Diode laser trans-scleral cyclophotocoagulation for glaucoma following silicone oil removal

Purpose: To evaluate the effect of trans-scleral cyclophotocoagulation (TSCP) on intraocular pressure (IOP) in eyes with medically uncontrolled secondary glaucoma persisting after intravitreal silicone oil removal. Methods: Clinical records of 21 eyes of 21 patients who underwent TSCP for medically uncontrolled glaucoma persisting after the removal of intravitreal silicone oil, injected during vitreoretinal surgery for proliferative vitreoretinopathy (PVR), were reviewed retrospectively. Diode laser contact TSCP was applied at a power setting of 1.5-2.5 W, for a maximum duration of 2 s, and a total of 40 spots (10 spots each quadrant). All the patients were evaluated for visual acuity, IOP and number of medications used. Results: The patients were followed up for a mean ± SD period of 39.9 ± 4.27 weeks (range 36-48 weeks). The IOP was found to have decreased significantly from a pretreatment value of 34.5 ± 5.37 mmHg (range 24-44 mmHg) to 20.47 ± 4.49 mmHg at 6 months of follow up (range 12-30 mmHg, P < 0.01, Student's paired t-test). The total number of glaucoma medications being used reduced from 3.38 ± 0.5 to 1.08 ± 0.80 postoperatively (P < 0.01, Wilcoxon's rank sum test). There was no significant difference in the visual acuity before and after the procedure. Thirteen eyes required a second sitting of TSCP, and five of these required a third sitting. For a successful outcome (IOP < 24 mmHg), a mean of 1.56 sittings (range 1-3 sittings) per eye were needed. Conclusion: Patients with medically uncontrolled glaucoma persisting after intravitreal silicone oil removal can be treated with TSCP; however, the reduction of IOP is variable. The IOP usually falls after a mean of 2-3 sittings of TSCP.