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Dr Najjar    Raymond

Dr Najjar    Raymond

​MSc, PhD

Academic Appointments

  • Assistant Professor SingHealth Duke-NUS Ophthalmology & Visual Sciences Academic Clinical Programme

Profile

Dr Najjar obtained his PhD in Neuroscience from the University of Lyon, France and did his postdoctoral training at Stanford University, USA. He has a broad background in neuroscience, circadian rhythms, photobiology, and vision and sleep research, with specific expertise in key techniques in these fields. Dr Najjar’s research focused not only on understanding the non-visual impact of light on physiology and behaviour, but also on technical applications related to this matter. Within that framework, he contributed to the contemporary understanding of the non-image-forming impacts of light detected by the retina, and led studies in the Antarctic, Stanford and France, to successfully implement spectrally and temporally tuned light regimens, to alleviate chronobiological disorders and associated health decrements.

Dr Najjar’s current clinical projects revolve around the development and implementation of original strategies utilizing artificial intelligence and custom-built handheld devices for screening and diagnosing ocular and neurological diseases. His ongoing experimental work focuses on understanding the neurobiology behind the light-based control of myopia and the development of non-invasive photic countermeasures to the worldwide myopia epidemic.

Dr Najjar has received several merit awards and was invited to lecture in various international meetings. He has also assumed different teaching responsibilities in sleep and vision.

Education

  • PhD (2012)
  • MSc (2008)

Professional Appointments and Committee Memberships

  • Member, Scientific Review Panel,  Singapore Eye Research Institute (2020 – present)
  • Member, Faculty and Professional Development Committee, SingHealth Duke-NUS Ophthalmology & Visual Sciences Academic Clinical Programme (2018 – present)
  • Instructor, SingHealth Duke-NUS Ophthalmology and Visual Sciences Academic Clinical Programme, (2016 – 2020)
  • Senior Research Fellow, Singapore Eye Research Institute (2015 – 2018)
  • Postdoctoral Research Fellow, INSERM Unit 846, France (2015 – 2015)
  • Postdoctoral Research Fellow, Stanford University, USA (2012 – 2015)
  • Head Teaching Assistant, Biology Department, Stanford University, USA (2012 – 2013)
  • Lecturer, Claude Bernard University, Lyon 1, France (2010 – 2012)
  • Research Fellow, Claude Bernard University Lyon 1, France (2008 – 2012)

Awards

  • Postdoctoral Scholarship, French Society of Research in Sleep Medicine (SFRMS) (2014)
  • Research Merit Award, Society for Research on Biological Rhythms (SRBR) (2014)
  • Excellence Award, Sleep Research Society (SRS) (2014)
  • Research Merit Award, Society for Research on Biological Rhythms (SRBR) (2012)
  • Research Scholarship, French Federation of the Blind and Visually Impaired (FAF) (2011)
  • Short Oral Communication Prize, XII. Congress of the European Biological Rhythms Society (2011)
  • Poster Prize, XI. Congress of the European Biological Rhythms Society Congress (2009)
  • MENRT Competitive Research Scholarship with honours, Ranked: 1st/21, Ministère de l'Enseignement Supérieur et de la Recherche Français, Lyon, France (2008)
  • Honour Award, Lebanese University, Lebanon (2007)

Research Interests

  • Artificial intelligence for the detection of optic disc abnormalities
  • Handheld chromatic pupillometry for the detection of ocular and neurological diseases
  • Light therapy strategies for myopia prevention
  • The neurobiology behind the impact of light on refractive error development
  • Eye movement in ocular and neurodegenerative diseases
  • Light therapy strategies for chronobiological disorders
  • Visual and non-visual photoreception  

Publications

  1. ​Biousse V, Newman NJ, Najjar RP*, Vasseneix C, …, Milea D, for the BONSAI Group, Optic disc classification by deep learning versus expert neuro‐ophthalmologists. Annals of Neurology 2020. JIF : 9.8, Times Cited: NA * Equal contribution.

  2. Milea, D*, Najjar RP*, …, Wong TY*, Biousse V*, for the BONSAI Group, Artificial Intelligence to Detect Papilledema from Ocular Fundus Photographs. N Engl J Med. 2020; 382:1687-1695. JIF : 70.8, Times Cited: 13 * Equal contribution.

  3. Milea D, Singhal S, Najjar RP. Artificial intelligence for detection of optic disc abnormalities. Current Opinion in Neurology. 2020; 33, 1, 106-110. JIF: 4.6, Times Cited: 2.

  4. Teikari P, Najjar RP, Schmetterer L, Milea D. Embedded deep learning in ophthalmology: Making ophthalmic imaging smarter. Therapeutic Advances in Ophthalmology. 2019 11:2515841419827172. JIF: NA, Times Cited: 7.

  5. Chougule P, Najjar RP, Finkelstein M, Nagaendran K, Milea D. Light-Induced Pupillary Responses in Alzheimer’s Disease. 2019, Front. Neurol. 10, 360.  JIF: 3.5, Times Cited: 4.

  6. Rukmini AV, Chew M, Finkelstein M, Atalay E, Baskaran M, Nongpiur ME, Gooley JJ, Aung T, Milea D, Najjar RP. Effects of low and moderate refractive errors on chromatic pupillometry. Sci Reports. Mar 2019;7(1):10190 JIF: 4.3, Times Cited: 0.

  7. Calligaro H, Coutanson C, Najjar RP, Mazzaro N, Cooper HM, Haddjeri N, Felder-Schmittbuhl M-P, Dkhissi-Benyahya O. Rod photoreceptors are required for the light-induced phase shift of the retinal clock in mammals. PloS Biology. 2019, 1;17(3):e2006211. JIF: 9.2, Times Cited: 5.

