Person: Antona Peñalba, Beatriz
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First Name
Beatriz
Last Name
Antona Peñalba
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Optometría y Visión
Area
Optica
Identifiers
9 results
Search Results
Now showing 1 - 9 of 9
Item The Computer-Vision Symptom Scale (CVSS17): Development and Initial Validation(IOVS (Investigative Ophthalmology & Vision Science, 2014) González Pérez, Mariano; Susi García, María Del Rosario; Antona Peñalba, Beatriz; Barrio de Santos, Ana Rosa; González Díaz-Obregón, EnriquePurpose.: To develop a questionnaire (in Spanish) to measure computer-related visual and ocular symptoms (CRVOS). Methods.: A pilot questionnaire was created by consulting the literature, clinicians, and video display terminal (VDT) workers. The replies of 636 subjects completing the questionnaire were assessed using the Rasch model and conventional statistics to generate a new scale, designated the Computer-Vision Symptom Scale (CVSS17). Validity and reliability were determined by Rasch fit statistics, principal components analysis (PCA), person separation, differential item functioning (DIF), and item–person targeting. To assess construct validity, the CVSS17 was correlated with a Rasch-based visual discomfort scale (VDS) in 163 VDT workers, this group completed the CVSS17 twice in order to assess test-retest reliability (two-way single-measure intraclass correlation coefficient [ICC] and their 95% confidence intervals, and the coefficient of repeatability [COR]). Results.: The CVSS17 contains 17 items exploring 15 different symptoms. These items showed good reliability and internal consistency (mean square infit and outfit 0.88–1.17, eigenvalue for the first residual PCA component 1.37, person separation 2.85, and no DIF). Pearson's correlation with VDS scores was 0.60 (P < 0.001). Intraclass correlation coefficient for test–retest reliability was 0.849 (95% confidence interval [CI], 0.800–0.887), and COR was 8.14. Conclusions.: The Rasch-based linear-scale CVSS17 emerged as a useful tool to quantify CRVOS in computer workers.Item High AC/A Accommodative Esotropia Strabismus Treated with Contact Lenses: A Single Case Design (N=1) Study(Binocular vision & strabismus quarterly, 2007) González Díaz-Obregón, Enrique; Barra Lázaro, Francisco; Sánchez Pérez, Isabel; Antona Peñalba, Beatriz; Barrio De Santos, Ana RosaBACKGROUND AND PURPOSE: The purpose was to determine the efficacy of two types of contact lenses (spherical disposable and aplanatic) as treatment in a patient with esotropia with a high Accommodative Convergence/Accommodation Ratio (AC/A). Due to the possibility of the appearance of accommodative insufficiency in this kind of patient, (i.e., following many years of bifocal glasses use), the elimination of the plus addition lens is advisable. Nevertheless, in some patients, this change leads to the appearance of a residual angle of esodeviation in near vision. It was expected that monofocal aplanatic contact lenses could achieve, due to their optical characteristics, an accurate and orthotropic binocular alignment, without aggravating an undesirable manifestation of the accommodative insufficiency. METHODS: An experimental design of a single case (N=1) was used in which the subject acted as his own control. With bifocal glasses the subject displayed stability in his binocular and accommodative system at every distance of vision for the past three years. We compared the efficacy of two different types of hydrophilic contact lenses to control the angle of deviation, both at distance and at near vision. RESULTS: Neither of the two contact lenses produced the results of stability and the correct binocular alignment that had been achieved with bifocal glasses. This subject experienced a worse manifest esodeviation in distance vision with aplanatic lenses than with the disposable ones. CONCLUSIONS: These monofocal contact lenses did not create acceptable binocular alignment and stability in a subject with a high AC/A accommodative esotropia.Item Intra-examiner repeatability and agreement in accommodative response measurements(Ophthalmic and Physiological Optics, 2009) Antona Peñalba, Beatriz; Sánchez Pérez, Isabel; Barrio De Santos, Ana Rosa; Barra Lázaro, Francisco; González Díaz-Obregón, EnriquePurpose: Clinical measurement of the accommodative response (AR) identifies the focusing plane of a subject with respect to the accommodative target. To establish whether a significant change in AR has occurred, it is important to determine the repeatability of this measurement. This study had two aims: First, to determine the intraexaminer repeatability of AR measurements using four clinical methods: Nott retinoscopy, monocular estimate method (MEM) retinoscopy, binocular crossed cylinder test (BCC) and near autorefractometry. Second, to study the level of agreement between AR measurements obtained with the different methods. Methods: The AR of the right eye at one accommodative demand of 2.50 D (40 cm) was measured on two separate