Treatment of corneal ulceration and bullous keratopathy using a nictitating membrane flap in two horses.

OBJECTIVE: The aim of this study was to describe placement of a nictitating membrane flap as a treatment for corneal ulceration and bullous keratopathy in two horses. ANIMALS STUDIED: A 13-year-old American Saddlebred mare presented for severe corneal edema, superficial stromal ulceration, and a central bulla of the left eye. A 4-year-old Trakhener stallion also presented with a large axial bulla of the left eye with concurrent severe corneal edema and a deep stromal ulcer. PROCEDURE: A complete ophthalmic examination was performed. Samples were obtained for corneal cytology, and both horses were started on aggressive medical therapy. Both underwent general anesthesia for placement of a nictitating membrane flap and a subpalpebral lavage system (SPLS). RESULTS: Corneal cytology for each horse revealed a mixed bacterial population. Moderate Pseudomonas aeruginosa was cultured from the mare, while Aspergillus species and a few Enterococcus gallinarum were cultured from the stallion. The bullae in both horses resolved at 3 and 4 weeks and vision returned in the affected eye 4.5 and 3 months postoperatively at the last follow-up, respectively. CONCLUSION: Aggressive medical management with concurrent placement of a nictitating membrane flap is effective to treat bullous keratopathy in two horses. The described treatments could be used to treat horses that develop severe or progressive bullous corneal lesions.

Aqueous angiography in pre-glaucomatous and glaucomatous ADAMTS10-mutant canine eyes: A pilot study.

OBJECTIVE: To evaluate intravenous scleral and intracameral aqueous angiography in normotensive (n = 4) and hypertensive glaucomatous (n = 6) ADAMTS10-mutant canine eyes. ANIMALS STUDIED: Ten ADAMTS10-mutant dogs were used in this study. PROCEDURES: Dogs were sedated and one eye from each dog underwent scleral angiography following intravenous injection of 0.25% indocyanine green (ICG). After a 24-h recovery period, the same eye underwent aqueous angiography via intracameral administration of ICG. Imaging of identical scleral sectors from the same eye was performed using a Heidelberg Spectralis® Confocal Scanning Laser Ophthalmoscope. Intrascleral vessel depth and lumen diameters were measured using Heidelberg Spectralis® optical coherence tomography and computer software. RESULTS: Scleral angiography permitted visualization of vascular components associated with conventional aqueous humor outflow pathways with an average time from injection to fluorescence of 35.8 ± 10.6 s (mean ± SD). Two normotensive eyes (2/10;20%) demonstrated turbulent dye movement, while 4 hypertensive eyes (4/10;40%) exhibited laminar flow. Aqueous angiography demonstrated dye fluorescence within the post-trabecular conventional aqueous humor outflow pathways in all 10 eyes at 34.3 ± 11.0 s post-injection. Sectoral and dynamic outflow patterns were observed primarily within the superotemporal sector in nine eyes (9/10; 90%). Seven eyes (7/10; 70%) demonstrated pulsatile dye movement and five eyes (5/10; 50%) exhibited laminar flow. The degree of laminar movement of dye was greatest in hypertensive eyes. Vessel lumen diameters measured 133.85 ± 28.36 µm and 161.18 ± 6.02 µm in hypertensive and normotensive eyes, respectively. CONCLUSIONS: Aqueous angiography allowed for visualization of fluorescent dye in the superotemporal sclera. Laminar flow and smaller lumen vessels were observed mainly in hypertensive eyes.

Localized alopecia and suppression of hypothalamic-pituitary-adrenal (HPA) axis in dogs following treatment with difluprednate 0.05% ophthalmic emulsion (Durezol®).

BACKGROUND: Despite the common use of topical ophthalmic corticosteroids in dogs, detailed reports on systemic and dermatologic adverse effects are limited. RESULTS: Nine purpose-bred research Beagles were treated with difluprednate 0.05% ophthalmic emulsion in one or both eyes 2-3 times daily. Some difluprednate treated dogs developed mild to severe alopecia of the periocular region, face, and distal pinna (5/9). The median duration of treatment prior to onset of dermatologic signs for difluprednate treated dogs was 550 days (453-1160 days). Diagnostic testing included complete blood count (CBC) and serum biochemistry, adrenocorticotropic hormone (ACTH) stimulation testing combined with endogenous ACTH measurement, and skin biopsy. The CBC and chemistry were within normal limits for all dogs. There were varying degrees of suppression of the hypothalamic-pituitary-adrenocortical (HPA) axis with difluprednate treatment. Dogs with the most profound alopecic changes had less pronounced HPA axis suppression compared to dogs with no integumentary changes. Skin biopsies demonstrated follicular atrophy and follicular keratosis. When topical difluprednate was reduced to unilateral therapy, the hair regrew on the untreated side of the face. In addition to the affected research dogs, a 7-year old female spayed Chihuahua that was being treated as a clinical patient with long-term difluprednate 0.05% ophthalmic emulsion developed generalized hypotrichosis on the head and body and a potbellied appearance. ACTH stimulation testing revealed suppression of the HPA axis with a mild increase in serum alkaline phosphatase (ALP) activity and a urine specific gravity of 1.016. The combination of clinical signs and laboratory abnormalities was supportive of iatrogenic hyperadrenocorticism. CONCLUSIONS: In dogs long-term use of difluprednate ophthalmic emulsion results in HPA axis suppression and in some cases iatrogenic hyperadrenocorticism. A novel pattern of localized alopecia is suspected to be related to dermal absorption and local action due to superior potency and penetration compared to other commonly utilized ophthalmic corticosteroids.

