One-year Efficacy of the Defocus Incorporated Multiple Segment Lens in Chinese Myopic Children

Effectiveness of repeated low-level red light in myopia prevention and myopia control

BACKGROUND/AIMS

To compare the effects of repeated low-level red light (RLRL) treatment on axial length growth and refractive error changes in myopic and premyopic children.

METHODS

Subjects were assigned randomly to four subgroups: myopia-RLRL group (M-RL), myopia-control group (M-C), premyopia-RLRL group (PM-RL) and premyopia-control group (PM-C). Subjects in the RLRL group completed a 12-month treatment composed of a 3 min RLRL treatment session twice daily, with an interval of at least 4 hours, for 7 days per week. Visits were scheduled before and at 1-month, 3-month, 6-month, 9-month and 12-month follow-up after the treatment. Repeated-measures analysis of variance was used to compare the spherical equivalent refractive errors (SE) and axial length (AL) changes between the groups across the treatment period.

RESULTS

After 12 months of treatment, in the myopia group, SE and AL changes were -0.078±0.375 D and 0.033±0.123 mm for M-RL and -0.861±0.556 D and 0.415±0.171 mm for M-C; in the premyopia group, the progression of SE and AL was -0.181±0.417 D and 0.145±0.175 mm for PM-RL and -0.521±0.436 D and 0.292±0.128 mm for PM-C. PM-RL indicated a lower myopia incidence than PM-C (2.5% vs 19.4%). Additionally, the percentage of AL shortening in the M-RL was higher than that in the PM-RL before the 9-month follow-up.

CONCLUSION

RLRL effectively delayed myopia progression in children with myopia and reduced the incidence of myopia in premyopic children. Moreover, RLRL exhibited a stronger impact on myopic children compared with premyopic individuals.

Different efficacy in myopia control: Comparison between orthokeratology and defocus-incorporated multiple segment lenses

PURPOSE

To compare the efficiency of orthokeratology (OK) and defocus-incorporated multiple segment (DIMS) lenses in myopia control in children.

METHODS

This prospective study involved 540 subjects (7-14 years) categorized into three groups: DIMS lenses (180 cases), OK lenses (180 cases), or single-vision spectacles (SVS) (180 cases). After a one-year follow-up, changes in axial length (AL) and differences among the groups were analyzed. The subjects were further divided into a low myopia degree subgroup (LM, -1.50 D ≤ SE ≤ -0.50 D), a moderate myopia degree subgroup (MM, -3.00 D ≤ SE ＜ -1.50 D), and a high myopia degree subgroup (HM, -5.00 D ≤ SE ＜ -3.00 D). A one-way ANOVA and multiple linear regression analysis were used to compare AL elongation and the factors influencing the different groups.

RESULTS

A total of 496 (92 %) subjects completed the study. The mean AL change in the OK lenses, DIMS lenses, and SVS were 0.20±0.18 mm, 0.30±0.22 mm, and 0.38±0.19 mm, respectively (P < 0.001). In the LM subgroup, the OK and DIMS groups showed similar AL changes, but both exhibited slower changes than the SVS group (P = 0.001). In the MM and HM subgroups, the OK lens performed the shortest AL elongation compared with the DIMS lenses and SVS (P < 0.001). Multiple regression analysis showed that the AL change was associated with age (β = -0.038 and P = 0.005), initial AL (β = -0.010 and P = 0.011), initial SE (β = 0.028 and P = 0.007), and interventions using OK lenses (β = -0.172 and P = 0.020) and DIMS lenses (β = -0.089 and P = 0.020).

CONCLUSION

Over a one-year treatment period, OK and DIMS lenses can significantly retard AL elongation compared with SVS. In addition, the OK lenses were more effective than the DIMS lenses in controlling AL in patients with higher degrees of myopia.

The Impact of Vergence Dysfunction on Myopia Control in Children Wearing Defocus Spectacle Lenses

Purpose

To investigate the impact of vergence dysfunction on myopia progression in children with Defocus incorporated multiple segments (DIMS) spectacle lenses.

Patients and Methods

We retrospectively enrolled children prescribed DIMS spectacle lenses to slow myopic progression. Baseline vergence dysfunction was determined according to phoria at distance and near. Axial length (AL) measurement and cycloplegic subjective refraction were performed before fitting the lenses and at six-month and one-year follow-ups. The six-month and one-year AL and spherical equivalent (SE) change from baseline were calculated and compared in subgroups stratified with the type of vergence dysfunction.

Results

Two hundred and ninety-two myopic children were included. Significant AL elongation and SE progression were observed at six months and one year (P < 0.05 for all comparisons). Multiple regression demonstrated that AL elongation at six months (P < 0.001) and one year (P < 0.001) was negatively correlated with age, and SE progression at six months was associated with age (P = 0.002). The AL elongation at six months in children with convergence excess was significantly greater than in normal myopic subjects (P = 0.011) and subjects with convergence insufficiency (P = 0.008), divergence excess (P = 0.007), divergence insufficiency (P = 0.024) and basic esophoria (P = 0.048) at six months.

