Gislin Dagnelie, Ph.D.
Associate Professor of Ophthalmology
Phone Number: (410) 614-4822
Email Address: gdagnelie@jhmi.edu
Dr. Dagnelie was trained at State University in Groningen, Netherlands, and the University of Amsterdam in the Netherlands. His research interests include the relationship between the physiology of early vision motion detection, motion perception, and related visual capabilities. Dr. Dagnelie has been a member of the Wilmer faculty since 1988 and is currently Assistant Professor in the Department of Ophthalmology and Executive director of Clinical Low Vision Services.
Education:
B.S. Physics, State University, Groningen, Netherlands, 1974
M.S. Experimental/Medical Physics, State University, Groningen, Netherlands, 1977
PhD. Experimental/Medical Physics, University of Amsterdam, Netherlands, 1986
Professional Experience:
2001-present Associate Professor of Ophthalmology, Johns Hopkins University School of Medicine
1998-present Director of Low Vision Education, JHU Dept of Ophthalmology Lions Vision Research and Rehabilitation Ctr.
1990-2001 Assistant Professor of Ophthalmology, Johns Hopkins University School of Medicine
1994-1998 Director of clinical low vision services, JHU Dept of Ophthalmology Lions Vision Research and Rehabilitation Ctr.
1988-1990 Instructor of Ophthalmology, the Johns Hopkins University School of Medicine; co-investigator research project "Studies of Retinitis Pigmentosa", NIH grant EY01791 (P.I. Robert W. Massof, Ph.D.).
1986-1988 Postdoctoral work: Psychophysics of foveal sensitivity in Retinitis Pigmentosa (Advisor: Robert W. Massof, Ph.D.).
1986-1987 Postdoctoral work: Liaison towards several NASA institutions for development of the Low Vision Enhancement System (Advisor: Robert W. Massof, Ph.D.).
Awards:
The 1988 Binkhorst Prize for ophthalmological research in the Netherlands, awarded for dissertation research
The 2001 William Weiss Award for research in retinitis pigmentosa
Research Projects Ongoing or Completed During the Last 3 Years:
Ongoing:
“Studies of simulated prosthetic vision” (Aug 2000 – Jul 2005)
This study aims at supporting the development of prosthetic vision through simulations in normally sighted and visually impaired volunteer subjects. Testing involves the presentation of “prosthetic” phosphene images through a view of a small number (16-256) of dots 1º-2º in diameter, with varying Gaussian intensity profiles. The images are presented to subjects using a head-mounted video display system, which provides built-in eye tracking. Three modes of presentation in the reading and face recognition testing are used. The first mode enables the subject to use the pixel raster as a movable window onto the stationary background by moving the computer mouse. In the second mode of testing, movement of the raster is controlled with the eye-tracking system. The raster is stabilized on the retina while allowing movement across the stationary image. The third mode allows raster movement through eye tracking while the underlying image can be moved with the computer mouse. The testing provides information regarding resolution and dot sizes required for pixelized vision and regarding the feedback of head and eye movement required for maximized visual information transfer. Indirectly the study also provides knowledge of spatiotemporal visual processing and visual perception under conditions of spatial sampling. Findings will be used to derive effective methods for intraoperative testing and to optimize further research with future visual prosthesis wearers.
(Study sponsored by the National Eye Institute)
“Clinical evaluation of the ASRÔ device for the treatment of vision loss from retinitis pigmentosa” (Nov ‘04- Oct.’06)
This study is an FDA-approved phase I/II clinical trial of the Optobionics ASR chip in retinitis pigmentosa patients. Eight patients were implanted in December 2004 and February 2005, and are being followed for any changes to their vision that may be attributed to the presence of the ASR implant in one eye. The hypothesis driving the study is that the small current emanating from the ASR will trigger the release of various nerve protective agents, which will in turn improve the health of the remaining photoreceptors, leading to better vision in the implanted eye.
(Study sponsored by Optobionics Corporation)
“Novel vision tests: data analysis from a RP lutein trial” (Apr 2003 – Mar 2005)
This study uses analysis of the stability and consistency of PC based test results to assess the validity of the PC-based tests. In addition, the study examines data collected from RP patients taking lutein supplements and additional control subjects (some with RP and others normally-sighted) to determine the time course and potential effects of lutein on vision in RP patients. Comparisons of PC-based outcome measures with lab-based outcome measures are made to evaluate the reproducibility of the PC-based methods. The PC based tests are weekly, self-administered tests on each participant’s home PC. Findings of the study may be useful in the development of an inexpensive, effective method of monitoring vision between clinic visits in future clinical trials.
