Ultrasound biomicroscopic imaging parameters associated with outcome in equine infectious ulcerative keratitis and stromal abscesses.

The research investigates the potential of corneal ultrasound biomicroscopy (UBM) in predicting the outcomes of equine corneal diseases through the evaluation of parameters like size and depth of lesion, presence of DMD, corneal thickness, and aqueous humour cell counts.

Method of Study

• 46 horses diagnosed with either infectious ulcerative keratitis or stromal abscess were studied.
• Corneal ultrasound biomicroscopy was performed on these horses. The horses were all presenting with infectious corneal diseases to the North Carolina State University Equine Ophthalmology Service from 2019 to 2023.
• Parameters such as lesion size and depth, presence of Descemet membrane disruption (DMD), corneal thickness, and aqueous humor cell counts (AHCC) were assessed.
• The UBM findings were compared with clinical exam findings, the presence of infectious organisms, and the final outcome (whether the cornea healed or had to be enucleated).

Results of the Research

• Evaluations were done on ultrasound biomicroscopes from 46 horses.
• An increased AHCC was found to be significantly related to larger and deeper corneal lesions on UBM, but not with DMD.
• Deep lesions and DMD were significantly related with having to enucleate the eye.
• Horses treated with systemic antibiotics had notably lower AHCC on UBM, but there was no differential in AHCC with the usage of other systemic or topical medications.
• No significant correlation was found between results of infectious disease, clinical findings, outcome, and UBM AHCC.

Conclusion and Implications

• UBM parameters including lesion depth, DMD, and AHCC could serve as useful diagnostic and prognostic tools for enhancing the ophthalmic exam of horses with corneal diseases.
• Deep corneal lesions and DMD viewed on UBM indicate a poor prognosis and suggest that aggressive surgical intervention may be necessary.