Radouil Tzekov

Radouil Tzekov, Ph.D.

Assoc Professor, Cop Dept of Pharmaceutical Science

Associate Professor, Ophthalmology

Courtesy Faculty, Medical Engineering

Volunteer Faculty, Dept. Pharmaceutical Sciences

Honorary Scientist III, Vision Research Program in Neurodegenerative Diseases

Contact Info 12901 Bruce B. Downs Blvd.
MDC 21
Tampa FL 33612

Academic Email: rtzekov@health.usf.edu

Academic Phone:(813) 974-1530


  • Certificate, Clinical Sciences, PERI, 2008
  • Postdoctoral fellowship, Visual function testing, Smith-Kettlewell Eye Research Institute, 2002
  • Postdoctoral fellowship, Visual function testing, Stanford University, 2001
  • Postdoctoral fellowship, Applied Vision Research, Retina Foundation of the SW, 2000
  • Postgraduate fellowship, Applied Vision Research, City University, 1997
  • PhD, Ophthalmology, Medical University, 1996
  • MD, Medicine, Medical Academy, 1984

Interdisciplinary and Emerging Signature Programs

  • Allergy, Immunology & Infectious Disease
  • Biomedical Engineering & Nanomedicine
  • Neurodegenerative Disease

Research Interests

  • Clinical visual electrophysiology and psychophysics; traumatic brain injury; retinal degenerative diseases; visual function in neuro-degenerative disease.


  • American Association for the Advancement of Science (AAAS) (Member, 2001 - Present)
  • New York Academy of Sciences (NYAS) (Member, 2001 - Present)
  • International Society for Clinical Electrophysiology of Vision (ISCEV) (Member, 1998 - Present)
  • Association for Research in Vision and Ophthalmology (ARVO) (Member, 1997 - Present)

