Scotopic sensitivity of central retina in early age-related macular degeneration.
OBJECTIVE
To test scotopic sensitivity and investigate whether there is rod system dysfunction in the central retina in early age-related macular degeneration (AMD).


METHODS
Scotopic (450 nm stimulus) and photopic (white light stimulus) sensitivity in 24 patients with early AMD was measured at 81 loci in central 25 degrees of retina, and compared with the age-match normal controls.


RESULTS
Mean scotopic sensitivity of AMD patients was significantly lower than that of the normal controls. The patients of reduced scotopic sensitivity were more than those of reduced photopic sensitivity. Scotopic sensitivity deficit decreased with increasing eccentricity with the greatest deficit was 2.5 degrees to 5.0 degrees.


CONCLUSIONS
Scotopic sensitivity was decreased in the early stage of AMD. The parafoveal rod cells were selectively damaged in AMD. Scotopic sensitivity testing in macula may be a useful tool to diagnose and measure the fundus dysfunction of AMD.
Chen
Changzheng
C
Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China.
Wu
Lezheng
L
Jiang
Futian
F
Liang
Jiongji
J
Wu
De-Zheng
DZ
D003623:Dark Adaptation / Q000502:physiology*; D005260:Female; D005654:Fundus Oculi; D006801:Humans; D008266:Macula Lutea / Q000503:physiopathology; D008268:Macular Degeneration / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D010786:Photoreceptor Cells; D012160:Retina / Q000503:physiopathology*; D015593:Retinal Drusen / Q000378:metabolism; D017948:Retinal Rod Photoreceptor Cells / Q000503:physiopathology*; D012684:Sensory Thresholds