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

SIGNIFICANCE: These data demonstrate that defocus incorporated multiple segment (DIMS) lens reduces myopia progression in children during the first year of use. PURPOSE: This study aimed to investigate the efficacy of DIMS myopia control spectacle lens in Chinese myopic children aged 6 to 15 years. METHODS: This is a retrospective study of 1-year longitudinal data. A total of 180 Chinese myopic children were selected from patients at Zhongshan Ophthalmic Center, Sun Yat-sen University, from February 2018 to January 2021. One group consisted of 90 children aged 6 to 15 years, with spherical equivalent refraction -0.50 to -7.75 D (-3.82 ± 1.57 D) and fitted with the DIMS lens. The other group consisted of 90 children fitted with single-vision spectacle lenses and matched with the DIMS group for age, sex, refraction, and progression of myopia in the previous year. One-year myopia progression was measured retrospectively in two groups. Unpaired t test was used to compare the myopia progression between the DIMS group and the control group. Pearson correlation was used to explore the relationship between myopia progression, age, and baseline refraction. RESULTS: After 1 year of DIMS lens wear, myopia progression was significantly lower in the DIMS group (-0.51 ± 0.50 vs. -0.85 ± 0.51 D, P < .001). Myopia progression was positively correlated with age in both groups. The difference between the DIMS and control groups was more pronounced for children aged 10 to 15 years than for children aged 6 to 9 years. CONCLUSIONS: This study confirms that the DIMS lens reduces myopia progression during the first year of use. Efficacy seems to increase with age.

Long-Term Axial Length Shortening in Myopic Orthokeratology: Incident Probability, Time Course, and Influencing Factors.

Purpose: Long-term axial length (AL) shortening in myopia is uncommon but noteworthy. Current understanding on the condition is limited due to difficulties in case collection. The study reported percentage, probability, and time course of long-term AL shortening in myopic orthokeratology based on a large database. Methods: This study reviewed 142,091 medical records from 29,825 subjects in a single-hospital orthokeratology database that were collected over 10 years. Long-term AL shortening was defined as a change in AL of -0.1 mm or less at any follow-up beyond 1 year. Incident probability was calculated based on multivariate logistic regression. Time course was estimated using mixed-effect regression model. Results: A total of 10,093 subjects (mean initial age, 11.70 ± 2.52 years; 58.8% female) with 80,778 visits were included. The number of subjects experienced long-term AL shortening was 1,662 (16.47%; 95% confidence interval, 15.75%-17.21%). Initial age showed significant impact on the incident occurrence (OR, 1.37; 95% confidence interval, 1.34-1.40; P < 0.001). The estimated probability of AL shortening was approximately 2% for subjects with initial age of 6 years and 50% for those aged 18. Among the 1662 AL shortening cases, the median magnitude of the maximum AL reduction was 0.19 mm. The shortening process mostly occurred within the initial 2 years. Subject characteristics had limited associations with the shortening rate. Conclusions: Long-term AL shortening is possible in subjects receiving myopic orthokeratology. Although age notably affect the incident probability, the time course seems to not vary significantly.

Analysis of the Prevalence and Situation of Myopia in Adolescents from South China.

PURPOSE: To conduct dynamic detection of refraction changes in adolescents with myopia and analyze the correlation between different reexamination times and factors that included age of onset, initial refractive power, and rate of myopia progression. METHODS: A total of 900 adolescents (aged 6-15 years) with myopia admitted to Zhongshan Ophthalmic Center between 2009 and 2013 were randomly selected in this investigation. All participants underwent objective refraction measurement with an autorefractometer (Topcon 8900) or streak retinoscopy and subjective refraction detection with an autorefractor (Nidek) or minus-lens procedures at different time intervals (6 months, 1, and 2 years). Accurate refractive power was obtained. All data were analyzed with SPSS 18.0 statistical software. RESULTS: The mean refractive power was increased by 0.56 ± 0.37 diopters(D) after 6 months, by 0.83 ± 0.45 D after 1 year, and by 1.50 ± 0.70 D after 2 years. Among the 900 adolescents, the most rapid increase in refractive power was observed at the age of 8 years at the 6-month reexamination, at the age of 8 and 9 years at the 1-year reexamination, and at the age of 7-9 years at the 2-year reexamination. The increase in index of refraction tended to diminish with aging. The different cycles of reexamination revealed a slowing of the rate of myopia progression along with the increase in the initial index of refraction. The highest rate of myopia progression was noted in low-myopic adolescents with initial refractive power ranging from -0.25 to 2.75 D. CONCLUSION: No positive correlation was documented between different cycles of reexamination and the refractive power. The increase in refractive power was associated with factors that included the reexamination cycle, age of onset, and initial refractive power.