Recent Publications

  • Das M, Tang X, Han JY, Mayilsamy K, Foran E, Biswal MR, Tzekov R, Mohapatra SS, Mohapatra S. CCL20-CCR6 axis modulated traumatic brain injury-induced visual pathologies. Journal of neuroinflammation. 16(1) : 115, 2019. http://www.ncbi.nlm.nih.gov/pubmed/31151410
  • Chen G, Tzekov R, Li W, Jiang F, Mao S, Tong Y. INCIDENCE OF ENDOPHTHALMITIS AFTER VITRECTOMY: A Systematic Review and Meta-analysis. Retina (Philadelphia, Pa.). , 2018. http://www.ncbi.nlm.nih.gov/pubmed/29370034
  • Frishman L, Sustar M, Kremers J, McAnany JJ, Sarossy M, Tzekov R, Viswanathan S. ISCEV extended protocol for the photopic negative response (PhNR) of the full-field electroretinogram. Documenta ophthalmologica. Advances in ophthalmology. , 2018. http://www.ncbi.nlm.nih.gov/pubmed/29855761
  • Lei L, Tzekov R, Li H, McDowell JH, Gao G, Smith WC, Tang S, Kaushal S. Inhibition or Stimulation of Autophagy Affects Early Formation of Lipofuscin-Like Autofluorescence in the Retinal Pigment Epithelium Cell. International journal of molecular sciences. 18(4) , 2017. http://www.ncbi.nlm.nih.gov/pubmed/28353645
  • Chen G, Tzekov R, Li W, Jiang F, Mao S, Tong Y. Subfoveal Choroidal Thickness in Central Serous Chorioretinopathy: A Meta-Analysis. PloS one. 12(1) : e0169152, 2017. http://www.ncbi.nlm.nih.gov/pubmed/28076442
  • Chen X, Tzekov R, Su M, Hong H, Min W, Han A, Li W. Correction: Auranofin Inhibits Retinal Pigment Epithelium Cell Survival through Reactive Oxygen Species-Dependent Epidermal Growth Factor Receptor/ Mitogen-Activated Protein Kinase Signaling Pathway. PloS one. 12(2) : e0172599, 2017. http://www.ncbi.nlm.nih.gov/pubmed/28222166
  • Chen G, Tzekov R, Li W, Jiang F, Mao S, Tong Y. Deep Anterior Lamellar Keratoplasty Versus Penetrating Keratoplasty: A Meta-Analysis of Randomized Controlled Trials. Cornea. 35(2) : 169-74, 2016. http://www.ncbi.nlm.nih.gov/pubmed/26583281
  • Tzekov R, Dawson C, Orlando M, Mouzon B, Reed J, Evans J, Crynen G, Mullan M, Crawford F. Sub-Chronic Neuropathological and Biochemical Changes in Mouse Visual System after Repetitive Mild Traumatic Brain Injury. PloS one. 11(4) : e0153608, 2016. http://www.ncbi.nlm.nih.gov/pubmed/27088355
  • Ortiz G, Odom JV, Passaglia CL, Tzekov RT. Efferent influences on the bioelectrical activity of the retina in primates. Documenta ophthalmologica. , 2016. http://www.ncbi.nlm.nih.gov/pubmed/28032236
  • Chen X, Tzekov R, Su M, Hong H, Min W, Han A, Li W. Auranofin Inhibits Retinal Pigment Epithelium Cell Survival through Reactive Oxygen Species-Dependent Epidermal Growth Factor Receptor/ Mitogen-Activated Protein Kinase Signaling Pathway. PloS one. 11(11) : e0166386, 2016. http://www.ncbi.nlm.nih.gov/pubmed/27846303
  • Tzekov R, Phifer J, Myers A, Mouzon B, Crawford F. Inflammatory changes in optic nerve after closed-head repeated traumatic brain injury: Preliminary study. Brain injury. 30(12) : 1428-1435, 2016. http://www.ncbi.nlm.nih.gov/pubmed/27834542
  • Chen G, Tzekov R, Li W, Jiang F, Mao S, Tong Y. SUBTHRESHOLD MICROPULSE DIODE LASER VERSUS CONVENTIONAL LASER PHOTOCOAGULATION FOR DIABETIC MACULAR EDEMA: A Meta-Analysis of Randomized Controlled Trials. Retina (Philadelphia, Pa.). , 2016. http://www.ncbi.nlm.nih.gov/pubmed/27096529
  • Tang X, Tzekov R, Passaglia CL. Retinal crosstalk in the mammalian visual system. Journal of Neurophysiology. : jn.01137.2015, 2016. http://www.ncbi.nlm.nih.gov/pubmed/26984426
