SightGlass DOT Lenses Show No Astigmatism Increase in Studies
Recent studies presented at the Netherlands Contact Lens Congress suggest that children wearing SightGlass Vision’s Diffusion Optics Technology (DOT) lenses do not experience an increase in astigmatism, a finding that addresses concerns raised about other myopia control lenses utilizing peripheral defocus technology.
The research, led by David Webley, senior director of clinical, medical and professional affairs at SightGlass Vision, analyzed data from two clinical trials: the North American CYPRESS study, involving 173 eyes of children aged 6-10, and the Chinese CATHAY study, encompassing 182 eyes of children aged 6-13. Researchers compared changes in refractive data between those wearing DOT lenses and control groups over a 12-month period.
According to the findings, neither the North American nor the Chinese data demonstrated a significant change in astigmatism rates. In the North American study, the percentage of eyes with astigmatism increased from 87% to 92%, although 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.
The findings arrive in response to questions about whether peripheral defocus lenses, such as those offered by MyoVision and Essilor Stellest, might contribute to increased astigmatism. SightGlass DOT lenses employ a different mechanism – contrast modulation – to control myopia. Webley theorized that the consistent power across the DOT lens surface, unlike the induced positive power in peripheral defocus lenses, may explain the lack of astigmatism development.
A separate study presented at the congress also examined the efficacy of SightGlass DOT lenses in North American and Chinese children, again utilizing the CYPRESS and CATHAY data. This analysis revealed that children wearing DOT lenses experienced slower progression of both axial length and cycloplegic spherical equivalent refraction compared to control groups. Axial length slowed by –0.15 ± 0.03 mm in North American children and –0.29 mm ± 0.04 mm in Chinese children. Cycloplegic spherical equivalent refraction slowed by 0.34 ± 0.07 D in North American children and 0.54 ± 0.09 D in Chinese children.
Fabio Carta, director of professional affairs for EMEA & Canada at SightGlass Vision, highlighted the consistency of these results across diverse populations. “There is a consistency of efficacy across diverse populations,” Carta said. “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.”
The studies were sponsored by SightGlass Vision. Webley and Carta can be reached for further information at [email protected] and [email protected], respectively.