The Newest Science on the SightGlass Vision DOT lens from ARVO 2023

The SightGlass Vision DOT lenses are one of the newest myopia controlling spectacle lenses on the market. At the most recent Association for Research in Vision and Ophthalmology (ARVO) 2023 meeting, six posters presented the latest research on the SightGlass Vision DOT lenses. 

The image above shows lead authors on this latest research, from left: Marcella McParland, Debbie Laughton, Francisco Javier Gantes-Nuñez, Dawn Meyer, Thomas Chalberg and Asiya Jabeen.

Authors: Thomas Chalberg¹, Deborah Laughton¹, Jennifer Hill¹, Vanessa Tasso¹, Graeme Young², Christopher Hunt², Jay Neitz³, Maureen Neitz³

1. SightGlass Vision Inc, Los Altos, California, United States
2. Visioncare Research Limited, Farnham, United Kingdom
3. University of Washington, Seattle, Washington, United States

This study included three years of a randomized controlled trial (Part 1), where children wore either one of two DOT lens designs (T1 or T2) or a standard single vision lens. SightGlass DOT lenses effectively reduced myopia progression in children aged 6 to 10 years over 36 months, with most of the benefits found within the first year. COVID-19-related visual environment and wearing time impacts may have resulted in the modest study outcomes over years 2 and 3. After three years, the T1 design was found to be more effective than the T2 design - children who switched over from T2 to T1 DOT lens type afterwards (Part 2) got the same effect as those who continued to wear T1. Overall, DOT lenses are safe and effective, validating that contrast theory could be another approach for managing myopia progression in children. 

Purpose: The discovery that L/M opsin mutations are associated with familial high myopia led to the hypothesis that elevated contrast signalling in the retina, whether from genetic predisposition or the visual environment, plays an important role in myopia development and progression. To evaluate this theory, novel spectacle lenses (DOT lenses) were designed to modulate retinal contrast. CYPRESS evaluated the safety and efficacy of DOT lenses in reducing myopia progression.

Methods: CYPRESS part 1 (NCT03623074) was a 3-year double-masked, randomized, controlled clinical trial. Myopic children aged 6-10 years (n=256) were recruited at 14 clinical sites in North America and dispensed spectacles with one of two DOT lens designs (T1, T2) or standard single-vision control lenses. Children completing part 1 (n=200) were invited to enroll in CYPRESS part 2 (NCT04947735), in which T1 (n=35) and Control groups (n=42) continued with their original lens assignment and the T2 group (n=21) were crossed over to T1 lenses. Axial Length (AL) and cycloplegic Spherical Equivalent Refraction (SER) were measured at baseline, 12, 24, 36 and 42 months.

Results: In part 1 after 36 months, AL mean change ± SE from baseline was 0.59 ± 0.04 mm, 0.67 ± 0.05 mm and 0.72 ± 0.04 mm, and SER mean change from baseline was -0.83 ± 0.09 D, -1.19 ± 0.11 D and -1.16 ± 0.09 D, for T1, T2 and Control, respectively. Both co-primary endpoints of AL and SER were met, with a difference between means (T1 minus Control) of - 0.13 mm for AL (p=0.018) and 0.33 D for SER (p=0.008). Most of the benefit accrued within Year 1. During Years 2-3, which coincided with COVID-19, the children reported altered school routines, which likely impacted study outcomes.

In part 2, LS mean change ± SE from 36 to 42 months in AL was 0.08 ± 0.01 mm for T1 and 0.12 ± 0.01 mm for Control (p=0.013) and in SER was -0.12 ± 0.03 D for T1 and -0.21 ± 0.04 D for Control (p=0.051). Mean AL and SER progression in part 2 was not statistically different between the original T1 group and those who crossed over from T2 to T1 (AL p=0.28, SER p=0.85).

Conclusions: DOT spectacle lenses are safe and effective at reducing myopia progression in children age 6-10, with additional benefit evident after 3-years of wear. Changes in lifestyle, behaviour and schooling during the COVID-19 pandemic may have impacted treatment efficacy in Part 1.

Authors: Debbie Laughton¹, Jennifer Hill¹, Vanessa Tasso¹, Jay Neitz², Maureen Neitz², Kellie Hogan³, Thomas Chalberg¹

1. SightGlass Vision Inc, Los Altos, California, United States
2. University of Washington, Seattle, Washington, United States
3. Phoenix Feather Stats, Georgia, United States

This study highlights the need to be cautious when comparing results between different clinical trials due to differences in study design and in particular, age range of participants enrolled. Physiological eye growth (observed in persistent emmetropic eyes) is most rapid in younger children, in co-ordination with general body growth. Physiological axial length growth is estimated to account for over half of the axial length growth observed in myopic children under 10.5 years. Therefore physiological axial length growth may limit what can be achieved with myopia control and will depress percentage measures of efficacy. Age-independent estimates of efficacy can be derived by subtracting age-expected physiological axial length growth from observed myopic axial length growth, often termed ‘pathological’ or ‘corrected’ myopic AL growth. The CYPRESS clinical trial enrolled children aged 6-10 years and when the age-matched physiological eye growth component was subtracted from test and control group measures, full-time wear of SightGlass DOT lenses reduced ‘pathological’ AL growth by 83% after 2 years and 73% after 3 years. Centile growth charts are a useful tool to evaluate and compare a child’s progression to expected age-related AL growth. 

Purpose: Axial length is a robust primary outcome measure for longitudinal clinical trials evaluating the efficacy of myopia control therapies. However, axial length growth, in coordination with increases in body stature, is evident even in persistent emmetropic eyes and is most rapid before preadolescence. The purpose of this research was to evaluate treatment efficacy of DOT spectacle lenses in respect to physiological emmetropic and pathological myopic eye growth to derive an age-independent estimate of axial length growth.

