[Fixation points and retinal sensitivity observed in reading text by patients with bilateral macular atrophy].

PURPOSE

To study by use of a scanning laser ophthalmoscope(SLO). How patients with bilateral macular atrophy use their retinas in reading Japanese sentences of varying sizes.

METHODS

Thirty-eight eyes of 19 patients with bilateral macular atrophy were examined. Sentences of a fixed length (MNREAD-J sentences) were projected onto the patients' retinas with the SLO, and the size of the letters was varied. Patients were asked to read aloud the sentences slowly, and both their voices and retinal images were recorded simultaneously on videotape so that we could locate the retinal area they were using for reading. We compared these fixation points in reading with simple fixation points obtained by SLO microperimetry.

RESULTS

In 21 eyes, the patients used the same area of the retina in all measurements. In 15 eyes, the fixation points for reading differed from the fixation area measured by microperimetry. In 8 of the 15 eyes, the fixation area for reading changed as the letter size was altered. In 2 eyes, oral reading was impossible, and no fixation point was established.

CONCLUSIONS

The combination of SLO with reading evaluation clarified the fixation area for oral reading. Multiple fixation points were thought to be present quite commonly in eyes with macular degeneration. The fixation point was thought to be determined by the macular condition and the size of the letters being read.