title: Maintaining ocular safety with light exposure, focusing on devices for optogenetic stimulation.
abstract: Optogenetics methods are rapidly being developed as therapeutic tools for treating neurological diseases, in particular, retinal degenerative diseases. A critical component of the development is testing the safety of the light stimulation used to activate the optogenetic proteins. While the stimulation needs to be sufficient to produce neural responses in the targeted retinal cell class, it also needs to be below photochemical and photothermal limits known to cause ocular damage. The maximal permissible exposure is determined by a variety of factors, including wavelength, exposure duration, visual angle, pupil size, pulse width, pulse pattern, and repetition frequency. In this paper, we develop utilities to systematically and efficiently assess the contributions of these parameters in relation to the limits, following directly from the 2014 American National Standards Institute (ANSI). We also provide an array of stimulus protocols that fall within the bounds of both safety and effectiveness. Additional verification of safety is provided with a case study in rats using one of these protocols.
authors.affiliation: Weill Cornell Medical College, Department of Physiology and Biophysics, New York, NY 10065, USA.
authors.forename: Boyuan
authors.initials: B
authors.lastname: Yan
authors.affiliation: Weill Cornell Medical College, Department of Physiology and Biophysics, New York, NY 10065, USA.
authors.forename: Maksim
authors.initials: M
authors.lastname: Vakulenko
authors.affiliation: University of Florida College of Medicine, Department of Ophthalmology, Gainesville, FL 32603, USA.
authors.forename: Seok-Hong
authors.initials: SH
authors.lastname: Min
authors.affiliation: University of Florida College of Medicine, Department of Ophthalmology, Gainesville, FL 32603, USA.
authors.forename: William W
authors.initials: WW
authors.lastname: Hauswirth
authors.affiliation: Weill Cornell Medical College, Department of Physiology and Biophysics, New York, NY 10065, USA. Electronic address: shn2010@med.cornell.edu.
authors.forename: Sheila
authors.initials: S
authors.lastname: Nirenberg
mesh_terms: D000818:Animals; D003315:Cornea / Q000528:radiation effects*; D005136:Eye Proteins / Q000378:metabolism; D006801:Humans; D008027:Light; D062308:Optogenetics / Q000379:methods*; D010775:Photic Stimulation; D051381:Rats; D020318:Rats, Long-Evans; D012160:Retina / Q000528:radiation effects*; D012162:Retinal Degeneration / Q000628:therapy*; D057488:Visual Prosthesis
chemical_list: D005136:Eye Proteins
keywords: Ocular safety; Optogenetics; Retinal prosthetics