Abstract
Purpose :
Although trabeculectomy is the most commonly used surgical modality in the management of glaucoma, its success rate is only 60-75% after four years, due to bleb scarring. Bleb needling to lyse scar tissue and allow better aqueous outflow is one possible solution to improve intraocular pressure (IOP) lowering in these patients. Some perform bleb needling in the office using a slit-lamp microscope, but the reported success rate is variable and often low. One study found bleb needling to be effective in only 13% of patients after 4 years. We previously reported that a modified bleb needling technique performed in the operating room by a single surgeon maintains IOP at or below the target IOP in 64% of patients after 1 year. We now report outcomes of this technique as performed by multiple surgeons in a larger sample of patients over a longer duration of follow up.
Methods :
In this retrospective study, we assessed consecutive patients undergoing intraoperative bleb needling at the Wilmer Eye Institute, Johns Hopkins Hospital. In this technique, an infusion cannula is placed in the anterior chamber and fibrotic adhesions within the bleb are lysed using a 25-G needle that is inserted subconjunctivally from a site posterior to the bleb. The continuous infusion of balanced salt solution from the anterior chamber causes bleb elevation, guiding the endpoint of lysis for the procedure. Subconjunctival injection of 5-fluorouracil or mitomycin C is given at the conclusion of each case. Success was defined as achieving a previously determined target IOP.
Results :
Needling was performed for 109 eyes at an average of 4.3 years from the time of trabeculectomy (SD=6.4). We observed a 78% success rate and a mean IOP lowering of 6.7 mmHg (95% CI, -9.3, -4.5) at 1 year post-op, and 55% and -8.9 mmHg (95% CI, -11.2, -6.6) at 4 years, respectively. 78% of patients did not require medications after 1 year, and nearly half after 4 years. The average medication change was -0.8 at year 1 (95% CI, -1.0, -0.5) and -0.5 at year 4 (95% CI, -1.0, -0.1), with few post-operative complications noted.
Conclusions :
Using the modified bleb needling technique, reductions in IOP were maintained in the majority of patients over a four-year period, despite an average time from trabeculectomy of over four years. Bleb needling should thus be considered as treatment option to avoid more invasive procedures such as tube shunts or repeat trabeculectomy.
This is a 2020 ARVO Annual Meeting abstract.