Focal Macular Electroretinograms in Eyes with Wet Type Age-Related Macular Degeneration
Hiroaki Nishihara 1,
Mineo Kondo 1*,
Kohei Ishikawa 1,
Tadasu Sugita 1,
Chang-Hua Piao 1,
Yoshiharu Nakamura 1,
and
Hiroko Terasaki 1
1 Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
* To whom correspondence should be addressed. E-mail: kondomi{at}med.nagoya-u.ac.jp.
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Abstract |
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Purpose. To study the properties of the focal macular electroretinograms (fmERGs) in eyes with untreated wet type age-related macular degeneration (AMD).
Methods. fmERGs were recorded from 157 eyes of 157 consecutive patients with untreated wet type AMD (113 men and 44 women; age, 71.3 ± 8.0 years). The fmERGs were recorded under direct fundus observation using a modified infrared fundus camera and a 15° stimulus spot. The amplitudes and implicit times of the fmERGs recorded from the AMD patients were compared to those from 21 age-similar normal controls.
Results. The amplitudes of fmERGs in the AMD patients were significantly smaller (P <0.001), and the implicit times were significantly longer (P <0.001) than the corresponding values in the control eyes. There was a significant correlation between the amplitude and implicit time of the fmERG and the visual acuity (logMAR), but the degree of correlation was weak. There was no significant difference in the b/a amplitude ratio between the AMD patients and normal controls.
Conclusions. The significant reduction in the amplitude and severe delay in the implicit times of both the a- and b-waves of the fmERGs indicate that there are significant functional alterations in both the inner and outer retinal layers of the macular area of eyes with the wet type AMD.
Key Words:
electrophysiology, electroretinography, age-related macular degeneration
