Effect of Supplementary Lenses on logMAR Visual Acuity.
Background: While previous studies have examined the effect of supplementary plus lenses on visual resolution, albeit sometimes using sub-optimal techniques, the effect of overminusing an accommodating patient (adding additional minus lens power) is less clear. This study assessed distance logMAR vi...
| Publicado en: | Optometry & Visual Performance Vol. 4; no. 5; pp. 280 - 285 |
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| Autores principales: | , , |
| Formato: | research tables/charts Journal Article |
| Publicado: |
Optometric Extension Program
Nov2016
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=119834308&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 119834308 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 23253479 HOOW jtl: Optometry & Visual Performance issn: 23253479 maglogo: N pubinfo: dt: Nov2016 vid: 4 iid: 5 pid: 46881 pub: Optometric Extension Program place: Lutherville Timonium, Maryland artinfo: ui: 119834308 119834308 119834308 119834308 ppf: 280 ppct: 5 formats: tig: atl: Effect of Supplementary Lenses on logMAR Visual Acuity. aug: au: Rosenfield, Mark Portello, Joan K. Pereira, Stephen affil: SUNY College of Optometry, New York, New York sug: subj: Visual Acuity Ocular Physiology Physiology Lenses Study Methods Step Power Analysis of Variance Effect Size Post Hoc Analysis Regression Sensitivity and Specificity Scales ab: Background: While previous studies have examined the effect of supplementary plus lenses on visual resolution, albeit sometimes using sub-optimal techniques, the effect of overminusing an accommodating patient (adding additional minus lens power) is less clear. This study assessed distance logMAR visual acuity (VA) through plus and minus lenses added to the optimal refractive correction. Methods: The study was performed on 20 subjects. After determining the distance refractive correction, supplementary spherical lenses ranging from +1.00 to -1.00D (in 0.12D steps) were introduced in random order, and logMAR resolution VA was measured through these lenses using Landolt C optotypes at a viewing distance of 4m. Results: As expected, +1.00 and +0.75D lenses produced a significant reduction in VA. However, no significant change was observed for lenses ranging from +0.50 to -1.00D. The mean VA for this range of lenses was -0.14 logMAR (SD=0.10). Within the range from plano to +1.00D, a significant positive linear correlation was observed between VA and supplementary lens power, described by the function logMAR VA = 0.36F - 0.19 (where F = lens power). Conclusion: In accommodating individuals, the effect of supplementary lens power between +1.00 and -1.00D is predictable. Plus lenses produce a linear increase in logMAR VA, with 1D of defocus producing a loss of approximately 3 lines of logMAR acuity, while no significant change in VA was found when minus lenses were added. Previous findings on the effect of fogging lenses as a check for induced hyperopia may have over-estimated the expected reduction in VA. pubtype: Academic Journal doctype: research tables/charts Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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