By Rajat N. Agrawal, M.D.
Patients with advanced Retinitis Pigmentosa (RP) and Age-related Macular Degeneration (AMD) have limited treatment options at this time. Treatments like Vitamin A therapy for RP and laser and newer anti-VEGF injections for AMD are currently being advised, but they are not much help in advanced condition of these diseases. Stem cells treatment, gene therapy and retinal transplantation are not yet ready for clinical practice.
Artificial Retinal Implant Project is currently focused on restoring sight to such patients. Our group, along with Second Sight Medical Products based in Sylmar, CA, has successfully implanted a 16-electrode ARGUS-I® device in 6 patients with advanced RP, with encouraging results. In 2007, a clinical trial was begun with a 60-electrode ARGUS-II® device in a multicentric trial that is spread around the United States, Europe and Mexico. So far, 19 patients have been implanted with the device.
A routine retinal surgery is performed to implant the device in the eye. The device incorporates a coil placed on the surface of the eye, with an array of electrodes being placed on the surface of the retina. A coil on the glasses worn by the patient wirelessly communicates with the secondary coil on the eye. A video camera on the glasses digitizes the image and sends the information via a microprocessor to the implant. Specific stimulation of the electrodes allows for visual perception by the patient in the form of spots of light, described as “phosphenes.”
We are also in development of a 1000-electrode device that is likely to give better visual benefit to patients, with a possible increase in visual field. Although many advances have been made in the field of artificial retina, with encouraging results from clinical trials so far, the reality of a commercially available device is still a few years away.
For more information, please contact Rajat N. Agrawal, M.D., Doheny Eye Institute, University of Southern California, Los Angeles, California, ragrawal@doheny.org, (323) 442-6776.
About Dr. Agrawal
Rajat N. Agrawal, M.D., is an Ophthalmologist and a Vitreo-Retinal Surgeon. He is currently Asst. Professor of Clinical Ophthalmology, Director of the Center for Retinal Degenerative Diseases, Study Director of the Artificial Retina Implant Project, and Co-Director of Intraocular Implants at the Doheny Eye Institute, University of Southern California, Los Angeles, California.
Dr. Agrawal received his Medical degree (MBBS) from Government Medical College, Nagpur, India, followed by an Ophthalmology residency in Mumbai, India, and certification by the National Board (Ophthalmology). He underwent Fellowship training in Vitreo-Retinal Diseases and Surgery at the Medical Research Foundation (Sankara Nethralaya), Chennai, India, and worked at a Consultant Vitreo-Retinal Surgeon for more than 7 years, involved in clinical care, research and teaching and training retina fellows and residents. He was later invited to the Chinese University of Hong Kong, and by the Government of the Commonwealth of Bahamas to teach and train local ophthalmologists in retinal surgical techniques.
Dr. Agrawal was later recruited into the Doheny Eye Institute in Los Angeles in 2003, where he is currently based. In addition to the routine clinical work, he is significantly involved in the Artificial Retinal Implant project, which aims at perfecting a complex artificial retinal device that will allow patients with advanced retinitis pigmentosa and age-related macular degeneration see again. In addition, he is also involved in developing techniques for using stem cells in retinal degenerative disorders, development of nano-drug delivery devices, surgical instrumentation and newer surgical techniques.
