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

Abstract

Summary 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.

Penetrating keratoplasty for treatment of corneal abscesses in horses – case report

“…In our cases all three horses had been treated before referral without success, furthermore the location and extent of the lesions warranted the surgery. Penetrating keratoplasty in the management of stromal abscessation was previously described and positive visual results were obtained (Hendrix 1995;Whittaker 1997). Either fresh or frozen donor cornea can be utilized in PKs.…”

“…Corneal SA in the horse is a major disease that has the potential to render a previously normal eye extremely painful and blind . A SA may develop during the healing of a minor corneal defect if the surrounding epithelial cells migrate and divide over the defect, thus sealing microorganisms within the stroma (Hendrix 1995). The disease consists of two major components: the corneal lesion itself, which is an accumulation of inflammatory cells and debris with or without an infectious agent or foreign body, and the secondary uveitis that follows the corneal insult (Andrew 2010).…”

“…If medical therapy alone is insufficient or the SA is situated deep within the stroma or results in severe iridocyclitis, a surgical approach is indicated. Surgical management has been associated with a more rapid recovery time and better visual outcome (Hendrix 1995). There is a lack of case reports from European clinics.…”

Ocular Pathology

“…21 Cytology and culture of the fluorescein-negative lesion often do not identify any infectious agents due to the healed corneal epithelium. Diagnosis of a corneal stromal abscess is mainly based on clinical signs.…”

Use of free conjunctival grafts in horses: ten cases

“…Debridement of necrotic tissue as a sole surgical procedure may be indicated when a corneal ulcer is less than half of the corneal thickness. 2,5,6 Although the use of free or island conjunctival grafts has been described, 3,7 to the authors' knowledge, the literature refers to them only occasionally in case series. The use of conjunctival grafts may be indicated if an ulcer is deeper than half the corneal thickness, if it is unresponsive to more conservative treatment, if a penetrating corneal laceration cannot be directly sutured, or the corneal closure requires more direct support.…”