Choroidal thickness and area over 3 years in the Bifocal Lenses in Nearsighted Kids (BLINK) Study

Abstract

Purpose : We previously reported the choroid thickened after 2 weeks of +2.50D add multifocal contact lens (MFCL) wear. Here, we report longitudinal choroid data over 3 years.

Methods : A total of 281 of 294 myopic children aged 7-11 years in the BLINK Study contributed data. Participants were randomly assigned to wear single vision contact lenses (SVCL), +1.50D add, or +2.50D add center-distance MFCLs. Spectral-domain optical coherence tomography star scans (30° B-scans; 6 meridians; right eye) were acquired before and 2 weeks after starting contact lens wear, and then yearly in follow-up mode. B-scans were cropped by 2° per side to eliminate most edge and optic nerve artifacts. Validated semi-automated routines were used to segment the retinal pigmented epithelium/choroid boundary and choroid/sclera boundary. Repeated measures linear regression was used to test for the effect of treatment group and visit on subfoveal choroidal thickness and choroidal area within the central 26° of the 6 B-scans, adjusting for baseline thickness/area, clinic site, sex, age, photopic pupil size, and baseline axial length.

Results : Baseline mean (±SD) subfoveal choroidal thickness (303 ± 58 µm) and choroidal area (2.25 ± 0.39 mm²) did not differ between groups (both p ≥ .85). Mean (±SE) subfoveal choroidal thickness and area across all visits after initiating contact lens wear were greater in the +2.50D MFCL group than the SVCL group by 7 ± 3 µm (p = .013) and 0.06 ± 0.02 mm² (p = .004), respectively. These group differences did not change through the 3-year study (group by visit interaction; both p ≥ .54). There were no significant differences between the +1.50D MFCL and SVCL groups in subfoveal thickness (p = .28) or area (p = .27). Other than initial thickening in the +2.50D group after initiating MFCL wear, there were no significant changes over 3 years in either subfoveal thickness (p = .07) or choroidal area (p = .12).

Conclusions : There was an initial increase in choroidal thickness and area 2 weeks after initiating +2.50D MFCL wear that was maintained over the next 3 years. There were no other significant differences in the choroid throughout the 3-year study.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.