SightGlass DOT Lenses: A Latest Era in Myopia Control and Astigmatism Management?
Recent studies are shedding light on the potential of SightGlass Vision’s Diffusion Optics Technology (DOT) lenses in managing myopia progression and, crucially, minimizing the risk of astigmatism development – a concern raised with some other myopia control methods. Presented at the Netherlands Contact Lens Congress, findings from trials in both North America and China suggest a promising safety profile for DOT lenses regarding astigmatism.
Addressing Concerns About Astigmatism Increase
The discussion around astigmatism and myopia control has intensified with the rise of peripheral defocus lenses. Some research indicated a potential link between these lenses and an increase in astigmatism. This prompted questions about whether SightGlass DOT lenses, utilizing a different mechanism – contrast modulation – might share the same risk. David Webley, BSc, MCOptom, FBCLA, senior director of clinical, medical and professional affairs at SightGlass Vision, addressed these concerns directly, stating, “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.”
Study Findings: No Significant Astigmatism Changes
Researchers analyzed data from two key trials: the CYPRESS study in North America (173 eyes, ages 6-10) and the CATHAY study in China (182 eyes, ages 6-13). The results were reassuring. Neither study demonstrated a significant change in astigmatism rates after 12 months of wearing SightGlass DOT lenses compared to control lenses. In the North American study, the percentage of eyes with astigmatism rose slightly from 87% to 92%, while in the Chinese study, it decreased from 91% to 88%.
How Does DOT Differ? The Contrast Modulation Approach
Webley explained the potential reason for the difference: “With DOT lenses, we just reduce the contrast slightly compared to peripheral defocus, which induces some positive power in the lenses. We could theorize that, because the power is consistent across the lens, there is unlikely to be any change within the astigmatic correction and that might not be the same in a peripheral defocus lens.” This suggests that the mechanism of action of DOT lenses may inherently minimize the risk of altering astigmatism.
Consistent Efficacy Across Populations
Beyond astigmatism, the studies also confirmed the efficacy of SightGlass DOT lenses in slowing myopia progression across different populations. Fabio Carta, DipOptom, FBCLA, director of professional affairs for EMEA & Canada at SightGlass Vision, highlighted this consistency. “There is a consistency of efficacy across diverse populations,” he noted. “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.” Specifically, axial length slowed by –0.15 ± 0.03 mm among North American children and –0.29 mm ± 0.04 mm among Chinese children, while cycloplegic spherical equivalent refraction slowed by 0.34 ± 0.07 D among North American children and 0.54 ± 0.09 D among Chinese children.
Future Directions and Ongoing Research
While these findings are encouraging, researchers emphasize the require for continued investigation. Webley cautioned, “It’s important that it’s just one study, and I don’t think we can conclude very clearly that peripheral defocus lenses increase astigmatism.” Further research will be crucial to fully understand the long-term effects of different myopia control methods and to refine treatment strategies for individual patients.
Frequently Asked Questions
- What is SightGlass DOT? SightGlass Diffusion Optics Technology (DOT) lenses are designed to slow myopia progression using contrast modulation.
- Does DOT increase astigmatism? Current studies suggest no significant link between DOT lenses and an increase in astigmatism.
- Is DOT effective in different populations? Studies demonstrate consistent efficacy in slowing myopia progression in both North American and Chinese children.
- How does DOT differ from peripheral defocus lenses? DOT lenses reduce contrast, while peripheral defocus lenses induce positive power, potentially impacting astigmatism differently.
For more information: Fabio Carta can be reached at [email protected]. David Webley can be reached at [email protected].
