Quantifying refractive error in companion dogs with and without nuclear sclerosis: 229 eyes from 118 dogs.

PubMed ID: 37986551

Author(s): Francis JM, Mowat FM, Ludwig A, Hicks JM, Pumphrey SA. Quantifying refractive error in companion dogs with and without nuclear sclerosis: 229 eyes from 118 dogs. Vet Ophthalmol. 2023 Nov 20. doi: 10.1111/vop.13163. Online ahead of print. PMID 37986551

Journal: Veterinary Ophthalmology, Nov 2023

OBJECTIVE To evaluate the relationship between nuclear sclerosis (NS) and refractive error in companion dogs.

ANIMALS STUDIED One hundred and eighteen companion dogs.

PROCEDURES Dogs were examined and found to be free of significant ocular abnormalities aside from NS. NS was graded from 0 (absent) to 3 (severe) using a scale developed by the investigators. Manual refraction was performed. The effect of NS grade on refractive error was measured using a linear mixed effects analysis adjusted for age. The proportion of eyes with >1.5 D myopia in each NS grade was evaluated using a chi-square test. Visual impairment score (VIS) was obtained for a subset of dogs and compared against age, refractive error, and NS grade.

RESULTS Age was strongly correlated with NS grade (p 1.5 D was documented in 4/58 (6.9%) eyes with grade 0 NS, 12/91 (13.2%) eyes with grade 1 NS, 13/57 (22.8%) eyes with grade 2 NS, and 7/23 (30.4%) eyes with grade 3 NS. Risk of myopia >1.5 D was significantly associated with increasing NS grade (p = .02). VIS was associated weakly with refractive error, moderately with age, and significantly with NS grade.

CONCLUSIONS NS is associated with visual deficits in some dogs but is only weakly associated with myopia. More work is needed to characterize vision in aging dogs.