[The function of the retina in malattia leventinese (dominant drusen) (author's transl)].

Malattia leventinese was studied clinically and by electroretinography in 27 members of an affected family and in two additional cases. Typical changes in the central fundus consist of agglomerations of drusen, varying in size, number and localization. These distinct ophthalmoscopic changes occur in young adults, but characteristically remain asymptomatic for one to five decades. Then, metamorphopsia and diffuse color vision deficiency introduce a rapid decay in visual acuity. These changes in function are observed in parallel with large fields of confluent drusen, atrophy of the pigment epithelium and of the retina and with patchy pigmentations in the central fundus. The electroretinogram (ERG) of the subjects with drusen revealed "low normal" amplitudes of the b-waves of both, the cone- and rod system. These ERG-data suggest discrete but widespread functional abnormalities in the outer and middle layers of the retina well before the onset of the clinical symptomatology. In contrast, subnormal ERGs (b-wave amplitudes below 2 standard deviations of normal controls) were recorded in the advance cases, and reflected the severity of functional and structural changes.