Associations between axial length, corneal refractive power and lens thickness in children and adolescents: The Ural Children Eye Study

Differences in anterior ocular biometric characteristics among 6-year-old children with different myopic shift rates: A 2-year longitudinal study

BACKGROUND

To investigate longitudinal changes in anterior ocular features during slow and fast myopic shift in 6-year-old children.

METHODS

In total, 242 eyes of first-year primary school children in Shanghai, China, were included in this study. All children underwent an initial examination and were subsequently followed-up for two years. All participants underwent comprehensive examinations, including ocular biometric assessment and cycloplegic autorefraction. Children were divided into two groups based on the degree of myopic shift in 2 years: group A (slow myopic shift, < 1.0 D, N = 145) and group B (fast myopic shift, > 1.0 D, N = 88). Detailed anterior ocular biometric data were compared between the two groups.

RESULTS

In both groups, the axial length and anterior chamber depth (ACD) increased significantly over the follow-up period (P < 0.001). Anterior corneal surface curvature showed a flattening trend in both flat and steep meridians in group A, while these parameters exhibited steepening changes in group B. Lens thickness (LT) decreased significantly from 3.60 ± 0.20 mm to 3.45 ± 0.17 mm in group B (P < 0.001), but not in group A (P = 0.387). The average lens tilt significantly decreased from 5.21 ± 1.26° to 4.95 ± 1.23° in group A (P = 0.043), but it exhibited no significant change in group B (P = 0.181). Furthermore, LT and ACD were significantly correlated with spherical equivalent changes (P < 0.01).

CONCLUSIONS

Children with slow and fast myopic shift demonstrated comparable ACD deepening changes but showed distinct variations in corneal curvature and lens characteristics.

Factors influencing dominant eye selection in refractive surgery patients: A correlation analysis

OBJECTIVE

This study aims to reveal the factors influencing the selection of the dominant eye in refractive surgery patients, and enhance the accuracy of clinical evaluation and surgical treatment.

METHODS

A retrospective study method was employed. The ocular biometric parameters were analyzed in 4,114 patients who underwent refractive surgery at the affiliated hospital of Southwest Medical University from 2019 to 2023.

RESULTS

The study found that 79.07% of the patients had the right eye as the dominant eye, while 20.93% had the left eye. Although there was no significant difference between the dominant and non-dominant eyes in terms of uncorrected visual acuity and Kappa angle, the dominant eye performed better in aspects such as spherical lens, eye axis, and corneal flat curvature. Furthermore, univariate and multivariate logistic regression results showed that best-corrected visual acuity, pupil diameter, horizontal displacement x-value of the Kappa angle, and astigmatism vector J45 were significant influencing factors for the selection of the dominant eye.

CONCLUSION

There are numerous factors affecting the dominant eye, and the most important core factor is J45. This study comprehensively evaluated the possible factors affecting the dominant eye in patients undergoing refractive surgery, which provides a foundation for the designation of refractive surgical modalities and assurance of surgical outcomes, and opens up new perspectives on understanding the mechanisms of the formation and development of the dominant eye.