Effects of ophthalmic disease on concentrations of plasma fibrinogen and serum amyloid A in the horse.

The research studies the impact of ophthalmic diseases (like ulcerative keratitis and uveitis) on the systemic inflammatory response in horses, focusing on the levels of two acute phase proteins – fibrinogen and serum amyloid A in peripheral blood. The results demonstrated no significant increases in these protein levels due to these eye diseases, suggesting that if detected, a non-ocular inflammation source should be suspected.

Objective and Methodology

• The study aimed to assess if ocular diseases, specifically ulcerative keratitis and uveitis, cause systemic inflammation in horses by increasing the concentrations of the acute phase proteins, fibrinogen and serum amyloid A in peripheral blood.
• The method involved collecting whole blood and serum samples from 38 mature horses affected by these conditions, 9 healthy horses (used as negative controls), and 10 horses with systemic inflammatory disease but no ocular problems (the positive controls). The protein concentrations in these blood samples were then assayed.

Findings and Results

• The concentrations of both fibrinogen and serum amyloid A were found to be statistically different in the positive control group compared to the negative control and those with ocular diseases (P<0.126).
• However, there was no significant difference in these protein levels among the negative control group and the horses suffering from the two ocular diseases (P<0.001).
• This indicates that the horses’ ocular diseases did not raise the levels of these two proteins, suggesting these conditions don’t induce a systemic inflammatory response.

Conclusion and Implications

• The study concluded that neither ulcerative keratitis nor anterior uveitis are associated with elevated peripheral blood levels of the acute phase proteins fibrinogen and serum amyloid A, challenging the assumption that these eye conditions could cause a systemic inflammatory response in horses.
• In practical terms, this means that if a clinician finds elevated levels of plasma fibrinogen or serum amyloid A in a horse with ocular diseases, they should suspect a source of inflammation unrelated to the eye condition.