Elevated IOP Associated With Angle Closure Extent, Anterior Chamber Depth

An ophthalmologist examines a patient's eyes with a slit
DHAKA, BANGLADESH – 2021/09/13: An ophthalmologist examines a patient’s eyes with a slit lamp during the Free Medical Eye Camp at Bangladesh Eye Trust Hospital. (Photo by Sazzad Hossain/SOPA Images/LightRocket via Getty Images)
Parameters such as angle closure extent and anterior chamber depth may affect intraocular pressure, particularly in women, a study suggests.

The degree of angle closure and the anterior chamber depth (ACD) under a certain threshold have a significant joint association with a rise in intraocular pressure (IOP), especially in women with angle closure, according to a cross-sectional study published in the British Journal of Ophthalmology.

Researchers sought to explore the association between the extent of angle-closure and other quantitative anterior segment parameters with IOP. They analyzed 2027 participants (mean age, 61±6.7 years, range, 49-85 years). All participants underwent swept-source optical coherence tomography (SS-OCT) imaging. Exclusion criteria included previous history of glaucoma and ocular surgery or trauma. A total of 45.7% of the study population had hypercholesterolaemia, 42.5% had hypertension, and 11.2% had diabetes mellitus (DM).

The investigators found that iridotrabecular contact (ITC) index above a threshold of ~60% (95% CI 34% to 92%) is significantly associated with higher IOP. Independent of the degree of ITC, ACD was also significantly associated with greater IOP below a threshold of 2.5 mm (95% CI; 2.33-2.71 mm). Higher ITC index and shallower ACD had a joint association with IOP, particularly in women with gonioscopic angle closure (R2 52.7%; P <.05).  

“Based on our findings, we recommend to consider both, the extent of angle closure and ACD in the evaluation of primary angle closure suspect (PACS) subjects,” according to the investigators. “Future studies should assess if longitudinal changes in these parameters reflect a change in IOP.”

Study limitations include the limited number of eyes with gonioscopic angle closure and the possibility of inaccurate IOP measurement. 

Disclosure: This research was supported by the Biomedical Research Council. Please see the original reference for a full list of disclosures.  


Porporato N, Chong R, Xu BY, et al. Angle closure extent, anterior segment dimensions and intraocular pressure. Br J Ophthalmol. Published online March 2, 2022. doi:10.1136/bjophthalmol-2021-320453