Canine Descemet Stripping Endothelial Keratoplasty with a Tissue Insertion Device: Technique and Long-Term Outcome.

Introduction. We describe a case of canine Descemet's stripping endothelial keratoplasty (DSEK) using an open-source canine tissue delivery device. Case Presentation. We follow the four-year outcomes of a 1.5-year-old Tibetan Terrier who presented with difficulty seeing, diffuse corneal edema, and central corneal thickness of 1400 microns in the left eye. To perform DSEK, a polycarbonate carrier and insertion device was designed for canine corneas that measure up to 15 mm in diameter. The tissue was loaded into the inserter prior to surgery with the endothelium facing inwards and the stroma facing the cartridge wall. From the cartridge, the graft was pulled into the eye using microforceps and an anterior chamber maintainer. We assessed preoperative endothelial cell count, postoperative corneal clearance, and graft adhesion. The donor was a two-year-old Airedale Terrier who died one day prior to surgery, with endothelial cell density of 3149 cells/mm2. One week after DSEK, the cornea began to clear, and pachymetry of the donor and graft total was 1410 microns. This improved to 800 microns at 4 months and continued improving in its clarity at the last postoperative visit 4 years after surgery. Discussion. We demonstrate the feasibility of conducting canine endothelial keratoplasty with a specially designed tissue delivery device and the potential of long-term corneal clearance after DSEK in canine eyes.

Endothelial keratoplasty for corneal endothelial dystrophy in a dog.

OBJECTIVE: To assess the efficacy of an endothelial keratoplasty procedure at defined intervals to 1 year postoperatively for the treatment of corneal endothelial dystrophy (CED) in a canine patient. PROCEDURE: A dog diagnosed with CED with progressive corneal edema underwent an endothelial keratoplasty. The patient was examined pre- and postoperatively with slit lamp biomicroscopy and ultrasonic pachymetry. RESULTS: Mean central corneal thickness (CCT) measured with pachymetry was >1400 µm preoperatively and decreased postoperatively to 725 µm. The transplanted donor tissue became transparent 2 weeks postoperatively and incorporated with the recipient cornea. The graft remained transparent throughout the duration of the postoperative period evaluated in this study (2 weeks postoperatively to 1 year). The canine patient was comfortable pre- and postoperatively. CONCLUSIONS: Endothelial keratoplasty is a potential therapeutic option for canine cases with progressive corneal thickening due to CED. As this is a single case study, further investigation into the use of endothelial keratoplasty to treat CED is warranted. Moreover, canine patients with CED might serve as a surgical model for human patients with Fuchs' Endothelial Corneal Dystrophy.

Effect of prophylactic topical hypotensive medications in reducing the incidence of postoperative ocular hypertension after phacoemulsification in dogs.

OBJECTIVE: To determine whether topical hypotensive medications prevent postoperative ocular hypertension (POH) after phacoemulsification. ANIMALS STUDIED: 52 client-owned dogs (88 eyes). PROCEDURES: Diabetic and nondiabetic dogs having undergone phacoemulsification were included in this retrospective study. The control group received no ocular hypotensive medications. The treatment groups received latanoprost, dorzolamide, or dorzolamide/timolol, beginning immediately after surgery, for 2-week duration. IOPs were obtained at initial examination followed by 4 h, 24 h, 7 days, and 14 days postoperatively. POH was defined as an IOP above 20 mmHg (POH20) or 25 mmHg (POH25). RESULTS: POH20 occurred in 33 of 87 eyes (37.93%), including 11 of 21 eyes (52.38%) in the control group, three of 23 eyes (13.04%) in the latanoprost group, eight of 15 eyes (53.33%) in the dorzolamide group, and 11 of 28 eyes (39.29%) in the dorzolamide/timolol group. Active treatment groups were compared to the control group, and the overall group effect was not significant (P = 0.11). POH25 occurred in 22 of 86 eyes (25.58%), including seven of 21 eyes (33.33%) in the control group, two of 23 eyes (8.70%) in the latanoprost group, five of 15 eyes (33.33%) in the dorzolamide group, and eight of 27 eyes (29.63%) in the dorzolamide/timolol group. Active treatment groups were compared to the control group, and the overall group effect was not significant (P = 0.31). Intraoperative use of intracameral tissue plasminogen activator significantly decreased the chances of POH25 (P = 0.0063). CONCLUSIONS AND CLINICAL RELEVANCE: The latanoprost group had a substantially lower percentage of POH 20 and POH25 compared to the control and other active treatment groups, although statistical significance was not achieved. Intraoperative intracameral tissue plasminogen activator decreased the incidence of POH25.

Surgical outcome of cats treated for aqueous humor misdirection syndrome: a case series.

