Purpose

The aim of this study is to present the earliest functional changes in Stargardt disease in family with three affected and one unaffected children.

Material and methods

Four children: three girls (4, 7, 10, year old) and one boy (13 year old) and their parents (34 rear old mother and 36 year old father) were examined. Visual acuity (Snellen card), color perception (Ishihara’s cards), electroretinography (flash full-field ERG – standard and chromatic) and electrooculography (EOG) were done. For ERG and EOG LKC equipment and UTAS E-2000 program was used.

Results

13 year old boy has had visual acuity about 5/50 for about 3 years, nystagmus and no color perception. On his ocular fundus abnormal macular reflex (like beaten metal) was seen. Visual acuity about 5/12 was found in 7 year old girl during routine examination at school, but color perception and ocular fundus were normal. The others examined family members had visual acuity 5/5 without correction and no changes on ocular fundus. Color perception was normal in girls and mother. The father had red-green deficiency. Arden ratio in EOG was below normal (1.4) only in boy but dark trough and light peak amplitudes were lower than normal also in girls 4 and 7 year old and these two girls were also suspected of Stargardt’s disease. ERG was nearly abolished in boy and markedly abnormal in his 7 year old sister. In father’s ERG small reduction of cone function especially after chromatic stimulations was found. ERG was normal and similar in mother and 10 year old daughter. ERG was not done in the youngest girl. Two years later loss of visual acuity to 4/50 occurred in girl previously 7 and to 5/6 in the youngest sister.

Conclusions

Detail analysis of EOG and ERG results may lead to diagnose retinal dystrophy in preclinical stadium.