Trends in retinal damage thresholds from 100-millisecond near-infrared laser radiation exposures: a study at 1,110, 1,130, 1,150, and 1,319 nm.
OBJECTIVE
Retinal damage thresholds from 100-millisecond exposures to laser radiation for wavelengths between 1,100 and 1,350 nm have never previously been established. We sought to determine the retinal damage threshold for 100-millisecond exposures of near-infrared (NIR) laser radiation wavelengths at 1,110, 1,130, 1,150, and 1,319 nm. These data were then used to create trends for retinal damage thresholds over the 1,100-1,350 nm NIR region based upon linear absorption of laser radiation in ocular media and chromatic dispersion of the eye.


METHODS
The paramacula and macula areas of the retina in Macaca mulatta (rhesus) subjects were exposed for 100 milliseconds to NIR laser radiation wavelengths using a Coherent OPO laser for 1,110, 1,130, and 1,150 nm and a Lee laser for 1,319 nm. Probit analysis was used to establish the estimated damage threshold in the retina for 50% of exposures (ED(50)). Using trends of transmitted energy to the retina, refractive error of the eye and linear absorption of the retina, a scaling factor (SF) method was created to fit the experimental data, predicting retinal damage thresholds over the 1,100-1,350 nm region.


RESULTS
The experimental retinal damage threshold, ED(50), for 100-millisecond exposures for laser radiation wavelengths at 1,110, 1,130, and 1,319 nm were determined to be 193, 270, and 13,713 mW of power delivered to the cornea, respectively. The retinal damage threshold for the 1,150 nm wavelength was statistically undetermined due to laser-power limitations, but was achieved in one out of three subjects tested.


CONCLUSIONS
The SF predicts the experimental 100- millisecond NIR ED(50) value for wavelengths between 1,100 and 1,350 nm.
Vincelette
Rebecca L
RL
Department of Biomedical Engineering, Cockrell School of Engineering, University of Texas, Austin, Texas 78712, USA. rebecca.vincelette@gmail.com
Rockwell
Benjamin A
BA
Oliver
Jeff W
JW
Kumru
Semih S
SS
Thomas
Robert J
RJ
Schuster
Kurt J
KJ
Noojin
Gary D
GD
Shingledecker
Aurora D
AD
Stolarski
Dave J
DJ
Welch
Ashley J
AJ
D000818:Animals; D007259:Infrared Rays / Q000009:adverse effects; D007834:Lasers / Q000009:adverse effects*; D008253:Macaca mulatta; D008297:Male; D011829:Radiation Dosage; D011832:Radiation Injuries; D012160:Retina / Q000293:injuries* / Q000528:radiation effects*