Vitelliform dystrophy: long-term observations on New Zealand pedigrees.

Long-term observations on 29 patients from four pedigrees with vitelliform dystrophy (Best's disease) are described. The majority of patients were examined at yearly intervals and had a mean follow-up of 7.4 years. For analysis, eyes were staged according to Mohler and Fine's classification. Although vitelliform dystrophy exhibited considerable polymorphism in the study group 'recognisable stages', such as egg-yolk cysts, scrambled cysts or pseudohypopyon, were present in 48% of eyes at the initial examination. Egg-yolk cysts and pseudohypopyons were found to be the most evanescent of stages lasting on average 2.0 and 2.4 years respectively. Evolution of lesions did not necessarily follow a regular progression through the later stages of the vitelliform classification. Several unusual features such as recurrent pseudohypopyon, apparent regeneration of retinal pigment epithelium, exudative retinal detachments and development of stellate pigment figures were observed during the study. The majority of patients retained 6/12 or better visual acuity until the fourth decade when vision deteriorated. Correlations between changes in visual acuity and staging of the fundal lesions were made. Similarities between the group of patients reported, and a comparative group from overseas' have been discussed.