Dataset Information

Long-Wavelength-Filtered Light Transiently Inhibits Negative Lens-Induced Axial Eye Growth in the Chick Myopia Model.

ABSTRACT:

Purpose

Eye growth and myopia development in chicks, and some other animal models, can be suppressed by rearing under near-monochromatic, short-wavelength blue light. We aimed to determine whether similar effects could be achieved using glass filters that transmit a broader range of short and middle wavelengths.

Methods

On day 6 or 7 post-hatch, 169 chicks were assigned to one of three monocular lens conditions (-10 D, +10 D, plano) and reared for 7 or 10 days under one of four 201-lux lighting conditions: (1) B410 long-wavelength-filtered light, (2) B460 long-wavelength-filtered light, (3) Y48 short-wavelength-filtered light, or (4) HA50 broadband light.

Results

At 7 days, B410 (but not B460) long-wavelength-filtered light had significantly inhibited negative lens induced axial growth relative to Y48 short-wavelength-filtered light (mean difference in experimental eye = -0.249 mm; P = 0.006) and HA50 broadband light (mean difference = -0.139 mm; P = 0.038). B410 filters also inhibited the negative lens-induced increase in vitreous chamber depth relative to all other filter conditions. Corresponding changes in refraction did not occur, and biometric measurements in a separate cohort of chicks suggested that the axial dimension changes were transient and not maintained at 10 days.

Conclusions

Chromatic effects on eye growth can be achieved using filters that transmit a broad range of wavelengths even in the presence of strong cues for myopia development.

Translational relevance

Broad-wavelength filters that provide a more "naturalistic" visual experience relative to monochromatic light have potential to alter myopia development, although the effects shown here were modest and transient and require exploration in further species.

SUBMITTER: Riddell N

PROVIDER: S-EPMC8411858 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundIn the past decade and during the COVID pandemic, the prevalence of myopia has reached epidemic proportions. To address this issue and reduce the prevalence of myopia and its complications, it is necessary to develop more effective interventions for controlling myopia. In this study, we investigated the combined effects of narrowband lights and competing defocus on eye growth and refraction in chicks, an important step in understanding the potential for these interventions to control myopia. This is the first time these effects have been characterized.MethodsThree groups of five-day-old chicks (n = 8 per group) were raised in three different lighting conditions: white, red, and blue for 13 days in a 12/12-h light/dark diurnal cycle. One eye was randomly selected for applications of a dual-power optical lens (- 10 D/ + 10 D, 50∶50), while another eye was left untreated as control. Vitreous chamber depth (VCD), axial length (AL), choroidal thickness (CT) and refractive errors were measured at pre-exposure (D0) and following 3 (D3), 7 (D7), 10 (D10), and 13 days (D13) of light exposure.ResultsUnder white light, the dual-power lens induced a hyperopic shift [at D13, mean spherical equivalent refraction (SER), treated vs. control: 4.81 ± 0.43 D vs. 1.77 ± 0.21 D, P < 0.001] and significantly reduced the progression of axial elongation (at D13, change in AL, treated vs. control: 1.25 ± 0.04 mm vs. 1.45 ± 0.05 mm, P < 0.01). Compared to white light alone, blue light alone induced a hyperopic shift (at D13, mean SER, blue vs. white: 2.75 ± 0.21 D vs. 1.77 ± 0.21 D, P < 0.01) and significantly reduced axial elongation (at D13, change in AL, blue vs. white: 1.17 ± 0.06 mm vs. 1.45 ± 0.05 mm, P < 0.01) in control eyes. When comparing all conditions, eyes exposed to blue light plus dual-power lens had the least axial elongation (at D13, change in AL, 0.99 ± 0.05 mm) and were the most hyperopic (at D13, mean SER, 6.36 ± 0.39 D).ConclusionsBoth narrowband blue light and dual-power lens interventions were effective in inducing a hyperopic shift in chicks, and provided protection against myopia development. The combination of these interventions had additive effects, making them potentially even more effective. These findings support the use of optical defocus interventions in combination with wavelength filters in clinical studies testing their effectiveness in treating myopia in children.