Ocular phenotype of white Doberman pinschers.

Images taken from WDP (top row) and black standard-color Doberman pinscher (bottom row). An image of WDP head (A) demonstrates lightly-pigmented nose, lips, and eyelid margins compared with the same darkly pigmented structures in SDP (E). A close-up image of WDP eye (B) shows: non-pigmented leading edge of the nictitating membrane (NM), tan-colored iris base transitioning to blue at pupillary margin, and oval-shaped dyscoric pupil aperture. The black arrowheads (in B) demarcate a region of significant iridal stromal thinning that was noted on examination to transilluminate (not shown in image) with retroillumination by light reflected from the tapetum lucidum. SDP eye (F) shows: darkly pigmented margin of the nictitating membrane (NM) and brown iris with a round pupil aperture. WDP gonioscopy image (C), which allows visualization of structures lying within the iridocorneal angle (in images C & G, this region lies between the words “LIMBUS” and “IRIS”) shows fibers of the pectinate ligament (demarcated by black arrowheads) are of a similar tan-color to the iris base, whereas fibers of the pectinate ligament (demarcated by white arrowheads) are dark brown in SDP (G). WDP fundus image (D) shows yellow-colored tapetum lucidum (labeled “TAPETUM”) and significant hypopigmentation of the retinal pigment epithelium and choroid allowing visualization of the choroidal vasculature. SDP fundus image (H) shows green-colored tapetum lucidum (labeled “TAPETUM”) and heavy pigmentation of the non-tapetal fundus. For orientation purposes, images taken at higher magnification (B–D and F–H) have the superior (S) and inferior (I) globe positions labeled.