Sonographic examination of the anterior eye segment in companion animals.: Part 2:: Pathological changes

Objective: Evaluation of high resolution ultrasound as a diagnostic tool in veterinary ophthalmology. Material and methods: Pathological changes of the anterior segment and the retinal-vitreous-periphery of the eye in 125 dogs and 36 cats were imaged using a linear array ultrasound probe with a median frequency of 12 MHz. In addition bulbar, orbital and adnexal changes of the eyes of two guinea pigs and three rabbits were scanned. Histological specimens were taken for comparison when an enucleation was unavoidable. Results: High resolution ultrasound offers the possibility to image lesions of the anterior and bulbar wall part of the eyeball and ocular adnexa in detail. This non-invasive method is well tolerated. Comparing the utilized method with an ultrasound biomicroscope, which is used in human medicine, it was apparent that the latter is superior in imaging delicate structures of tissue. Overall the probe used in this study seems to be an appropriate alternative in veterinary use as it has a higher penetration, can be handled more easily and has a wider range of applications. Clinical relevance: High resolution ultrasound was capable to show pathological changes in the eyes of companion animals which have not yet been visualized with standard ophthalmic ultrasound. Focal points of the examination are lesions of the iris, ciliary body and lens, the diagnosis of glaucoma, trauma, the control of the course of an illness and the review of the operational outcome of lens extractions and artificial lens implantations.