SightGlass DOT Lenses Show No Astigmatism Increase in Studies

SightGlass DOT Lenses Show No Link to Astigmatism, Studies Find

New research presented at the Netherlands Contact Lens Congress indicates that SightGlass Vision’s Diffusion Optics Technology (DOT) lenses do not increase the risk of astigmatism in children undergoing myopia control treatment. The findings, stemming from studies conducted in both North America and China, address concerns raised about potential astigmatic side effects associated with some myopia control methods.

The research comes as other myopia control techniques, specifically those utilizing peripheral defocus, have faced scrutiny regarding a possible link to increased astigmatism. SightGlass’s DOT lenses employ a different mechanism – contrast modulation – to slow the progression of nearsightedness.

“It’s important that it’s just one study, and I don’t think People can conclude very clearly that peripheral defocus lenses increase astigmatism,” explained David Webley, BSc, MCOptom, FBCLA, senior director of clinical, medical and professional affairs at SightGlass Vision. “But we’re getting a lot of questions from [eye care professionals] in the field of, ‘Do your lenses lead to an increase in astigmatism as well as controlling myopia?’”

Astigmatism Rates Remain Stable in Trials

Webley and colleagues analyzed data from two trials: the CYPRESS study in North America (173 eyes, ages 6-10) and the CATHAY study in China (182 eyes, ages 6-13). The analysis compared rates of astigmatism between those wearing DOT lenses and control groups at 12 months. Results showed no statistically significant changes in astigmatism rates in either study population. In the North American trial, the percentage of eyes with astigmatism increased slightly from 87% to 92%, while in the Chinese study, it decreased from 91% to 88%.

“If you’re concerned by a patient whose astigmatism is seen to be increasing with their myopia control, we can clearly say there isn’t any link between DOT and astigmatism development,” Webley stated. “If you’re concerned about that happening with your existing solution or with your existing patients, then DOT might be a good solution for you to use.”

Webley theorized that the difference in astigmatism outcomes may be related to the mechanism of action. DOT lenses subtly reduce contrast across the lens, while peripheral defocus lenses induce positive power. The consistent power distribution in DOT lenses, he suggests, may minimize changes in astigmatic correction.

Similar Efficacy Across Populations

The Netherlands Contact Lens Congress also saw the presentation of data comparing the efficacy of DOT lenses in North American and Chinese children. This analysis, led by Fabio Carta, DipOptom, FBCLA, director of professional affairs for EMEA & Canada at SightGlass Vision, examined axial length and cycloplegic spherical equivalent refraction changes over 12 months.

The study found that DOT lenses slowed the progression of both axial length and cycloplegic spherical equivalent refraction in both populations. North American children experienced a slowing of axial length by –0.15 ± 0.03 mm, while Chinese children saw a slowing of –0.29 mm ± 0.04 mm. Similarly, cycloplegic spherical equivalent refraction slowed by 0.34 ± 0.07 D in North American children and 0.54 ± 0.09 D in Chinese children.

“There is a consistency of efficacy across diverse populations,” Carta told Healio. “If you see other clinical trials with other products in the same myopia field, you can see differences between different populations. So, it was something new.”

These findings add to a growing body of evidence supporting the use of SightGlass DOT lenses for myopia control. Further research continues to evaluate the long-term effects and broader applicability of this technology.