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Tiarnán Keenan, M.D., Ph.D.

Stadtman Tenure-Track Investigator

Contact Information:


10 Center Drive
Building 10, Room 10D45
Bethesda, Maryland 20892


Tiarnán Keenan is staff clinician in retinal disease in the Division of Epidemiology and Clinical Applications at the National Eye Institute (NEI). He received his undergraduate and medical degrees as a scholar at the University of Oxford. Funded by the UK National Institute of Health Research, he completed integrated academic-clinical training in ophthalmology and biomedical research predominantly at the Manchester Royal Eye Hospital and the Oxford Eye Hospital. He was awarded a Ph.D. at the University of Manchester for biochemical analyses of human macular tissue in relation to age-related macular degeneration (AMD). As a Fulbright scholar at the Moran Eye Center (University of Utah), he conducted post-graduate research into the genetics and mechanisms of AMD. He was admitted as a fellow (FRCOphth) into the UK Royal College of Ophthalmologists and, as a Bayer Global Ophthalmology Awards Program awardee, completed fellowship training in medical retinal disease at NEI.

He sits on the program committee for ARVO, is section editor for Eye, acts as grant reviewer for Fight For Sight (UK), and contributes to the Ryan Initiative for Macular Research.

Current research

Dr. Keenan’s research is focused on adult retinal disease, particularly age-related macular degeneration (AMD), the leading cause of legal blindness in all developed countries. This includes research into the diagnosis, treatment, and prevention of AMD, together with disease mechanism discovery.

His experience and research span multiple disciplines. In genetics, his research into genotype-phenotype relationships has suggested that AMD consists of multiple partially distinct disease entities. His biochemical and anatomical research has provided insights into how AMD arises at the molecular level. In the clinical arena, his research involves examining how AMD behaves over time and how its progression may be slowed. For example, he has completed a landmark study of geographic atrophy, the dry form of advanced AMD, and is currently undertaking a detailed study showing how particular dietary patterns can slow down AMD progression. In the field of artificial intelligence, he is harnessing the power of deep learning to perform automated diagnosis, classification, and risk prediction of AMD from simple retinal photographs.

Overall, the goal of his research is to understand why and how AMD comes about, so that new treatments can be designed that target the underlying disease more effectively.

Selected publications

Christakis PG, Agrón E, Klein ML, Clemons TE, Campbell JP, Ferris FL, Chew EY, Keenan TD, for the Age-Related Eye Diseases Study Research Group. Incidence of macular atrophy following untreated neovascular age-related macular degeneration: Age-Related Eye Disease Study Report 40. Ophthalmology (in press)

Keenan TD, Vitale S, Agrón E, Domalpally A, Antoszyk AN, Elman MJ, Clemons TE, Chew EY; Age-Related Eye Disease Study 2 Research Group. Visual Acuity Outcomes after Anti-Vascular Endothelial Growth Factor Treatment for Neovascular Age-Related Macular Degeneration: Age-Related Eye Disease Study 2 Report Number 19. Ophthalmol Retina. 2019 Jun 11. pii: S2468-6530(19)30073-9. doi: 10.1016/j.oret.2019.06.001. [Epub ahead of print]

Keenan TD, Wiley HE, Agrón E, Aronow ME, Christen WG, Clemons TE, Chew EY; Age-Related Eye Disease Study and Age-Related Eye Disease Study 2 Research Groups. The Association of Aspirin Use with Age-Related Macular Degeneration Progression in the Age-Related Eye Disease Studies: Age-Related Eye Disease Study 2 Report No. 20. Ophthalmology. 2019;126(12):1647-1656

Keenan TD, Dharssi S, Peng Y, Chen Q, Agrón E, Wong WT, Lu Z, Chew EY. A Deep Learning Approach for Automated Detection of Geographic Atrophy from Color Fundus Photographs. Ophthalmology. 2019;126(11):1533-1540

Keenan TD, Klein B, Agrón E, Chew EY, Cukras CA, Wong WT. Choroidal thickness and vascularity vary with disease severity and subretinal drusenoid deposit presence in non-advanced age-related macular degeneration. Retina. 2019 [Epub ahead of print]

Keenan TD, Agrón E, Domalpally A, Clemons TE, van Asten F, Wong WT, Danis RG, Sadda S, Rosenfeld PJ, Klein ML, Ratnapriya R, Swaroop A, Ferris FL 3rd, Chew EY; AREDS2 Research Group. Progression of Geographic Atrophy in Age-related Macular Degeneration: AREDS2 Report Number 16. Ophthalmology. 2018;125(12):1913-1928

Keenan TD, Toso M, Pappas C, Nichols L, Bishop PN, Hageman GS. Assessment of Proteins Associated With Complement Activation and Inflammation in Maculae of Human Donors Homozygous Risk at Chromosome 1 CFH-to-F13B. Invest Ophthalmol Vis Sci. 2015;56(8):4870-9

Keenan TD, Pickford CE, Holley RJ, Clark SJ, Lin W, Dowsey AW, Merry CL, Day AJ, Bishop PN. Age-dependent changes in heparan sulfate in human Bruch's membrane: implications for age-related macular degeneration. Invest Ophthalmol Vis Sci. 2014;55(8):5370-9

Keenan TD, Goldacre R, Goldacre MJ. Associations between age-related macular degeneration, Alzheimer disease, and dementia: record linkage study of hospital admissions. JAMA Ophthalmol. 2014;132(1):63-8

Last updated: April 18, 2024