Choroidal imaging features of KIF11-associated retinopathy: expanding the ocular phenotype.

backgroundTo characterize foveal architecture and choroidal morphology in KIF11-associated retinopathy using multimodal imaging, and to assess for pachychoroid-like features using quantitative choroidal thickness (CT) and choroidal vascularity index (CVI).

methodsIn this retrospective case series, multimodal imaging from two patients (four eyes) with genetically confirmed KIF11-associated retinopathy was analyzed. En-face optical coherence tomography (OCT) images of the macular and inferior peripheral retina were spatially aligned to widefield fundus images to enable fovea-centered spatial mapping. The choroid was segmented and binarized on OCT B-scans to derive quantitative macular CT and CVI measurements, and CT measurements in the mid-peripheral and peripheral retina. Pixel-based measurements were converted to microns using image-scale calibration. Measurements from both eyes were compared with a healthy control.

resultsBoth KIF11 patients demonstrated bilateral fovea plana, inferior chorioretinal dysplasia, and inferotemporal vascular dragging. Sub-macular CT showed altered spatial patterning relative to a reference control, with lower overall thickness and increased inter-eye variability. In control eyes, CT demonstrated fovea-centered distribution, whereas patient eyes showed disrupted spatial organization, most pronounced in P1 (OD: R² = 0.41; OS: R² = 0.52). Sub-macular CVI ranged from 58 to 65% and demonstrated increased variability in spatial patterning, with reduced quadratic model fit in KIF11 patient eyes (P1 OS: R² = 0.09). Inferior retinal regions showed diffusely increased CT, with focal maximal thickening immediately temporal to chorioretinal dysplasia, forming a sharp, reproducible transition zone. Beyond this, CT progressively decreased with increasing temporal distance from the atrophic border. The ratio of CT at the transition point relative to distal temporal measurements consistently exceeded 1.0.

conclusionsKIF11-associated retinopathy may demonstrate regional pachychoroid-like choroidal phenotype with spatially patterned dysplasia, most pronounced adjacent to areas of chorioretinal atrophy. These preliminary findings may implicate choroidal structural and vascular abnormalities as potential contributors to disease pathogenesis and expand the recognized ocular phenotype of KIF11-related retinal disease. Given the exploratory nature and limited sample size of this study, further studies, on a larger sample size, are warranted to further characterize choroidal morphology in KIF11-associated retinopathy. CLINICAL TRIAL NUMBER: Not applicable.