Abstract

Volume.117 Number.8

Original article : Case report

Long-term Observation over Ten Years of Four Cases of Cone Dystrophy with Supernormal Rod Electroretinogram
Natsuko Nakamura1, Kazushige Tsunoda1, Kaoru Fujinami1, Kei Shinoda2, Kaoru Tomita3, Tetsuhisa Hatase4, Tomoaki Usui5, Masakazu Akahori1, Takeshi Iwata1, Yozo Miyake6
1 National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center
2 Department of Ophthalmology, School of Medicine, Teikyo University
3 Heiwa Eye Clinic
4 Division of Ophthalmology and Visual Science, Graduate School of Medical and Dental Sciences, Niigata University
5 Akiba Eye Clinic
6 Aichi Medical University

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.
Cases: 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.
Conclusion: The long-term courses in Japanese patients were variable. The OCT was helpful in evaluating the disease progression.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 117: 629-640, 2013.

Key words
Cone dystrophy, KCNV2, Electroretinogram (ERG), Optical coherence tomography (OCT), Long-term follow-up
Reprint requests to
Kazushige Tsunoda, M.D.　National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center. 2-5-1 Higashigaoka, Meguro-ku, Tokyo 152-8902, Japan
Received: 14 December 2012. Accepted in revised form: 8 March 2013.
Nihon Ganka Gakkai Zasshi 117: 629-640,2013