Causes, treatment, and outcome of hyphema, fibrin, and vitreal hemorrhage in horses: 219 cases (2012-2023).

The research paper examines the causes, treatments, and outcomes of eye conditions, specifically hyphema, fibrin, and/or vitreal hemorrhage, in horses. The study determines that using intracameral TPA for treatment significantly reduces resolution time and occurrence of adverse ocular sequelae.

Methodology and Participants

• The study is carried out retrospectively, with the researchers examining the records of 225 horses (equivalent to 219 eyes) that were diagnosed with hyphema, fibrin, and/or vitreal hemorrhage.
• The researchers looked at various factors including the horse’s signalment – the breed, age, and gender attributes, and the findings from ophthalmic examinations, the identified causes of these eye conditions, the treatments used, and the eventual outcomes.

Findings

• The study discovered that the most common causes of intraocular fibrin or hemorrhage were equine recurrent uveitis (in 42 out of 219 horses), followed by corneal stromal abscess (in 32 horses), then corneal stromal ulcer (in 25 horses), and lastly, trauma (in 21 horses).
• The study also found that eyes treated with intracameral tissue plasminogen activator (TPA) had significantly fewer days to resolution (around 9 days on average) than those not treated with TPA (around 28 days on average).

Sequelae

• The study observed that ocular sequelae (a condition which is the consequence of a previous disease or injury) such as cataracts, synechiae (adhesions within the eye), and vision loss were significantly less common in eyes treated with TPA.
• In eyes suffering from hyphema, cataracts, synechiae, and vision loss were reported in 9, 6, and 5 out of 36 eyes, respectively.
• Despite 41 horses undergoing enucleation (removal of an eye) upon initial diagnosis due to severe disease, less than 10% of horses with follow-up required an enucleation.

Conclusions

• The research concludes that the presence of blood products in a horse’s eyes suggests severe ocular disease. However, if the eye is not removed at the time of presentation, there’s a good chance of maintaining the eye.
• The study further concludes that the use of intracameral TPA in horses with anterior chamber fibrin, specifically, results in fewer adverse ocular sequelae.