  • Tzekov R, Richards D. The Glaucomas. Volume 2. Open Angle Glaucoma and Angle Closure Glaucoma. Editors: R. Sampaolesi, J.R, Sampaolesi, J. Zárate, (2014), 962 p., hardcover with DVD, ISBN: 978-3-642-35499-1, Springer. 2014, XLIX, 1062 illus., 685 illus. in color. Graefe's archive for clinical and experimental ophthalmology. 254(1) : 203-4, 2016. http://www.ncbi.nlm.nih.gov/pubmed/26728901
  • Chen G, Li, W; Tzekov R; Jiang F; Mao S; Tong Y. BEVACIZUMAB VERSUS RANIBIZUMAB FOR NEOVASCULAR AGE-RELATED MACULAR DEGENERATION: A Meta-analysis of Randomized Controlled Trials. Retina. 35(2) : 187-193, 2015.
  • McCulloch DL, Marmor MF, Brigell MG, Hamilton R, Holder GE, Tzekov R, Bach M. ISCEV Standard for full-field clinical electroretinography (2015 update). Documenta ophthalmologica. 130(1) : 1-12, 2015. http://www.ncbi.nlm.nih.gov/pubmed/25502644
  • Tzekov R. Full-field ERG in diabetic retinopathy: a screening tool? Graefe's archive for clinical and experimental ophthalmology. 253(7) : 987-988, 2015. http://www.ncbi.nlm.nih.gov/pubmed/25956999
  • Tzekov R, Madow B. Visual Electrodiagnostic Testing in Birdshot Chorioretinopathy. Journal of ophthalmology. 2015: 680215, 2015. http://www.ncbi.nlm.nih.gov/pubmed/26246903
  • McCulloch DL, Marmor MF, Brigell MG, Hamilton R, Holder GE, Tzekov R, Bach M. Erratum to: ISCEV Standard for full-field clinical electroretinography (2015 update). Documenta ophthalmologica. Advances in ophthalmology. 131(1) : 81-3, 2015. http://www.ncbi.nlm.nih.gov/pubmed/26059396
  • Ojo JO, Bachmeier C, Mouzon BC, Tzekov R, Mullan M, Davies H, Stewart MG, Crawford F. Ultrastructural Changes in the White and Gray Matter of Mice at Chronic Time Points After Repeated Concussive Head Injury. Journal of neuropathology and experimental neurology. 74(10) : 1012-35, 2015. http://www.ncbi.nlm.nih.gov/pubmed/26360375
  • Chen G, Tzekov R, Li W, Jiang F, Mao S, Tong Y. Pharmacogenetics of Complement Factor H Y402H Polymorphism and Treatment of Neovascular AMD with Anti-VEGF Agents: A Meta-Analysis. Scientific reports. 5: 14517, 2015. http://www.ncbi.nlm.nih.gov/pubmed/26411831
  • Zheng Q Ren Y Tzekov R Hua S Li M Pang J Qu J Li W. iTRAQ-Based Proteomic Analysis of Visual Cycle-Associated Proteins in RPE of rd12 Mice before and after RPE65 Gene Delivery. J Ophthalmol.. 2015: 918473, 2015.
  • Tzekov R, Mullan M. Vision function abnormalities in Alzheimer disease. Survey of ophthalmology. 59(4) : 414-33, 2014. http://www.ncbi.nlm.nih.gov/pubmed/24309127
  • Tzekov R, Quezada A, Gautier M, Biggins D, Frances C, Mouzon B, Jamison J, Mullan M, Crawford F. Repetitive Mild Traumatic Brain Injury Causes Optic Nerve and Retinal Damage in a Mouse Model. Journal of neuropathology and experimental neurology. 73(4) : 345-61, 2014. http://www.ncbi.nlm.nih.gov/pubmed/24607965
  • Chen G, Li W, Tzekov R, Jiang F, Mao S, Tong Y. Ranibizumab monotherapy or combined with laser versus laser monotherapy for diabetic macular edema: a meta-analysis of randomized controlled trials. PloS one. 9(12) : e115797, 2014. http://www.ncbi.nlm.nih.gov/pubmed/25541937
  • Byrne M, Tzekov R, Wang Y, Rodgers A, Cardia J, Ford G, Holton K, Pandarinathan L, Lapierre J, Stanney W, Bulock K, Shaw S, Libertine L, Fettes K, Khvorova A, Kaushal S, Pavco P. Novel Hydrophobically Modified Asymmetric RNAi Compounds (sd-rxRNA) Demonstrate Robust Efficacy in the Eye. Journal of ocular pharmacology and therapeutics : the official journal of the Association for Ocular Pharmacology and Therapeutics. 29(10) : 855-64, 2013. http://www.ncbi.nlm.nih.gov/pubmed/24180627
