Microphthalmia, aphakia and agenesis of the optic chiasm and tract in a wild fox squirrel (Sciurusniger).

We describe gross and histopathological features of multiple ocular and neuro-ophthalmic abnormalities in a fox squirrel (Sciurus niger). Ophthalmic findings included severe bilateral microphthalmos, with the right eye more affected than the left. Histopathology confirmed severe microphthalmia, aphakia, disorganized retinal tissue and small optic nerves, as well as agenesis of the optic chiasm and optic tract. This combination of neuro-ophthalmic abnormalities has not been previously described in wild animals.

Congenital anterior staphyloma associated with Peters' anomaly and aphakia in a Holstein calf.

A Holstein calf was born with a large protruding right eye and a central corneal opacity. Enucleation was the first choice of treatment. The calf had a good prognosis and was raised for milking purposes. Macroscopically, the enucleated eye was characterized by the protruded cornea, adherence of the iris to the central posterior cornea and aphakia. Microscopically, central corneal thickening and a defect in the endothelium and Descemet's membrane were observed. These data suggest that this represents a case of unilateral anterior segment dysgenesis consistent with congenital corneal staphyloma with Peters' anomaly and aphakia. Neither a mutation of the WFDC1 gene in multiple ocular defects nor any other identifiable cause for ocular anomalies was detected.

Congenital ocular and adnexal disorders in reptiles.

Ocular and adnexal congenital disorders are those that manifest at birth and could involve single or multiple tissues. Several abnormalities have been reported in literature affecting reptilian ocular and/or adnexal tissues. The objectives of this review are: (i) review those disorders previously reported in reptile literature; (ii) present new cases; (iii) provide a basic classification of them according to the moment of occurrence and (iv) indirectly, encourage the clinician dealing with these cases to go further in their diagnosis. The authors consider that categorizing ocular and adnexal congenital disorders could help the clinician to deal with them. The categorization of these disorders required an intense review of cases previously reported in literature and allows the authors suspect that some of them could not have been accurately diagnosed according to the definitions of the anomalies and/or not accurately described. The authors consider that ocular and adnexal congenital disorders could have been underestimated in reptiles and further studies could be helpful to promote the description of new disorders and to expand the knowledge about those previously reported. The review will first describe abnormalities reported during organogenesis (describing possible etiopathogenesis, cases reported, an approach to their diagnosis and recommended therapeutic options).Then a mention of the ocular disorders occurring after organogenesis is made. These disorders are divided when possible in those affecting all or most part of the globe and those affecting only specific tissues (surface ectoderm, neurocrest and mesenchyma and neuroectoderm).

Bilateral microphthalmia and aphakia associated with multiple eye abnormalities in a free-living European red deer calf (Cervus elaphus).

A free-living European red deer calf (Cervus elaphus) was euthanized due to bilateral microphthalmia. Lens was missing, replaced by proliferating squamous epithelial cells; hyperplastic squamous cells, sebaceous and mucinous glands were observed within the cornea with the characteristics of inclusion cyst. Findings were consistent with congenital microphthalmia/aphakia, with multiple eye abnormalities.

[Aphakia in a German Holstein calf]. / Aphakie bei einem Kalb der Rasse Deutsche Holsteins.

Aphakia and further malformations of both eyes were diagnosed in a female German Holstein calf. Besides aphakia of the left eye, the calf exhibited microphthalmia, glaucoma and a hypoplastic uveoscleral tissue. Additional findings in the right eye were buphthalmus and glaucoma. Instead of aphakia, pathohistological and investigations revealed a very small (microphakia) and luxated lens. Neither the clinical nor the pathological examination revealed further malformations of other organs. A BVD infection could be excluded as cause for the ocular malformations observed. A deficiency or excess of vitamine A was unlikely because this would have also applied to all other calves born at the same time on the farm. An inbreeding coefficient of 3.168% for the malformed calf and the exclusion of environmental causes for these malformations of the eyes let us suppose a hereditary problem.

Use of biometry and keratometry for determining optimal power for intraocular lens implants in dogs.

Axial length and corneal curvature were determined by use of A-scan ultrasonography and keratometry on both eyes of dogs of various breeds, sizes, and ages. Mean axial length was 20.43 +/- 1.48 mm; axial length was not related to age or sex, but was significantly greater (P = 0.047) in dogs of larger breeds. Mean corneal curvature was 39.94 +/- 2.61 diopters. Dogs of large breeds had significantly (P less than 0.001) flatter corneas. Mild, roughly symmetric astigmatism was detected in a majority of dogs. Use of mean values in a theoretic artificial intraocular lens power equation suggests that aphakic dogs require an implant of approximately 40 diopters to achieve emmetropia.