K L Graham1, S-E Byosiere2, L C Feng2, M Sanders3, P C Bennett2, K Caruso4, C I McCowan5,6, A White1,7. 1. Clinical Ophthalmology and Eye Health, Sydney Medical School, University of Sydney, Sydney, New South Wales 2000, Australia. 2. School of Psychology and Public Health, La Trobe University, Melbourne, Victoria 3083, Australia. 3. Animal Eye Care, Melbourne, Victoria 3145, Australia. 4. Eye Clinic for Animals, Sydney, New South Wales 2065, Australia. 5. University of Melbourne Veterinary Hospital, University of Melbourne, Melbourne, Victoria 3030, Australia. 6. Department of Economic Development, Jobs, Transport and Resources, Melbourne, Victoria 3000, Australia. 7. Centre for Vision Research, Westmead Institute for Medical Research, Westmead, New South Wales 2145, Australia.
Abstract
OBJECTIVES: To describe preliminary use of a forced-choice preferential looking task for the clinical assessment of vision in dogs. MATERIALS AND METHODS: The vision of 18 pet dogs was investigated in two separate studies using a forced-choice preferential looking task: multiple observers watched eye, head and body movements on video recordings to identify cues suggesting when a dog had seen the feature of interest. Human observer reliability was determined using eight dogs and computer-generated stimuli. Visual acuity was assessed using computer-generated grating stimuli: in real-time, an observer watched each dog's eye movement patterns and behaviour to decide whether each grating was seen. Stimuli were presented in a step-wise manner and were controlled by the observer. Acuity was estimated as the highest spatial frequency the dog was determined to have seen. RESULTS: Median estimated visual acuity was better at 1 m compared to that at 3 m. Average test time was longer at a 3-m distance than at 1 m. Inter- and intra-observer reliability was better from 1 m than from 3 m. CLINICAL SIGNIFICANCE: Preliminary use of a forced-choice preferential looking task for measurement of visual acuity in dogs has potential use as a clinical tool for the assessment of vision in dogs.
OBJECTIVES: To describe preliminary use of a forced-choice preferential looking task for the clinical assessment of vision in dogs. MATERIALS AND METHODS: The vision of 18 pet dogs was investigated in two separate studies using a forced-choice preferential looking task: multiple observers watched eye, head and body movements on video recordings to identify cues suggesting when a dog had seen the feature of interest. Human observer reliability was determined using eight dogs and computer-generated stimuli. Visual acuity was assessed using computer-generated grating stimuli: in real-time, an observer watched each dog's eye movement patterns and behaviour to decide whether each grating was seen. Stimuli were presented in a step-wise manner and were controlled by the observer. Acuity was estimated as the highest spatial frequency the dog was determined to have seen. RESULTS: Median estimated visual acuity was better at 1 m compared to that at 3 m. Average test time was longer at a 3-m distance than at 1 m. Inter- and intra-observer reliability was better from 1 m than from 3 m. CLINICAL SIGNIFICANCE: Preliminary use of a forced-choice preferential looking task for measurement of visual acuity in dogs has potential use as a clinical tool for the assessment of vision in dogs.