Sex differences in canine anterior chamber dimensions: Potential implications for primary angle-closure glaucoma

Area of Science:

• Veterinary Ophthalmology
• Comparative Anatomy
• Ocular Imaging

Background:

• Glaucoma is a significant ocular disease in dogs.
• Understanding anatomical risk factors is crucial for early detection and prevention.
• Previous studies have not fully elucidated sex-based anatomical differences in canine eyes.

Purpose of the Study:

• To investigate anatomical variations in the aqueous humor outflow pathway between male and female dogs.
• To correlate these anatomical differences with potential glaucoma risk factors.

Main Methods:

• Ultrasound biomicroscopy (UBM) was used to examine 30 canine eyes.
• Key parameters measured included peripheral anterior chamber depth (ACD), iridocorneal angle (ICA), angle-opening distance (AOD), ciliary cleft dimensions (CCW, CCL, CCA), and ciliary muscle thickness (Lf-CMT, LRf-CMT).
• Data were analyzed for gender-based differences.

Main Results:

• A significant sex difference was observed in peripheral anterior chamber depth (ACD), with females exhibiting shallower ACD compared to males.
• No significant gender-based differences were found in iridocorneal angle (ICA), angle-opening distance (AOD), ciliary cleft parameters, or ciliary muscle parameters.

Conclusions:

• Peripheral ACD is significantly shallower in female dogs than in male dogs.
• This anatomical finding may represent a risk factor contributing to the higher incidence of primary angle-closure glaucoma observed in female dogs.