus based incision and Mitomycin C (MMC).
Methods:
A retrospective chart review of all patients who underwent surgical revision to restore the function of a failed trabeculectomy between 2007 and 2014. Of the sixty-five eyes operated 59 originally had trabeculectomy with MMC and 6 originally had phacotrabeculectomy with MMC. All cases were performed by one surgeon (PRC). The technique involved a conjunctival incision 8 mm posterior to the limbus, conjunctival elevation, resection of scar tissue overlying the scleral flap, application of 0.4 mg/ml of MMC, and reopening of the original scleral flap and sclerostomy. This was followed by suturing of the scleral flap and conjunctival wound. Frequency application of topical steroids, laser suture lysis, and other techniques were employed as needed in the postoperative period to maintain function of the reformed filtering blebs.
Results:
Sixty-five eyes of sixty patients underwent surgical bleb revision of failed trabeculectomies with MMC. Mean IOP was significantly reduced from 21.0±7.8 mmHg preoperatively to 11.4±5.1 mmHg at 1 year (p value < 0.0001), to 10.4±4.7 mmHg at 2 years (p value < 0.0001), to 10.9±4.6 mmHg at 3 years, and to 10.1±3.7 mmHg at 5 years (p value < 0.0001). The number of the glaucoma medications used was reduced from 2.38 0.68 to 0.55± 0.68 at 1 year (p value < 0.0001), 0.76± 0.75 at 3 years (p value < 0.0001), and 0.76± 0.77 at 5 years after surgery (p value < 0.0001). By Kaplan-Meier survival analysis, the overall cumulative success rates at 1, 3, 6, 12, and 24 months were 84.6%, 83.1%, 81.3%, 75.6%, and 68% respectively. .Four cases required a second procedure (7%), transient choroidal effusions occurred in 4 eyes (7%), corneal decompensation in 1 eye (1.7%), and ptosis in 1 (1.7%).<br />
Conclusions:
Surgical bleb revision is an effective and safe surgery for long term control of IOP following failed trabeculectomy. It is an excellent alternative to a tube shunt procedure or repeat trabeculectomy in appropriately selected cases.