Bilateral nodular lymphocytic conjunctivitis in a horse.

The research article discusses a rare case of bilateral nodular lymphocytic conjunctivitis in a horse, where surgical excision didn’t provide an effective cure, and the condition was ultimately treated with topical corticosteroid therapy.

Case Presentation

• The subject of the study was a Russian jumper horse that showed symptoms of an ocular perilimbal conjunctival mass.
• Upon clinical examination, two conjunctival masses of varying size and structure were found, affecting both eyes of the horse.

Clinical Procedure and Observations

• Medical practitioners attempted complete excision of the left-eye mass and partial biopsy of the right-eye mass.
• The left-eye mass exhibited a rapid recurrence post excision but experienced a complete resolution after being treated with topical corticosteroid therapy.
• The histopathological features of both masses were quite similar, demonstrating chronic, focal lymphocytic conjunctivitis and follicular lymphoid hyperplasia.

Laboratory Assessment

• Special histopathologic staining techniques such as Gomori methenamine silver and acid-fast stains were used to aid in the diagnosis.
• Immunohistochemistry tests were conducted for CD3, BLA36, and lysozyme. Still, these efforts didn’t identify any etiologic agents.
• The test results established that the inflammatory lesion comprises a diverse array of lymphocytes and macrophages, leading to the condition of nodular lymphocytic conjunctivitis.

Comparison and Outcome

• The observed lesions were clinically similar to what has been reported as ‘conjunctival pseudotumor’ in horses.
• Equine conjunctival pseudotumor/nodular lymphocytic conjunctivitis has typically been reported as a unilateral condition with good prognosis if partially or completely surgically excised.
• However, in this instance, being the first reported case of bilateral nodular lymphocytic conjunctivitis in a horse, surgical excision alone failed to have a curative effect and called for the use of topical corticosteroid therapy for complete recovery.