Choroidal thinning may be associated with gender and age in children with myopia, according to findings published in Eye and Vision.
Researchers conducted a study of 168 myopic children (mean age 9.3±1.1 years, 52.4% boys, spherical equivalent of refraction (SER) range, -4.00 to -0.75). They performed comprehensive eye exams, cycloplegic refraction, anterior segment evaluations, and fundus exams at baseline and at 6 month follow up periods for 2 years. They also obtained spectral-domain optical coherence tomography images at baseline and 1 and 2 year follow up. Mean baseline measurements of SER, axial length (AL), subfoveal choroidal thickness, and visual acuity were -2.38±0.61 D, 24.58±0.72 mm, 231.58±54.04 µm, and 0.00±0.02 logMAR, respectively. Investigators randomly assigned participants to 1 of 3 treatment groups; personalized progressive addition lenses (PPAL) (n=59), fixed progressive addition lenses (FPAL) (n=48), or single vision lenses (SVL) (n=61) They observed no baseline differences between the cohorts after stratifying by lens type.
At 2 years follow up, the change in SER was −1.42±0.69 D for the PPAL, 0.65±0.26 D for the FPAL, and −1.48±0.57 D for the SVL cohorts with no significant differences among the groups (P =.537). AL was 0.65±0.23, −1.61±0.64, and 0.70±0.23 mm (P =.960), and subfoveal choroidal thickness was 202.17±46.7793, 210.87±68.29, and 209.51±64.98 μm (P =.578) for the PPAL, FPAL, and SVL groups, respectively.
Investigators noted significant changes in retinal nerve fiber layer thickness (P =.027), SER, AL, and choroidal thickness (all P <.001) from baseline, but no significant change in ganglion cell layer and inner plexiform layer thicknesses (P =.352). Researchers also observed a significant correlation between changes in AL and changes in SER at 1 and 2 year follow ups (year 1, r= −0.661, B= −0.234; year 2, r= −0.677, B= −0.233; both P <.001).
Researchers also noted that subfoveal choroidal thickness changes were more pronounced among girls (β, 17.258; P =.001), those with greater axial length elongation (β, −43.579; P =.002), patients with thicker baseline subfoveal choroidal thickness (β, −0.081; P =.046), and older children (β, −4.411; P =.049) at 2 year follow up.
After stratifying children into stable (SER increase ≤1.00 D, n=39) and rapid myopia progression (SER increase >1.00 D, n=129) groups, they observed no baseline differences for stable and rapid progressors. The choroid of the rapid progressors continued to thin during follow-up (P <.001) but investigators did not witness this among the stable progression cohort (P =.119).
Although changes in CT have often been attributed to compensatory AL growth, researchers conclude, “We believe that the change of CT during the myopic progression was not entirely due to the passive stretch thinning caused by the expansion of the vitreous chamber.”
Study limitations include failure to account for possible confounding factors of puberty-related growth on changes in CT measurements.
Xu M, Yu X, Wan M, et al. Two‑year longitudinal change in choroidal and retinal thickness in school‑aged myopic children: exploratory analysis of clinical trials for myopia progression. Eye Vis. 2022;9(1):5. doi:10.1186/s40662-022-00276-4