Conclusion

The present research demonstrated that vergence dysfunction influences myopia progression for myopic children with DIMS, and the children with convergence excess suffer from the greatest myopia progression among different types of vergence dysfunction.

New Designs of Spectacle Lenses for the Control of Myopia Progression: A Scoping Review

Myopia control with new designs of spectacle lenses is a flourishing area of research. The present work reviews the effectiveness of new designs (DIMSs, defocus-incorporated multiple segments; CARE, cylindrical annular refractive element; HALs/SALs, highly/slightly aspherical lenslets; DOT, diffusion optics technology) aiming at slowing myopia progression. A search through the PubMed database was conducted for articles published between 1 January 2003 and 28 February 2023. Publications were included if they documented baseline central refraction (SER) and/or axial length (AL) data, and the change in these parameters, in myopic children wearing new designs of spectacle lenses (treatment group) compared to myopic children using single-vision lenses, SVLs (control group). The selection process revealed nine suitable articles. Comparing the mean and standard error values of the treatment and control groups, the highest differences in the change in the SER and AL were -0.80 (1.23) D [95% CI: -1.053 to -0.547; p < 0.001] and 0.35 (0.05) mm [95% CI: 0.252 to 0.448; p < 0.001], respectively; the effect of treatment provided by a HAL design, compared to SVLs, led to a deceleration of 54.8% in the SER and 50.7% in the AL. However, the heterogeneity of the results prevents reaching strong conclusions about the effectiveness of these new designs.

Evaluating the Effect of a Myopia Control Spectacle Lens Among Children in Israel: 12-Month Results

PURPOSE

To investigate the effectiveness of a novel spectacle lens designed to slow the progression of myopia in children.

DESIGN

A prospective, randomized, double blind clinical trial.

METHODS

One hundred twenty-six Israeli children aged 6-13 years with spherical equivalent (SER) refractive errors of -0.5 to -6.25 diopters (D) were randomized into either the Shamir Myopia Control (SMC) lens design group or the conventional single-vision spectacle lenses (SVL), the control group. Outcomes measured were changes in axial length and cycloplegic refraction as well as subjective rating of visual experience over a period of 12 months.

RESULTS

At 12 months, AL and SER progression were slowed by 0.11 mm (35%, P < .05) and 0.16 D (25%, P = .122), respectively. In the subgroup of 6-10-year-olds, AL and SER progression were slowed by 0.17 mm (41%, P < .05) and 0.31 D (43%, P < .05), respectively. Similarly, for the subgroup of children with 2 myopic parents AL and SER progression were slowed by 0.15 mm (45% P < .05) and 0.36 D (42%, P < .05), respectively. Subjective visual experience reported in the 12-month questionnaire revealed no difference between the SMC and SVL groups, and average daily wearing hours were also not different between the groups: 14 (±1.4) and 13.8 (±2.3) hours, respectively. The study continues to its second year.

CONCLUSIONS

SMC lenses were effective in slowing the progression of SER and AL, especially for younger children and those having 2 myopic parents. The subjective rating of visual experience and the daily duration of use reported by the SMC group at 12 months were similar to the control group, indicating good lens tolerability.

High myopia control is comparable between multifocal rigid gas-permeable lenses and spectacles

Purpose

Ocular pathology may be reduced by slowing myopia progression. The purpose of this study was to evaluate the potential of a novel custom-designed rigid gas permeable (RGP) contact lens to control high myopia by comparing the efficacy of multifocal RGP lenses and single-vision spectacles for high myopia control.

Methods

The medical records of children fitted with spectacles or multifocal rigid gas-permeable lenses between January 2018 and May 2020 were retrospectively reviewed. Children (5-17 years) with non-cycloplegic spherical equivalent refraction of ≤ -6.00 D or spherical equivalent refraction > - 6.00 D with baseline axial length ≥ 26.5 mm, and astigmatism of ≥ -2.00 D were included. Axial length and refraction were measured at baseline, before fitting the participants with multifocal rigid gas-permeable lenses or spectacles, and at 1- and 2-year follow-up visits. Changes in axial length were compared between the groups.

Results

Among the 77 children with 1-year follow-up data, the mean axial elongation was 0.20 ± 0.17 mm and 0.21 ± 0.14 mm in the multifocal rigid gas-permeable and control groups, respectively, without significant differences between groups (F = 0.004, p = 0.835). Among the 41 patients who completed 2 years of follow-up, the mean axial elongation values in the multifocal rigid gas-permeable and control groups were 0.21 ± 0.15 mm and 0.24 ± 0.13 mm, respectively, at the 1-year follow-up, and 0.37 ± 0.27 mm and 0.43 ± 0.23 mm, respectively, at the 2-year follow-up, without significant between-group differences at either time point (p = 0.224).

Conclusion

Axial length increased at a similar rate in both the control (spectacles) and multifocal rigid gas-permeable lens groups, suggesting that multifocal rigid gas-permeable lenses have no significant impact on controlling high myopia progression compared with spectacles.