A survey of ocular ultrasound abnormalities in horse: 145 cases

To describe the association of clinical and ultrasonographic (US) findings in horses affected by visual impairments, to estimate the most frequent ultrasonographic alteration as well importance and limits of US as a part of ophthalmic evaluation in equine patients.

One-hundred-forty-five horses referred to the Veterinary Teaching Hospitals of the University of Perugia and Camerino for ocular problems were submitted to ophthalmic examination and ocular ultrasound. The following group of abnormalities was established: corneal alteration, cataract, synechiae, iris prolapse, anterior chamber alterations, vitreous opacities, globe reduction, globe enlargement, retinal detachment, lens subluxation/luxation, lens rupture, intraocular masses, retrobulbar masses. Specificity, sensitivity, positive and negative predictive value and related 95% confidence interval were calculated. Kappa value was estimated for concordance evaluation.

A total of 384 clinical alterations were observed during ophthalmological examination, while 357 were found by ultrasound investigation. A very good agreement was found for lens subluxation/luxation, intraocular masses, iris prolapse, globe enlargement, lens rupture, vitreous opacities and cataract. Moderate agreement was found for retinal detachment, anterior chamber alterations and synechiae. Corneal alteration and globe reduction resulted in a fair and poor agreement, respectively.

Ultrasonography affords the benefit of providing a complete cross-sectional view of the eyeball, facilitating the identification of ocular diseases in cases of loss of transparency of ocular media. It also represents an indispensable aid whenever anterior opacification precludes the use of ophthalmoscopic or biomicroscopic examination techniques.