Yuhua Zhang


Yuhua Zhang, Ph.D.


Office Address:
150 N. Orange Grove Rm. 244, Pasadena, CA 91103

Affiliations

Associate Professor, Ophthalmology
Research Interests

Retina is the only portion of the central nervous system (CNS) that can be studied non-invasively through the unique optical window of the eye. In principle, the neural, glial, and vascular tissue in the retina of a living human subject can be observed at the histologic-level. Retinal imaging has thus been serving as a major diagnostic modality for retinal disease, and playing a critical role for clinical management of systemic and CNS diseases. The research of Advanced Ophthalmic Imaging Laboratory (AOIL) focuses on developing advanced ophthalmoscopy, with an emphasis on adaptive optics (AO) imaging, to facilitate in vivo study of chorioretinal disease and systemic disease at the cellular and sub-cellular level.

In the AOIL, we have developed state-of-art high resolution retinal imaging instruments that integrate adaptive optics (AO), scanning laser ophthalmoscopy (SLO), and optical coherence tomography (OCT). SLO and OCT represent two modern revolutionary imaging mechanisms that reveal the 3-D retinal structure in the living eye. AO is a technique that can compensate the eye’s optical defects thereby enabling SLO and OCT with (near) diffraction limited resolution. The AOIL AO-SLO-OCT has imaged cone and rod photoreceptors in the living human retina. Another imaging instrument that was recently built in the AOIL is a high speed adaptive optics near-confocal scanning ophthalmoscope (AONCO). This device can image the living human retina with a frame rate up to 800 Hz, representing the fastest en face imaging instrument for the living human eye in the world to date. High speed high resolution imaging enables direct and accurate measurement of the movement of individual erythrocytes and leukocytes flowing in human retinal capillaries without using any exogenous contrast agents, opening a new horizon for studying high-order retinal hemodynamics that reflect the mechanical property of retina capillaries. A new generation of technology is being developed toward to in vivo imaging of the retina at the molecular level. We are looking forward to gaining the ability to unveil the molecular signatures of retinal health by objective characterization of the compounds in the retina and its supportive retinal pigment epithelium (RPE), which are associated with retinal metabolism and implicated in the process of aging and in the pathogenesis of various retinal diseases.

The long term goal of the AOIL is to develop technological advancements that improve understanding and treatment of diseases that blind the human eye and affect central nervous system. With research grants from the National Institute of Health, the National Sciences Foundation, the EyeSight Foundation of Alabama, the International Retinal Research Foundation, and the Keck Foundation, the AOIL AO-SLO-OCT has been employed for in vivo investigation of age-related macular degeneration, a leading causing of central vision loss in more than 10 million older Americans. Advance AO enhanced retinal imaging is providing important avenues to study a variety of common medical and neurologic conditions such as hypertension, diabetes, and Alzheimer’s disease.

Publications

A selected list of publications:

1. Zhang Y, Poonja S, and Roorda A, MEMS based Adaptive Optics Scanning Laser OphthalmoscopyOpt. Lett.. 2006; 31, 1268-1270. PMID: 16642081
2. Sincich LC, Zhang Y, Tiruveedhula P, Horton1 JC, and Roorda A. Resolving Single Cone Inputs to Visual Receptive FieldsNat Neurosci. 2009; 12(8):967-9. PMID: 19561602
3. Meadway A, Girkin CA, Zhang YA dual-modal retinal imaging system with adaptive opticsOpt. Express , 21(24):29792-29807 (2013). PMID: 24514529
4. Meadway A, Wang X, Curcio CA, Zhang YThe microstructure of subretinal drusenoid deposits revealed by adaptive optics imagingOpt. Express, 2014; 5 (3):713-727. PMID: 24688808
5. Zhang Y, Wang X, Rivero EB, Clark ME, Witherspoon CD, Spaide RF, Girkin CA, Owsley C, and Curcio CA, Photoreceptor perturbation around subretinal drusenoid deposits revealed by adaptive optics scanning laser ophthalmoscopyAm J Ophthalmol. 2014; 158(3):584-96.e1. PMID: 24907433
6. Zhang T, Gordara P, Rivero EB, Griffin RL, Wang X, Curcio CA, and Zhang YVariability in human cone topography assessed by adaptive optics scanning laser ophthalmoscopyAm J Ophthalmol. 2015; 160(2):290-300. PMID: 25935100
7. Yu Y, Zhang T, Meadway A, Wang X, Zhang YHigh speed adaptive optics for human eye. Opt. Express. 2015; 23(18):23035-52. PMID: 26368408
8. Lu J, Gu B, Wang X, Zhang Y, Adaptive Optics Parallel Confocal Scanning Ophthalmoscopy. Opt. Lett.. 2016, 41(16): 3852-3855. PMID 27519106
9. Litts KM, Wang X, Clark ME, Owsley C, Freund KB, Curcio CA, Zhang YExploring photoreceptor reflectivity through multimodal imaging of outer retinal tubulation in advanced age-related macular degenerationRetina. 2017 May; 37(5):978-988. doi: 10.1097/IAE.0000000000001265. PMID: 27584549; PMCID: PMC5332477
10. Zhang Y, Wang X, Gordara P, Zhang T, Witherspoon CD, Spaide RF, Owsley C, Curcio CA, Dynamism of dot subretinal drusenoid deposits in age-related macular degeneration demonstrated with adaptive optics imagingRetina. 2017 Feb 10. doi: 10.1097/IAE.0000000000001504. PMID: 28196054
11. Xu X, Liu X, Wang X, Owsley C, Curcio CA, Zhang YRetinal pigment epithelium degeneration associated with subretinal drusenoid deposits in age-related macular degenerationAm J Ophthalmol. 2017 Mar;175:87-98. PMID 27986424
12. Gu B, Lu J, Wang X, Tam J, Twa MD, Girkin CA, and Zhang YNoninvasive in vivo characterization of erythrocyte motion in human retinal capillaries using high-speed adaptive optics near-confocal imagingOpt. Express 9, 3653-3677 (2018). https://doi.org/10.1364/BOE.9.003653, PMID: 30338146 PMCID: PMC6191635
13. Lu J, Gu B, Wang X, Zhang YHigh-speed adaptive optics ophthalmoscopy with anamorphic point spread functionOpt. Express. 2018, 26(11): 14356-14374. https://doi.org/10.1364/OE.26.014356, PMID: 29877476 PMCID: PMC6005671
14. Zhang Y, Wang X, Sadda SR, Clark ME, Witherspoon CD, Spaide RF, Owsley C, Curcio CA. Lifecycles of individual subretinal drusenoid deposits and evolution of outer retinal atrophy in age-related macular degenerationOphthalmology Retina. 2020;4(3):274-283.PMC7065956
15. Zhang Y, Wang X, Clark ME, Curcio CA, Owsley C. Imaging of Age-Related Macular Degeneration by Adaptive Optics Scanning Laser Ophthalmoscopy in Eyes With Aged Lenses or Intraocular LensesTransl Vis Sci Technol. 2020; 9(8):41. Published 2020 Jul 29. PMID: 32855887, PMCID: PMC7422803