Effect of diode laser contact transscleral pars plana photocoagulation on intraocular pressure in glaucoma

Purpose : To evaluate the efficacy of diode laser contact transscleral pars plana photocoagulation (CTPPP) for intraocular pressure (IOP) control in glaucoma and its clinical application. Method : A prospective, non‐randomized hospital‐based pilot study was conducted. Fourteen patients with poor visual acuity (VA worse than 6/60) and medically uncontrolled, refractory glaucoma were recruited, and CTPPP was performed after informed consent. Results : Mean preoperative IOP was 41.0 mmHg (SD 12.6, range 27?70, n = 14). At 1 week postoperatively, IOP was reduced in 12 of 14 (86%) patients to a mean of 28.6 mmHg (SD 15.8, range 3?55, n = 14). This represented a mean decrease of 12.4 mmHg. Mean IOP was 34.0 mmHg (SD 17.4, range 5?71, n = 14) and 31.6 mmHg (SD 13.4, range 5?22, n = 12) at 4 and 12 weeks, respectively. The IOP reduction was significant at 1 week (P = 0.001, paired t‐test) and at 12 weeks (P = 0.04, paired t‐test). The two patients with preoperative pain reported abolition of pain after the procedure. Seven of 13 patients on preoperative antiglaucoma eye drops did not require eye drops postoperatively. Conclusions : Diode laser CTPPP was found to significantly reduce IOP in the majority of patients at 1 week postoperatively, with less but still significant effect at 12 weeks. Its potential application as a procedure for short‐term IOP reduction in medically uncontrolled glaucoma requiring filtering surgery needs to be further investigated.