MICROPULSE TRANSSCLERAL CYCLOPHOTOCOAGULATION IN THE TREATMENT OF REFRACTORY GLAUCOMA

C.L. Ho, E.Y.M. Wong and P.T.K. Chew

Singapore National Eye Centre, National University Hospital, Singapore

Purpose: To evaluate the efficacy, safety and peri-operative pain response of a novel method of transscleral cyclophotocoagulation(TCP) using micopulse 810nm diode laser in a prospective pilot study.

Method: TCP was performed on 16 eyes with end-stage refractory glaucoma using the Iris Oculight SLX diode laser with a modified Zeiss ball tip probe under periocular anaesthesia. 28 shots of 2 Watts, 2 seconds pulse envelope with micropulse duration of 100 microseconds & interpulse duration of 300 microseconds was applied over 360 degrees in each eye. Total energy delivered was less than most published settings for conventional diode TCP.

Results: Statistically significant intraocular pressure(IOP) lowering from pre-operative mean of 44 mmHg to post-operative means of 28 mmHg at 1 week and 35 mmHg at 3 weeks was achieved (p<0.05, paired t-test). Percentages of patients with at least 20% & 30% IOP lowering were 75 & 63 at 1 week, 50 & 36 at 3 weeks, 42 & 25 at 6 weeks and 40 & 20 at 12 weeks respectively. Intra- & post-operative pain scores as well as post-operative inflammation appeared to be significantly less than conventional TCP. No significant complications including post-operative hypotony or phthisis were encountered.

Conclusions: Micropulse TCP appears to be safe & effective in lowering IOP in refractory glaucoma in the short term, with decreased peri-operative pain & inflammation compared to conventional diode TCP. Controlled comparative studies may further define its role in glaucoma management.