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Visual Acuity

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Visual Acuity – Free Register to Access Experts & Abstracts

Deborah K Vanderveen – One of the best experts on this subject based on the ideXlab platform.

  • uncorrected Visual Acuity in children with monofocal pseudophakia
    Journal of Cataract and Refractive Surgery, 2013
    Co-Authors: Bharti R Nihalani, Deborah K Vanderveen
    Abstract:

    Purpose To report uncorrected distance and near Visual Acuity in pediatric eyes treated with primary monofocal intraocular lens (IOL) implantation. Setting Boston Children’s Hospital, Boston, Massachusetts, USA. Design Retrospective chart review. Methods Records of children older than 5 years who had uneventful monofocal IOL implantation targeted for emmetropia within ±1.00 diopter (D) spherical equivalent were reviewed. Eyes with secondary IOL placement and sulcus-fixated IOLs were excluded. Vision was tested using the Mentor BVAT or M&S system for distance and the standard Jaeger near card for near Visual Acuity. Keratometry, axial length, type of IOL, and preoperative and postoperative refractions were recorded. The main outcome measure was uncorrected Visual Acuity at distance and near. Good Visual Acuity was defined as 20/40 or better. Results Forty-one eyes of 25 children had uncorrected distance and near Visual Acuity recorded in the early postoperative period. The mean age was 11.2 years ± 3.6 (SD). Twenty eyes (49%) had good Visual Acuity at distance and near, 11 had good Visual Acuity at distance only, 6 had good Visual Acuity at near only, and 4 had worse than 20/40 at distance and near. Thirty eyes (70%) had with-the-rule astigmatism. All but 2 eyes (95%) had 20/70 or better uncorrected Acuity at distance and near. In children with bilateral pseudophakia, 12 (75%) of 16 had 20/40 or better uncorrected Acuity at distance and near. Conclusion Monofocal IOL placement resulted in good uncorrected distance and near Visual Acuity in almost 50% of pediatric eyes and in 75% of patients when targeted within ±1.00 D of emmetropia. Financial Disclosure Neither author has a financial or proprietary interest in any material or method mentioned.

Philip J. Rosenfeld – One of the best experts on this subject based on the ideXlab platform.

  • Novel method for analyzing snellen Visual Acuity measurements.
    Retina-the Journal of Retinal and Vitreous Diseases, 2010
    Co-Authors: Ninel Z. Gregori, William J. Feuer, Philip J. Rosenfeld
    Abstract:

    PURPOSE: Most retrospective reviews convert Snellen Visual Acuity measurements obtained during routine clinic visits to logarithm of the minimum angle of resolution (logMAR) units so that statistical manipulations can be performed. However, Visual Acuity measurements expressed as logMAR units are not intuitively interpretable by clinicians. A more intuitive approach is presented here which uses the conversion of Snellen Visual Acuity fractions to Early Treatment Diabetic Retinopathy Study (ETDRS) letter scores for statistical manipulations. METHODS: Snellen Visual Acuity measurements were converted to approximate ETDRS (approxETDRS) letter scores for statistical manipulations and then converted back to Snellen equivalent fractions. The formula to convert Snellen Visual Acuity measurements to approxETDRS letter scores is 85 + 50 x log (Snellen fraction), which may be rounded to the nearest letter. RESULTS: A linear relationship exists between true ETDRS letter scores, approxETDRS letter scores, and logMAR units. The interconversion between Snellen Visual Acuity measurements, logMAR units, and approxETDRS letter scores was prepared in a tabular form for easy reference. The same outcomes (in Snellen fractions) were obtained with statistical manipulation of either approxETDRS letter scores or logMAR conversions. CONCLUSION: Conversion of Snellen Visual Acuity fractions to approxETDRS letter scores for the purpose of performing statistical manipulations provides more readily interpretable outcomes compared with the current strategy of converting Snellen Visual Acuity fractions to logMAR units.

Bharti R Nihalani – One of the best experts on this subject based on the ideXlab platform.

