Anterior and posterior segment measurements in healthy French bulldogs: normative data by optical coherence tomography

The objective of this study was to establish reference values for optical coherence tomography (OCT) assessment of anterior and posterior segment ocular structures in healthy French Bulldogs. A total of 18 French Bulldogs (34 eyes), including both males and females, were evaluated. All dogs underwent a complete ophthalmic examination and were confirmed to be free of abnormalities in both anterior and posterior segment anatomical structures. The analysis of anterior segment structures included central corneal thickness (CCT), corneal epithelial thickness (CET), and iridocorneal angle (ICA). Analysis of posterior segment structures included thickness measurements of the total retina (TR), inner retina (IR), outer retina (OR), and ganglion cell complex (GCC). OCT images were obtained using the Optovue iVue SD-OCT device. For statistical analysis, data normality was assessed using the D’Agostino-Pearson test. Paired Student’s t-tests and Mann–Whitney U test were applied with the significance level set at 5% (p < 0.05). The mean ± standard deviation for CCT, CET, ICA, TR, and GCC were 561.97 ± 45.26 µm, 78.88 ± 8.77 µm, 55.68 ± 9.88 µm, 187.70 ± 23.90 µm, and 72.38 ± 9.52 µm, respectively. Pearson's correlation analysis revealed a statistically significant negative correlation between age and ganglion cell complex (GCC) thickness (r = − 0.39, p = 0.024). This finding suggests that GCC thickness progressively decreases with age. These values reported here may serve as reference standards for the evaluation of ocular surface integrity, iridocorneal angle, and retinal structures in French Bulldogs.