occasions in 61 visually normal subjects of mean age 19.7 years (range 18-32 years). The intraexaminer repeatability of the tests, and agreement between them, were estimated by the Bland-Altman method. We determined mean differences (MD) and the 95% limits of agreement [coefficient of repeatability (COR) and coefficient of agreement (COA)]. Results: Nott retinoscopy and BCC offered the best repeatability, showing the lowest MD and narrowest 95% interval of agreement (Nott: -0.10 +/- 0.66 D, BCC: -0.05 +/- 0.75 D). The 95% limits of agreement for the four techniques were similar (COA = +/- 0.92 to +/- 1.00 D) yet clinically significant, according to the expected values of the AR. The two dynamic retinoscopy techniques (Nott and MEM) had a better agreement (COA = +/- 0.64 D) although this COA must be interpreted in the context of the low MEM repeatability (COR = +/- 0.98 D). Conclusions: The best method of assessing AR was Nott retinoscopy. The BCC technique was also repeatable, and both are recommended as suitable methods for clinical use. Despite better agreement between MEM and Nott, agreement among the remaining methods was poor such that their interchangeable use in clinical practice is not recommended.Item 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, IsabelBackground: 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.Item Repeatability and agreement in the measurement of horizontal fusional vergences(Ophthalmic and Physiological Optics, 2008) Antona Peñalba, Beatriz; Barrio De Santos, Ana Rosa; Barra Lázaro, Francisco; González Díaz-Obregón, Enrique; Sánchez Pérez, María IsabelPurpose: This study was designed to determine the repeatability of fusional vergence rangesmeasured using the rotary prisms in the phoropter and in free space using the prism bar. The level of agreement between the two methods was also investigated.. Methods: In two separate sessions, negative and positive fusional vergence ranges (NFV and PFV, respectively) were measured at distance and near in 61 young adults (mean age 19.74, S.D. 2.5 years) who were unfamiliar with the methods used. Base-in and base-out blur, break and recovery points were sequentially determined. Both sets of measurements were obtained by the same examiner. At each distance, NFV was determined first and then PFV. The repeatability of the tests and agreement between measurements made with the phoropter rotary prisms and the prism bar were estimated by the Bland and Altman method. Results: For both the phoropter rotary prisms and prism bar, NFV measurements showed better repeatability than PFV at both near and distance. Mean differences recorded for the NFV break and recovery points were non-significant (under 0.5D), while those observed for PFV were generally greater than 2D. When agreement between the two tests was assessed, it was found that break points were higher when determined using the phoropter rotary prisms, while recovery points were generally higher for the prism bar method. In clinical terms, according to the expected values of the NFV and PFV, agreement between the two techniques can be described as fair, because although mean differences were never greater than 5.5D, 95% agreement intervals were as wide as ±8.00D for NFV and ±13.19D for PFV. Conclusions: The two methods used to measure fusional vergences showed fairly good inter- session repeatability for measuring NFV but repeatability was reduced for PFV measurements. The level of agreement observed between the two methods was such that their interchangeable use in clinical practice is not recommended.Item Strabometry precision: intra-examiner repeatability and agreement in measuring the magnitude of the angle of latent binocular ocular deviations (heterophorias or latent strabismus)(Binocular vision & strabology quarterly, Simms-Romano's, 2011) Antona Peñalba, Beatriz; González Díaz-Obregón, Enrique; Barrio De Santos, Ana Rosa; Barra Lázaro, Francisco; Sánchez Pérez, Isabel; Cebrián, José LuisBACKGROUND AND PURPOSE: This study was designed to compare heterophoria measurements obtained using the methods: prisms cover test (prism alternate cover test), von Graefe technique, Maddox rod test and modified Thorington test. Given the different methodological features of these tests, our working hypothesis was that these tests would not be interchangeable and repeatability would vary. METHODS: Horizontal deviation measurements were made at: far distance (six meters) and near distance (40 centimeters) on two occasions in 61 young subjects of mean age 19.7 years (range 18 -32 years), with essentially normal eyes and vision, who were not familiar with the methods used. Statistical repeatability and agreement were determined using the Bland and Altman method. RESULTS: Repeatability: No difference between the results of the various heterophoria tests was statistically significant. Coefficients of repeatability were always best when the tests were conducted at far, the cover test being the most repeatable. Agreement: Mean differences between absolute values