Effect of laser peripheral iridotomy using argon and neodymium-YAG lasers on corneal endothelial cell density: 7-year longitudinal evaluation.

ABSTRACT

PURPOSE: To evaluate the changes in corneal endothelial cell density (ECD) over a 7-year period after laser peripheral iridotomy (LPI) using argon and neodymium-doped yttrium aluminum garnet (NdYAG) lasers. STUDY DESIGN: Retrospective case series. METHODS: Eyes that underwent prophylactic LPI using argon and NdYAG lasers were followed up for 7 years. Central corneal endothelial cells were observed by use of noncontact specular microscopy preoperatively and at 1 and 7 years postoperatively. Changes in ECD and the associations between preoperative ECD and the total energy of the NdYAG laser were evaluated. RESULTS: Fifty-one eyes of 51 patients were followed up for 7 years. The ECD significantly decreased after LPI (P < 0.049), and the reduction rate at 1 year after the surgery (1.69 ± 4.80%, 95% CI 0.34%-3.04%) was significantly higher than the annual reduction rates after 1 year (0.17 ± 0.85%/y, P = 0.036, 95% CI -0.07% to 0.41%). No association was found between the preoperative ECD and the total laser energy. CONCLUSIONS: Long-term evaluation indicated that the reduction in ECD after argon-NdYAG laser LPI was present but small during the initial year and was negligible after 1 year.