Comparison of conjunctival pedicle flap to corneal fixation strength achieved by Tisseel® fibrin glue, ethyl cyanoacrylate adhesive, ReSure® hydrogel sealant, and conventional suturing with 8-0 VICRYL® ophthalmic suture

OBJECTIVE

To determine and compare the fixation strength of conjunctival pedicle flaps to cornea achieved via conventional ophthalmic suture and three different adhesive compounds.

ANIMALS STUDIED

Ex vivo porcine globes.

PROCEDURES

Following a 6 mm wide 500-micron-restricted depth lamellar keratectomy, conjunctival pedicle flaps were secured to the keratectomy site with either 8-0 VICRYL® suture or one of three adhesive products, including Tisseel® bioadhesive, ReSure® synthetic adhesive, or ethyl cyanoacrylate adhesive (n = 10 per surgical group). Adhesive application protocol varied by product based upon adhesive biocompatibility. Corneoconjunctival tissues were then harvested, clamped in a tensile testing device, and loaded at a rate of 1 mm/s under video surveillance until the point of failure. Peak load was determined for each test and used to compare fixation strength between samples.

RESULTS

Forty conjunctival flaps were performed, with 6 omitted from evaluation due to dehiscence prior to tensile testing. Of the 34 flaps analyzed, 10 were secured with suture, 10 with cyanoacrylate, 8 with ReSure®, and 6 with Tisseel®. Flaps secured with suture withstood significantly higher applied tensile force compared with cyanoacrylate (p = .02474), ReSure® (p = .00000), and Tisseel® (p = .00002). Flaps secured with cyanoacrylate withstood significantly greater force than those secured with ReSure® and Tisseel® (p = .01194 and 0.01798, respectively). There was no significant difference in fixation strength between ReSure® and Tisseel® glue (p = .95675).

CONCLUSIONS

Conjunctival pedicle flap fixation using 8-0 VICRYL® suture fixation was able to withstand significantly greater maximum tensile force compared to ReSure®, Tisseel®, or cyanoacrylate adhesives. Fixation strength achieved with cyanoacrylate adhesive was significantly greater than that achieved with ReSure® or Tisseel®.

Clinical comparison of tear film breakup time measurements in normal dogs using three different methods of fluorescein solution administration

OBJECTIVE

To evaluate whether the method of fluorescein administration affects the results of tear film breakup time (TFBUT) measurement in normal dogs.

ANIMALS STUDIED

Thirty-seven client and hospital staff owned dogs over 1 year of age with no known comorbidities or administration of systemic or topical ophthalmic medications.

PROCEDURES

A prospective randomized three-way crossover study was conducted. All dogs received an abbreviated ophthalmic examination to rule out ocular surface disease. Using a 30-min washout interval period, each dog's right eye was received: (a) direct application of fluorescein stain strip with one drop of sterile eyewash, (b) direct application of fluorescein stain strip with two drops of sterile eyewash, or (c) application of one drop from a premade fluorescein solution (dilution of one strip in 0.3 mL sterile eyewash). Eyes were assessed using the cobalt blue filter of a slit lamp biomicroscope. TFBUT measurements were summarized as means ± standard deviation. The methods were compared using mixed model analysis of variance. All analyses were performed using sas version 9.4.

RESULTS

Thirty-seven dogs met the inclusion criteria. Mean TFBUT ± standard deviation (SD) for the three described methods were: (a) 16.58s ± 6.9, (b) 15.98s ± 7.1, and (c) 16.43s ± 8.1. No differences between fluorescein stain application techniques were observed (p = .92).

CONCLUSION

The technique of fluorescein solution administration did not affect TFBUT measurement in this population of healthy dogs.

Causes, outcomes, and owner satisfaction of dogs undergoing enucleation with orbital implant placement

OBJECTIVE

To describe clinical and histopathologic pre-operative diagnoses as well as associated post-operative complications following orbital silicone implantation in dogs undergoing enucleation and evaluate owner satisfaction.

