Internal slcerostomy with the Nd: YAG contact laser versus thermal sclerostomy in cynomolgus monkeys

Internal sclerostomy with the neodymium:YAG (Nd:YAG) contact laser was performed in the right eye of four cynolmogus monkeys. Two additional primates underwent thermal sclerostomies in their right eyes. The left eyes served as controls. On average, the laser sclerostomies successfully lowered intraocular pressure by more than 3 mmHg compared to the control eye and for a longer duration (days ± SD; 70 ± 22.9 days) than the thermal sclerostomy (37 ± 21.2 days). The average difference in intraocular pressure (± SD) between the operated eyes and the unoperated controls eyes was 6.8 ± 0.5 mmHg in the laser-treated group versus 4.7 ± 0.9 mmHg in the surgical group, a statistically significant difference (p = 0.037). Histologically, there was less inflammation five days postoperatively in the laser-treated eyes than in the eyes that underwent thermal sclerostomy. Internal sclerostomy using the Nd:YAG contact laser may prove to be an effective alternative to glaucoma filtration surgery.