OBJECTIVE: To evaluate the clinical outcome of cats treated surgically for aqueous humor misdirection syndrome. METHODS: A retrospective analysis of cats treated surgically between January 1, 2006, and January 1, 2013, for aqueous humor misdirection syndrome was performed. Signalment, medical therapy, eyes affected, intraocular pressures prior to and after surgery, surgical procedures performed, postoperative complications, and visual status were evaluated. RESULTS: Seven cats (nine eyes) fit the inclusion criteria. Six of seven cats were female, and five of seven cats were diagnosed with bilateral aqueous humor misdirection syndrome. Three surgical approaches were evaluated as follows: (i) phacoemulsification and posterior capsulotomy, (ii) phacoemulsification, posterior capsulotomy and anterior vitrectomy, and (iii) phacoemulsification, posterior capsulotomy, anterior vitrectomy, and endocyclophotocoagulation. The mean age at diagnosis was 12.9 years. Seven of nine eyes had controlled intraocular pressure (≤25 mmHg) during the first 6 months postoperatively. All cats were visual with controlled intraocular inflammation at 1 year postoperatively; however, one eye had an elevated intraocular pressure. All cats were continued on topical antiglaucoma and anti-inflammatory medications following surgery with the mean number of drops per day decreasing from 3.9 drops/day prior to surgery to 2.2 drops/day postoperatively. CONCLUSIONS: Surgical management for feline aqueous humor misdirection syndrome may be a viable option to maintain a visual and normotensive status in cats that no longer have successful control of intraocular pressure with medical therapy.

Ocular lesions following suspected lightning injury in a horse.

PURPOSE: To describe the gross and histopathological ocular findings in a horse following suspected lightning injury. METHODS: The eyes of a 2-year-old thoroughbred gelding were clinically and histopathologically evaluated following a severe lightning storm following euthanasia because of visual impairment. RESULTS: Severe corneal edema and hydrops were noted clinically oculus dexter. Indirect ophthalmoscopy revealed bilateral symmetrical raised hyporeflective peripapillary geographic lesions. Histopathologic evaluation revealed corneal edema in the right eye with normal corneal endothelium. Posterior segment evaluation revealed localized, pericentral choroidal lesions characterized by the presence of hemorrhage, early fibrosis, and minimal lymphoplasmacytic, neutrophilic, and histiocytic inflammation with spindle cell proliferation. The retinas overlying the choroidal lesions were necrotic and mostly absent. Peripheral to the focal lesion, the retina abruptly returned to normal architecture peripheral to a zone of apoptotic photoreceptors. Centrally, swollen axons extended into the optic disc. CONCLUSIONS: There have been few descriptions of ocular lesions in animals following suspected lightning injury. We believe these findings to be unique because of the type of thermal injury that may be characteristic of lightening injury. We do not know whether these lesions would have progressed over time.

A review of orbital and intracranial magnetic resonance imaging in 79 canine and 13 feline patients (2004-2010).

OBJECTIVE: To review the distribution of orbital and intracranial disease in canine and feline patients undergoing magnetic resonance imaging (MRI) following referral to a veterinary ophthalmologist and to correlate results of MRI with pathologic conditions including neoplasia, suspected optic neuritis (ON) and orbital cellulitis. Recognized and emerging imaging techniques are reviewed. PROCEDURE: Medical records of 79 canine and 13 feline patients were reviewed. RESULTS: Neoplasia was diagnosed in 53/92 (57.6%) of patients. The most prevalent types of neoplasia were carcinoma (16/53, 30.1%), sarcoma (11/53, 20.8%), lymphoma (8/53, 15.1%) and presumptive meningioma (9/53, 17.0%). Carcinomas and sarcomas were characterized by bony lysis and intracranial/sinonasal extension. Lymphoma was generally unilateral, less invasive and originated from the ventromedial orbit. Intracranial masses representing presumptive meningiomas frequently exhibited a 'dural tail' sign. Diagnosis of suspected ON was made in 13 of 92 (14.1%) patients. Results of MRI in patients with suspected ON included unilateral optic nerve hyperintensity (3/13, 23.0%), bilateral optic nerve hyperintensity (1/13, 7.7%) and optic chiasmal hyperintensity (3/13, 23.0%). Seven suspected ON patients demonstrated intracranial multifocal patchy contrast enhancement (7/13, 53.8%). Diagnosis of orbital cellulitis was made in 12/92 (13.0%) patients. CONCLUSIONS: Orbital neoplasia was the most common pathologic condition detected. Essential Roentgen characteristics are helpful when diagnosing pathologic processes and providing prognoses in cases of orbital or intracranial disease. Magnetic resonance imaging comprises an important diagnostic component in cases of suspected ON. Emerging contrast and functional MRI techniques as well as SI data may increase our ability to characterize disease processes.