  8. Prayag A, Najjar RP, Gronfier C. Melatonin suppression is exquisitely sensitive to light and primarily driven by melanopsin in humans. Journal of Pineal Research. 2019 May;66(4):e12562. JIF: 15.2, Times Cited: 27.

  9. Najjar RP, Reynier P, Caignard A, Procaccio V, Amati-Bonneau P, Mack H, Milea D. Retinal Neuronal Loss in Visually Asymptomatic Patients with Myoclonic Epilepsy with Ragged-Red Fibers (MERRF) Journal of Neuro-ophthalmology. 2019 Mar;39(1):18-22. JIF: 2.0, Times Cited: 2.

  10. Najjar RP, Sharma S, Atalay E, Rukmini AV, Sun C, Lock J-Z, Baskaran M, Perera SA, Husain R, Gooley JJ, Lamoureux E, Aung T, Milea D. Pupillary responses to full-field chromatic stimuli are reduced in patients with early-stage primary open-angle glaucoma. Ophthalmology. Sept 2018;125(9):1362-71. JIF: 8.2, Times Cited: 16.

  11. Rukmini AV, Najjar RP, Atalay E, Sharma S, Lock JZ, Baskaran M, Nongpiur M, Gooley JJ, Aung T, Milea D.  Pupillary responses to light are not affected by narrow irido-corneal angles. Sci Reports. Aug 2017;7(1):10190 JIF: 4.3, Times Cited: 3.

  12. Najjar RP, Sharma S, Drouet M, Leruez S, Baskaran M, Nongpiur ME, White O, Fielding J, Lamirel C, Milea D. Disrupted Eye Movements in Preperimetric Primary Open-Angle Glaucoma. Invest Ophthalmol Vis Sci. Apr 2017;58: 2430–37. JIF: 3.7, Times Cited: 10.

  13. Najjar RP, Zeitzer JM, 2017, Anatomy and Physiology of the Circadian System, Mitchell G. Miglis, in Sleep and Neurologic Disease, San Diego: Academic Press, 1, 29–53. Times Cited: 4.

  14. Sharma S, Ang M, Najjar RP, Sng C, Cheung CY, Rukmini AV, Schmetterer L, Milea D. Optical coherence tomography angiography in acute non-arteritic anterior ischaemic optic neuropathy. Br J Ophthalmol. Aug 2017;101: 1045–51; JIF: 3.8, Times Cited: 55.

  15. Hung SM, Milea D, Rukmini DV, Najjar RP, Tan JH, Viénot F, Dubail M, Tow SLC, Aung T, Gooley JJ, Hsieh P-J. Cerebral Neural Correlates of Melanopsin-based Photoreception in Humans, Neuroimage, Feb 2017;146: 763–69, JIF: 6.8, Times Cited: 15.

  16. McBean AL*, Najjar RP*, Schuchard RA, Hall CD, Wang C-A, Ku B, Zeitzer JM. Standing Balance and Spatiotemporal Aspects of Gait Are Impaired Upon Nocturnal Awakening in Healthy Late Middle-Aged and Older Adults. J Clin Sleep Med. Nov 2016; 12(11): 1477–86. JIF: 2.7, Times Cited: 6.

  17. Najjar RP, Teikari P, Cornut PL, Knoblauch K, Denis P, Cooper HM, Gronfier C. Heterochromatic Flicker Photometry for Objective Lens Density Quantification. Invest Ophthalmol Vis Sci. Mar 2016;57(3):1063-71. JIF: 3.7, Times Cited: 17.

  18. Najjar RP, Zeitzer JM. Temporal integration of light flashes by the human circadian system (Clinical Trial). J Clin Invest. Feb 2016;126(3):938-47. JIF: 14.1, Times Cited: 40.

  19. Najjar RP, Wolf L, Taillard J, Schlangen LJM, Salam A, Cajochen C, Gronfier C. Chronic artificial blue-enriched white light is an effective countermeasure to delayed circadian phase and neurobehavioral decrements. PLoS ONE, Jul 2014; 9:e102827. JIF: 4.24, Times Cited: 65.

  20. Najjar RP, Chiquet C, Teikari P, Cornut P-L, Claustrat B, Denis P, Cooper HM, Gronfier C. Aging of non-visual spectral sensitivity to light in humans: compensatory mechanisms? PLoS ONE, Jan 2014; 9:e85837. JIF: 4.2, Times Cited: 81.

Research Trials

  • ​Artificial intelligence for the detection of optic disc abnormalities (2019 – present)
  • The drive for refractive error control: interactions between light and optics (2019 – present)
  • Patterns of bright light for the prevention of myopia: a reverse-translational study (2018 – present)
  • Handheld chromatic pupillometry for the detection of ocular diseases (2015 – present)
  • The impact of light on ocular growth and metabolomics in a chicken model of myopia (2015 – 2019)
  • Development of a novel test (SCoPE: Singapore Colour Pupillometry Evaluation) for assessing photoreceptor dysfunction in patients with glaucoma using the pupillary light reflex (2014 – 2019)
  • Eye movements and pupillary responses in neuro-ophthalmology, quantified with head-mounted infrared oculography (2016 – 2018)
  • Blue-deprived light as a countermeasure to reduced sleepiness and increased falls in the elderly during nocturnal awakenings (2013 – 2016)
  • Ultrashort (msec) light exposure as a countermeasure to circadian desynchrony (2011 – 2015)
  • Blue-enriched white light to alleviate chronobiological disorders on the Concordia polar station (2009 – 2012)
  • The impact of aging on non-image forming response to light (2008 – 2012)
  • The development of a refined and affordable lens density measurement setup (2009 – 2013
  • Refined flicker photometry technique to measure ocular lens density (2008 – 2010)