Multimodal Advanced Imaging and Long-Term Follow-Up of Peters Anomaly Type 2, With Presumed Lenticular Material in the Cornea, in a Scottish Terrier.

Abstract

Objective: To describe the clinical findings and advanced in vivo imaging features of a bilateral case of peters anomaly type 2 in a dog.

Animal studied: An 8-week-old male scottish terrier presented with bilateral central corneal leukomas and was followed clinically for 3 years.

Procedures: Complete ophthalmic examination was performed at multiple time points. Ocular ultrasonography, optical coherence tomography (OCT), and in vivo confocal microscopy (IVCM) were performed under sedation at 37 weeks of age to further evaluate anterior segment structures obscured by corneal opacity.

Results: Both eyes displayed central leukoma and iridocorneal adhesions consistent with anterior segment dysgenesis. The left eye had a keratolenticular adhesion, progressive cataract formation, microphthalmia, goniodysgenesis, and secondary glaucoma. A defect involving the posterior corneal stroma, descemet's membrane, and endothelium, with extension of the keratolenticular adhesion into the mid-stroma was demonstrated in detail with OCT. Endothelial cell loss, endothelial polymegathism and pleomorphism, stromal fibrosis, vascularization, and multiple highly refractile structures within the mid-stroma consistent with presumed lenticular material were visualized with IVCM. The right eye had a mild central corneal leukoma and incipient cataract, with spontaneous separation of the keratolenticular adhesion and no further clinically significant abnormalities.

Conclusions: This report documents peters anomaly type 2 in a dog using OCT and IVCM. Advanced imaging allowed detailed evaluation of anterior segment abnormalities that were not fully appreciable on clinical examination and revealed presumed lenticular remnants within the corneal stroma, a finding not previously described in veterinary medicine.