Relative pupillary block is one of the most important mechanisms of the attack of primary angle-closure glaucoma and iris dynamics plays a vital anatomical role during the occurrence of pupillary block. Investigation of the changes of iris configuration during physiologic or pharmacologic pupil dilation is thus important to better understand this process.
The paper by Aptel and Denis presents a novel geometrical method with AS-OCT to estimate the changes of the 3-dimensional iris volume after pharmacologic mydriasis. Even after a patent laser peripheral iridotomy, the iris volume of the fellow eyes in primary acute angle-closure patients still significantly increased after pupil dilation, compared to the significant decrease in open angles subjects. This differential response of the iris to pupil dilation may indicate a particular behavior of the iris stroma in PACG patients and normal subjects, which offers a new insight into the importance of the iris dynamics in the pathogenesis of angle-closure.
Since different iris colors, iris shapes and numbers of iris crypts are the main commonly known factors affecting the behavior of iris dynamics, the authors have suggested a similar study in Asian subjects with different mentioned factors.