OPHTALMIC ABNORMALITIES IN 160 HORSES IN ITALY: A FOUR YEARS OBSERVATIONAL STUDY

Purpose: To describe the clinical and ultrasonographic ophthalmic abnormalities in horses referred to the Veterinary Teaching Hospitals of the University of Perugia and Camerino between January 2015 and December 2018. Material / methods: Complete ophthalmic examination and ocular low-frequency ultrasound (4MHz; Logiq C5 Premium ultrasonograph, GE Healthcare Italia, Milan, Italy) were assessed in one-hundred-sixty horses. Adnexa, anterior and posterior segments and, retrobulbar space abnormalities were assessed. Specificity, sensitivity, positive (PPV) and negative predictive value (NPV) and related 95% confidence interval (CI) were calculated. The analysis of multivariate categorical data was evaluated using the Kappa value which was interpreted according to Landis and Koch (1977) as follow: no agreement= < 0.01: poor= 0.01 to 0.20; fair= 0.21 to 0.40; moderate= 0.41 to 0.60; good= 0.61 to 0.80; very good= 0.81 to 1.00. Results: Among 160 horses , 42 adnexa abnormalities, 180 anterior segment abnormalities, 164 posterior segment abnormalities and 16 retrobulbar space abnormalities were found. The most common complaints were recurrent uveitis (n=35, 22%), keratitis/keratouveitis (n=31, 19%) and corneal ulceration/perforation (n=20, 20%) Four hundred-two abnormalities were observed clinically, while 370 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 alterations (keratitis, keratouveitis, ulceration, perforation and stromal abscess) and globe reduction resulted in a fair and poor agreement, respectively. Discussion:. The poor agreement (k= 0.1) observed for the corneal alterations corresponds to a significant lack in diagnostic capability of low-frequency ultrasound, compared to the clinical assessment. Ultrasonography affords the benefit of providing a complete cross-sectional view of the globe, facilitating the identification of ocular diseases in cases of loss of transparency of ocular media. Particular attention and special care must be implemented in cases of corneal ulceration and perforation to avoid any additional trauma.