The use of progressive addition lenses to improve the daily visual function of children receiving topical atropine treatment.

PURPOSE: To evaluate the changes in visual function when progressive addition lenses (PAL) are added in children using topical atropine as a myopia control therapy. Daily visual complaints and the determination of their near correction were studied. METHODS: Forty children aged 7-12 years were recruited. Distance and near visual acuity, accommodative lag, heterophoria, near point of convergence and stereopsis were examined, and a questionnaire of daily visual complaints was administered. RESULTS: Significant differences in visual functions were found after the near correction was prescribed. Significant improvements in distance and near visual acuity, lag of accommodation and binocular visual function were observed, and fewer visual complaints were reported at the Harmon distance. CONCLUSION: The use of PAL is helpful for children undergoing topical atropine treatment for myopia control, particularly those receiving medium to high doses. This combination therapy could also be applied to younger children who have a low tolerance to contact lenses, with less risk of ocular adverse effects.

The Impact of Clinical Atropine Use in Taiwanese Schoolchildren: Changes in Physiological Characteristics and Visual Functions.

Taiwan is commonly noted for its high prevalence of myopia, as well as a long history of more than 20 years of using atropine to control myopia. However, the clinical implications are rarely discussed. This is a cross-sectional study investigating the influence of topical atropine instillation on ocular physiology, visual function, and visual discomfort in children. Aged 7 to 12 years, 212 schoolchildren were recruited and divided into the atropine group and the non-atropine group. Physiological characteristics such as pupil size and intraocular pressure were measured, and a variety of visual functions was also evaluated. A questionnaire was used to investigate the side effects and visual complaints caused by atropine treatment. There was a significant difference in pupil size (OD: 5.40 ± 0.90 vs. 6.60 ± 1.01 mm; OS: 5.42 ± 0.87 vs. 6.64 ± 1.00 mm, p < 0.001) between the two groups. Reductions in near visual acuity, accommodation, convergence ability, and stereopsis were observed in the atropine group. The horizontal pupil diameter enlarged, and visual functions were greatly affected after administration of topical atropine. The changes in visual function during atropine therapy need to be carefully monitored by clinicians, while patient compliance is usually the key to success.

The Correlations between Horizontal and Vertical Peripheral Refractions and Human Eye Shape Using Magnetic Resonance Imaging in Highly Myopic Eyes.

The aim of this study was to determine the relationship between relative peripheral refraction and retinal shape by 2-D magnetic resonance imaging in high myopes. Thirty-five young adults aged 20 to 30 years participated in this study with 16 high myopes (spherical equivalent < -6.00 D) and 19 emmetropes (+0.50 to -0.50 D). An open field autorefractor was used to measure refractions from the center out to 60° in the horizontal meridian and out to around 20° in the vertical meridian, with a step of 3 degrees. Axial length was measured by using A-scan ultrasonography. In addition, images of axial, sagittal, and tangential sections were obtained using 2-D magnetic resonance imaging. The highly myopic group had a significantly relative peripheral hyperopic refraction and showed a prolate ocular shape compared to the emmetropic group. The highly myopic group had relative peripheral hyperopic refraction and showed a prolate ocular form. Significant differences in the ratios of height/axial (1.01 ± 0.02 vs. 0.94 ± 0.03) and width/axial (0.99 ± 0.17 vs. 0.93 ± 0.04) were found from the MRI images between the emmetropic and the highly myopic eyes (p < 0.001). There was a negative correlation between the retina's curvature and relative peripheral refraction for both temporal (Pearson r = -0.459; p < 0.01) and nasal (Pearson r = -0.277; p = 0.011) retina. For the highly myopic eyes, the amount of peripheral hyperopic defocus is correlated to its ocular shape deformation. This could be the first study investigating the relationship between peripheral refraction and ocular dimension in high myopes, and it is hoped to provide useful knowledge of how the development of myopia changes human eye shape.

Peripheral Refraction in Myopic Children with and without Atropine Usage.

