Background and objective: To study the need, the safety and the success rate of Nd:Yag goniopuncture in eyes that underwent deep sclerectomy with collagen implant.
Patients and methods: The first 100 patients that underwent deep sclerectomy with collagen implant were prospectively followed. Deep sclerectomy with collagen implant is a non-penetrating filtering surgery which allows filtration of aqueous from the anterior chamber to the subconjunctival space through a remaining trabeculo-Descemet's membrane without opening the anterior chamber. Goniopunctures with Nd:Yag laser were performed at the site of surgery when the filtration through the trabeculo-Descemet's membrane was considered to be insufficient with elevated intraocular pressure. The laser treatment was performed using a Lasag 15 gonioscopy contact lens (CGA1). Goniopunctures were performed using the free-running Q-switched mode with an energy ranging from 2 to 4 mJ.
Results: Of 100 patients who underwent deep sclerectomy with collagen implant, goniopunctures with Nd:Yag laser were performed in 41 patients (41%). The mean time between deep sclerectomy with collagen implant and goniopuncture was 9.9 months +/-1.2 months (+/-SE). The mean IOP before laser treatment was 22.2 mm +/-7.0 mm Hg and decreased to 12.5 mm +/-5.8 mm Hg immediately after laser treatment and remained stable for the next 2 years of follow-up. The immediate success rate of goniopuncture was 83%. Choroidal detachment occurred in two patients (5%).
Conclusion: Nd:Yag goniopuncture is an efficient and safe treatment for low filtration through the trabeculo-Descemet's membrane after deep sclerectomy with collagen implant.