Macular function testing in a German pedigree with North Carolina macular dystrophy.

BACKGROUND

Our purpose was to investigate central visual function in North Carolina macular dystrophy (MCDR1). A German family with genetically proven MCDR1 was followed for more than 20 years.

METHODS

In addition to routine clinical examinations, static and kinetic fundus perimetry was performed with the scanning laser ophthalmoscope. The center of fixation was determined.

RESULTS

Visual acuity was 0.6 or better in all but one eye of seven members of this family and did not markedly change during follow-up. Fundus examination confirmed that the fixation was at the nasal edge of the central scar in five affected eyes with reduced stability of fixation. One eye had a prominent gliotic membrane, and fixation was within this area.

CONCLUSIONS

Patients had nearly normal visual acuity even though they presented with deep central scotomas and a shift of the center of fixation away from the fovea. Because MCDR1 has good long-term functional prognosis, there might be an early transdifferentiation of the new locus of fixation.