Selective loss of the photopic negative response in patients with optic nerve atrophy.
OBJECTIVE
To determine how the photopic negative response (PhNR) is altered in patients with optic nerve atrophy.


METHODS
Ten patients with optic nerve atrophy induced by compression, trauma, or inflammation were examined. There were 6 men and 4 women with a mean age of 52.4 years. Ten age-matched control subjects were examined with the same protocol. Full-field electroretinograms were recorded, and the retinal nerve fiber layer thickness surrounding the optic nerve head was measured by means of optical coherence tomography.


RESULTS
The amplitudes of the rod, maximum, cone, and 30-Hz flicker electroretinograms of the affected eyes were not different from those of the corresponding waves of the contralateral unaffected eyes or control eyes. In contrast, the amplitude of the PhNR was significantly smaller in the affected eyes than in the contralateral (P =.005) or control (P<.001) eyes. The decrease in amplitude of the PhNR preceded thinning of the retinal nerve fiber layer. There was a significant correlation between the PhNR amplitude and retinal nerve fiber layer thickness in eyes with optic nerve atrophy (r = 0.879; P<.001).


CONCLUSIONS
Selective reduction and loss of the PhNR amplitude was found in eyes with optic nerve atrophy, which suggests that the PhNR can be used to evaluate the function of ganglion cells or their axons.
Department of Ophthalmology, Iwate Medical University School of Medicine, Morioka, Iwate, Japan.
Yasutaka
Y
Gotoh
Shigeki
S
Machida
Yutaka
Y
Tazawa
D000328:Adult; D000368:Aged; D003623:Dark Adaptation; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009474:Neurons / Q000502:physiology; D009896:Optic Atrophy / Q000503:physiopathology*; D010775:Photic Stimulation; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology; D041623:Tomography, Optical Coherence