Modified penetrating keratoplasty with Acell®bioscaffold implant in seven horses with deep full-thickness corneal stromal abscess

Effects of corneoconjunctival transposition, posterior lamellar keratoplasty and modified deep lamellar endothelial keratoplasty on streak retinoscopy in equine cadaver eyes

OBJECTIVE

Evaluate the effects of corneoconjunctival transposition (CCT), posterior lamellar keratoplasty (PLK) and modified deep lamellar endothelial keratoplasty (DLEK) on streak retinoscopy in equine cadaver eyes.

METHODS

Intraocular pressure (IOP) was maintained at 25 ± 3 mmHg in 35 equine cadaver eyes. Streak retinoscopy was performed prior to (NO VISCO) and following (VISCO) intracameral injection of 1.0 ml of viscoelastic. Following optical coherence tomography (OCT), an axial CCT [n = 11] or PLK [n = 12], or peripheral DLEK [n = 12] was performed. Streak retinoscopy and OCT were repeated postoperatively.

RESULTS

Postsurgical net meridional and spherical refraction for CCT [Horizontal (H): 3.4 (95% CI 2.4-4.4) diopters (D), p < .001, Vertical (V): 3.5 (95% CI 2.7-4.4) D, p < .001, Spherical: 3.5 (95% CI 2.6-4.3) D, p < .001] and PLK [H: 3.2 (95% CI 2.2-4.1) D, p < .001, V: 2.8 (95% CI 2.0-3.6) D, p < .001, Spherical: 3.0 (95% CI 2.2-3.8) D, p < .001] were significantly increased from presurgical (VISCO) values. No difference between presurgical (VISCO) and postsurgical values were identified for the DLEK. Postoperative OCT revealed space between anterior and posterior corneal grafts and corneal undulation associated with suture placement.

CONCLUSION

Meridional and spherical refraction had a hyperopic shift following CCT and PLK, with a significantly higher value in the vertical meridian for the CCT. Pre- and postoperative refraction was not significantly different for the DLEK. This supports that the DLEK has a lesser effect on immediate postoperative refraction compared with CCT or PLK.

Dorsally placed commercially available subpalpebral lavage systems have low complication rates in horses

OBJECTIVE

To retrospectively evaluate the complication rate following dorsal placement of a commercially available 1-hole subpalpebral lavage system (SPL) at a veterinary teaching hospital.

ANIMALS

102 client-owned horses with ophthalmic disease.

PROCEDURES

Medical records of horses (2010 to 2020) with ophthalmic disease were reviewed to determine whether a commercially available SPL system was dorsally placed. Data collected from the medical record included signalment, presenting complaint(s), diagnosis, ophthalmic procedures performed, SPL laterality, hospital service that placed the SPL, anesthetic technique for placement (general anesthesia or sedation with local nerve blocks), duration of SPL management while hospitalized or at home, type of enclosure for the horse, use of eye protection, duration of time the SPL was in place, location of SPL management (home vs hospital), types and numbers of medications administered, recorded complications, and outcome of the globe. Complications experienced during treatment were categorized as either ocular or nonocular. The χ2 test for independence test and Fisher exact test were performed to examine the relationship between the department that placed the SPL, method of anesthesia, antimicrobial administration, type of facial protection used, and complication type and rate.

RESULTS

Overall complication rate for SPL systems was 29.1% (37/127), with 21.2% (27/127) being ocular complications and 7.9% (10/127) being nonocular complications. SPL complication rate was not affected by any variable that was examined.

CLINICAL RELEVANCE

Commercially available SPL systems placed dorsally have a low ocular complication rate. These SPL systems may be placed by veterinarians with varied training backgrounds and managed at home without significantly increasing complication rate.

Case Series Describing the Use of Low-Temperature Vacuum-Dehydrated Amnion (Omnigen) for the Treatment of Corneal Ulcers in Cats and Dogs: 46 Cases (2016-2017)

Amniotic membrane is widely used in the treatment of ocular surface disorders in human and veterinary patients. Preservation and storage of amnion has proven challenging, prompting the development of new preservation techniques. Omnigen, a novel low-temperature vacuum-dehydrated amnion, is reported to possess enhanced structural properties and biochemical stability in vitro, but its clinical use in veterinary patients is not well described. This study aims to document and describe the varied use of Omnigen for the surgical treatment of corneal ulceration in cats and dogs. A total of 45 patients (46 eyes) were recruited from the clinical record system of the Royal Veterinary College (London) between January 2016 and December 2017. Brachycephalic breeds were over-represented (37/45; 82.2%). Omnigen was used as a standalone graft in 5/46 (10.9%) eyes, as a supplementary graft in 29/46 (63.0%) eyes and as a patch in 12/46 (26.1%) eyes. Graft failure occurred in 10/46 eyes (21.7%). At final examination 43/46 eyes (93.5%) had healed and 31/33 eyes (93.9%) were visual. This study demonstrates the successful use of Omnigen for the surgical treatment of corneal ulceration in cats and dogs. Further studies are needed to clarify its properties and benefits in the clinical field.

Corneoconjunctival transposition with and without ACell® for deep corneal ulcer repair in 18 dogs

OBJECTIVE

To document a case series using corneoconjunctival transposition (CCT) surgery with and without bioscaffolding matrix (ACell^® ) to repair deep corneal ulcers and perforations in dogs.

ANIMALS STUDIED

Eighteen dogs of various breeds that presented with deep or perforating corneal ulcers.

PROCEDURES

Corneoconjunctival transposition grafts with or without ACell^® were sutured using a simple interrupted 8-0 or 9-0 polyglactin 910 pattern.

RESULTS

A total of eighteen dogs (19 eyes) were diagnosed with deep corneal ulcers (n = 7) and perforating corneal ulcers (n = 12). A CCT was performed in all eyes, with ten of them additionally receiving an ACell^® graft. The majority of lesions were located axially in 14/19 (81%) eyes. Grafts were harvested from dorsal (n = 8), temporal (n = 5), ventral (n = 4), or nasal (n = 2) quadrants. Brachycephalic breeds (13/18) were over-represented. Keratoconjunctivitis sicca was present in 10/19 eyes (52.6%). Bacterial isolates were cultured from 8/19 eyes. Post-operative therapy included topical antibiotics, plasma, cycloplegics, oral antibiotics, and oral nonsteroidal anti-inflammatory drugs. CCT integration with and without ACell^® occurred at a median of 20 days (range 7-38 days) post-operatively with no significant difference between groups. Median follow-up time was 188 days. Short-term post-operative complications included granulation tissue formation (19/19), corneal edema (4/19), graft retraction (4/19), and anterior synechia (1/19). Long-term complications in 14 eyes with follow-up >30 days included superficial corneal pigmentation (6/14) and epithelial inclusion cysts (5/14). Two eyes were nonvisual at last follow-up due to cataract formation.

CONCLUSIONS

Corneoconjunctival transposition with ACell^® can be utilized for corneal ulcer repair in dogs.

[Surgical treatment of a perforated cornea in a zebra]

Microsurgical procedures in zoo and wildlife animals are challenging because of the reduced perioperative sterility and postoperative care. This case report describes the positive result of the surgical treatment of a perforated corneal ulceration with prolapsed iris in an 18-year-old Grévy's zebra mare. The postoperative development and the results of the histomorphological examination 3.5 years after surgery are described.