Even though the fovea occupies only 0.02% of the total area of the retina, 40% of primary visual cortex is devoted to processing visual signals that arise there. Thus, it is not surprising that diseases affecting the structure or function of the foea are especially devastating to visually guided behaviors. Yet fundamental gaps remain in our concepts of how the fovea develops, how foveal structure is disrupted during aging and disease, and how the fovea interacts with more central visual system structures to determine key features of visual function. The overall goal of this proposal is to address these issues using a novel combination of noninvasive imaging technologies including functional magnetic resonance imaging (fMRI), optical coherence tomography (OCT) and adaptive optics scanning light ophthalmoscopy (AOSLO). Albinism is an inherited disorder characterized by absent or reduced melanin pigment in the eye, and often in the skin and hair, with all types manifesting the visual features of foveal hypoplasia, macular translucency, photosensitivity, refractive errors, nystagmus, impaired stereopsis, altered retinostriate decussation, and reduced visual acuity. These specific retinal and cortical features of albinism make it a perfect experiment of nature to examine the knowledge gaps listed above. We propose to do this through the following specific aims: 1) Define the spectrum of foveal morphology in albinism and assess the relationship between pit morphology and retinal melanin, 2) Identify retinal factors contributing t visual deficits in albinism, and 3) Determine the cortical correlates of visual deficits in albinis. The results of this project will provide a more comprehensive understanding of the interrelationships linking melanin, retinal morphology, and cortical organization. This will offer insight into the basis for vision deficits in albinism, which may alter current phenotype/genotype classifications. This work is expected to have a significant positive impact by providing a new framework for understanding and targeting clinical therapies to alleviate the behavioral manifestations of albinism, and by producing sensitive tools for assessing therapeutic outcomes. This proposal directly addresses emerging needs outlined in the National Eye Institute's August 2012 Publication, Vision Research: Needs, Gaps, & Opportunities, and incorporates specific program objectives of the NEI Retinal Diseases Panel: (1) Characterize the macula and perifoveal regions of the retina to better understand the predilection of the macula for disease. (2) Improve understanding of the roles of neuronal activity and molecular events in the formation of central visual circuits during development. (3) Continue to develop and apply noninvasive technologies such as fMRI, OCT, adaptive optics, and confocal imaging to better understand retinal function and changes in disease states.

Public Health Relevance

The human fovea underlies the majority of our visual function (including color vision and high spatial acuity vision) and is negatively affected in a number of retinal diseases such as albinism and Age-Related Macular Degeneration (AMD). The work proposed in this grant tackles fundamental issues in neurobiology, including testing models of foveal development, understanding how the fovea and visual cortex are disrupted in albinism, and modeling how the fovea interacts with the thalamus and cortex to determine key features and limitations of human vision. These studies will accelerate the application of our non-invasive imaging approach to define therapeutic potential in patients with albinism on an individualized basis and provide anatomical outcome measures for use in emerging therapeutic trials.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY024969-03
Application #
9185323
Study Section
Diseases and Pathophysiology of the Visual System Study Section (DPVS)
Program Officer
Flanders, Martha C
Project Start
2014-12-02
Project End
2018-11-30
Budget Start
2016-12-01
Budget End
2017-11-30
Support Year
3
Fiscal Year
2017
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
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
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
Strampe, Margaret R; Wirostko, William J; Carroll, Joseph (2017) A case of congenital retinal macrovessel in an otherwise normal eye. Am J Ophthalmol Case Rep 8:18-21
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
Linderman, Rachel; Salmon, Alexander E; Strampe, Margaret et al. (2017) Assessing the Accuracy of Foveal Avascular Zone Measurements Using Optical Coherence Tomography Angiography: Segmentation and Scaling. Transl Vis Sci Technol 6:16
Wilk, Melissa A; Huckenpahler, Alison L; Collery, Ross F et al. (2017) The Effect of Retinal Melanin on Optical Coherence Tomography Images. Transl Vis Sci Technol 6:8
Cunefare, David; Cooper, Robert F; Higgins, Brian et al. (2016) Automatic detection of cone photoreceptors in split detector adaptive optics scanning light ophthalmoscope images. Biomed Opt Express 7:2036-50
Cooper, Robert F; Sulai, Yusufu N; Dubis, Adam M et al. (2016) Effects of Intraframe Distortion on Measures of Cone Mosaic Geometry from Adaptive Optics Scanning Light Ophthalmoscopy. Transl Vis Sci Technol 5:10
McCafferty, Brandon K; Wilk, Melissa A; McAllister, John T et al. (2015) Clinical Insights Into Foveal Morphology in Albinism. J Pediatr Ophthalmol Strabismus 52:167-72

Showing the most recent 10 out of 11 publications