Effect of short-term peripheral myopic defocus on ocular biometrics using Fresnel “press-on” lenses in humans

Abstract

This study assessed axial length and choroidal thickness changes following short-term peripheral myopic defocus in normal adult subjects. Twenty subjects underwent defocus sessions by viewing a full-field projected movie 4 m away for 4 h in the morning, while wearing spectacle lenses, corrected for distance vision in both eyes. The right eye, serving as the test eye, was peripherally defocused using a Fresnel lens overlay of + 3.50 D with a central clear aperture of 11.5 mm (correlating to a clear central visual field of approximately 23°), while the left eye served as the control (with no Fresnel lens overlay). A subset of 10 subjects from the same cohort also underwent additional defocus sessions with + 5.00 D of peripheral defocus. Axial length was measured and radial sub-foveal choroidal scans were obtained before and after the defocus sessions. The increase in axial length of the test eyes were significantly less than the control eyes under both peripheral defocus conditions (p < 0.05). The difference in mean change for choroidal thickness between test and control eyes was not significant for either dioptric condition. Our results demonstrated that short-term peripheral myopic defocus significantly inhibited axial elongation in adult humans, without significant changes in choroidal thickness.

Biometric and refractive changes following the monocular application of peripheral myopic defocus using a novel augmented-reality optical system in adults

“…The two types of defocus, myopic and hyperopic, can elicit short-term ( i.e., transient) or long-term ( i.e., more permanent) physiological responses in the eye. Our preliminary work demonstrated that inhibiting axial length using Fresnel lenses of + 3.50D and + 5.00D to achieve short-term peripheral myopic defocus is possible in young adults 17 . Similar work has also established the short-term and long-term 14 , 15 , 17 – 19 physiological responses seen in axial length following myopic and hyperopic defocus stimuli in animal 15 and human studies 14 , 19 .…”

“…Our preliminary work demonstrated that inhibiting axial length using Fresnel lenses of + 3.50D and + 5.00D to achieve short-term peripheral myopic defocus is possible in young adults 17 . Similar work has also established the short-term and long-term 14 , 15 , 17 – 19 physiological responses seen in axial length following myopic and hyperopic defocus stimuli in animal 15 and human studies 14 , 19 . For example, one study found that human eyes significantly shortened (−8 ± 9 µm) after being exposed to 40 min of myopic defocus, with a rapid recovery back to baseline after approximately 35 min 20 .…”

Effects of air pollution on myopia: an update on clinical evidence and biological mechanisms

“…Peripheral hyperopia defocus indicates that peripheral images are focused behind the retinal surface, whereas the foveal image falls exactly on the retina (Rotolo et al 2017 ). Animal experiments have proposed a mechanism in which the retina can “read” the direction of focus of incoming light rays on the retina and affect the choroid to actively change its thickness to move the retina towards the image plane via changes in retinal homeostasis mediated by neurotransmitters (Kubota et al 2021 ). If the focal plane is behind the retina in areas of the visual field, axial growth is promoted owing to thinning of the subfoveal choroid (Schaeffel 2017 ; Kubota et al 2021 ).…”

“…Animal experiments have proposed a mechanism in which the retina can “read” the direction of focus of incoming light rays on the retina and affect the choroid to actively change its thickness to move the retina towards the image plane via changes in retinal homeostasis mediated by neurotransmitters (Kubota et al 2021 ). If the focal plane is behind the retina in areas of the visual field, axial growth is promoted owing to thinning of the subfoveal choroid (Schaeffel 2017 ; Kubota et al 2021 ). Accumulating evidence has demonstrated that alterations of the focal plane can be related to ocular surface diseases, and the biophysical property changes of corneal cells involved in these diseases may reflect myopia progression, as the cornea contributes more than 60% of the focusing power (Xin et al 2021 ).…”

Short-Term Myopic Defocus and Choroidal Thickness in Children and Adults

“… 23 , 24 However, in humans, transient defocus-induced choroidal thickness changes reported in previous studies are small, on the order of 5 to 20 µm, 25 , 26 and therefore difficult to precisely quantify given the resolution of modern instrumentation. Furthermore, several studies have reported that no significant changes in the choroid were observed with myopic defocus 13 , 26 , 27 or that choroidal thickening only occurs in emmetropic but not myopic eyes. 28 …”