PURPOSE: To compare the patterns of relative peripheral refractions of myopic children who were currently on atropine treatment for myopia control and myopic children who did not use atropine. METHODS: Chinese children (n = 209) aged 7 to 12 years participated in the study, 106 used atropine and 103 did not. Participants were also classified into three groups: emmetropes (SE: +0.50 to -0.50 D), low myopes (SE: -0.50 to -3.00 D), and moderate myopes (SE: -3.00 to -6.00 D). The central and peripheral refractions along the horizontal meridians (for both nasal and temporal fields) were measured in 10-degree steps to 30 degrees. RESULTS: There were no statistically significant differences in spherical equivalent and astigmatism of the three refractive groups in either the nasal or temporal retina. The atropine group showed a significant relative myopia in the temporal 30° field in spherical equivalent compared to the emmetropic group (t 49 = 3.36, P=0.02). In eyes with low myopia, the atropine group had significant relative myopia in the nasal 30° and temporal 30° fields (t 118 = 2.59, P=0.01; t 118 = 2.06, P=0.04), and it is also observed at 20° and 30° of the nasal field for the moderate myopic group (t 36 = 2.37, P=0.02; t 2.84 = 2.84, P=0.01). CONCLUSION: Significant differences in relative peripheral refraction were found between the atropine group and its controls. The findings suggested that the eyes that received atropine may have a less prolate shape and thus explain why using atropine is effective in controlling myopia progression.

Dot Motion Perception in Young Adult Emmetropes and Myopes.

SIGNIFICANCE: Central motion perception, as assessed by minimum displacement detection, was reduced in highly myopic eyes. Peripheral motion detection may be influenced by myopia, particularly in the inferior-nasal retina. PURPOSE: Motion discrimination is a complex visual task processed mainly via the magnocellular pathway. We investigated whether it is affected in myopia. METHODS: Ninety young adults aged 18 to 28 years participated: 30 emmetropes (spherical equivalent refractions +1.00 to -0.50 diopters [D]), 30 low myopes -1.00 to -4.75 D) and 30 higher myopes (<-5 D). Random dot patterns were used to measure motion perception thresholds for minimum displacement (Dmin), maximum displacement (Dmax), and motion coherence tasks. Each task was performed centrally and at four oblique peripheral visual field locations (at 3.65 and 12 degrees for Dmin and Dmax tasks, respectively). Macular retinal thickness was measured with optical coherence tomography. RESULTS: The central Dmin task was correlated significantly with refraction (r = -0.303, P = .004) and axial length (r = +0.224, P = .04), and the superior-temporal field Dmin task was correlated significantly with axial length (r = 0.230, P = .04). Higher myopes had poorer performance than emmetropes by 25% (higher values). For the Dmin peripheral task and for Dmax and coherence tasks at both central and peripheral locations, there were no significant correlations with refraction or axial length. At three of four positions, the peripheral Dmin task was correlated significantly with thickness in the corresponding retinal region: superior-temporal Dmin (Pearson r = -0.357, P < .001), inferior-nasal Dmin (r = -0.237, P = .03) and inferior-temporal Dmin (r = -0.233, P = .03). CONCLUSIONS: Central motion perception, as assessed by minimum displacement detection, was reduced by 25% in highly myopic eyes. Peripheral motion detection may be influenced by myopia, particularly in the inferior-nasal retina. Retinal stretching due to axial elongation may be linked to reduced performance in higher myopes.

Visual backward masking performance in young adult emmetropes and myopes.

PURPOSE: To investigate how temporal processing is altered in myopia and during myopic progression. METHODS: In backward visual masking, a target's visibility is reduced by a mask presented quickly after the target. Thirty emmetropes, 40 low myopes, and 22 high myopes aged 18 to 26 years completed location and resolution masking tasks. The location task examined the ability to detect letters with low contrast and large stimulus size. The resolution task involved identifying a small letter and tested resolution and color discrimination. Target and mask stimuli were presented at nine short interstimulus intervals (12 to 259 ms) and at 1000 ms (long interstimulus interval condition). RESULTS: In comparison with emmetropes, myopes had reduced ability in both locating and identifying briefly presented stimuli but were more affected by backward masking for a low contrast location task than for a resolution task. Performances of low and high myopes, as well as stable and progressing myopes, were similar for both masking tasks. Task performance was not correlated with myopia magnitude. CONCLUSIONS: Myopes were more affected than emmetropes by masking stimuli for the location task. This was not affected by magnitude or progression rate of myopia, suggesting that myopes have the propensity for poor performance in locating briefly presented low contrast objects at an early stage of myopia development.