In both humans and dogs, the primary risk factor for
glaucoma is high intraocular pressure (IOP), which may be caused by iridocorneal angle (ICA) abnormalities. Oxidative stress has also been implicated in retinal ganglion cell damage associated with
glaucoma. A suspected inherited form of
glaucoma was recently identified in Eurasier dogs (EDs), a breed for which pedigrees are readily available. Because of difficulties in assessing ICA morphology in dogs with advanced
glaucoma, we selected a cohort of apparently healthy dogsfor the investigation of ICA morphological status, IOP and plasma concentrations of oxidative stress
biomarkers. We aimed to establish correlations between these factors, to identify predictive markers of
glaucoma in this dog breed. A cohort of 28 subjects, volunteered for inclusion by their owners, was selected by veterinary surgeons. These dogs were assigned to four groups: young males, young females (1-3 years old), adult males and adult females (4-8 years old). Ocular examination included ophthalmoscopy, tonometry, gonioscopy, biometry and ultrasound biomicroscopy (UBM), and the evaluation of oxidative stress
biomarkers consisting of measurements of plasma
glutathione peroxidase (GP) activity and
taurine and metabolic precursor (
methionine and
cysteine) concentrations in plasma. The prevalence of pectinate ligament abnormalities was significantly higher in adult EDs than in young dogs. Moreover, in adult females, high IOP was significantly correlated with a short axial globe length, and a particularly large distance between Schwalbe's line and the anterior lens
capsule. GP activity levels were significantly lower in EDs than in a randomized control group of dogs, and plasma
taurine concentrations were higher. Hence, ICA abnormalities were associated with weaker
antioxidant defenses in EDs, potentially counteracted by higher plasma
taurine concentrations. This study suggests that EDs may constitute an appropriate canine model for the development of
glaucoma. This cohort will be used as a sentinel for longitudinal monitoring.