In Vivo Imaging of Corneal Endothelial Dystrophy in Boston Terriers: A Spontaneous, Canine Model for Fuchs' Endothelial Corneal Dystrophy

Abstract

PurposeBoston Terriers (BTs) have a greater prevalence of corneal endothelial dystrophy (CED), in comparison to other canine breeds. Similar to Fuchs' endothelial corneal dystrophy (FECD), this condition is characterized by endothelial cell degeneration with secondary corneal edema. This study assessed corneal morphology using in vivo confocal microscopy (IVCM) and Fourier-domain optical coherence tomography (FD-OCT) in BTs with and without CED.MethodsThe corneas of 16 BTs with CED and 15 unaffected, age-matched BTs underwent clinical evaluation and were imaged using IVCM and FD-OCT. A two-sample t-test or Mann-Whitney rank sum test were used to statistically compare parameters between groups. Data are presented as mean ± SD or median (range).ResultsMean age did not significantly differ between affected and unaffected dogs at 10.0 ± 2.0 and 10.6 ± 2.4 years, respectively (P = 0.437). Females (69%) were overrepresented among the CED-affected dogs. In CED patients, IVCM demonstrated endothelial polymegathism and pleomorphism. Corneal endothelial density was significantly less (P < 0.001) in dogs with CED (1026 ± 260 cells/mm2) versus age-matched controls (2297 ± 372 cells/mm2). Fourier-domain OCT demonstrated a significant increase (P < 0.01) in central corneal and endothelium-Descemet's complex thickness in dogs with CED versus age-matched controls at 1019 (485–1550) or 536 (464–650) μm and 32 (22–56) or 25 (15–34) μm, respectively.ConclusionsCorneal endothelial dystrophy in BTs is a bilateral, adult-onset condition that shares many similarities with FECD. Thus, CED could serve as a spontaneous disease model to study the pathogenesis of and develop novel treatments for FECD.

Superficial keratectomy as a treatment for non‐healing corneal ulceration associated with primary corneal endothelial degeneration

“…This point of corneal decompensation is reported to occur once endothelial cell counts are below 500‐800 cells/mm 2 in dogs . This point of decompensation may vary between cases as affected dogs are reported to have cell counts between 499‐2750 cells/mm 2 . Corneal endothelial cell densities can decrease because of a heritable genetic predisposition (CEDys), age‐related cell loss (CEDeg), or following surgical trauma (eg following cataract extraction surgery) .…”

“…CEDeg occurs in a wide variety of breeds and is associated with advanced age . CEDys is recognized in certain breeds such as Chihuahua, Boston terrier, and Dachshund where the age of onset is comparatively young, and the disease is considered heritable . When the instrumentation required to directly visualize corneal endothelial cells (confocal microscopy, specular microscopy) is not available, PCED is diagnosed with exclusion of diseases that cause secondary endothelial dysfunction including keratitis, glaucoma, or uveitis .…”

Effects of 5% sodium chloride ophthalmic ointment on thickness and morphology of the normal canine cornea

“…With advancements in technology, use of alternative modalities such as FD‐OCT are increasing in veterinary ophthalmology particularly for patients with corneal disease . In FD‐OCT, corneal thickness measurements are obtained using noninvasive, high‐resolution, cross‐sectional imaging of the cornea but this technique is slower to perform, requires greater expertise, and requires sedation for some canine patients.…”

Biomechanical relationships between the corneal endothelium and Descemet's membrane

“…While there are several animal models for FCED, including transgenic mice 153,154 and Boston terriers 173 , the biophysical attributes of DM and endothelium in these species remains uncharacterized. Given the challenges in observing the early development of FCED, in vitro cell models of the disease could help us fill these knowledge gaps.…”