Effectiveness of a Spectacle Lens with a Specific Asymmetric Myopic Peripheral Defocus: 12-Month Results in a Spanish Population.

BACKGROUND: Different designs of ophthalmic lenses have been studied to control the progression of myopia in children. This study aims to evaluate the short-term efficacy of a new design of ophthalmic lens with asymmetric myopic peripheral defocus (MPDL) on myopia progression in children compared to a control group wearing a single-vision lens (SVL). METHODS: Children aged 5 to 12 with myopia up to -0.50 D, astigmatism and anisometropia under 1.50 D, and corrected visual acuity over 20/20 were randomized to either the study group (MPDL) or control group (SVL). The myopia progression was evaluated by measuring axial length (AL) growth (IOL Master; Zeiss) over a period of one year. RESULTS: Ninety-two subjects were recruited. Forty-six children were randomly assigned to the control group, and 46 to the study group. In total, 83 children completed the clinical trial, with a mean age of 10.81 [9.53-11.92] years, among which 59.04% were female. After one year of treatment, there was less AL elongation in the study group compared to the control group (0.16 ± 0.16 mm vs. 0.24 ± 0.16 mm, p = 0.034). CONCLUSIONS: The MPDL significantly reduced the absolute growth of AL by 39% (p = 0.014) and relative growth of AL by 37.3% (p = 0.012) after 12 months in comparison to the control group in a Spanish population.

Correlation between reading time and characteristics of eye fixations and progressive lens design.

OBJECTIVE: The purpose of this study is to evaluate reading time and characteristics of fixations at different distances when looking through different areas of progressive power lenses (PPL) with different power distributions by means of eye-tracking technology. METHOD: A wearable eye tracker system (Tobii-Pro Glasses 3) was used to record the pupil position of 28 PPL subjects when reading at near and distance vision while using 3 different PPL designs: a PPL optimized for distance vision (PPL-Distance), a PPL optimized for near vision (PPL-Near) and one of them balanced for a general use (PPL-Balance). Subjects were asked to read out loud a text displayed on a digital screen located at 5.25m and 0.37m when they were looking through the central and peripheral regions of each PPL. Reading time, total duration of fixations, and the number of fixations were analyzed for each reading condition and PPL. Statistical analysis was carried out using Statgraphics Centurion XVII.II Software. RESULTS: The analysis of eye movements at distance-reading vision showed a statistically significant lower reading time (p = 0.004) and lower total duration of fixations (p = 0.01) for PPL-Distance. At near-reading vision, PPL-Near provided statistically significant lower reading time (p<0.001), lower total duration of fixations (p = 0.02), and less fixation count(p<0.001) in comparison with PPL-Balance and PPL-Distance. CONCLUSIONS: Reading time and fixations characteristics are affected by the power distribution of a PPL. A PPL design with a wider distance region provides better distance-reading performance while a PPL with a wider near area performs better at a near-reading task. The power distribution of PPLs influences the user performance at vision-based tasks. Thus, to provide the user with the best visual experience, PPL selection must consider user needs.

Early Detection of Refractive Errors by Photorefraction at School Age.

Early detection and treatment of refractive defects during school age are essential to avoid irreversible future vision loss and potential school problems. Previously, vision screening of preschool children used methods based on subjective visual acuity; however, technologies such as photorefraction have promoted the detection of refractive errors quickly and easily. In this study, 1347 children from 10 schools in Madrid aged 4 to 12 years participated in a program of early detection of visual problems, which consisted of visual screening composed of anamnesis and photorefraction with a PlusOptix A12R. The prevalence of refractive errors was analyzed in terms of spherical equivalent, cylinder and its orientation, and potential cases of development of high myopia or amblyopia. Hyperopia predominates in the early years, but the number of myopic subjects is higher than that of hyperopic subjects from the age of ten onwards. At all ages, the predominant orientation of astigmatism was with-the-rule. On average, 80% of the myopic subjects were uncorrected. Potential high myopia increased with age, from 4 to 21% of the measured population. Potential amblyopia cases decreased across age groups, from 19 to 13.7%. There is a need to raise awareness of the importance of vision screening at school age to address vision problems.