  • uncorrected Visual Acuity in children with monofocal pseudophakia
    Journal of Cataract and Refractive Surgery, 2013
    Co-Authors: Bharti R Nihalani, Deborah K Vanderveen
    Abstract:

    Purpose To report uncorrected distance and near Visual Acuity in pediatric eyes treated with primary monofocal intraocular lens (IOL) implantation. Setting Boston Children’s Hospital, Boston, Massachusetts, USA. Design Retrospective chart review. Methods Records of children older than 5 years who had uneventful monofocal IOL implantation targeted for emmetropia within ±1.00 diopter (D) spherical equivalent were reviewed. Eyes with secondary IOL placement and sulcus-fixated IOLs were excluded. Vision was tested using the Mentor BVAT or M&S system for distance and the standard Jaeger near card for near Visual Acuity. Keratometry, axial length, type of IOL, and preoperative and postoperative refractions were recorded. The main outcome measure was uncorrected Visual Acuity at distance and near. Good Visual Acuity was defined as 20/40 or better. Results Forty-one eyes of 25 children had uncorrected distance and near Visual Acuity recorded in the early postoperative period. The mean age was 11.2 years ± 3.6 (SD). Twenty eyes (49%) had good Visual Acuity at distance and near, 11 had good Visual Acuity at distance only, 6 had good Visual Acuity at near only, and 4 had worse than 20/40 at distance and near. Thirty eyes (70%) had with-the-rule astigmatism. All but 2 eyes (95%) had 20/70 or better uncorrected Acuity at distance and near. In children with bilateral pseudophakia, 12 (75%) of 16 had 20/40 or better uncorrected Acuity at distance and near. Conclusion Monofocal IOL placement resulted in good uncorrected distance and near Visual Acuity in almost 50% of pediatric eyes and in 75% of patients when targeted within ±1.00 D of emmetropia. Financial Disclosure Neither author has a financial or proprietary interest in any material or method mentioned.

Ninel Z. Gregori – One of the best experts on this subject based on the ideXlab platform.

  • Novel method for analyzing snellen Visual Acuity measurements.
    Retina-the Journal of Retinal and Vitreous Diseases, 2010
    Co-Authors: Ninel Z. Gregori, William J. Feuer, Philip J. Rosenfeld
    Abstract:

    PURPOSE: Most retrospective reviews convert Snellen Visual Acuity measurements obtained during routine clinic visits to logarithm of the minimum angle of resolution (logMAR) units so that statistical manipulations can be performed. However, Visual Acuity measurements expressed as logMAR units are not intuitively interpretable by clinicians. A more intuitive approach is presented here which uses the conversion of Snellen Visual Acuity fractions to Early Treatment Diabetic Retinopathy Study (ETDRS) letter scores for statistical manipulations. METHODS: Snellen Visual Acuity measurements were converted to approximate ETDRS (approxETDRS) letter scores for statistical manipulations and then converted back to Snellen equivalent fractions. The formula to convert Snellen Visual Acuity measurements to approxETDRS letter scores is 85 + 50 x log (Snellen fraction), which may be rounded to the nearest letter. RESULTS: A linear relationship exists between true ETDRS letter scores, approxETDRS letter scores, and logMAR units. The interconversion between Snellen Visual Acuity measurements, logMAR units, and approxETDRS letter scores was prepared in a tabular form for easy reference. The same outcomes (in Snellen fractions) were obtained with statistical manipulation of either approxETDRS letter scores or logMAR conversions. CONCLUSION: Conversion of Snellen Visual Acuity fractions to approxETDRS letter scores for the purpose of performing statistical manipulations provides more readily interpretable outcomes compared with the current strategy of converting Snellen Visual Acuity fractions to logMAR units.

Pentti Laurinen – One of the best experts on this subject based on the ideXlab platform.

  • NEW Visual Acuity TEST FOR PRE-SCHOOL CHILDREN
    Acta Ophthalmologica, 2009
    Co-Authors: Lea Hyvärinen, Risto Nasanen, Pentti Laurinen
    Abstract:

    A new test chart was developed for the measurement of Visual Acuity of pre-school children. The symbols of the test are circle, square, apple and house. These were so designed that each symbol measures Visual Acuity similarly. This feature of the test was verified experimentally. The Visual Acuity values measured by the individual symbols correlated highly with the Visual Acuity values measured with the whole test (0.82-0.86). The correlation between the Visual Acuity values measured repeatedly, the reliability of the new test, was found to be 0.94 for adult subjects. The new Visual Acuity test thus fulfils the statistical criteria of a good Visual Acuity test. Because both children and nurses seem to like the new test, it may be useful in the assessment of Visual Acuity in pre-school children.