Distinguishing Familial from Acquired Traits in the Retinal Blood Vessel Arborization.

ABSTRACT

Purpose: It has been suggested that retinal blood vessel arborization (RBVA) is unique to each individual. We examined this claim in a pedigree that included two pairs of monozygotic twins. Methods: Fundus photographs were taken of subjects belonging to this pedigree to compare the pattern of their RBVA. Pattern prevalence within the general population was estimated from a pre-existing clinical database. Results: The optic nerve head (ONH) RBVA disclosed the following patterns pattern A, outgrowth, with angle sizes ranging from 12° to 86°, toward the macula, made by the central retinal (CR) vein; pattern O, circular shape delimited by the CR artery on the nasal side and CR vein on the temporal (macula) side; and pattern Y, a double-Y shape (upright in the superior retina and upside down in the inferior retina) made by the four branches-inferior temporal and nasal and superior temporal and nasal-of the CR artery. The prevalence of patterns A, O, and Y was estimated at 11%, 2.8%, and 2.7%, respectively, from our pre-existing clinical database. Pattern A was the most frequently noted in our pedigree, with a prevalence of 26% to 29%, a value significantly larger (P < 0.05) than that measured in our sample of the general population. Of note, familial similarity is progressively lost as we move away from the ONH. Conclusions: Relatives appear to share similar ONH RBVA patterns, suggesting that the ONH RBVA could be genetically transmitted as a familial trait. Arrangement of the more peripheral retinal blood vessels would create individuality. Translational Relevance Our results suggest the existence of a specific, reproducible, and transmissible retinal identifier, a feature that could potentially be associated with the prevalence of a given disease process, thus offering the possibility of identifying an underlying retinopathy long before its clinical manifestation and consequently optimize its management.