Analysis of the effects of corneal and lens characteristics on peripheral defocus of the retina and its relationship with myopia

This study investigated the effects of corneal and lens characteristics, including refractive power, thickness, and curvature, on peripheral defocus and their impact on different regions. A cross-sectional study was conducted involving 296 patients with myopia using data from the right eye. Peripheral retinal defocus was measured using a novel device, a multispectral refractive topographer, which can assess peripheral defocus. Retinal images were sequentially captured using single-wavelength monochromatic light at varying wavelengths to determine the refractive status of the fundus. Select relevant data at the corneal diameters of 4 mm, 6 mm, and 8 mm (superior, inferior, nasal and temporal). The refractive power of the superior cornea negatively correlated with peripheral defocus in inferior regions. Specifically, cornea refractive power at the 4 mm position below the cornea negatively correlated with peripheral defocus in inferior regions (r = -0.130, P < 0.05; r = -0.141, P < 0.05). Temporal corneal refractive power was negatively correlated with peripheral defocus in certain inferior regions. Nasal corneal refractive power negatively correlated with peripheral defocus in inferior regions and positively correlated with peripheral defocus in superior regions. Lens refractive power was positively correlated with peripheral defocus in superior regions and negatively correlated with peripheral defocus in inferior regions. Refractive media such as the cornea and lens are strongly associated with peripheral defocus in different regions. Among these, corneal refractive power exerts the most significant influence. Inferior peripheral defocus exhibits significant correlations with superior, temporal, and nasal corneal refractive powers. Temporal and inferior hyperopic peripheral defocus demonstrate a stronger association with myopia compared to other regions.