Abstract
Purpose: :
To report the rates of successful outcome at 12 months post-op in a consecutive series of bleb needle revisions performed from 2006-2010 by a single surgeon at Wake Forest University Eye Center and to identify patient characteristics associated with a successful outcome.
Methods: :
IRB approval was granted for a retrospective chart review. The results of 71 bleb needling procedures with at least 1 year of follow up data were included and the success or failure of the procedure was determined at different time points using the following criteria. Success was defined as IOP of <19mmHg or >20% reduction from pre-op level without the need for additional procedures. Secondary measures included number of glaucoma medications, complications of procedure, and change in visual acuity. Linear regression analysis was used to determine associations between various clinical criteria and successful outcome of the procedure.
Results: :
At 1 year after the needling procedure was performed, 49% met criteria for success with a mean IOP reduction of 21.6%. The number of medications used was reduced from an average of 1.9 to 1.3. Of the successful procedures, 50% required the use of topical medications while 50% did not. There was no significant change in visual acuity. There were 3 complications of the procedure recorded, 2 of which led to a significant decrease in visual acuity. Strong statistical associations with a successful outcome were found with both a shorter interval between the initial trabeculectomy and the needling procedure (p=0.016) as well as the attainment of a low immediate post-op IOP (p=0.04).
Conclusions: :
These data suggest that bleb needling is a safe and effective method to rescue a failed or failing bleb after trabeculectomy. The procedure was more successful when performed on blebs that failed after a relatively long period of successful filtration compared with those that failed shortly after the initial trabeculectomy. We postulate that early failure is more likely to be caused by fibrosis at the sclerostomy site whereas late failure is more likely due to bleb encapsulation, which is more amenable to treatment by needle revision. Attaining a lower IOP immediately after the procedure was associated with a higher rate of long term success.
Keywords: clinical (human) or epidemiologic studies: outcomes/complications