Comparison of two protocols of diode laser transscleral cyclophotocoagulation in refractory glaucoma

Diode laser transscleral cyclophotocoagulation (DLTSCPC) remains the most commonly used cyclodestructive procedure. Nonetheless, there is no common consensus on a standardized technique.

In this prospective randomized pilot study we compare the "pop"-titrated and "slow-burn" DLTSCPC techniques for a follow-up period of 3 months. The major outcomes of this study were intraocular pressure (IOP) before and after the procedure and the incidence of adverse events. Furthermore, postoperative pain, postoperative intraocular inflammation and corrected distance visual acuity (CDVA) were evaluated.

Mean baseline IOP decreased from 37.9 ± 12.7 mmHg in the pop group and 41.2 ± 9.6 mmHg in the slow-burn group to 20.3 ± 13.9 mmHg and 21.3 ± 13.4 mmHg at the final follow-up visit, corresponding to a 45.8 ± 31.7% and 46.3 ± 32.6% reduction respectively. 64.3% and 57.1% of patients had IOP ≥6 and≤ 21 mmHg in the pop and slow-burn groups respectively. The occurrence of adverse events was similar in both groups, with 1 case of hyphema in the pop group and 2 cases in the slow-burn group, and 1 case of hypotony in each group. Mean CDVA remained unchanged until the end of follow-up from 2.05 ± 0.84 to 2.04 ± 0.8 logMAR in the pop group and from 1.93 ± 0.78 to 1.89 ± 0.7 logMAR in the slow-burn group. Nonetheless, 4 eyes in each group encountered CDVA loss. Postoperative pain and inflammation were also similar between groups.

At the 3^rd postoperative month, safety and efficacy was similar in the two techniques. The relative ease of the slow-burn technique may make its application more appealing to ophthalmic surgeons beyond glaucoma specialists.