  • Lei L, Tzekov R, McDowell JH, Smith WC, Tang S, Kaushal S. Formation of lipofuscin-like material in the RPE Cell by different components of rod outer segments. Experimental eye research. 112(7) : 57-67, 2013. http://www.ncbi.nlm.nih.gov/pubmed/23603319
  • Lei L, Tzekov R, Tang S, Kaushal S. Accumulation and autofluorescence of phagocytized rod outer segment material in macrophages and microglial cells. Molecular vision. 18: 103-13, 2012. http://www.ncbi.nlm.nih.gov/pubmed/22275801
  • Zheng Q, Ren Y, Tzekov R, Zhang Y, Chen B, Hou J, Zhao C, Zhu J, Zhang Y, Dai X, Ma S, Li J, Pang J, Qu J, Li W. Differential Proteomics and Functional Research following Gene Therapy in a Mouse Model of Leber Congenital Amaurosis. PloS one. 7(8) : e44855, 2012. http://www.ncbi.nlm.nih.gov/pubmed/22953002
  • Meklenburg J, Clancy EA, Tzekov R. Signal processing techniques for oscillatory potential extraction in the electroretinogram: automated highpass cutoff frequency estimation. Documenta ophthalmologica. Advances in ophthalmology. 125(2) : 101-11, 2012. http://www.ncbi.nlm.nih.gov/pubmed/22777656
  • Clemson CM, Tzekov R, Krebs M, Checchi JM, Bigelow C, Kaushal S. Therapeutic potential of valproic acid for retinitis pigmentosa. The British journal of ophthalmology. 95(1) : 89-93, 2011. http://www.ncbi.nlm.nih.gov/pubmed/20647559
  • Tzekov R, Stein L, Kaushal S. Protein misfolding and retinal degeneration. Cold Spring Harbor perspectives in biology. 3(11) : a007492, 2011. http://www.ncbi.nlm.nih.gov/pubmed/21825021
  • Kleinberg TT, Tzekov RT, Stein L, Ravi N, Kaushal S. Vitreous substitutes: a comprehensive review. Survey of ophthalmology. 56(4) : 300-23, 2011. http://www.ncbi.nlm.nih.gov/pubmed/21601902
  • Messias A, Zrenner E, Tzekov R, McGee D, Peters T, Wilhelm B, Baryluk A, Kubota R, Gekeler F. Single doses of all-trans-N-retinylacetamide slow down the ERG amplitude recovery after bleaching in rats. Documenta ophthalmologica. Advances in ophthalmology. 120(2) : 165-74, 2010. http://www.ncbi.nlm.nih.gov/pubmed/20012154
  • Akula JD, Hansen RM, Tzekov R, Favazza TL, Vyhovsky TC, Benador IY, Mocko JA, McGee D, Kubota R, Fulton AB. Visual cycle modulation in neurovascular retinopathy. Experimental eye research. 91(2) : 153-61, 2010. http://www.ncbi.nlm.nih.gov/pubmed/20430026
  • Tzekov R, Lin T, Zhang KM, Jackson B, Oyejide A, Orilla W, Kulkarni AD, Kuppermann BD, Wheeler L, Burke J. Ocular changes after photodynamic therapy. Investigative ophthalmology & visual science. 47(1) : 377-85, 2006. http://www.ncbi.nlm.nih.gov/pubmed/16384988
  • Tzekov R. Ocular toxicity due to chloroquine and hydroxychloroquine: electrophysiological and visual function correlates. Documenta ophthalmologica. Advances in ophthalmology. 110(1) : 111-20, 2005. http://www.ncbi.nlm.nih.gov/pubmed/16249962
  • Brigell M, Dong CJ, Rosolen S, Tzekov R. An overview of drug development with special emphasis on the role of visual electrophysiological testing. Documenta ophthalmologica. Advances in ophthalmology. 110(1) : 3-13, 2005. http://www.ncbi.nlm.nih.gov/pubmed/16249953
  • Tzekov RT, Serrato A, Marmor MF. ERG findings in patients using hydroxychloroquine. Documenta ophthalmologica. Advances in ophthalmology. 108(1) : 87-97, 2004. http://www.ncbi.nlm.nih.gov/pubmed/15104171
  • Tzekov RT, Gerth C, Werner JS. Senescence of human multifocal electroretinogram components: a localized approach. Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv für klinische und experimentelle Ophthalmologie. 242(7) : 549-60, 2004. http://www.ncbi.nlm.nih.gov/pubmed/15085352
