RT Journal Article
SR Electronic
T1 Iris volume change with physiologic mydriasis to identify development of angle closure: the Zhongshan Angle Closure Prevention Trial
JF British Journal of Ophthalmology
JO Br J Ophthalmol
FD BMJ Publishing Group Ltd.
SP 366
OP 371
DO 10.1136/bjo-2022-322981
VO 108
IS 3
A1 Liao, Chimei
A1 Quigley, Harry
A1 Jiang, Yuzhen
A1 Huang, Shengsong
A1 Huang, Wenyong
A1 Friedman, David
A1 Foster, Paul J
A1 He, Mingguang
YR 2024
UL http://bjo.bmj.com/content/108/3/366.abstract
AB Aims To assess dynamic change of iris area (Iarea) and volume (VOL) with physiologic pupil dilation for progression of primary angle closure suspects.Methods Participants underwent baseline examinations including gonioscopy and anterior segment OCT (AS-OCT) as part of the Zhongshan Angle Closure Prevention Trial. The AS-OCT images were obtained both in the dark and light. Progression was defined as development of primary angle closure or an acute angle closure attack. Static ocular biometrics and dynamic changes were compared between progressors and non-progressors and multivariable logistic regression was developed to assess risk factors for progression.Results A mean 16.8% decrease in Iarea and a mean 6.26% decrease in VOL occurred with pupil dilation, while 22.96% non-progressors and 40% progressors presented VOL increases with pupil dilation. Iarea in light and dark and VOL in light were significantly smaller in progressors. In a multivariable logistic model, older age (p=0.008), narrower horizontal angle opening distance (AOD) 250 µm from the scleral spur (AOD250, p=0.001), flatter iris curvature (IC, p=0.006) and lower loss of iris volume (ΔVOL, p=0.04) were significantly associated with progression. With receiver operating characteristic analysis, the area under the curve for ΔVOL alone was 0.621, while that for the combined index (age, AOD250, IC and ΔVOL) was 0.824. Eyes with elevated intraocular pressure had less VOL loss compared with progressors developing peripheral anterior synechiae alone (p=0.055 for ΔVOL adjusted for pupil enlargement).Conclusion A smaller change in ΔVOL is an additive risk factor to identify eyes more likely to develop angle closure disease.Trial registration number ISRCTN45213099.Data are available upon reasonable request.