Comparison of the original Amsler grid with the modified Amsler grid: result for patients with age-related macular degeneration.

Abstract

To compare the sensitivity of the original Amsler grid presenting white lines on a black background with that of the modified standard version of the grid presenting black lines on a white background in the detection of visual disturbances. One hundred eighty-two patients (182 eyes) with dry and exudative age-related macular degeneration and a history of metamorphopsia were instructed to use an Amsler grid. None of the patients were familiar with an Amsler grid or had used it previously. If the disease was present in both eyes, one eye was chosen as the study eye by randomization. Both grid types were presented and used for documentation of central visual field changes. The sequence of presentation of the respective grid was also chosen by randomization. Original Amsler grid questions were used for grading ("metamorphomas" and "scotomas"). Visual acuity of patients ranged from 0.1 to 0.7. Subgroup analysis was performed based on the visual acuity levels. For the overall study population, the original Amsler grid provided significantly better results than the modified version. Evaluation of data for the different subgroups showed no significant difference between patients with visual acuity ranging from 0.1 to 0.3. For patients with visual acuity of 0.5 or better, the original Amsler grid was significantly more informative and reliable than the modified version. For patients with macular diseases, use of the original Amsler grid (white lines on a black background) should be recommended. This is particularly important for patients with visual acuity of 0.5 or better.