Short-Term Clinical Outcomes of a Novel Corneal Prosthetic Device in a Rabbit Model.

PURPOSE: To evaluate the clinical performance and biocompatibility of a novel synthetic corneal device. METHODS: Synthetic, single-piece, foldable, suturable, optic-and-skirt design prototype devices were fabricated using expanded polytetrafluoroethylene. A combination of intralamellar and full-thickness penetrating techniques was used for implantation. A topical antibiotic-steroid regimen was used postoperatively. Rabbits were examined weekly using penlight and at monthly intervals under an operating microscope with integrated optical coherence tomography. Optical quality, retention, and complication rates at 3 and 6 months were assessed. RESULTS: Nineteen rabbits underwent surgery. There were no device-related intraoperative complications. Creation of lamellar pocket was problematic in 2 younger rabbits with inadequate chamber depth. Two rabbits had early postoperative infectious keratitis attributed to bandage contact lens wear, which was ceased. Rabbits were treated using fourth-generation fluoroquinolone drops and did well over a period of 6 months without device extrusion or further complications. Four other rabbits had late postoperative infectious keratitis because of exposed suture(s), which progressed to endophthalmitis. One rabbit had sterile keratolysis and retraction of the anterior corneal lamella. There was no retinal detachment, glaucoma, anterior or posterior synechiae, or cataract formation in any of the rabbits. All devices remained in situ with clear optics without spoliation. Light microscopic examination of the globes demonstrated intact epithelium overlying the skirt and new collagen integration into the porous structure of the skirt without significant inflammation. CONCLUSION: Our results demonstrated favorable short-term anatomical clinical outcomes of this novel synthetic corneal prosthesis. Further studies are warranted to characterize the biointegration of this device.

Adult-onset hypothyroidism in a lynx (Lynx canadensis).

A 19-yr-old female lynx (Lynx canadensis) presented for an acute onset of anorexia and reluctance to move. Physical examination, radiography, hematology, and serum biochemistry revealed evidence of renal failure, presumptive uremic gastritis, chronic intervertebral disk disease at T13-L1, and markedly low serum levels of total thyroxine (1.54 nmol/L) and total triixodothyronine (0.55 nmol/L). Twenty-five hours after its original presentation, the lynx exhibited horizontal nystagmus, which has been suggested as a clinical sign associated with hypothyroidism in domestic dogs. The lynx was euthanatized because of poor prognosis, and medical management concerns related to its chronic renal failure. Necropsy examination substantiated that the lynx had true hypothyroidism with 60-90% of the thyroid gland replaced with adipose tissue. Although feline adult-onset hypothyroidism may have low incidence, it should still be considered as a cause of nonspecific signs of disease in cats, as well as signs suggestive of hypothyroidism. Routine monitoring of baseline exotic felid thyroid levels throughout life would help to identify normal values and diagnose a potential disease that has obscure clinical signs.