HOAs May Influence Axial Growth in Combined Ortho-K, Atropine Treatment

For children undergoing combined 0.01% atropine and orthokeratology treatment (AOK), higher-order aberrations (HOAs) may influence axial growth, according to research published in Eye and Vision. Since individuals treated with orthokeratology (OK) alone experienced similar retinal image quality with those treated with AOK, this finding suggests that retinal image quality cannot explain the slower axial growth observed with combined AOK treatment.

Researchers included 68 pediatric patients in the investigation and randomly assigned participants 1:1 to treatment with AOK (n=33; mean age, 9.3 years; 15 girls) or OK (n=35; mean age, 9.1 years; 15 girls) for 2 years. The team compared visual Strehl ratio based on the optical transfer function (VSOTF) derived from combined LOA and HOA, LOA alone, and HOA alone for fixed 3 mm and natural photopic pupil diameters. They also compared individual Zernike coefficients for a fixed 3 mm pupil size of 2nd to 4th orders, root mean square (RMS) of LOA, HOA (3rd to 4th orders inclusive), and coma between the 2 cohorts.

Patients treated with AOK demonstrated a significantly lower VSOTF based on HOA only compared with participants treated with OK at all post treatment visits in photopic conditions (all P <.05), the report shows. However, interactions between HOA and LOA resulted in comparable overall retinal image quality between the 2 groups at all visits (all P >.05). The VSOTF based on HOAs only, LOA only, or HOA and LOA combined, were not different between the 2 groups for a fixed 3mm pupil size (all P >.05), and individuals treated with AOK experienced slower axial elongation (P <.001) and had a larger photopic pupil size (P <.001) compared with participants undergoing OK.

“[R]etinal image quality cannot account for the improved effect in retarding axial elongation resulted from the combination treatment,” the study authors explain. “However, reduced VSOTF based on HOA only and less axial elongation in the AOK group, could point to a potential visual signal related to HOA that may slow eye growth.”

Study limitations include an ethnically homogeneous cohort, which may limit generalizability of the findings.