Carles Otero

Does the Badal optometer stimulate accommodation accurately

To study whether the accommodation response to Badal optometer is equivalent to the response for real space targets.

Repeatability of aberrometric measurements with a new instrument for vision analysis based on adaptive optics

PURPOSE To evaluate intersession and intrasession repeatability of aberration data obtained with a new visual simulator based on adaptive optics, which includes a Hartmann-Shack aberrometer (Adaptive Optics Vision Analyzer; Voptica S.L., Murcia, Spain). METHODS Thirty-one healthy right eyes were included in the study. To evaluate intrasession repeatability, three consecutive measurements without repositioning the patient or realigning the eye were obtained. Intersession repeatability was evaluated in three sessions. Aberrometric data computed from the second to the fifth order for a 4-mm pupil were used. Statistical analysis included the repeated measures analysis of variance (or the Wilcoxon signed rank test), the coefficient of repeatability, the Bland-Altman method, and the intraclass correlation coefficient. RESULTS No significant differences in the intrasession and intersession repeatability analysis for any of the parameters (P > .05) were found, suggesting a consistent variability of the instrument over time. Similar coefficient of repeatability values were obtained in the three sessions. The Bland-Altman analysis confirmed differences close to zero and the variations were independent of the mean within and between sessions. The intersession intraclass correlation coefficient values were generally above 0.75, suggesting moderate to high repeatability. However, some exceptions were found in the intrasession analysis. CONCLUSIONS The findings suggest that the new instrument provides consistent and repeatable aberrometric data. It is therefore a suitable tool to perform consistent and repeatable visual simulations.

Spherical subjective refraction with a novel 3D virtual reality based system.

Purpose To conduct a clinical validation of a virtual reality-based experimental system that is able to assess the spherical subjective refraction simplifying the methodology of ocular refraction. Methods For the agreement assessment, spherical refraction measurements were obtained from 104 eyes of 52 subjects using three different methods: subjectively with the experimental prototype (Subj.E) and the classical subjective refraction (Subj.C); and objectively with the WAM-5500 autorefractor (WAM). To evaluate precision (intra- and inter-observer variability) of each refractive tool independently, 26 eyes were measured in four occasions. Results With regard to agreement, the mean difference (±SD) for the spherical equivalent (M) between the new experimental subjective method (Subj.E) and the classical subjective refraction (Subj.C) was −0.034 D (±0.454 D). The corresponding 95% Limits of Agreement (LoA) were (−0.856 D, 0.924 D). In relation to precision, intra-observer mean difference for the M component was 0.034 ± 0.195 D for the Subj.C, 0.015 ± 0.177 D for the WAM and 0.072 ± 0.197 D for the Subj.E. Inter-observer variability showed worse precision values, although still clinically valid (below 0.25 D) in all instruments. Conclusions The spherical equivalent obtained with the new experimental system was precise and in good agreement with the classical subjective routine. The algorithm implemented in this new system and its optical configuration has been shown to be a first valid step for spherical error correction in a semiautomated way.

Comparison of the Adaptive Optics Vision Analyzer and the KR-1 W for measuring ocular wave aberrations.

The aim was to assess the agreement in the measurement of ocular aberrations between a new Adaptive Optics Vision Analyzer (AOVA, Voptica, Murcia, Spain) and a commercial aberrometer (KR‐1 W, Topcon, Tokyo, Japan), both based on the Hartmann–Shack technique.

Random Changes of Accommodation Stimuli: An Automated Extension of the Flippers Accommodative Facility Test

ABSTRACT Purpose: To study the accommodative dynamics for predictable and unpredictable stimuli using manual and automated accommodative facility tests Materials and Methods: Seventeen young healthy subjects were tested monocularly in two consecutive sessions, using five different conditions. Two conditions replicated the conventional monocular accommodative facility tests for far and near distances, performed with manually held flippers. The other three conditions were automated and conducted using an electro-optical system and open-field autorefractor. Two of the three automated conditions replicated the predictable manual accommodative facility tests. The last automated condition was a hybrid approach using a novel method whereby far and near-accommodative-facility tests were randomly integrated into a single test of four unpredictable accommodative demands. Results: The within-subject standard deviations for far- and near-distance-accommodative reversals were (±1,±1) cycles per minute (cpm) for the manual flipper accommodative facility conditions and (±3, ±4) cpm for the automated conditions. The 95% limits of agreement between the manual and the automated conditions for far and near distances were poor: (−18, 12) and (−15, 3). During the hybrid unpredictable condition, the response time and accommodative response parameters were significantly (p < 0.05) larger for accommodation than disaccommodation responses for high accommodative demands only. The response times during the transitions 0.17/2.17 D and 0.50/4.50 D appeared to be indistinguishable between the hybrid unpredictable and the conventional predictable automated tests. Conclusions: The automated accommodative facility test does not agree with the manual flipper test results. Operator delays in flipping the lens may account for these differences. This novel test, using unpredictable stimuli, provides a more comprehensive examination of accommodative dynamics than conventional manual accommodative facility tests. Unexpectedly, the unpredictability of the stimulus did not to affect accommodation dynamics. Further studies are needed to evaluate the sensitivity of this novel hybrid technique on individuals with accommodative anomalies.

Effect of apparent depth cues on accommodation in a Badal optometer: Apparent depth cues on accommodation Otero,Aldaba, Martínez-Navarro and Pujol

The aim was to analyse the effect of peripheral depth cues on accommodation in Badal optometers.

Effect of apparent depth cues on accommodation in a Badal optometer

The aim was to analyse the effect of peripheral depth cues on accommodation in Badal optometers.