Abstract
Purpose::
To determine the efficacy of MVR blade needling of failed filtration blebs as a major operative procedure, followed by serial subconjunctival 5-FU injections.
Methods::
A retrospective review of the 51 eyes of 49 consecutive patients who underwent trabeculectomy and subsequent needling-revision with MVR blade, between January 2003 and December 2005. Patients undergoing needling had either flat or encapsulated blebs, with uncontrolled intraocular pressures (IOPs). Success was defined as absolute with IOP <21mmHg or as qualified success with IOP <21mmHg on anti-glaucoma medication. All cases were conducted in the operating room, topical tetracaine 0.5% was instilled, patients were prepped with povidone-iodine 5%, then draped. An angled MVR blade advanced subconjunctivally at the posterior aspect of the filtration bleb, then manipulated under the scleral flap. The anterior chamber was then entered via the ostium, freeing any scar tissue in the process. This was followed by a serial subconjunctival 5-FU injection. The main outcome measures were IOP and number of antiglaucoma medications.
Results::
The mean follow-up was 23.4 ± 9.2 months. The average time to MVR needling from original trabeculectomy was 10.0 ± 7.2months. The mean pre-operative IOP was 24 ± 5.8mmHg, which was subsequently 17.9, 17.1, 18.5, 18.6, 18.0, 15.6, 17.4 and 14.8 on post-operative day 1, week 2, months 1, 3, 6, 9, 12, 24 and 36 respectively (p<0.05 for 12, 24 and 36 months). At the final visit, success was absolute in 29 eyes (56.9%) and qualified in 14 eyes (27.5%). Minor complications occurred in 15.7% of patients, including hyphaema (6 patients), hypotony (2 patients). 7 patients (13.7%) required further surgical intervention, including re-do trabeculectomy, tube surgery and transcleral cyclodiode.
Conclusions::
Bleb needling-revision can prevent more invasive intervention in a significant number of patients with failed filtration blebs. MVR needling appears to be a safe and effective technique to revive failed filtration blebs. Further randomised controlled studies are required to compare their efficacy to slit-lamp bleb revisions.
Keywords: intraocular pressure