Amniotic membrane grafting for traumatic complete spectaculectomy and keratomalacia in a Boelen’s python (Simaliaboeleni)

Abstract

Objective: To describe the surgical repair of traumatic complete spectaculectomy and keratomalacia in a snake. Animals: A 10.5-year-old, female, Boelen's python (Simalia boeleni) was presented with iatrogenic, near-complete spectaculectomy associated with bacterial keratitis, keratomalacia, and hypopyon. Procedures: Corneal samples for cytological evaluation and bacterial culture were collected. Following medical stabilization of the bacterial keratitis, a double-layered dry amniotic membrane graft was placed. The first amniotic membrane layer was placed over the cornea with the edges tucked under the peripheral remnants of the spectacle and secured in place with fibrin glue. The second amniotic membrane layer was placed over the entirety of the spectacle remnant and secured in place with a combination of fibrin glue and sutures. Topical and systemic antimicrobials, topical ophthalmic lubricants, and systemic non-steroidal anti-inflammatory therapy were administered postoperatively. Results: Heterophilic keratitis was identified by cytology and Enterobacter cloacae, Pseudomonas aeruginosa, and Staphylococcus sciuri were cultured from the corneal samples. The amniotic membrane grafts remained in place for several weeks. At 4 months postoperatively, the spectacle was completely regenerated, the subspectacular space restored, and the cornea was transparent. Spectacular vascularization and fibrosis then slowly cleared over the following 6 months. Conclusions and clinical relevance: Amniotic membrane grafting with fibrin glue is a relatively simple and effective surgical method to reconstruct extensive defects in the reptilian spectacle and to assist in the management of bacterial keratitis associated with spectacle avulsion.

Anatomy, Physiology, and Disorders of the Spectacle, Subspectacular Space, and Its Lacrimal Drainage System in Squamates

“…Regeneration of the spectacle has been described in two snake species for the treatment of a near-complete spectaculectomy or spectacle avulsion by use of porcine small intestinal submucosal or amniotic membrane grafting combined with application of topical ointments [ 51 , 52 ]. In both cases, full regeneration of the spectacle following two or more shedding cycles was observed; based on these results, grafts are considered to serve as a scaffold for the healing of larger or complete spectacular defects [ 51 , 52 ].…”

“…It has been postulated that in cases of traumatic near-complete spectaculectomy or avulsion of the spectacle, spontaneous regeneration will not occur and intensive treatment, including the use of grafting, is necessary [ 31 , 51 , 52 ]. Based on our experiences, however, topical application of antimicrobial ointments until a first shed has occurred has a fair chance of resulting in complete regeneration of the spectacle and subspectacular space if the basal layers at the transition zone are still intact.…”