RT Journal Article
SR Electronic
T1 Long-term effect of YAG laser iridotomy on corneal endothelium in primary angle closure suspects: a 72-month randomised controlled study
JF British Journal of Ophthalmology
JO Br J Ophthalmol
FD BMJ Publishing Group Ltd.
SP 348
OP 353
DO 10.1136/bjophthalmol-2020-315811
VO 105
IS 3
A1 Chimei Liao
A1 Jian Zhang
A1 Yuzhen Jiang
A1 Shengsong Huang
A1 Tin Aung
A1 Paul J Foster
A1 David Friedman
A1 Mingguang He
YR 2021
UL http://bjo.bmj.com/content/105/3/348.abstract
AB Purposes To evaluate the effect of YAG laser peripheral iridotomy (LPI) on corneal endothelial cell density (ECD) and morphology in primary angle closure suspects (PACS) over 72 months.Methods The Zhongshan Angle Closure Prevention Trial is a single-centre randomised controlled trial. Subjects with bilateral PACS received YAG LPI prophylactic treatment in one eye randomly, while the fellow eye served as control. Central corneal ECD and morphology were assessed using non-contact specular microscopy (SP-2000P, Topcon) at baseline, 6, 18, 36, 54 and 72 months postoperatively. Mixed model analysis was conducted to compare the difference between treated and fellow eyes.Results A total of 875 participants were included, with a mean age of 59.3±5.0 years and 83.5% female. The ECD declined significantly (p<0.001) over time in both treated and fellow eyes, but the treated eyes showed more progressive cell loss with increasing time (p<0.001). The difference in ECD loss between LPI-treated and fellow eyes was not significant at each follow-up until 72 months (4.9% in LPI eyes vs 4.2% in non-LPI eyes, p=0.003). Mean cell areas increased significantly over time in both treated and fellow eyes (p<0.001), but no longitudinal change was observed for hexagonality. In LPI-treated eyes, no significant correlation was found between age, gender, ocular biometrics, intraocular pressure and laser settings with endothelium change, except for time effect (p<0.01).Conclusion ECD decreases over time primarily due to ageing effect. YAG LPI does not appear to cause clinically significant corneal endothelial damage over 72 months after treatment.Trial registration number ISRCTN45213099.