The use of hyaluronic acid subdermal filler for entropion in canines and felines: 40 cases.

PURPOSE: To evaluate the use of hyaluronic acid (HA) subdermal filler in canines and felines for entropion. METHODS: Complete ophthalmologic examination was performed by a board-certified veterinary ophthalmologist or ABVO-approved resident. Each case was characterized as primary, secondary, spastic or cicatricial entropion. HA subdermal filler, specifically Restylane® and Restylane Silk® , were utilized in dogs and cats, respectively. Subdermal injection was performed 1-2 mm from the eyelid margin in the affected area until normal eyelid conformation was achieved. All patients did not require sedation or general anesthesia. RESULTS: Forty animals (28 dogs and 12 cats) were included in the study. No local reaction to the HA dermal filler or any other complications other than minor skin bleeding at the injection sites were noted in all patients. Resolution of entropion and secondary complications including corneal ulceration, epiphora, and blepharospasm were noted by the first week after injection in the majority of cases. Three canines and one feline case failed to resolve the entropion, necessitating additional permanent surgical intervention. Two cases were submitted for histopathological analysis. Median follow-up time for all cases was 152.5 days (mean: 194.6 ± 142.7 days; range 9-419 days). Five patients died or were euthanized during the study for unrelated causes. CONCLUSIONS: Hyaluronic acid (HA) subdermal filler appears to be a safe, easy, reliable method for mild to moderate eyelid entropion not requiring general anesthesia. This procedure may be especially appropriate for geriatric patients and those with high anesthetic risk with entropion.

Comparing human peritoneal fluid and phosphate-buffered saline for drug delivery: do we need bio-relevant media?

An understanding of biological fluids at the site of administration is important to predict the fate of drug delivery systems in vivo. Little is known about peritoneal fluid; therefore, we have investigated this biological fluid and compared it to phosphate-buffered saline, a synthetic media commonly used for in vitro evaluation of intraperitoneal drug delivery systems. Human peritoneal fluid samples were analysed for electrolyte, protein and lipid levels. In addition, physicochemical properties were measured alongside rheological parameters. Significant inter-patient variations were observed with regard to pH (p < 0.001), buffer capacity (p < 0.05), osmolality (p < 0.001) and surface tension (p < 0.05). All the investigated physicochemical properties of peritoneal fluid differed from phosphate-buffered saline (p < 0.001). Rheological examination of peritoneal fluid demonstrated non-Newtonian shear thinning behaviour and predominantly exhibited the characteristics of an entangled network. Inter-patient and inter-day variability in the viscosity of peritoneal fluid was observed. The solubility of the local anaesthetic lidocaine in peritoneal fluid was significantly higher (p < 0.05) when compared to phosphate-buffered saline. Interestingly, the dissolution rate of lidocaine was not significantly different between the synthetic and biological media. Importantly, and with relevance to intraperitoneal drug delivery systems, the sustained release of lidocaine from a thermosensitive gel formulation occurred at a significantly faster rate into peritoneal fluid. Collectively, these data demonstrate the variation between commonly used synthetic media and human peritoneal fluid. The differences in drug release rates observed illustrate the need for bio-relevant media, which ultimately would improve in vitro-in vivo correlation.

Determination of Schirmer tear test-1 values in clinically normal alpacas (Vicugña pacos) in North America.

PURPOSE: To determine the normal reference range for Schirmer tear test-1 (STT-1) values in eyes of healthy alpacas (Vicugña pacos). METHODS: Complete ophthalmic examinations were performed on forty healthy alpacas (80 eyes). STT-1 values were obtained in both eyes of all alpacas using a commercial STT strip of a single lot number. Data were analyzed, using a doubly repeated measures ANOVA design, Student's paired t-test, and Pearson correlation test, with P ≤ 0.05 considered significant. RESULTS: The STT-1 values ± standard deviation (SD) were 20.80 ± 4.01 mm/min OD, 20.00 ± 4.13 mm/min OS, and 20.88 ± 4.04 mm/min OU (range 15.50-30.50 mm/min). No significant differences in STT-1 were found between OD and OS. STT-1 was not significantly affected by breed. Schirmer tear test-1 values were significantly increased by 3.45 mm/min for every 10 year increase in age. CONCLUSIONS: This study provides a reference range of STT-1 in the healthy alpaca which can assist veterinarians in diagnosing potential keratoconjunctivitis sicca, tear film abnormalities, as well as ocular surface diseases in alpacas.

Use of equine amniotic membrane free-island grafts for treatment of a midstromal corneal ulcer and descemetocele in a snow leopard (Panthera uncia).

CASE DESCRIPTION A 7-year-old sexually intact female snow leopard (Panthera uncia) was examined because of blepharospasm, periocular discharge, ventral deviation of the upper eyelid cilia, third eyelid prolapse, and corneal opacity of the right eye. CLINICAL FINDINGS An ophthalmic examination performed with the patient anesthetized revealed a 3 × 3-mm ulcer that extended approximately 60% of the depth of the right cornea and was accompanied by perilesional and intralesional cellular infiltrates and active vascularization. The upper eyelid of the right eye also had a previously repaired coloboma resulting in trichiasis. TREATMENT AND OUTCOME Surgical intervention was elected after 5 weeks of medical management including topical administration of autologous serum and topical, subconjunctival, and systemic administration of antimicrobials failed to yield any improvement in the ulcer. Equine amniotic membrane free-island graft placement and eyelid revision surgeries were performed. Two and a half weeks later, a descemetocele was diagnosed ventrolateral to the original ulcer, and a second equine amniotic membrane free-island grafting procedure was performed. Both grafts healed without further intervention. CLINICAL RELEVANCE Equine amniotic membrane free-island grafts were used to successfully repair a corneal ulcer and descemetocele in a snow leopard. The grafting procedure spared the affected globe and resulted in satisfactory cosmesis and functional vision. This procedure should be considered as an option for corneal repair in nondomestic species for which postoperative care and medical treatment options are limited.

