Abstract
Abstract: :
Purpose: Retinal image quality in the human infant eye is proposed to influence both neural and optical development through experience–dependent processes. The effects of lower order aberrations (defocus and astigmatism) have been studied extensively. The goal of this study was to measure higher order aberrations in young infant eyes and to investigate the effects of higher–order aberrations on infants’ retinal image quality. Methods: The Complete Ophthalmic Analysis System Aberrometer (COAS, Wavefront Sciences Inc.) was used to measure infants’ monochromatic higher–order aberrations. Eyes of infants aged 5 to 7–weeks–, and adults (younger than 40 years of age) were measured without cycloplegia. To compensate for the different dimensions of infant and adult eyes, wavefront errors over a 4mm pupil diameter in adults and 2.75 mm in infants were compared. Results: When wavefronts are compared across pupil diameters scaled to eye size, higher–order RMS of infants’ eyes are similar to those of adults. All individual 3rd and 4th order Zernike coefficients for both adults and infants were lower than +/–0.15µm and are typically much smaller than the second–order aberrations, defocus and astigmatism. There were no significant difference (p>0.05) in the levels of 3rd order monochromatic aberrations between adult and infant eyes. Although most adult eyes had positive spherical aberration (Z40), negative spherical aberration was observed in about half of the infant eyes. Also, infant eyes exhibited larger levels of quadrafoil (Z4+4). Conclusions: When pupil size is scaled to eye size, higher–order monochromatic aberrations degrade infant and adult image quality similarly.
Keywords: optical properties • infant vision