Colour Vision in Stargardt Disease.

PURPOSE: To investigate the type and severity of acquired colour vision deficiencies (CVDs) in molecularly proven Stargardt disease (STD) and to establish whether a relationship exists between best-corrected visual acuity (BCVA) and full-field electroretinography (ffERG), and the degree of CVD.

METHODS

A retrospective, cross-sectional study of 73 patients with a molecularly proven diagnosis of STD, who underwent extensive colour vision evaluation, using pseudo-isochromatic and arrangement tests. Thirteen patients underwent Nagel anomaloscopy.

RESULTS

Normal colour vision was found in almost 20% of patients. Red/green (R/G) CVDs increased as BCVA declined. About 45% of all R/G CVDs were of the deutan type, although protan type CVDs became progressively apparent when moving from the high to the low BCVA group. An additional blue/yellow CVD was noted in about 25% of patients. In 10/13 patients, a pseudoprotanomaly was noted on anomaloscopy. Severe CVDs leading to scotopization were noted in patients with low BCVA and/or long-standing disease. No statistically significant differences in ERG results were found between groups with or without a CVD.

CONCLUSIONS

The degree and type of colour vision deficiency in STD patients correlate better with BCVA than with ffERG results. The presence of specific CVDs may help to establish a diagnosis of STD. A battery of colour vision tests is required to properly evaluate CVDs in STD.