ranged from 1.7 prism diopters to 5.1 prism diopters for measurements at far and from 2.1 prism diopters to 3.4 prism diopters at near. CONCLUSIONS: The alternating prism cover test was the most repeatable test for measuring latent horizontal deviations. Among the subjective tests, the modified Thorington test was the most repeatable. The low level of agreement observed between the different tests makes their interchangeable use in clinical practice not recommended.Item Repeatability of the Modified Thorington Card Used to Measure Far Heterophoria(Optometry and Vision Science, 2014) Cebrián, José Luis; Antona Peñalba, Beatriz; Barrio De Santos, Ana Rosa; González Díaz-Obregón, Enrique; Gutiérrez Hernández, Ángel Luis; Sánchez Pérez, María IsabelPurpose. To determine the interexaminer and intraexaminer repeatability of the modified Thorington test (TH) for distance vision in young adults and to compare these results with those observed for the heterophoria tests most commonly used in clinical practice. Agreement among tests was also assessed. Methods. Distance heterophoria was quantified on two separate occasions by two examiners in 110 subjects aged 18 to 32 years (mean, 19.74 years; SD, 2.5 years) using four different tests: cover test (CT) Von Graefe, Maddox rod, and modified TH. The repeatability of the tests and agreement between them was estimated by the Bland and Altman method whereby the mean difference and the 95% limits of agreement were determined as the coefficient of repeatability (COR) and coefficient of agreement. Results. The Thorington test showed best interexaminer repeatability (COR = +/- 1.43 Delta), followed closely by CT (COR = +/- 1.65 Delta), whereas best intraexaminer repeatability was observed for CT (COR = +/- 1.28 Delta) followed by TH (COR = +/- 1.51 Delta). Among the different combinations of tests, TH and CT showed best agreement indicated by the lowest coefficient of agreement (+/- 2.23 Delta) and a low mean difference (-0.63 Delta) between measurements. Conclusions. Good interexaminer and intraexaminer repeatability was observed for both TH and CT, and agreement between the two tests was also good. Given the simple administration of the TH, we recommend its clinical use to quantify distance horizontal heterophoria.Item Intraexaminer repeatability and agreement in stereoacuity measurements made in young adults(International journal of ophthalmology., 2015) Antona Peñalba, Beatriz; Barrio De Santos, Ana Rosa; Sánchez Pérez, María Isabel; González Díaz-Obregón, Enrique; González Montero, María GuadalupeAIM: To determine the repeatability and agreement of stereoacuity measurements made using some of the most widely used clinical tests: Frisby, TNO, Randot and Titmus. METHODS: Stereoacuity was measured in two different sessions separated by a time interval of at least 24h but no longer than 1wk in 74 subjects of mean age 20.6y using the four methods. The study participants were divided into two groups: subjects with normal binocular vision and subjects with abnormal binocular vision. RESULTS: Best repeatability was shown by the Frisby and Titmus [coefficient of repeatability (COR): 依13 and 依12s arc respectively] in the subjects with normal binocular vision though a clear ceiling effect was noted. In the subjects with abnormal binocular vision, best repeatability was shown by the Frisby (COR: 依69s arc) and Randot (COR: 依72s arc). In both groups, the TNO test showed poorest agreement with the other tests. CONCLUSION: Therepeatabilityof stereoacuitymeasures was low in subjects with poor binocular vision yet fairly good in subjects with normal binocular vision with the exception of the TNO test. The reduced agreement detected between the tests indicates they cannot be used interchangeably.Item Validity and repeatability of a new test for aniseikonia(Investigative Ophthalmology & Visual Science, 2007) Antona Peñalba, Beatriz; Barra Lázaro, Francisco; Barrio de Santos, Ana Rosa; González Díaz-Obregón, Enrique; Sánchez Pérez, IsabelPURPOSE. The Aniseikonia Inspector 1.1 (AI) is a new software product to measure aniseikonia using red-green anaglyphs. The purpose of this study was to test whether the AI is a valid and reliable test. METHODS. There were two groups of sample subjects: one at risk of aniseikonia, with anisometropia greater than or equal to 1.00 D (n = 29), and a control group (n = 45). The validity was studied by comparing the measured aniseikonia with the aniseikonia simulated with size lenses. The reliability was estimated by the Bland-Altman statistical method. RESULTS. The results showed that the AI underestimated aniseikonia and that the underestimation was greater in the horizontal than in the vertical direction. The reliability was low, with biases that were clinically insignificant, but the 95% limits of agreement were around +/- 2%. The behavior of the test was similar in both groups of subjects. CONCLUSIONS. The reliability of the AI is only moderate, and professionals are therefore warned to use the results of this test with caution.