CASE REPORT

A 45 year old Japanese man first noticed night blindness at junior high school age, followed by a slowly progressive loss of visual acuities and fields. At presentation, the best visual acuity was 10/200 in each eye. Goldmann perimetries revealed generalised narrowing of the peripheral field and marked loss of central visual sensitivities. Bright flash electroretinogram (ERG) in a fully dark adapted state was not recordable in either eye. Ophthalmoscopies revealed advanced stage of retinitis pigmentosa (Fig l). There was no Mizuo’s phenomenon1 in the fundus. This patient reported that he had felt relatively better vision (“good day”) on every other day that alternated with worse vision (“bad day”).

Furthermore, he claimed that bad day was repeated after physical stress or alcohol drinking, followed by a good day to return to the ordinary cycle. In our 10 years’ observation, the profile of day to day variation was reproducible. To quantitatively assess the characteristic visual symptoms, perimetric tests were performed in both …