¹Ankara University, Faculty of Veterinary Medicine, Surgery Department, TR-06070 Ankara - TÜRKİYE
²Ankara University, Graduate School of Health Sciences, TR-06070 Ankara - TÜRKİYE DOI : 10.9775/kvfd.2026.36738 Distinct craniofacial morphology in brachycephalic cats may alter ocular anatomy and predispose these breeds to specific ophthalmic conditions. This study evaluated the relationship between craniofacial conformation and optic nerve diameter (OND), optic nerve sheath diameter (ONSD), and ocular biometric parameters using high-resolution ultrasonography. Twenty-six clinically healthy cats were enrolled and categorized into brachycephalic and non-brachycephalic groups (n=13 per group). Comprehensive ophthalmic examinations, tonometry, and standardized ultrasonographic measurements -including axial globe length (AGL), lens thickness (LT), and vitreous chamber depth (VCD)- were performed. Although no statistically significant differences were detected between groups, several morphological tendencies emerged. Brachycephalic cats demonstrated shorter AGL and horizontal lens diameter, alongside increased anterior chamber depth and LT. Conversely, VCD appeared reduced in brachycephalic cats, potentially reflecting a more compact intraocular configuration associated with their craniofacial structure. By generating standardized ultrasonographic measurements, this study contributes to the establishment of morphology-specific reference intervals for OND and ONSD. Given the current scarcity of feline-specific normative data, these findings provide an essential preliminary framework to assist clinical diagnostics and neurological assessments in feline ophthalmology. Keywords : Anatomic variations, Diagnostic imaging, Feline eye, Morphometry, Ocular ultrasound