[Long-term observation over ten years of four cases of cone dystrophy with supernormal rod electroretinogram].
BACKGROUND
'Cone dystrophy with a supernormal rod electroretinogram (ERG)' is rare form of cone dystrophy, and no longitudinal description of the disease course has been reported in a Japanese population. Here, we describe long-term courses of 10 to 15 years in four Japanese patients with mutations in the KCNV2 gene.


METHODS
Four patients from three families were recruited. Two were siblings (Case 1, 24 y/o women; Case 2, 17 y/o man), and two were sporadic cases (Case 3, 17 y/o women; Case 4, 21 y/o women). All the patients presented with characteristic ERG findings. There were minimal abnormalities in fundus appearance: slight mottling of retinal pigment epithelium in the macula in all four cases, and granular change in the macula in Case 4. The visual acuity in Cases 1 and 2 did not change during the follow-up period, but the acuity in Cases 3 and 4 gradually decreased. Photoreceptor abnormalities in optical coherence tomography were found in all the cases, but were more severe in Cases 3 and 4.


CONCLUSIONS
The long-term courses in Japanese patients were variable. The OCT was helpful in evaluating the disease progression.
National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo 152-8902, Japan.
Natsuko
N
Nakamura
Kazushige
K
Tsunoda
Kaoru
K
Fujinami
Kei
K
Shinoda
Kaoru
K
Tomita
Tetsuhisa
T
Hatase
Tomoaki
T
Usui
Masakazu
M
Akahori
Takeshi
T
Iwata
Yozo
Y
Miyake
D000293:Adolescent; D017677:Age Distribution; D004596:Electroretinography; D005124:Eye Abnormalities / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D009154:Mutation / Q000235:genetics; D012162:Retinal Degeneration / Q000235:genetics*; D058499:Retinal Dystrophies / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult