Is conversion of decimal visual acuity measurements to logMAR values reliable?
Τίτλος | Is conversion of decimal visual acuity measurements to logMAR values reliable? |
Publication Type | Journal Article |
Year of Publication | 2019 |
Authors | Mataftsi, A., Koutsimpogeorgos D., Brazitikos P., Ziakas N., & Haidich A-B. |
Journal | Graefes Arch Clin Exp Ophthalmol |
Volume | 257 |
Issue | 7 |
Pagination | 1513-1517 |
Date Published | 2019 Jul |
ISSN | 1435-702X |
Λέξεις κλειδιά | Adolescent, Adult, Aged, Aged, 80 and over, Female, Humans, Male, Middle Aged, Orthoptics, Reproducibility of Results, Vision Tests, Visual Acuity, Young Adult |
Abstract | PURPOSE: To assess if conversion of decimal visual acuity (VA) to logMAR is reliable for clinical and research purposes.METHODS: Right eye VA of 74 consecutive patients was measured with 5 min interval, using (a) the ETDRS chart (VAlog), (b) a decimal chart at 6 m (VA6m), and (c) a decimal chart at 4 m (VA4m). VA was the smallest line whereby four of five optotypes were correctly identified. Decimal scores were converted to logMAR using the formula logMAR = -log(decimal acuity). The agreement between VAlog, VA4m, and VA6m was assessed by the Bland-Altman method.RESULTS: Linear regression analysis of the difference between VAlog and VA6m or VA4m showed a significant slope (p = 0.001), with greater disagreement at higher VA values, i.e., poorer acuity. There was considerable lack of agreement, with discrepancies of up to 0.2 logMAR when VA was measured around 0.5 logMAR.CONCLUSION: Converting decimal VA to logMAR produces overestimation of its true value, especially in lower acuities. |
DOI | 10.1007/s00417-019-04344-9 |
Alternate Journal | Graefes Arch Clin Exp Ophthalmol |
PubMed ID | 31069515 |