Abstract
Purpose::
Laser induced retinal damage can degrade visual motor performance by limiting the normal retinal input to the motor system. To reveal the visual sensory component of a visual motor task, spectral sensitivity functions were derived from spectral visual pursuit motor data.
Methods::
Three non human primates (NHPs) were trained to perform a visual pursuit motor task. Spectral sensitivity functions were derived by obtaining reciprocal threshold target energy for monochromatic spectral targets ranging from 460 to 620 nm, normalized with respect to maximum source energy at 560 nm. Measurements were made of NHP tracking performance before and after exposure to a 543 nm, 250 msec duration laser pulse. Laser exposures were at levels of 2 log units below retinal damage threshold.
Results::
Pre-exposure spectral sensitivity functions revealed three spectral peaks in regions comparable to the trichromatic cone system peaks. Post exposure spectral sensitivity measurements at exposure levels 2 log units below retinal damage threshold revealed transient changes in the shape of the peaks post exposure persisting upto 6 min post exposure. Sensitivity deficits were observed in the spectral region of the laser source and less frequently sensitivity increases in more distal spectral regions suggesting alterations in inner retinal opponently related photoreceptor systems.
Conclusions::
Spectral sensitivity measurements for complex NHP pursuit motor performance are capable of revealing transient exposure effects for both outer and inner retinal neural systems.
Keywords: laser • retina • photoreceptors