  • Kulkarni AD, Kuppermann BD, Tzekov RT, Lin T, Burke JA. Vitreous surgery in pigmented rabbits using the new, noncontact wide-field viewing system. American journal of ophthalmology. 137(1) : 212-3; author reply 213, 2004. http://www.ncbi.nlm.nih.gov/pubmed/14700687
  • Penrose PJ, Tzekov RT, Sutter EE, Fu AD, Allen AW, Fung WE, Oxford KW. Multifocal electroretinography evaluation for early detection of retinal dysfunction in patients taking hydroxychloroquine. Retina (Philadelphia, Pa.). 23(4) : 503-12, 2003. http://www.ncbi.nlm.nih.gov/pubmed/12972762
  • Tzekov RT , Locke KG, Hood DC, Birch DG. Cone and rod ERG phototransduction parameters in retinitis pigmentosa. Investigative ophthalmology & visual science. 44(9) : 3993-4000, 2003. http://www.ncbi.nlm.nih.gov/pubmed/12939320
  • Marmor MF, Serrato A, Tzekov R. Comparison of conventional ERG parameters and high-intensity A-wave analysis in a clinical setting. Documenta ophthalmologica. Advances in ophthalmology. 106(3) : 281-7, 2003. http://www.ncbi.nlm.nih.gov/pubmed/12737506
  • Serrato A, Tzekov R, Marmor MF. The lens-coating agent and the electroretinogram. Documenta ophthalmologica. Advances in ophthalmology. 106(3) : 225-30, 2003. http://www.ncbi.nlm.nih.gov/pubmed/12737498
  • Birch DG, Hood DC, Locke KG, Hoffman DR, Tzekov RT. Quantitative electroretinogram measures of phototransduction in cone and rod photoreceptors: normal aging, progression with disease, and test-retest variability. Archives of ophthalmology. 120(8) : 1045-51, 2002. http://www.ncbi.nlm.nih.gov/pubmed/12149058
  • Pham RT, Tzekov RT, Biesman BS, Marmor MF. Retinal evaluation after 810 nm Dioderm laser removal of eyelashes. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 28(9) : 836-40, 2002. http://www.ncbi.nlm.nih.gov/pubmed/12269879
  • Mata NL Tzekov RT Liu X Weng J Birch DG Travis G. Delayed dark-adaptation and lipofuscin accumulation in abcr+/- mice: implications for involvement of ABCR in age-related macular degeneration Invest Ophthalmol Vis Sci. 42(8) : 1685-1690, 2001.
  • Tzekov RT, Liu Y, Sohocki MM, Zack DJ, Daiger SP, Heckenlively JR, Birch DG. Autosomal dominant retinal degeneration and bone loss in patients with a 12-bp deletion in the CRX gene. Investigative ophthalmology & visual science. 42(6) : 1319-27, 2001. http://www.ncbi.nlm.nih.gov/pubmed/11328746
  • Tzekov RT, Sohocki MM, Daiger SP, Birch DG. Visual phenotype in patients with Arg41Gln and ala196+1bp mutations in the CRX gene. Ophthalmic genetics. 21(2) : 89-99, 2000. http://www.ncbi.nlm.nih.gov/pubmed/10916183
  • Weng J, Mata NL, Azarian SM, Tzekov RT, Birch DG, Travis GH. Insights into the function of Rim protein in photoreceptors and etiology of Stargardt's disease from the phenotype in abcr knockout mice. Cell. 98(1) : 13-23, 1999. http://www.ncbi.nlm.nih.gov/pubmed/10412977
  • Tzekov R, Arden GB. The electroretinogram in diabetic retinopathy. Survey of ophthalmology. 44(1) : 53-60, 1999. http://www.ncbi.nlm.nih.gov/pubmed/10466588
  • Arden G, Wolf J, Berninger T, Hogg CR, Tzekov R, Holder GE. S-cone ERGs elicited by a simple technique in normals and in tritanopes. Vision research. 39(3) : 641-50, 1999. http://www.ncbi.nlm.nih.gov/pubmed/10341991
  • Yankov E, Nakova A, Tzekov R. Spectral sensitivity of the visual system as revealed by evoked potentials in normal and anomalous trichomats. Acta physiologica et pharmacologica Bulgarica. 24(4) : 91-100, 1999. http://www.ncbi.nlm.nih.gov/pubmed/11098295