. Inherited retinal degenerations affect approximately 1 in 1,500 individuals in the US, and given the extreme genotypic and phenotypic heterogeneity, the prospect of treating these devastating diseases is a formidable task. Nevertheless, trials examining novel therapeutic strategies are underway. An important key to success in the early phases of such trials is selection of patients with reasonable therapeutic potential ? for example, a retina with no remaining cone photoreceptors would not be the best target for a gene therapy approach aiming to restore cone function. In addition, current clinical tools for assessing retinal structure are relatively insensitive and macroscopic, limiting the ability to monitor therapeutic response in these patients. As such, there is a need for sensitive, noninvasive, high-resolution techniques to assess photoreceptor structure. The Advanced Ocular Imaging Program has made significant advances on this front ? advancing innovative adaptive-optics (AO) imaging instrumentation for probing photoreceptor inner- and outer-segment structure with single-cell resolution, creating software for extracting quantitative metrics of the photoreceptor mosaic, and developing tools for making accurate and reliable measurements of photoreceptor structure from optical coherence tomography (OCT) images of the retina. From a clinical perspective, these tools are in relative infancy, thus we propose to help accelerate their translation through the following specific aims: 1) Define the variability in the remnant cone population in human patients with achromatopsia (ACHM), 2) Characterize the integrity of the photoreceptor mosaic in individuals with L/M opsin mutations, and 3) Elucidate the rod/cone contribution to the photoreceptor layers in OCT images. The specific diseases being studied have a wide range of rod/cone involvement, are current or emerging targets for treatment efforts, and continue to represent a major strength of our multidisciplinary research team. This work is expected to have a significant positive impact, with the high-resolution genotype-phenotype relationships identified here providing a better understanding of the therapeutic potential in patients with inherited retinal degenerations as well as producing validated tools for assessing photoreceptor structure in emerging clinical trials. Our proposal addresses two emerging needs identified in the NEI Publication ?Vision Research: Needs, Gaps, and Opportunities?: ?Characterize the macula and perifoveal regions of the retina to better understand the predilection of the macula for disease,? and ?Translate high-resolution retinal imaging technologies, like adaptive optics, into cost-effective and easy-to-use platforms for routine clinical use.?

Public Health Relevance

. The rapid growth in therapeutic trials for inherited retinal degenerations brings with it a need for sensitive, noninvasive, high-resolution imaging tools for assessing photoreceptor structure. While in vivo imaging has seen dramatic growth in recent years, limitations concerning interpretation prevent realization of their full translational potential. By developing novel analysis tools and using multiple imaging modalities, this proposal aims to characterize photoreceptor structure in patients with a variety of inherited retinal diseases. These studies will advance our understanding of fundamental disease mechanisms, facilitate defining therapeutic potential on an individualized basis, and provide a foundation for the development of anatomical outcome measures for therapeutic trials.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY017607-13
Application #
9994928
Study Section
Diseases and Pathophysiology of the Visual System Study Section (DPVS)
Program Officer
Shen, Grace L
Project Start
2008-08-15
Project End
2021-08-31
Budget Start
2020-09-01
Budget End
2021-08-31
Support Year
13
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Medical College of Wisconsin
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
937639060
City
Milwaukee
State
WI
Country
United States
Zip Code
53226
Patterson, Emily J; Kalitzeos, Angelos; Kasilian, Melissa et al. (2018) Residual Cone Structure in Patients With X-Linked Cone Opsin Mutations. Invest Ophthalmol Vis Sci 59:4238-4248
Georgiou, Michalis; Kalitzeos, Angelos; Patterson, Emily J et al. (2018) Adaptive optics imaging of inherited retinal diseases. Br J Ophthalmol 102:1028-1035
Davidson, Benjamin; Kalitzeos, Angelos; Carroll, Joseph et al. (2018) Automatic Cone Photoreceptor Localisation in Healthy and Stargardt Afflicted Retinas Using Deep Learning. Sci Rep 8:7911
Warren, Clinton C; Young, Jonathon B; Goldberg, Mara R et al. (2018) Findings in Persistent Retinopathy of Prematurity. Ophthalmic Surg Lasers Imaging Retina 49:497-503
Strampe, Margaret R; Huckenpahler, Alison L; Higgins, Brian P et al. (2018) Intraobserver Repeatability and Interobserver Reproducibility of Ellipsoid Zone Measurements in Retinitis Pigmentosa. Transl Vis Sci Technol 7:13
Hirji, Nashila; Georgiou, Michalis; Kalitzeos, Angelos et al. (2018) Longitudinal Assessment of Retinal Structure in Achromatopsia Patients With Long-Term Follow-up. Invest Ophthalmol Vis Sci 59:5735-5744
Salmon, Alexander E; Cooper, Robert F; Langlo, Christopher S et al. (2017) An Automated Reference Frame Selection (ARFS) Algorithm for Cone Imaging with Adaptive Optics Scanning Light Ophthalmoscopy. Transl Vis Sci Technol 6:9
Wilk, Melissa A; Wilk, Brandon M; Langlo, Christopher S et al. (2017) Evaluating outer segment length as a surrogate measure of peak foveal cone density. Vision Res 130:57-66
Litts, Katie M; Cooper, Robert F; Duncan, Jacque L et al. (2017) Photoreceptor-Based Biomarkers in AOSLO Retinal Imaging. Invest Ophthalmol Vis Sci 58:BIO255-BIO267
Wilk, Melissa A; Dubis, Adam M; Cooper, Robert F et al. (2017) Assessing the spatial relationship between fixation and foveal specializations. Vision Res 132:53-61

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