Vision Science Commons^™

Evaluating Outer Segment Length As A Surrogate Measure Of Peak Foveal Cone Density, Melissa A. Wilk, Brandon M. Wilk, Christopher S. Langlo, Robert F. Cooper, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Adaptive optics (AO) imaging tools enable direct visualization of the cone photoreceptor mosaic, which facilitates quantitative measurements such as cone density. However, in many individuals, low image quality or excessive eye movements precludes making such measures. As foveal cone specialization is associated with both increased density and outer segment (OS) elongation, we sought to examine whether OS length could be used as a surrogate measure of foveal cone density. The retinas of 43 subjects (23 normal and 20 albinism; aged 6–67 years) were examined. Peak foveal cone density was measured using confocal adaptive optics scanning light ophthalmoscopy (AOSLO), and OS …

Multimodal Imaging Of Photoreceptor Structure In Choroideremia, Lynn W. Sun, Ryan D. Johnson, Vesper Williams, Phyllis Summerfelt, Alfredo Dubra, David V. Weinberg, Kimberly E. Stepien, Gerald A. Fishman, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Purpose

Choroideremia is a progressive X-linked recessive dystrophy, characterized by degeneration of the retinal pigment epithelium (RPE), choroid, choriocapillaris, and photoreceptors. We examined photoreceptor structure in a series of subjects with choroideremia with particular attention to areas bordering atrophic lesions.

Methods

Twelve males with clinically-diagnosed choroideremia and confirmed hemizygous mutations in the CHM gene were examined. High-resolution images of the retina were obtained using spectral domain optical coherence tomography (SD-OCT) and both confocal and non-confocal split-detector adaptive optics scanning light ophthalmoscope (AOSLO) techniques.

Results

Eleven CHM gene mutations (3 novel) were identified; three subjects had the same mutation and one …

Evaluating Descriptive Metrics Of The Human Cone Mosaic, Robert F. Cooper, Melissa A. Wilk, Sergey Tarima, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Purpose: To evaluate how metrics used to describe the cone mosaic change in response to simulated photoreceptor undersampling (i.e., cell loss or misidentification).

Methods: Using an adaptive optics ophthalmoscope, we acquired images of the cone mosaic from the center of fixation to 10° along the temporal, superior, inferior, and nasal meridians in 20 healthy subjects. Regions of interest (n = 1780) were extracted at regular intervals along each meridian. Cone mosaic geometry was assessed using a variety of metrics − density, density recovery profile distance (DRPD), nearest neighbor distance (NND), intercell distance (ICD), farthest neighbor distance (FND), percentage of …