Evaluation of a New Non-Mydriatic Handheld Fundus Camera for Fundus Imaging in Cats: A Retrospective Study: 208 Cases (2023-2024).

Abstract

BACKGROUND: In small animals such as cats, fundus imaging plays a critical role in early diagnosis of eye diseases and monitoring of treatment processes. Traditional methods usually require dilation of the pupil, which in some cases may require anaesthesia or cause discomfort for the animals. In recent years, non-mydriatic fundus cameras, especially with the development of handheld models, offer a new alternative that simplifies this process. These cameras allow high-quality fundus images to be obtained without the need for pupil dilation. This helps veterinarians save time and resources during examinations, while also providing a less stressful experience for the animals. OBJECTIVES: Evaluation of the use and image quality of the new non-mydriatic handheld fundus camera (Aurora, Optomed, Oulu, Finland) for fundus imaging in cats. METHODS: Fundus photographs of 208 cats were obtained using a handheld, non-mydriatic fundus camera. Undilated colour images of each eye centred on the optic disc were taken in a dimly lit room using a non-mydriatic fundus camera. The image acquisition protocol consisted in a single 50° colour photo centred on the cats optic disc. Images were evaluated for normal and pathological fundus. In addition, the obtained fundus images were evaluated in terms of centration, clarity and visible range parameters, with the quality score of each parameter varying between 2 (excellent) and 0 (ungradable). RESULTS: Although 204 of 208 cats had a normal fundus, four cats had retinal pathology. The optic disc was defined as well-centred in 412 of 416 eyes, partially centred in 3 eyes and not centred in 1 eye. Fundus vessels were clearly visible in 409 eyes, recognisable in 6 eyes and not recognisable in 1 eye. The entire image was visible in 413 eyes; more than 80% of the image was visible in 2 eyes, and less than 80% of the image was visible in 1 eye. The mean image quality scores for image centration, clarity and visible range were 1.99, 1.98 and 1.99, respectively, in 416 eyes. CONCLUSIONS: The evaluated fundus camera appears to be suitable for use in fundus imaging in non-dilated eyes of cats, and the quality of the images obtained is significantly satisfactory.