Use of subdermal hyaluronic acid injections and a free labial mucocutaneous graft for the repair of feline eyelid agenesis.

OBJECTIVE: To describe a technique to repair feline eyelid agenesis using a hyaluronic acid (HA) subdermal filler injection to allow for acute soft tissue expansion, followed by a free labial mucocutaneous graft. MATERIALS AND METHODS: Thirty-nine colobomatous eyelids in 24 feline patients with secondary keratitis were recruited to the study group. RESULTS: Keratitis and trichiasis were markedly resolved in 27/39 (69.2%) eyelids after a single procedure. Post-operative HA subdermal filler injections were required to resolve 5/39 (12.8%) eyelids that had mild post-operative trichiasis, and 1/39 (2.5%) eyelids that had post-operative lateral canthal collapse. Complications occurred in 6/39 (15.4%) cases, consisting of distal graft necrosis (n = 2 eyes), suture rubbing the cornea (n = 2 eyes), moderate trichiasis (n = 1 eye) and graft adherence to the episclera (n = 1 eye). CONCLUSION: The technique was successful in enhancing corneal protection, cosmesis and eyelid function and should be considered as a surgical option for any degree of eyelid agenesis in feline patients.

Recurrent corneal hemangiosarcoma in a cat with subsequent extension into the orbit.

A 7-year-old neutered female Domestic Short-haired cat was presented for evaluation of ulceration and severe vascularization of the left cornea. Ophthalmic examination revealed a large red irregular mass over the whole cornea in the left eye. A lamellar keratectomy was performed. Histopathology revealed a chronic lymphoplasmacytic, histocytic, neutrophilic ulcerative keratitis with fibrosis and vascularization. The tumor recurred within 3 months, and another lamellar keratectomy and sclerotomy were performed. The lesion was diagnosed histopathologically as a hemangiosarcoma with incomplete margins. The mass recurred locally 6 weeks later, and an enucleation was performed. Histopathology revealed infiltration of the limbus and connective tissue beyond the sclera. Seven weeks later, a fluctuant swelling was found in the left orbit. Computed tomography confirmed a soft tissue attenuating mass measuring 33 x 24 mm diameter in the orbit. There was no sign of metastasis. Clinical remission was achieved with combined chemotherapy with doxorubicin and radiation therapy. The patient remained in clinical remission 20 months post-chemotherapy.

Use of a chronic soft tissue expansion device to facilitate blepharoplasty in a horse with lower-lid cicatricial ectropion with a 14-year follow-up.

A 3-year-old Thoroughbred filly presented to a referral equine hospital for surgical correction of a severe cicatricial lateral lower eyelid ectropion OD, with secondary exposure keratitis. The severity of the ectropion deemed that conventional ectropion repairs would be unsuccessful. Therefore, a soft tissue expansion device was used to create sufficient local tissue for a rotational graft with tension-relieving horizontal incisions to be performed to facilitate closure and acceptable eyelid apposition. The keratitis had resolved by two months postoperatively. There were no long-term complications and only mild recurrence of the keratitis observed 14-years postoperatively.

Microsporidial stromal keratitis in a cat.

A 12 year-old female spayed felid presented after a 35 day history of right eye pain. On examination, a sub-epithelial opacity was identified in the cornea. A lamellar keratectomy was performed and histopathological analysis revealed low numbers of 2x4um, Gram, Hamatoxylin-eosin and Gomori methanamine-silver positive spores. Transmission electron microscopy found ultrastructural findings consistent with the phylum Microspora. To the author's knowledge, this is only the second case of microsporidial stromal keratitis reported in a felid.

Optical coherence tomography of the retina, nerve fiber layer, and optic nerve head in dogs with glaucoma.

