Analysis of the Ocular Refractive State in Fighting Bulls: Astigmatism Prevalence

Abstract EN

The purpose of this study was to describe the ocular refractive state (ORS) of fighting bulls.

The study consisted of 90 ophthalmological healthy animals (85 in post-mortem and 5 in living conditions, resp.).

The ORS of the eyes (2 per animal) was determined using streak retinoscopy.

In vivo animals were assessed at a fighting bull farm facility.

Post-mortem measurements were carried out at a local arena.

The ORS along the horizontal meridian ranged between −1.00 and +2.50 diopters (D), with a mean of +0.66±0.85 D in post-mortem animals.

Values for in vivo conditions were similar (+0.75±0.46 D).

Left and right eyes were highly correlated in both sets (p<0.001).

A fairly good correlation was also observed when comparing living and post-mortem eyes in the same animals.

Anisometropia ≥ 1.00 D was diagnosed in 3 animals.

Astigmatism (≥+0.5 D) was detected in 93% of the eyes.

To our knowledge, the ORS of the fighting bull has been reported for the first time.

Although values vary among individuals, all eyes presented a marked astigmatism.

Whereas the horizontal meridian was slightly hyperopic, the vertical meridian was always closer to emmetropia.

These results represent a starting point to understand the ocular optics of this kind of animals, which might benefit the selection of animals at the farm before being sent to the bullfighting arena.