U. Kretschmann et al., Familial macular cone dystrophy: diagnostic value of multifocal ERG and two-color threshold perimetry, GR ARCH CL, 237(5), 1999, pp. 429-432
Citations number
12
Categorie Soggetti
Optalmology
Journal title
GRAEFES ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
Background: It is difficult to detect receptor dysfunction in patients with
marked bilateral visual loss but only mild morphological alterations of th
e fundus.
Methods: Two patients, father and son, with visual acuity loss to 20/100 we
re examined. Using the multifocal ERG, 61 local cone ERGs from each eye wer
e derived from the central Visual field. The dark-adapted two-color thresho
ld perimetry using stimuli of 500 nm and 656 nm for rod and cone function w
as investigated along the horizontal meridian of the visual field.
Results: In the multifocal ERG of both patients a macular response was abse
nt. From eccentricity at and anterior to 5 degrees, good multifocal cone ac
tivity was recorded. Cone thresholds were markedly diminished in the macula
. The rod thresholds were borderline in the father and normal in the son.
Conclusions: Multifocal ERG is a novel technique, very well suited to revea
l the topography of cone function. Using two-color threshold perimetry affo
rds an opportunity to differentiate between rod and cone functional defects
. Both together helped to establish the diagnosis of macular cone dystrophy
in the present family.