# Occult zonulopathy detected during cataract surgery in patients with acute primary angle closure: a retrospective study

## TL;DR

This study found that a hidden eye condition called occult zonulopathy is strongly linked to acute primary angle closure, a type of eye emergency.

## Contribution

The study is the first to show a significant association between occult zonulopathy and acute primary angle closure.

## Key findings

- APAC patients had a much higher rate of occult zonulopathy compared to controls.
- Occult zonulopathy remained a strong risk factor for APAC after adjusting for axial length and sex.
- APAC eyes showed shallower anterior chambers and more anterior lens positions, regardless of zonulopathy.

## Abstract

Whether occult zonulopathy contributes to the development of acute primary angle closure (APAC) remains elusive. This study aimed to determine the association between occult zonulopathy detected during cataract surgery and APAC and to investigate the biometric characteristics of APAC patients with or without occult zonulopathy.

Retrospective case-control study. A total of 27 Chinese unilateral APAC subjects and 132 control subjects with comprehensive ophthalmic examinations were recruited. Occult zonulopathy was identified with the intraoperative signs during cataract surgery. The proportion of occult zonulopathy was compared between the APAC and control groups. A multivariate logistic analysis was conducted to determine the association between occult zonulopathy and APAC. The ocular biometric parameters were compared between APAC and the contralateral eyes in APAC patients with or without occult zonulopathy.

APAC patients (63.0%) had a significantly larger proportion of occult zonulopathy than control subjects (1.5%, P < 0.001). In the multivariate logistic analysis, occult zonulopathy was significantly associated with APAC after adjusting the axial length (AL) and sex (OR = 126.49, 95% CI [20.89–766.02]; P < 0.001). Compared to contralateral eyes, shallower central anterior chamber depth, more anterior lens position and relative lens position were found in APAC eyes both with and without occult zonulopathy (all P < 0.05), but no difference in AL and lens thickness.

A larger proportion of occult zonulopathy was significantly associated with APAC. Occult zonulopathy could be a risk factor for APAC by inducing forward shifting of the lens.