Scleral rupture in dogs, cats, and horses.

The research paper presents a retrospective study that examined historical cases of scleral rupture as a consequence of blunt trauma in dogs, cats, and horses, and documented the common clinical symptoms, findings from ultrasonography, and histological results.

Animals Studied and Procedures

• The research reviewed 33 cases in total: 30 small animals (dogs or cats) and 3 horses, all of which had been diagnosed with scleral rupture.
• B-mode ultrasonography was conducted on 20 of these animals, while histopathological analysis was performed on 18 globes that had been surgically removed (enucleated).

Results

• Among the small animals studied, 80% showed hyphema (blood in the anterior chamber of the eye), 60% had subconjunctival hemorrhage (bleeding under the tissue covering the white part of the eye), and 53% had swelling of the eyelids and conjunctiva.
• All horses studied exhibited swelling of the eyelids and conjunctiva. Two-thirds also had hyphema and subconjunctival hemorrhage, and presented with a collapsed anterior chamber (the front part of the eye).
• Ultrasonographic indicators of scleral rupture included areas with unclear scleral borders shown in 90% of the cases, and echoic or hyperechoic contents in the anterior and posterior chambers (55%) and in the vitreous humor (80%).
• The most common locations of scleral rupture in small animals were the posterior pole, beside the optic nerve, near the junction between the cornea and sclera (limbus), and on the dorsal side of the globe. In horses, the rupture tended to occur at the limbus.
• On histopathology, the most common findings in the small animals were hemorrhages in the anterior, posterior chambers and vitreous humor, retinal detachment, choroidal edema and hemorrhages, and detachment of the choroid due to excessive bleeding (suprachoroidal hemorrhage) with similar lesion patterns found in the horse globes examined.

Conclusions

• The study concluded that the most common observable symptoms of scleral rupture in animals are hyphema, subconjunctival hemorrhage, and swelling of the eyelids and conjunctiva.
• Indicators of a scleral rupture on an ultrasonograph included ill-defined scleral margins and hypoechoic material within the globe’s cavities.
• Key histopathological signs included globe hemorrhages, and choroidal and retinal detachment.
• The most common locations of these ruptures were the posterior pole and areas near the optic nerve in small animals, and the limbus in horses.