Refractive errors in mixed breed dogs of different ages

Area of Science:

• Veterinary Ophthalmology
• Animal Refractive Error Studies
• Canine Eye Health

Background:

• Refractive errors, including myopia and hyperopia, can affect animal vision.
• Understanding age-related changes in canine refractive states is crucial for ophthalmic care.
• Limited data exists on the prevalence and range of refractive errors across different canine age groups.

Purpose of the Study:

• To investigate the occurrence and spectrum of refractive errors in clinically healthy dogs of varying ages.
• To determine if age significantly influences the prevalence of emmetropia, myopia, hyperopia, or anisometropia in mesocephalic dogs.

Main Methods:

• Ophthalmic examinations were performed on 99 mixed-breed mesocephalic dogs across three age groups: adult, senior, and geriatric.
• Refractive states were assessed bilaterally using a handheld autorefractor without sedation.
• Statistical analysis (ANOVA, t-test) was employed to compare refractive error prevalence between age groups.

Main Results:

• Emmetropia was observed in 36-43% of dogs across age groups.
• Ametropia was common, with hyperopia being the most frequent refractive state in all age groups (41-47%).
• Myopia ranged up to -2.75 D and hyperopia up to 2.5 D, with no statistically significant differences found between age groups.

Conclusions:

• Ametropia is a prevalent condition in dogs, irrespective of age.
• Hyperopia is the predominant refractive error among ametropic dogs in all studied age categories.
• Further research may explore genetic or environmental factors influencing refractive errors in canines.