ANIMALS STUDIED

One hundred and eighty-six dogs who underwent enucleation with orbital implant.

PROCEDURES

Medical records from dogs that underwent enucleation with orbital implant performed at Virginia-Maryland Veterinary Teaching Hospital between 2007 and 2019 were reviewed. Owners were surveyed via telephone regarding client satisfaction.

RESULTS

Enucleation followed by orbital implant placement occurred in 215 eyes of 186 dogs. The most common pre-operative diagnoses were glaucoma (68.8%), uveitis (17.7%), cataracts (15.8%), intraocular neoplasia (13.0%), and lens luxation (10.7%). The most common histopathologic diagnoses were retinal degeneration (46.5%), uveitis (39.5%), cataract (29.8%), retinal detachment (27.4%), and secondary glaucoma (26.5%). Fourteen eyes (6.5%) from ten dogs had post-operative complications reported including orbit cellulitis (n = 11), implant migration (n = 1), and implant extrusion (n = 1). Five of these dogs (50%) had concurrent diabetes mellitus. Median complication time from surgery was 41 days (range: 11-541 days). Ninety-five owner survey responses were completed with a median time of 6.3 years following surgery. Most owners, 85.3% (n = 81), were satisfied with the post-operative outcome.

CONCLUSION

Enucleation with implantation of an orbital implant is a viable and safe method for irreversibly blind eyes. Diabetes mellitus may be a risk factor for the development of post-operative complications. Intraocular neoplasia was not associated with development of post-operative complications. Results of this study indicated high owner satisfaction rates for improving cosmetic appearance after enucleation in dogs.

Descemet's membrane detachments, ruptures, and separations in ten adult horses: Clinical signs, diagnostics, treatment options, and preliminary results

OBJECTIVE

To describe the clinical presentation, diagnostic imaging results, and treatment outcomes of a series of presumed spontaneous Descemet's membrane detachments (DMD), ruptures, or separations (DMRS) in the adult horse.

ANIMALS STUDIED

Ten adult horses of various breeds with DMD or DMRS.

PROCEDURES

Descemet's membrane detachments/DMRS were diagnosed via slit lamp biomicroscopy, ultrasound biomicroscopy (UBM), and/or optical coherence tomography (OCT). Penetrating keratoplasty (PK) with heterologous corneal donor tissue (n = 1), superficial lamellar keratectomy, and Gundersen inlay flaps alone (GF, n = 1) or with subsequent intracamerally assisted corneal tissue welding (CTW, n = 2), or CTW alone (n = 5) were performed in 9/10 horses. One horse underwent spontaneous resolution (n = 1).

RESULTS

Ten horses were diagnosed with either unilateral DMD (n = 4) or DMRS (n = 6). Seven of ten eyes remained visual during the follow-up period (8.16 ± 6.57 months). Graft transparency was good for the eye treated with PK. The horse that underwent GF alone was functionally blind due to persistent corneal edema. The clinical signs resolved in 3/5 horses that underwent CTW alone, but 2/5 eyes were enucleated due to corneal perforation. Both eyes treated with combined GF/CTW had significant corneal clearing with one having evidence of reattachment on UBM and OCT.

CONCLUSIONS

Descemet's membrane detachments separations presents differently than typical DMD and advanced corneal imaging modalities may aid in their diagnosis. Corneal tissue welding using infraCG as the photosensitive agent, or in combination with Gundersen inlay flaps, represents a feasible treatment option for management of equine DMD/DMRS as described in the present case series.

A case of basal cell carcinoma of the nictitating membrane in a dog

A case of a basal cell carcinoma (BCC) of the nictitating membrane (NM) in a 9-year-old female spayed dachshund is reported. Computed tomography and resection of the NM followed by cryosurgery was performed. Although uncommon, BCC should be considered as a differential diagnosis for tumors of the NM.