(Study sponsored by the National Eye Institute)
“Trainable visual aids for object detection and identification” (Oct 2002 – Sep 2005)
This study aims to combine software and hardware in the development of a customized, versatile, self-contained, portable system to aid visually impaired users in interactions with others and the environment. The study is designed to demonstrate and evaluate the ability of the hardware system to perform several visual tasks including: rapid detection and localization of visual environmental cues, rapid detection of people and their actions (including an estimation of facial expressions, gaze and other social/emotional indicators), and rapid recognition and identification of familiar people and objects. Visually impaired users of the portable prototype visual aid will provide feedback. Software development is based on a wearable computer vision system developed and tested in collaboration with the Center for Artificial Vision Research at Korea University and Computer Engineering departments of Johns Hopkins University and Massachusetts Institute of Technology.(Study sponsored by the National Science Foundation)
“Enhanced retinal prosthetics through infrared imaging” (May 2003 – Apr 2005)
The purpose of this study is to determine the advantages of using infrared and fused infrared/visible wavelength imaging, relative to the use of visible wavelength input only, while conducting a variety of human performance tasks. To estimate the benefits of the heat-mediated IR imagery to low vision patients and retinal implant recipients, this study compares the results from vision-based tasks completed by normally sighted subjects wearing a head mounted simulator with those normally sighted subjects using conventional video simulated images and the results of initial retinal prosthesis patients. Findings of the study will aid in the development of a fused Infrared/Visual front end to a retinal implant system.
(Study sponsored by an SBIR from the National Eye Institute to Advance Medical Electronics)
Completed:
"R21 project: Effects of lutein in retinitis pigmentosa" July 2000 – April 2003)
The major goal of this project is to study the short-term effects of lutein supplementation on visual function in retinitis pigmentosa patients.
“Development of quantitative means to assess visual function in patients with end-stage retinal degenerations, and identifying optimal strategies to convey pixelized imagery,” subprogram of AMD Center Grant (Jan 2000 - Jun 2004).
The long-term goals of this project are to: 1) continue the development of a battery of accurate vision tests for individuals with advanced vision loss, and 2) use these vision measures in developing optimal conditions for future prosthetic vision.
Representative publications:
Hayes J, Yin VT, Piyathaisere D, Weiland JD, Humayun MS, Dagnelie G. Visually guided performance using simulated prosthetic vision. Artificial Organs, 27, 1016-1028 (2003).
Thompson RW, Barnett GD, Humayun MS, Dagnelie G. Facial recognition using simulated prosthetic vision. Invest Ophthalmol Visual Sci, 44, 5035-5042 (2003).
Semba RD, Dagnelie G. Are lutein and zeaxanthin conditionally essential nutrients for eye health? Med Hypoth, 61, 465-72 (2003).
Humayun MS, Weiland JD, Fujii GY, Greenberg R, Williamson R, Little J, Mech B, Cimmarusti V, Van Boemel G, Dagnelie G, de Juan E. Visual perception in a blind subject with a chronic microelectronic retinal prosthesis. Vision Res 43, 2573-2581 (2003).
Margalit E, Maia M, Weiland JD, Greenberg RJ, Fujii GY, Torres G, Piyathaisere DV, O'Hearn TM, Liu W, Dagnelie G, Scribner DA, de Juan Jr. E, Humayun MS. Retinal Prosthesis for the blind. Survey of Ophthalmology 47, 335?356 (2002).
Dagnelie G, Zorge IS, McDonald TM. Lutein improves visual function in some retinal degeneration patients—a pilot study via Internet. Optometry 71, 147-64 (2000).
Weiland JD, Humayun MS, Dagnelie G, de Juan Jr, E. Understanding the origin of visual percepts elicited by electrical stimulation of the human retina. Graefe's Archive Ophthalmol 237, 1007-13 (1999).
Weisz JM, Humayun MS, de Juan Jr E, del Cerro M, Sunness JS, Dagnelie G, Soylu M, Rizzo L, Nussenblatt RB. Allogenic fetal retinal pigment epithelial cell transplant in a patient with geographic atrophy. Retina 19, 540-5 (1999).
Humayun MS, de Juan Jr E, Weiland JD, Dagnelie S, Katona S, Greenberg R, Suzuki S. Pattern electrical stimulation of the human retina. Vision Research 39, 2569-76 (1999).
