Tilted disc syndrome may mimic false visual field deterioration.

PURPOSE: Tilted disc syndrome is a congenital anomaly of the eye characterized by mostly upper temporal visual field defects. The aim of the present study was to evaluate the effect of gradual myopic correction in the improvement of visual field defects associated with tilted disc syndrome.
METHODS: The visual field was examined in 38 eyes of 24 patients using standard Goldmann perimetry. The isoptres IV-4e, I-4e, I-3e and I-2e were plotted. The defective isoptres were tested again with gradually increasing myopic correction until no further change was noted.
RESULTS: The most common type of defect was a relative upper temporal defect (19 eyes). Temporal relative defects were found in five eyes, upper altitudinal field defects in six eyes, an enlarged blind spot in four eyes, and an inferior field defect in one eye. The visual field defect partly or totally disappeared with increased myopic correction in 18 (50%) eyes. The mean improvement was 17.0 +/- 6.2 degrees and the mean additional myopic correction was 3.1 +/- 1.5 D.
CONCLUSIONS: Even a small change in near correction during visual field examination may imply worsened or improved visual field defects in tilted disc syndrome. To prevent a false interpretation of field deterioration in a patient with tilted disc syndrome and glaucoma, visual field assessment should include examination with the myopic correction that provides the maximal improvement of the defective visual field.