[Reading performance in the scar stage of age-related macular degeneration].

PURPOSE

To evaluate reading performance in patients with age-related macular degeneration (AMD).

SUBJECTS AND METHODS

Six normal subjects over 50 years of age and 40 patients with AMD were evaluated. Near visual acuity, critical print size, and maximum reading speed were tested to compare the data from normal subjects with those from AMD patients. Scanning laser ophthalmoscope (SLO) microperimetry was performed to observe fixation in AMD patients.

RESULTS

The mean critical print size for normal subjects was 0.15 logarithm of the minimum angle of resolution (log MAR) and the mean maximum reading speed was 307 characters/min. There was a plateau area in reading function where reading speed did not rise and stayed constant even though print size increased. The mean critical print size for AMD patients was 0.97 log MAR, and the mean maximum reading speed was 140 characters/min. The critical print size and maximum reading speed differed significantly between normal and AMD subjects. Eleven of the 40 patients with AMD did not have the character size and reading speed relationship, which means they manifested a plateau as seen in normal subjects. Eight of the 11 patients did not show stable fixation with SLO microperimetry.

CONCLUSIONS

The reading performance of AMD patients was remarkably impaired, especially in those with poorer visual function and no fixation.