Orbital rhabdomyosarcoma and traumatic neuroma following enucleation for a uveal schwannoma in a dog: a case report.

A 4-year-old, female spayed Siberian husky with history of a uveal schwannoma presented for orbital swelling 9 months after enucleation. A second, malignant tumor developed in the same orbit. Therefore, uveal schwannomas may warrant early surgical intervention in the dog.

Comparison of intraocular pressure measurements using rebound (TonoVet® ) and applanation (TonoPen-XL® ) tonometry in clinically normal alpacas (Vicugña pacos).

PURPOSE: To evaluate intraocular pressure (IOP) estimates in eyes of healthy alpacas (Vicugña pacos) using rebound (TonoVet® ) in comparison with applanation (TonoPen-XL® ) tonometry. METHODS: Complete ophthalmic examinations were performed on forty healthy alpacas (80 eyes). IOP measurements using both TonoVet® and TonoPen-XL® tonometers were obtained OU. Data were analyzed, using a doubly repeated-measures anova design and Student's paired t-test, with P ≤ 0.05 considered significant. RESULTS: The mean IOP values ±SD via rebound tonometry were 14.20 mm ± 2.58 mm OD, 14.22 mm ± 2.90 mm OS, and 14.21 ± 2.73 mmHg OU (range 8.67-20.67 mmHg). The IOP values ±SD via applanation tonometry were 12.49 ± 2.81 mmHg OD, 12.53 ± 2.79 mmHg OS, and 12.51 ± 2.78 mmHg OU (range 6.00-19.33 mmHg). There was a significant difference (P = 0.002) in the IOP obtained between the tonometers, with the rebound tonometer having a 1.7 mmHg (0.69-2.71 mmHg, 95% confidence interval (CI)) higher IOP compared to the applanation tonometer. No significant differences in IOP were found between OD and OS. Age, gender, and breed did not significantly affect IOP values. CONCLUSIONS: IOP readings from the rebound tonometer were statistically higher than those from the applanation tonometer; however, this is not considered clinically significant. The accuracy of rebound tonometry in diseased alpaca eyes remains to be determined.

Effect of topical latanoprost 0.005% on intraocular pressure and pupil diameter in normal and glaucomatous cats.

OBJECTIVE: To determine the effects of latanoprost on intraocular pressure (IOP) and pupil diameter (PD) in cats with inherited primary congenital glaucoma (PCG) and normal cats. ANIMALS STUDIED AND PROCEDURES: IOP and PD were measured in both eyes (OU) of 12 adult cats (six normal, six PCG), three times per week for 3 weeks prior to, for 3 weeks during, and for 2 weeks following twice-daily treatment with 0.005% latanoprost to the right eye (OD) and vehicle to the left (control) eye (OS). IOP and PD were measured hourly, for 8 h, 1 day prior to, and on the first and last days of treatment. Aqueous humor flow rate (AHF) was determined at baseline and at the end of the treatment phase in six normal cats. RESULTS: Mean IOP was significantly lower in treated vs. control eyes of PCG cats, for up to 8 h following a single latanoprost treatment, and a maximal IOP reduction of 63% occurred in treated eyes at 3 h. Latanoprost acutely lowered IOP in cats with PCG, but this effect appeared to diminish over 3 weeks of treatment. AHF was modestly increased in the treated eyes of normal cats after 3 weeks of latanoprost treatment, although IOP was not significantly affected. Latanoprost caused miosis, with rebound mydriasis at 24 h posttreatment, in the treated eyes of all cats. CONCLUSIONS: Further research is needed to determine the suitability and efficacy of latanoprost treatment for long-term IOP-lowering in cats with PCG or other forms of glaucoma.

Ventral transpalpebral anterior orbitotomy: surgical description and report of 3 cases.

PURPOSE: To describe a surgical approach to allow access to the ventral anterior canine orbit and report outcomes of three cases. SURGICAL TECHNIQUE: After induction of general anesthesia and aseptic preparation of the surgical site, a 2.5- to 3-cm curvilinear skin incision was created through the inferior eyelid at the level of the ventral orbital rim. A combination of sharp and blunt dissection facilitated entrance into the ventral anterior orbital space for the removal of diseased tissues or allows for drainage of purulent debris. Two-layer closure was performed, and postoperative lateral temporary tarsorrhaphy sutures were retained to provide globe protection. RESULTS: Three dogs underwent unilateral ventral transpalpebral anterior orbitotomy. Prior to surgery, apart from a complete ophthalmic examination, ocular ultrasound was used to diagnose orbital disease in two cases, and MRI was utilized in the third case. Exploratory orbitotomy revealed a large mucocele in case 1, orbital bacterial abscessation in case 2, and necrotizing zygomatic sialoadenitis in case 3. Clinical exophthalmos resolved immediately after surgery. The surgical site in all cases healed within 2 weeks. One patient had a superficial corneal ulceration 2 weeks after surgery which healed uneventfully. Recurrence of orbital disease was not noted in any case. CONCLUSIONS: Ventral transpalpebral anterior orbitotomy is a simple procedure that allows easy access to the ventral anterior orbit to allow for removal of diseased tissues or to facilitate drainage of abscessation. Recurrence of orbital disease was not seen in any patient, with one patient experiencing blindness as a long-term complication following the procedure.