Astigmatic Peripheral Defocus with Different Contact Lenses: Review and Meta-Analysis

ABSTRACT

Purpose: To review the level of relative peripheral defocus measured with different devices with potential use for myopia retention. To present comparative data of the change in astigmatic peripheral refraction with different contact lenses evaluated in different studies conducted in the same laboratory following the same methodology in myopic human eyes

Methods: A joint analysis of work, carried out at the same laboratory (CEORLab) in 137 myopic subjects with different types of contact lenses (CL), was performed to obtain the tangential (F_T = M − J0), sagittal (F_S = M + J0), and mean (M) power refractive errors (M and J0 are the refraction vector components). Orthokeratology, standard aspheric rigid gas-permeable (RGP), experimental RGP, experimental soft CL, and different multifocal soft CL were used to induce peripheral myopic defocus (236 peripheral refraction measures).

Results: Compared with values obtained in naked eye condition (baseline), only three of the eight approaches tested show statistically significant peripheral myopic defocus induction (p < 0.001) in both temporal and nasal retina (orthokeratology, experimental RGP, and Proclear multifocal CL with Add: +3.00 D). Standard aspheric RGP also produced a significant increase in myopic defocus for the F_T, of about −2.00 D. The experimental soft CL, designed to mimic the peripheral performance of the experimental RGP, induced a similar effect to the standard aspheric soft CL.

Conclusion: Orthokeratology, multifocal soft CL, and custom-designed RGP CL were able to generate a significant relative peripheral myopia in myopic eyes. Conversely, standard and experimental soft CL were not able to induce significant peripheral myopic and astigmatic defocus values.

KEYWORDS:

• Astigmatism
• myopia progression
• peripheral defocus
• peripheral refraction

Acknowledgment

The authors thank the companies that donated the contact lenses used in the study.

Funding

This study was supported by Fundação para Ciência e Tecnologia, Portugal through projects PTDC/SAU-BEB/098392/2008 and PTDC/SAU-BEB/098391/2008.

Declaration of interest

The authors declare that they do not have any proprietary or financial interest in any of the materials mentioned in this article.

Additional information

Funding

This study was supported by Fundação para Ciência e Tecnologia, Portugal through projects PTDC/SAU-BEB/098392/2008 and PTDC/SAU-BEB/098391/2008.