Visual acuity as measured with Landolt C chart and Early Treatment of Diabetic Retinopathy Study (ETDRS) chart.
BACKGROUND
We compared the Landolt C chart checked under normal clinical conditions and the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart, using standard clinical research protocols for subjects with normal vision, cataract and maculopathy.


METHODS
This prospective, comparative study was approved by the hospital Institutional Review Board. Patients with cataract and maculopathy were included, with the normal fellow eyes analyzed as normal vision group. Differences between the two charts were analyzed using Student's t-test.


RESULTS
Normal and cataract eyes showed no statistically significant differences between methods. In the maculopathy group, ETDRS acuity (0.714 ± 0.393) was better than Landolt C acuity (0.845 ± 0.579), but the differences were not statistically significant (p = 0.152). Furthermore, if after dividing visual acuity into subgroups, >20/200 and ≤20/200 by Landolt C acuity, the latter subgroup had significant differences between the two tests (p < 0.001). ETDRS acuity (1.014 ± 0.319) was better than Landolt C acuity (1.419 ± 0.385). The average acuity difference was 4 lines.


CONCLUSIONS
For maculopathy patients with VA ≤ 20/200, the ETDRS chart had a better score than the Landolt C chart.
Kuo
Hsi-Kung
HK
Department of Ophthalmology, Chang Gung Memorial Hospital - Kaohsiung Medical Center, Chang Gung University College of Medicine, Taiwan. d2767@cgmh.org.tw
Kuo
Ming-Tse
MT
Tiong
Ing-Soo
IS
Wu
Pei-Chang
PC
Chen
Yung-Jen
YJ
Chen
Chih-Hsin
CH
D000293:Adolescent; D000328:Adult; D000368:Aged; D002386:Cataract / Q000145:classification / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012164:Retinal Diseases / Q000145:classification / Q000503:physiopathology; D012680:Sensitivity and Specificity; D014787:Vision Tests / Q000295:instrumentation*; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult