Person:
Antona Peñalba, Beatriz

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First Name
Beatriz
Last Name
Antona Peñalba
URI
https://hdl.handle.net/20.500.14352/79924
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Optometría y Visión
Area
Optica
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2008 - 20092
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Author: Barrio De Santos, Ana Rosa × Subject: 617.7-001.15 ×

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Now showing 1 - 2 of 2
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    Comparing methods of determining addition in presbyopes
    (Clinical and Experimental Optometry, 2008) Antona Peñalba, Beatriz; Barra Lázaro, Francisco; Barrio De Santos, Ana Rosa; Gutiérrez Hernández, Ángel Luis; Piedrahita Alonso, María Elena; Martín Pérez, Yolanda
    Background: The use of plus lenses to compensate for the reduction in the range of accommodation associated with presbyopia, brings the near point of accommodation to a comfortable distance for near visual tasks. Our aim was to compare the tentative near addition determined using the most common procedures with the final addition prescribed in presbyopic patients. Methods: Sixty-nine healthy subjects with a mean age of 51.0 years (range 40 to 60 years) were studied. Tentative near additions were determined using seven different techniques: dynamic retinoscopy, amplitude of accommodation (AA), age-expected addition, binocular fused cross-cylinder with and without myopisation, near duochrome, and balance of negative and positive relative accommodation. The power of the addition was then refined to arrive at the final addition. Results: The mean tentative near additions were higher than the final addition for every procedure except for the fused cross-cylinder without initial myopisation and ageexpected addition methods. These biases were small in clinical terms (less than 0.25 D) with the exception of the AA procedure (0.34 D). The intervals between the 95% limits of agreement differed substantially and were always higher than ±0.50 D. Conclusions: All the techniques used displayed similar behaviour and provided a tentative addition close to the final addition. Due to the wide agreement intervals observed, the likelihood of error is high and supports the idea that any tentative addition has to be adjusted according to the particular needs of each patient. Among the methods examined here, we would recommend the age-expected procedure, as this technique produced results that correlated best with the final addition.
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    Repeatability intraexaminer and agreement in amplitude of accommodation measurements
    (Graefe's Archive for Clinical and Experimental Ophthalmology, 2009) Antona Peñalba, Beatriz; Barra Lázaro, Francisco; Barrio De Santos, Ana Rosa; González Díaz-Obregón, Enrique; Sánchez Pérez, Isabel
    Background: Clinical measurement of the amplitude of accommodation (AA) provides an indication of maximum accommodative ability. To determine whether there has been a significant change in the AA, it is important to have a good idea of the repeatability of the measurement method used. The aim of the present study was to compare AA measurements made using three different subjective clinical methods: the push-up, push-down, and minus lens techniques. These methods differ in terms of the apparent size of the target, the end point used, or the components of the accommodation response stimulated. Our working hypothesis was that these methods are likely to show different degrees of repeatability such that they should not be used interchangeably. Methods: The AA of the right eye was measured on two separate occasions in 61 visually normal subjects of mean age 19.7 years (range 18 to 32). The repeatability of the tests and agreement between them was estimated by the Bland and Altman method. We determined the mean difference (MD) and the 95% limits of agreement for the repeatability study ( COR) and for the agreement study (COA). Results: The COR for the push-up, push-down, and minus lens techniques were +/- 4.76, +/- 4.00, and +/- 2.52D, respectively. Higher values of AA were obtained using the pushup procedure compared to the push-down and minus lens methods. The push-down method also yielded a larger mean AA than the negative-lens method. MD between the three methods were high in clinical terms, always over 1.75D, and the COA differed substantially by at least +/- 4.50D. The highest agreement interval was observed when we compared AA measurements made using minus lenses and the push-up method (+/- 5.65D). Conclusions: The minus lens method exhibited the best repeatability, least MD (-0.08D) and the smallest COR. Agreement between the three techniques was poor.