Dagnelie G, Vogelstein JV. Phosphene Mapping Procedures for Prosthetic Vision. In: Vision Science and its Applications, OSA Technical Digest (Optical Society of America, Washington DC, 1999), pp. 294-7.
Dagnelie G (1998). Testing vision beyond legal blindness: early beginnings of a visual function test battery. Vision Science and its Applications, Technical Digest 98-1 (Optical Soc Am), 54-57.
Dagnelie G, Humayun H, Greenberg R, de Juan Jr E. The physiological connection: stimulating the human and amphibian retina. Proc IEEE Intl Conf on Neural Networks 1997, 2012-2017.
Dagnelie G, Sunness JS, de Juan Jr E, Humayun MS. A test battery to monitor visual function in blind volunteers for retinal cell transplantation. Invest Ophthalmol Vis Sci 38, S333 (1997).
Dagnelie G. [Restoring sight on the threshold of the 21st century] (Dutch). Klinische Fysica 1996-1, 10-13 (1996).
Massof RW, Alibhai S, Deremeik JT, Glasner NM, Baker FH, DeRose JL, Dagnelie G. Low vision rehabilitation: documentation of patient evaluation and management. J Vision Rehab 10(2), 3-31 (1996).
Dagnelie G, Massof RW. Towards an artificial eye. IEEE Spectrum 33(5), 20-29 (1996).
Turano K, Dagnelie G, Herdman SJ. Visual stabilization of posture in age-related macular degeneration. Invest Ophthalmol Vis Sci 37, 1483 - 1491 (1996).
Humayun M, Propst R, de Juan Jr E, Dagnelie G, Greenberg R, Phillips H and Hickingbotham D (1996). Local electrical stimulation of the human retina: a step towards an intraocular visual prosthesis. Arch Ophthalmol. 114, 40-46.
Massof RW, Dagnelie G, Deremeik JT, DeRose JL, Alibhai S, Glasner NM. Low vision rehabilitation in the US health care system. J Vision Rehab 9(3), 3-31 (1995).
McCloskey M, Rapp B, Yantis S, Rubin G, Bacon WF, Dagnelie G, Gordon B, Aliminosa D, Boatman DF, Badecker W, Johnson DN, Tusa RJ, Palmer E. (1995). A developmental deficit in localizing objects from vision. Psychol Sci 6, 112 - 117 (1995).
Sunness JS, Schuchard RA, Shen N, Rubin GS, Dagnelie G and Haselwood D. Landmark driven fundus perimetry using the scanning laser ophthalmoscope (SLO). Invest Ophthalmol Vis Sci 36, 1863-1874 (1995).
Dagnelie G and Massof RW (1994). Sub-microvolt electroretinograms: negotiating the pitfalls of electricity and noise. Noninvasive Assessment of the Visual System, Technical Digest 94-2 (Optical Soc Am), 354 - 357.
Turano K, Herdman SJ and Dagnelie G (1993). Visual stabilization of posture in retinitis pigmentosa and in artificially restricted visual fields. Invest Ophthalmol Vis Sci 34, 3004 - 3010.
Dagnelie G (1993). Foveal Ferry-Porter data in RP patients: saturation at high intensities. Noninvasive Assessment of the Visual System, Technical Digest 93-3 (Optical Soc. Am.), 342 - 345.
Dagnelie G and Massof RW (1993). Foveal cone involvement in retinitis pigmentosa progression assessed through psychophysical impulse response parameters. Invest Ophthalmol Vis Sci 34, 243 - 255.
Dagnelie G and Massof RW (1993). Foveal cone involvement in retinitis pigmentosa progression assessed through flash-on-flash parameters. Invest Ophthalmol Vis Sci 34, 231 - 242.
Dagnelie G (1992). Temporal impulse responses from flicker sensitivities: practical considerations. JOSA A9, 659 - 672.
Dagnelie G (1991). Design for a shoebox-size, computer-controlled, three-color temporal contrast sensitivity tester. Noninvasive Assessment of the Visual System, Technical Digest 91-1 (Optical Soc. Am.), 60 - 63.
Dagnelie G and Massof RW (1990). Temporal impulse response from flicker sensitivity: application to Retinitis Pigmentosa patients. Noninvasive Assessment of the Visual System, Technical Digest 90-3 (Optical Soc. Am.), 226 - 229.
