Management of corneal epithelial defects in a population of mature chuck‐will’s‐widows (Antrostomus carolinensis) in South Florida

Abstract

PurposeTo describe ocular clinical findings, gross/histopathologic findings, and treatment regimens in a series of migratory chuck‐will's‐widows (Antrostomus carolinensis) (CWW) with corneal epithelial defects.MethodsSeven CWW were presented to the South Florida Wildlife Center (SFWC). Four presented with bilateral (OU) corneal ulceration; two developed corneal ulceration OU; one had no ocular lesions. Treatment protocols for patients with corneal ulcers included the following: medical therapy only or medical therapy combined with an additional procedure. Four patients including the bird with no ocular lesions were euthanized, and one patient died. Their globes were submitted for histopathology. Two patients were released.ResultsClinical findings prior to enucleation included superficial corneal ulceration with redundant epithelium persisting weeks to >1 month. On histopathology, epithelium in nonulcerated globes was remarkably thin; this was considered normal. Common histopathologic findings of ulcerated globes revealed epithelial and conjunctival attenuation with an acellular superficial stromal layer and hypercellular mid‐stromal layer. One globe healed with medical therapy and cotton tip applicator debridement. Four globes healed by combination of medical therapy, equine amnion, nictitating membrane (NM) flap, and temporary tarsorrhaphy. No globes healed with diamond burr debridement or grid keratotomy.ConclusionsFactors that may be contributing to these corneal epithelial defects include, but are not limited to, normally thin epithelium, exposure keratopathy, neurotrophic disease, epithelial turnover and inadequate stem cell recruitment, inherited/genetic causes, and unidentified infectious agents (eg, viral etiologies). Of the 12 eyes treated, one healed with medical therapy/cotton tip applicator debridement, and four healed with medical therapy/equine amnion/nictitating membrane flap/temporary tarsorrhaphy.

Application of a modified nictitating membrane flap in a fledgling feral pigeon (Columba livia domestica) with bullous keratopathy

“…Considering the insufficient tamponade effect of tarsorrhaphy, refractoriness to medical treatment, and unsuitable body condition for long surgery in this case, NMF was the best option for the patient, with modifications required based on the anatomic features of the avian nictitating membrane. There is a report that NMF was applied in a bird with corneal epithelial defects 19 . The NMF was performed with one suture knot, but this method would not have been suitable in our case where greater tension was required on the nictitating membrane due to the protruding cornea.…”

“…There is a report that NMF was applied in a bird with corneal epithelial defects. 19 The NMF was performed with one suture knot, but this method would not have been suitable in our case where greater tension was required on the nictitating membrane due to the protruding cornea. The surgical method used in the present case could distribute the pulling force of the nictitating membrane across almost the entire leading edge.…”