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
2 results
Search Results
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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 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.