Choroidal Thickness Decreased in Acute Primary Angle Closure Attacks with Elevated Intraocular Pressure

Area of Science:

• Ophthalmology
• Retinal Diseases
• Choroidal Imaging

Background:

• Acute primary angle closure (APAC) is a condition characterized by a sudden increase in intraocular pressure (IOP).
• Choroidal thickness (CT) is a key indicator of ocular health, and its changes can reflect various pathological processes.

Purpose of the Study:

• To investigate the changes in choroidal thickness (CT) in patients experiencing unilateral acute primary angle closure (APAC) attacks.
• To compare the CT between the affected eye and the unaffected fellow eye in patients with unilateral APAC.

Main Methods:

• The study included 23 patients diagnosed with unilateral APAC.
• Enhanced depth imaging-optical coherence tomography (EDI-OCT) was used to measure CT in both macular and peripapillary regions of both eyes.
• A comparative analysis of CT was performed between the APAC-affected eyes and the fellow eyes.

Main Results:

• APAC-affected eyes exhibited significantly higher intraocular pressure (IOP) (39.4 mmHg) compared to fellow eyes (13.3 mmHg).
• Subfoveal choroidal thickness (SFCT) was significantly reduced in APAC-affected eyes (208.5 μm) versus fellow eyes (258.4 μm).
• CT was notably thinner in APAC-affected eyes across macular and peripapillary regions compared to fellow eyes.

Conclusions:

• Acute primary angle closure with elevated IOP is associated with a significant reduction in choroidal thickness.
• The observed thinning of the choroid in APAC eyes may be attributed to vasoconstriction within choroidal blood vessels.
• This reduction in CT could potentially compromise retinal blood supply, leading to retinal ischemia.