Laser-induced retinal damage threshold measurements with wavefront correction.
An adaptive optics (AO) system was incorporated into a laser retinal exposure setup in order to correct for refractive error and higher-order aberrations of the nonhuman primate (NHP) eye during an in vivo retinal ED(50) measurement. Using this system, the ED(50) for a 100-ms, 532-nm small spot size exposure was measured to be 1.05 mJ total intraocular energy (TIE), a reduction of 22% from the value measured without aberration correction. The ED(50) for a 3.5-ns, 532-nm exposure was measured to be 0.51 microJ TIE, the lowest ED(50) reported for a ns-duration exposure. This is a reduction of 37% from the value measured without aberration correction and is a factor of only 2.6 higher than the maximum permissible exposure (MPE) for a 3.5-ns, visible wavelength small spot size exposure. The trend of in vitro measurements using retinal explants suggests that the in vivo ED(50) for small spot-size exposures could potentially be one order of magnitude smaller than the previously reported in vivo ED(50). Distortion of the incident laser beam by ocular aberrations cannot fully explain the discrepancy between the in vivo measurements with no aberration correction and the in vitro results.
Lund
Brian J
BJ
Northrop Grumman, 4241 Woodcock Drive, Suite B100, San Antonio, Texas 78228, USA. brian.lund@ctr.brooks.af.mil
Lund
David J
DJ
Esdall
Peter R
PR
D000818:Animals; D017076:Computer-Aided Design; D019781:Corneal Topography / Q000295:instrumentation* / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers / Q000009:adverse effects*; D007928:Lethal Dose 50; D008252:Macaca fascicularis; D008253:Macaca mulatta; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000209:etiology* / Q000503:physiopathology*; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012160:Retina / Q000293:injuries* / Q000503:physiopathology*; D042261:Retinoscopes; D012680:Sensitivity and Specificity