New visual acuity chart for patients with macular hole.
OBJECTIVE
To evaluate the usefulness of a new multiple-letter visual acuity chart (MLAC) for the measurement of visual acuity in patients with macular hole.


METHODS
Visual acuity was measured using a standard visual acuity chart (Landolt rings, also referred to as C's) and with the MLAC in normal subjects and in patients with a cataract or a macular hole. The MLAC has 14 plates (45 x 45 cm), and on one plate, many Landolt C's were printed with the gaps pointing in the same direction and all of one size. The sizes of the letters and gaps were made to give equivalent visual acuities of 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.5, and 2.0. The spacing between the letters was 33.3% of the diameter of the C's. Each chart projected many C's onto the macular area (5 degrees x 5 degrees ), which permitted the measurement of visual acuity at an extrafoveal point without the patient having to search for the extrafoveal point with the best acuity.


RESULTS
There was no difference in the acuity measurement determined with the standard chart and the MLAC in normal subjects and patients with cataracts. Twelve of 16 patients with open macular hole, however, demonstrated higher acuity measurement (more than two lines) on the MLAC than on the standard chart. The improvement of visual acuity measurement after successful macular hole surgery was significantly less with the MLAC than with the standard chart.


CONCLUSIONS
Our results suggest that the standard acuity chart, when administered before surgery, underestimates the patient's potential visual acuity after surgery, whereas the MLAC provides a better estimate of the patient's postoperative acuity. The MLAC can be a useful tool for measuring visual acuity in patients with macular hole.
Horiguchi
M
M
Department of Ophthalmology, Fujita Health University School of Medicine, Toyoake City, Japan. masayuki@fujita-hu.ac.jp
Suzuki
H
H
Kojima
Y
Y
Shimada
Y
Y
D000368:Aged; D002386:Cataract / Q000503:physiopathology; D002387:Cataract Extraction; D006801:Humans; D008875:Middle Aged; D012029:Refraction, Ocular; D012167:Retinal Perforations / Q000503:physiopathology* / Q000601:surgery; D014787:Vision Tests / Q000295:instrumentation*; D014792:Visual Acuity / Q000502:physiology*; D014821:Vitrectomy