Diverse Segments Defocus Optimization spectacle lenses induce rapid changes in axial length and regional changes in choroidal thickness in children with myopia.

Purpose: To investigate rapid changes in axial length (AL) and regional changes in choroidal thickness (ChT) and the choroidal vessel index (CVI) in myopic children with myopia caused by optical defocus.

Methods: Sixty-two eyes of 31 children wearing Diverse Segments Defocus Optimization (DSDO) spectacle lenses and 58 eyes of 29 children wearing single-vision spectacle lenses (SVL) were included. All participants were fully corrected and evaluated before and immediately after 30 min of reading. ChT and CVI were measured using swept-source optical coherence tomography in different regions, including the central, inner and outer ring areas and the superior, inferior, nasal and temporal regions. AL was also measured.

Results: At baseline, ChT was significantly lower in the nasal quadrant than in other quadrants (all p < 0.001) and the CVI was significantly higher in the nasal quadrant than in the superior and temporal quadrants (all p < 0.01). After 30 min of reading, AL was significantly reduced in the DSDO group and increased in the SVL group. In the DSDO group, the ChT increased significantly in all areas, with the greatest increase observed in the inner ring area. In the SVL group, the ChT decreased in all areas, with the smallest decrease occurring in the inner ring area. CVI did not change significantly after reading in either group.

Conclusions: In the early stage of lens wear, SVL induced a rapid increase in AL and decreased ChT in different areas, while DSDO induced rapid AL shortening and increased ChT in varying regions. ChT differed more in the inner than in the outer ring regions, while the superior region showed the most significant change in ChT. These findings provide new perspectives for the optimal design of optical defocus lenses.