Regional cone-mediated dysfunction in age-related maculopathy evaluated by focal electroretinograms: relationship with retinal morphology and perimetric sensitivity.
OBJECTIVE
To assess regional cone-mediated function in age-related maculopathy (ARM) by focal electroretinograms (FERGs), and to compare FERGs with morphologic changes and perimetric sensitivity at corresponding locations.


METHODS
Twenty-six ARM patients and 12 age-matched controls were evaluated. FERGs were elicited by either a central (0-2.25 degrees , C) or a paracentral annular (2.25-9 degrees , PC) flickering (41 Hz) field, presented on a light-adapting background. Morphological changes (soft drusen and/or retinal pigment epithelium defects) at matched locations were assessed by fundus photography and fluorescein angiography. Perimetric sensitivity was measured by Octopus 10 degrees program (tM2).


RESULTS
When compared to controls, mean C and PC FERG amplitudes of patients were reduced (p < 0.01), and the mean PC FERG phase was delayed (p < 0.01). Both FERG delays and morphologic lesions tended to involve to a greater extent the PC compared to the C region. In the C region, perimetric losses were correlated with the extent of morphologic lesions (p < 0.05). In the PC region, perimetric losses were correlated with FERG amplitudes (p < 0.05).


CONCLUSIONS
In ARM, FERG losses are eccentricity-dependent, not quantitatively linked to retinal morphology, and correlated with perimetric losses, suggesting a heterogeneous dysfunction with loss of both C and PC perimetric sensitivities.
Piccardi
Marco
M
Institute of Ophthalmology, Catholic University, Rome, Italy.
Ziccardi
Lucia
L
Stifano
Giovanna
G
Montrone
Lucrezia
L
Iarossi
Giancarlo
G
Minnella
Angelo
A
Fadda
Antonello
A
Balestrazzi
Emilio
E
Falsini
Benedetto
B
D000368:Aged; D000369:Aged, 80 and over; D004596:Electroretinography; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D017949:Retinal Cone Photoreceptor Cells / Q000473:pathology / Q000502:physiology*; D012680:Sensitivity and Specificity; D058609:Visual Field Tests