Abstract
Purpose :
To study the incidence of acute angle closure (AAC) secondary to dilation in primary angle closure suspect (PACS).
Methods :
In this randomized controlled trial, 11,991 participants aged between 50 and 70 years were screened in the community from Guangzhou, China. People with bilateral PACS (defined as 180° or more angle closure without peripheral anterior synechiae or elevated intraocular pressure) were enrolled and received LPI in one randomly selected eye with the fellow remaining untreated. Tropicamide 0.5% and phenylephrine 5% were used to dilate the pupil at baseline and each follow up visit (2 weeks, 6, 18, 36, 54, and 72 months). Subjects who developed a post-dilation IOP > 30 mmHg were given 250 mg of acetazolamide and a drop of brimonidine.
Results :
Of the 889 subjects (1778 eyes) who underwent randomization, four eyes developed AAC after dilation; 1 bilateral AAC at the 2-week evaluation, 1 untreated eye at 54-month, and 1 untreated eye at 72 months. The incidence was 5.7/10,000 eye-year in untreated eyes versus 1.9/10,000 in LPI-treated eyes (p=0.363). The risk of acute attack was less than one per 1000 times of dilation in untreated eyes. All AAC patients were treated medically with resolution of the attack and LPI was performed in untreated eyes after AAC. No serious vision loss was observed.
Conclusions :
The incidence of AAC after dilation in this high-risk group was low. LPI provided a protective effect but did not completely eliminate the risk of AAC.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.