Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Sep;43(5):1110-1124.
doi: 10.1111/opo.13182. Epub 2023 Jun 16.

Impact of zone geometry on the introduction of myopic defocus in young adult eyes wearing multi-zone lenses

Raman Prasad Sah  1 , Dawn Meyer  1 , Matt Jaskulski  1 , Martin Rickert  1 , Xu Cheng  2 , Noel Brennan  2 , Pete S Kollbaum  1
Affiliations

Impact of zone geometry on the introduction of myopic defocus in young adult eyes wearing multi-zone lenses

Raman Prasad Sah et al. Ophthalmic Physiol Opt. 2023 Sep.

Abstract

Purpose: Multizone contact lenses control myopia progression by proposed introduction of myopic defocus. This project investigated how much of the pupil area and how many dioptres of myopic defocus are introduced by different lens zone geometries with near- and off-axis viewing.

Methods: Ten young myopic adults (18-25 years) binocularly wore four soft contact lenses including a single vision (SV), concentric-ring dual-focus (DF), centre-distance multifocal (MF) and a RingBoost™ (RB) multi-zone design containing a combination of coaxial and non-coaxial zones. A modified aberrometer captured aberrations and pupil sizes at four target vergences between -0.25 and -4.00 D (on-axis) and across the central ±30° of the horizontal retina (off-axis). Defocus was quantified as the difference between the measured refractive state and the target vergence within each zone of a multi-zone design within the pupil and compared with that of equivalent zone areas of the SV lens. The percentage of the pupil containing myopic defocused light for each lens was calculated.

Results: Defocus within the distance correction zones of multi-zone lenses was similar to that of the SV lens. When viewing on-axis at -0.25 D target vergence, on average 11% of the pupil was myopic with SV, whereas 62%, 84% and 50% of the pupil was myopic for the DF, MF and RB designs, respectively. At -4.00 D target vergence, all lenses exhibited a systematic decrease in the percentage of pupil area having myopic defocus (SV: 3%; DF: 18%; MF: 5% and RB: 26%). The off-axis proportions were similar across multi-zone lenses; however, multi-zone lenses retained approximately 1.25-3.0× more myopic defocus than the SV lens.

Conclusions: Subjects accommodated using the distance-correction zones of multi-zone lenses. Multi-zone contact lenses introduced significant myopic defocus on-axis and across the central ±30° retina. However, the magnitude and proportion of defocus were influenced by zone geometry, add power and pupil size.

Keywords: aberrations; accommodation; defocus; multi-zone lenses; myopia; zone geometry.

PubMed Disclaimer

References

REFERENCES

    1. Morgan IG, Ohno-Matsui K, Saw SM. Myopia. Lancet. 2012;379:1739-48.
    1. Holden BA, Fricke TR, Wilson DA, Jong M, Naidoo KS, Sankaridurg P, et al. Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmology. 2016;123:1036-42.
    1. Xu L, Wang Y, Wang S, Wang Y, Jonas JB. High myopia and glaucoma susceptibility: the Beijing Eye Study. Ophthalmology. 2007;114:216-20.
    1. Liu HH, Xu L, Wang YX, Wang S, You QS, Jonas JB. Prevalence and progression of myopic retinopathy in Chinese adults: the Beijing Eye Study. Ophthalmology. 2010;117:1763-8.
    1. Bullimore MA, Richdale K. Myopia control 2020: where are we and where are we heading? Ophthalmic Physiol Opt. 2020;40:254-70.

Publication types

LinkOut - more resources