OBJECTIVES: To describe the efficacy of porcine small intestinal submucosa in corneal reconstructive surgery in dogs and cats through a large retrospective study.METHODS: A retrospective evaluation of 106 cases of surgical reconstruction of the cornea with small intestinal submucosa seen between May 2005 and January 2010 was carried out. The corneal defect was filled by microsurgical grafting of porcine small intestinal submucosa. The biomaterial implant was deposited in one or several layers depending on the depth of the defect. The animals were examined 3, 6 and 12 weeks after surgery.RESULTS: Vision was preserved in all eyes at three months post-surgery. In 74 cases (69·8%) the corneal scar was either transparent or discrete, whilst in 32 cases (30·2%) a mild or marked scar was observed. Minor complications occurred in 9 cases (8·5%) with partial integration of the small intestinal submucosa and in 24 cases (22·6%) with faint or mild corneal pigmentation, without impairing vision. In cases followed over a period longer than three months, major complications occurred in five dogs resulting in vision impairment because of pronounced pigmentation.CLINICAL SIGNIFICANCE: Corneal grafting of porcine small intestinal submucosa is an effective method for corneal reconstruction resulting in corneal transparency in most cases. It is an excellent alternative to conventional conjunctival grafts.

Bovine pericardium graft offers a promising option for surgical reconstruction of the cornea following keratectomy for the management of corneal ulcers and sequestra.

Use of a porcine urinary bladder acellular matrix appears to be effective in the surgical management of deep corneal ulcers and feline corneal sequestra.

In both humans and dogs, the primary risk factor for glaucoma is high intraocular pressure (IOP), which may be caused by iridocorneal angle (ICA) abnormalities. Oxidative stress has also been implicated in retinal ganglion cell damage associated with glaucoma. A suspected inherited form of glaucoma was recently identified in Eurasier dogs (EDs), a breed for which pedigrees are readily available. Because of difficulties in assessing ICA morphology in dogs with advanced glaucoma, we selected a cohort of apparently healthy dogsfor the investigation of ICA morphological status, IOP and plasma concentrations of oxidative stress biomarkers. We aimed to establish correlations between these factors, to identify predictive markers of glaucoma in this dog breed. A cohort of 28 subjects, volunteered for inclusion by their owners, was selected by veterinary surgeons. These dogs were assigned to four groups: young males, young females (1–3 years old), adult males and adult females (4–8 years old). Ocular examination included ophthalmoscopy, tonometry, gonioscopy, biometry and ultrasound biomicroscopy (UBM), and the evaluation of oxidative stress biomarkers consisting of measurements of plasma glutathione peroxidase (GP) activity and taurine and metabolic precursor (methionine and cysteine) concentrations in plasma. The prevalence of pectinate ligament abnormalities was significantly higher in adult EDs than in young dogs. Moreover, in adult females, high IOP was significantly correlated with a short axial globe length, and a particularly large distance between Schwalbe's line and the anterior lens capsule. GP activity levels were significantly lower in EDs than in a randomized control group of dogs, and plasma taurine concentrations were higher. Hence, ICA abnormalities were associated with weaker antioxidant defenses in EDs, potentially counteracted by higher plasma taurine concentrations. This study suggests that EDs may constitute an appropriate canine model for the development of glaucoma. This cohort will be used as a sentinel for longitudinal monitoring.

Mydriasis induced by topical 0.5% tropicamide results in modification of the anterior segment which may influence the drainage of aqueous humor.