OBJECTIVE: To evaluate the retina and optic nerve head (ONH) in canine eyes predisposed to glaucoma using optical coherence tomography (OCT). ANIMALS: Twenty-five eyes (24 dogs). METHODS: Measures of peripapillary retinal, retinal nerve fiber layer (RNFL), and ganglion cell complex (GCC) thickness and ONH parameters were obtained in vivo by OCT of the unaffected eye in dogs diagnosed with unilateral primary glaucoma (predisposed; n = 12) and compared with measures of healthy control eyes (normal; n = 13). Repeatability and intrarater reliability were explored using intraclass correlation coefficients (ICC). RESULTS: Compared to normal eyes, predisposed eyes had a thinner retina in the temporal (P = 0.005), inferior quadrants (P = 0.003), and decreased inner retinal thickness (superior: P = 0.003, temporal: P = 0.001, inferior: P < 0.001, nasal: P = 0.001). Predisposed eyes had a thinner RNFL compared to normal eyes (P = 0.005), and when analyzed in quadrants, it was thinner in the superior (P < 0.001), temporal (P = 0.034), and nasal quadrants (P = 0.001). Repeatability (ICC 0.763-0.835) and intrarater reliability (ICC 0.824-0.942) were good to excellent for measures of retinal thickness and adequate for RNFL measurements (ICC 0.701-0.798). Reliable measurements of optic disk area were obtained and were similar between groups (P = 0.597). Measurements of parameters relying on automated software detection (GCC, optic cup, optic rim) had inadequate repeatability and reliability. CONCLUSION: Statistically significant differences in retinal and RNFL thicknesses were identified in normal and predisposed eyes. Reliable and consistent measurements of variables with manual adjustment of software detected parameters were obtained. Validation of OCT as a diagnostic tool for clinical assessment in canine glaucoma is warranted.

Early postoperative results of Descemet's stripping endothelial keratoplasty in six dogs with corneal endothelial dystrophy.

OBJECTIVE: To describe and assess the clinical outcome and intraoperative and postoperative complications of Descemet's stripping endothelial keratoplasty (DSEK) in the treatment of canine corneal endothelial dystrophy. ANIMALS STUDIED: Six dogs (six eyes) diagnosed with progressive corneal edema resulting from abnormal dystrophic endothelial cells underwent Descemet's stripping endothelial keratoplasty. PROCEDURES: Six patients underwent Descemet's stripping endothelial keratoplasty (DSEK). The patients were examined preoperatively and postoperatively at 24 hours, 7 days, 1, 2, and 3 months after surgery. Corneal edema and ultrasonic pachymetry were evaluated preoperatively and postoperatively. The positions of DSEK grafts were evaluated 3 months after surgery using optical coherence tomography. Intraoperative and postoperative complications were noted. RESULTS: The degree of corneal edema and corneal thickness improved postoperatively in all the patients (n = 6). Fibrin was encountered intraoperatively in one out of the six eyes (1/6) and postoperatively in two out of the six eyes (2/6). One out of the six DSEK grafts was partially scrolled (1/6). Secondary ocular hypertension was observed in one out of the six eyes (1/6). Corneal vascularization was encountered in four out of six patients (4/6). CONCLUSIONS: Descemet's stripping endothelial keratoplasty is an effective surgical treatment option for corneal endothelial dystrophy in dogs. Corneal edema resolved and corneal thickness reduced significantly. The early postoperative results are encouraging. Further investigation is warranted to document any long-term complications and to study the longevity of the transplanted grafts.

Development of a vision impairment score for the assessment of functional vision in dogs: Initial evidence of validity, reliability, and responsiveness.

AIM: To describe the development and initial validation of a questionnaire measuring functional vision in dogs. METHODS: A 17-item survey was designed to quantify functional vision in dogs. The Vision Impairment Score (VIS) was determined by summing responses to each question. Questions were assigned to one of five subcategories: overall vision, daily activities, peripheral vision, near vision, and distance vision. Content validity was established during development phases, and construct validity via comparing results of known groups (blind vs sighted; normal vs impaired vision; surgery to improve vision vs nonrestorative surgery), and through factor analysis. Concurrent criterion validity was determined with use of a validated health-related quality-of-life (HRQL) assessment tool. Reliability and responsiveness assessments were investigated using intraclass correlation coefficient (ICC) and effect size (ES), respectively. RESULTS: Responses (221) from 201 dog owners were included. Compared to sighted dogs (n = 153), blind dogs (n = 48) had a higher VIS and greater impairment in all subcategories. Among sighted dogs, a higher VIS was obtained in dogs with low vision compared to those with normal vision (P < 0.001). A higher VIS was associated with poorer HRQL (P < 0.001). Perfect reliability was obtained for 6/17 questions, and excellent reliability for 11/17 questions (intraclass correlation 1.0 and >0.9, respectively), and the VIS was highly responsive to therapeutic intervention (effect size 1.46). CONCLUSION: Results suggest the VIS may be clinically useful in assessing and obtaining a quantifiable measure of functional vision in dogs. Ongoing validation of the tool for clinical use is needed.