Corneal stromal abscesses in the horse: a review of 24 cases

The medical records of 24 horses with corneal stromal abscesses were reviewed. Twenty of the horses initially presented with a corneal ulcer, corneal opacity, or evidence of ocular pain. All of the horses were treated with topical antibiotics prior to referral. Most had also been treated with topical atropine sulphate and systemic flunixin meglumine. Ophthalmic examinations revealed focal, yellow-white corneal opacities, corneal vascularisation and evidence of iridocyclitis. Nine of the horses were treated primarily medically as the initial response to topical and systemic medication was rapid. Fifteen horses were treated both medically and surgically. Surgical treatment was undertaken when corneal rupture was imminent, the iridocyclitis was intractable or when there was minimal response to intensive medical therapy. The surgical procedure performed in most cases was a deep keratectomy with a conjunctival pedicle flap. Intraoperative specimens for cytology, culture, and/or histopathology contributed to the aetiological diagnosis in 5 of 8 cases in which preoperative cytology and cultures were nondiagnostic. All horses, excluding one that was enucleated at presentation for iris prolapse, had vision at discharge.