Dagnelie G (1990). Conversion of planimetric visual field data into solid angles and retinal areas. Clin Vision Sciences 5, 95 - 100 & 7, 459 - 460.
Massof RW, Dagnelie G, Benzschawel T, Palmer RW and Finkelstein D (1990). First order dynamics of visual field loss in retinitis pigmentosa. Clin Vision Sciences 5, 1 - 26.
Dagnelie G, Spekreijse H and van Dijk BW (1989). Topography and Homogeneity of Monkey V1 Studied subdurally by Means of Visually Evoked Potentials. Visual Neuroscience 3, 509 - 525.
Massof RW, Marcus S, Dagnelie G, Choy D, Sunness J and Albert M (1988). Theoretical interpretation and derivation of flash-on-flash threshold parameters in visual system diseases. Applied Optics 27, 1014 - 1024.
Dagnelie G, de Vries MJ, Maier J and Spekreijse H (1986). Pattern Reversal Stimuli: Motion or Contrast? Docum Ophthalmol 61, 343 - 349.
Dagnelie G (1986). Pattern and Motion Processing in Primate Visual Cortex. Ph.D. dissertation, University of Amsterdam. Available on microfilm through University Microfilm International, Ann Arbor; publication # DA87-09608.
Spekreijse H, Dagnelie G, Maier J and Regan D (1985). Flicker and Movement Constituents of the Pattern Reversal Response. Vision Res 25, 1297 - 1304.
Dagnelie G, van den Berg TJTP and Reits D (1978). Unfamiliar Effects of Flicker on the Human EEG. Docum Ophthalmol Proc 15, 173 - 178.
Biography:
Gislin Dagnelie, Ph.D., is an Associate Professor of Ophthalmology in the Johns Hopkins University School of Medicine. He is a native of the Netherlands, where he grew up in Rotterdam. From his father, a lung specialist, he inherited his interest in medicine, while the talents in engineering shared by many members of his mother's family made him decide to approach medical research through the physical sciences. He received a master's degree in experimental physics at the University of Groningen, and a Ph.D. in medical physics at the University of Amsterdam.
Since 1986, Dr Dagnelie has been a member of the research team at the Lions Vision Research and Rehabilitation Center, a division of the Wilmer Eye Institute at Johns Hopkins, directed by Dr Robert W. Massof. The goal of this Center is to improve the knowledge of visual function in the healthy and diseased human eye, and to combine the results of this research with modern technology in order to help patients gain the best possible use of their remaining vision. Dr Dagnelie's responsibilities within the Center cover several research areas within this field: One of his projects, sponsored by the Foundation Fighting Blindness, aims at developing precise tests to measure vision in people with advanced eye disease; a second project, sponsored by the National Eye Institute, studies the potential to convey visual information through a limited set of picture dots; these projects make use of vision enhancement equipment developed at the Lions Vision Center with support of NASA and the Department of Veterans Affairs. On the low vision rehabilitation side, Dr Dagnelie is managing a project using Medicare records to study the health effects of vision loss in the elderly. He has also studied the effects of nutrition on the progression of retinal diseases, in particular the effects of lutein (related to vitamin A) on retinitis pigmentosa, with sponsorship of the National Center for Complementary and Alternative Medicine.
Outside the Lions Vision Center, Dr Dagnelie is a co-investigator in two research projects aiming at restoration of retinal function in some diseases, under the direction of Drs Mark Humayun and Eugene de Juan. The first of these seeks to develop a small implantable device to be placed over the retina, inside the eye; such a retinal prosthesis would electrically stimulate the retina in patients who have lost the function of their rods and cones, but who still have intact secondary retinal cells and nerve fibers that would send information to the brain. The second project seeks to preserve and restore the function of rods and cones through implantation of a small photodiode chip, the Artificial Silicon Retina, in RP patients who still have useful form vision; this project is sponsored by Optobionics.
Outside his academic career, Dr Dagnelie is an amateur vocalist and violinist, and is actively engaged in an organization promoting international understanding through youth exchange.
People often wonder about the pronunciation of the name Gislin Dagnelie: both parts are French, but a creative ancestor modified Ghislain to Gislin, so even the French do not recognize it as such. To pronounce the last name, think "Daniel Lee" (stress on "Lee") with the two L's contracted into a single one, and the "a" pronounced as in "past" but shorter.
As for the first name, the "G" is pronounced like -s- in leisure and the "s" is not pronounced; the second syllable gets the stress and sounds like "-leng" with a very nasal -ng ("Zheeleng" comes close).
