Low-dose transscleral diode laser cyclophotocoagulation (TSCPC) as a potential single treatment for primary open-angle glaucoma (POAG) in Malawi?

Abstract

To investigate if low-dose 810 nm transscleral cyclophotocoagulation (TSCPC) can be used as single treatment in Malawian glaucoma patients. Forty-seven eyes of 28 patients with primary open-angle and pseudoexfoliation glaucoma were treated with TSCPC using 12 spots with 900 mW, 2,000 ms (1.8 J per spot); six spots in the upper half, six in the lower by sparing the 3 and 9 o'clock positions ±20°. Intraocular pressure (IOP) and uncorrected visual acuity (UVA) were measured by an independent examiner preoperatively, on the first postoperative day, after 2 weeks, and after 3 months. Twenty-four (86%) and 18 (64%) of 28 patients (31 of 47 eyes; 66%) completed follow-up at 2 weeks and at 3 months respectively. After a single treatment session, IOP decreased by at least 25 % in 88% (21 of 24) after 2 weeks, and in 50% (nine of 18) of patients after 3 months. Mean IOP was 38.5 mmHg before TSCPC, 23.5 mmHg (p < 0.001) after 1 day, 24.5 mmHg (p < 0.001) after 2 weeks, and 35.6 mmHg (p = 0.37) after 3 months. In three patients, however, IOP increased after 3 months to levels significantly higher than before TSCPC. Low-dose TSCPC caused a significant IOP lowering for up to 2 weeks (15 mmHg less from baseline) in most patients. After 3 months, this effect was stable in 50% of patients; in the other half, IOP nearly returned back to baseline.