Transconjunctival excision of an orbital conjunctival cyst using computer-assisted 3-D surgical planning in a dog.

Investigation of exophthalmos and blood-colored discharge from the left ventral punctum in a dog was consistent with a conjunctival cyst in the orbit. 3-D prints of the cyst and surrounding facial bones identified a successful transconjunctival approach without an orbitotomy and patency of the left lacrimal duct was reestablished.

Aqueous Angiography in Normal Canine Eyes.

Purpose: To conduct aqueous angiography (AA) using a clinically applicable technique in normal dogs and to compare findings to intravenous scleral angiography (SA). Methods: We examined 10 canine cadaver eyes and 12 eyes from live normal dogs. A gravity-fed trocar system delivered 2% sodium fluorescein and 0.25% indocyanine green (ICG) intracamerally (IC) in cadaver eyes. In vivo AA was subsequently performed in one eye of each of the 12 dogs via IC bolus of ICG under sedation. The same 12 dogs received SA via intravenous ICG (mean ± SD) 10.7 ± 3.3 days later. Identical scleral sectors were imaged using a Spectralis confocal scanning laser ophthalmoscope. Results: The gravity-fed trocar system permitted visualization of the conventional aqueous humor outflow (CAHO) pathways in cadaver eyes, but not in vivo. Fluorescence was observed superonasally in four of the 10 cadaver eyes within 24.0 ± 3.6 seconds. A single IC bolus of ICG showed CAHO pathways in vivo, demonstrating sectoral outflow patterns in the superotemporal sclera in 10 of the 12 eyes within 35.0 ± 4.3 seconds; four of the 12 eyes exhibited pulsatile aqueous movement. SA exhibited fluorescence patterns comparable to AA with weak pulsatile aqueous humor outflow. Conclusions: Angiography (AA or SA) in dogs permits visualization of the CAHO pathway and its vascular components in vivo. AA may be a more useful modality to assess aqueous humor outflow. Translational Relevance: Intracameral AA has potential utility for evaluating CAHO in vivo in dogs, an important animal model species.

Use of 3-dimensional printing in surgical exploration of a nasolacrimal duct obstruction in a dog.

A 1.5-year-old spayed female English setter dog was presented because of mucopurulent discharge emanating from the left medial canthal region of 8-months duration despite medical management and repeated nasolacrimal flushing. Dacryocystorhinography demonstrated obstruction at the level of the lacrimal sac. Three-dimensional (3-D) modelling software was used to print a 3-D construct of the facial bones and a drill guide over the region of obstruction. The 3-D prints were sterilized and utilized during surgery to facilitate access to the lacrimal sac. The left lacrimal sac was identified, explored, and flushed. Patency was re-established, and the dog was asymptomatic 7 months after surgery.

Utilisation d'une imprimante 3-dimensions dans l'exploration chirurgicale d'une obstruction du canal naso-lacrymal chez un chien. Une chienne stérilisée de race Setter anglais âgée de 1,5 ans fut présentée à cause d'un écoulement muco-purulent provenant de la région du canthus médial gauche qui dure depuis 8 mois malgré une gestion médicale et des drainages naso-lacrymaux répétés. Une dacryocystorhinographie a démontré l'obstruction au niveau du sac lacrymal. Un logiciel de modélisation en trois dimensions (3-D) fut utilisé pour imprimer un construit en 3-D des os faciaux et un guide-mèche de la région au-dessus de l'obstruction. Les impressions 3-D furent stérilisées et utilisées durant la chirurgie afin de faciliter l'accès au sac lacrymal. Le sac lacrymal gauche fut identifié, exploré et drainé. La perméabilité fut ré-établie, et le chien était asymptomatique 7 mois après la chirurgie.(Traduit par Dr Serge Messier).