Methods: Myopic children aged 6 to 10 years were enrolled in CYPRESS (NCT03623074): a 3-year double-masked, randomized, controlled clinical trial across 14 North American sites. 181 children were randomised to wear either DOT lenses (T1, n=88) or standard single-vision Control lenses (n=93). Children were advised to wear the study spectacles all waking hours, apart from when participating in high-impact sports or swimming. Children were classified as full-time wearers if they wore their study spectacles for near vision activities, as reported by parental questionnaires. Axial Length (AL) and Spherical Equivalent Refraction (SER) were measured at baseline, 12, 24 and 36 months. Physiological AL growth was calculated based on age-matched emmetropic eye growth data from the Orinda Longitudinal Study of Myopia and compared to AL growth observed in the CYPRESS study.

Results: A total of 154 children completed the 3-year study, of which 64% were classified as full-time wearers (T1 42/71, Control 57/83). After 3 years, the LS mean AL and SER (± SE) of the Control group increased by 0.72 ± 0.05 mm and -1.22 ± 0.12 D, respectively, in full-time wearers. Compared to Control, T1 progressed significantly less in AL (0.48 ± 0.06 mm, difference -0.24 mm, p=0.010) and SER (-0.65 ± 0.14 D, difference 0.56 D, p=0.003) in full-time wearers after 3 years. The calculated pathological AL change after 3 years was 0.08 ± 0.06 mm for T1 and 0.31 ± 0.05 mm for Control (difference -0.23 mm, p=0.003). The percentage reduction in pathological AL growth for T1 full-time wearers was 83% after 2 years and 73% after 3 years.

Conclusions: After 3 years, children who wore DOT spectacle lenses full-time had significantly less myopia progression than control group participants. Considering expected physiological AL change is important to understand and compare AL change in an age-independent manner.

Authors: Marcella McParland¹, Deborah Laughton¹, Jennifer Hill¹, Vanessa Tasso¹, Jay Neitz², Maureen Neitz², Thomas Chalberg¹

1. SightGlass Vision Inc, Los Altos, California, United States
2. University of Washington, Seattle, Washington, United States

COVID-19 social and schooling restrictions was found to reduce myopia progression in North American children participating in the CYPRESS (SightGlass DOT lens) clinical trial. During the pandemic, AL and SER progression in the CYPRESS trial participants decreased compared to pre-pandemic levels and age-matched expectations, with nearly halved progression from 12-36 months. Altered school routines were reported during this period. Post-pandemic, AL and SER progression returned to age-matched expectations. Similar effects have been observed in other myopia control studies.¹ The findings suggest that changes in lifestyle, behavior, and schooling time during the pandemic may have influenced the observed reduction in myopia progression.

Purpose: To investigate the effect of social restrictions during the COVID-19 pandemic on myopia progression in North American children.

Methods: Myopic children aged 6 to 10 years were enrolled in CYPRESS (NCT03623074): a double-masked, randomized, controlled clinical trial to evaluate the safety and efficacy of DOT spectacle lenses across 14 North American sites. Participant enrolment began in July 2018. The 24 to 36-month visits (from March 2020 to April 2022) coincided with COVID-19 social restrictions in North America. The 42-month visit window was January 2022 to September 2022 (when restrictions had ceased). Axial Length (AL) and Spherical Equivalent Refraction (SER) were measured at 0, 12, 24, 36 and 42 months.

AL progression of the CYPRESS Control group (n=42; wearing standard single vision spectacles) was compared to age-matched myopic AL growth data from the Orinda Longitudinal Study of Myopia (OLSM; collected between 1989 to 2001) to evaluate the potential impact of the COVID-19 pandemic.

Results: Pre-pandemic, Control group mean change in AL and SER (± SD) from 0-12 months was 0.32 ± 0.17 mm and -0.58 ± 0.52 D, respectively. AL and SER progression nearly halved during the pandemic (from 12-24 months AL 0.23 ± 0.18 mm, SER -0.35 ± 0.41 D; from 24-36 months AL 0.20 ± 0.15 mm, SER -0.34 ± 0.33 D). The children reported altered school routines during this period. Post-pandemic, AL and SER progression from 36-42 months (in 6 months) was 0.11 ± 0.09 mm and -0.22 ± 0.26 D, respectively. Comparison with age-matched AL growth data from the OLSM showed a difference between means (CYPRESS – OLSM) of +0.05 mm pre-pandemic, -0.08 mm during the pandemic and 0.00 mm post-pandemic.

Conclusions: The progression of myopia among CYPRESS Control children decreased during the COVID-19 pandemic. Changes in lifestyle, behaviour and schooling during the COVID-19 pandemic may have contributed to reduced myopia progression.

Authors: Dawn Meyer¹, Nitya Murthy¹, Martin Rickert¹, Pete S. Kollbaum¹

1. School of Optometry, Indiana University, Bloomington, Indiana, United States

Ten adult subjects viewed a distance target through DOT lenses and single vision lenses, and contrast sensitivity (CS) thresholds were measured at various spatial frequencies. CS was not significantly reduced when viewing through the central clear aperture or the treatment zone of DOT lenses, indicating that wearers would not experience substantial contrast reduction when wearing DOT lenses. An interesting addition to the experiment was measurement through a +0.50D induced blur, single vision (SV) lens, which also found no significant statistical or clinical difference in CS compared to SV full correction or DOT lenses measured through central or peripheral zones. These findings suggest that DOT lenses maintain contrast sensitivity comparable to SV lenses and +0.50 defocus, and the DOT patterns are unlikely to cause significant decreases in contrast perception.

Purpose: Diffusion Optics Technology (DOT) spectacle lenses from SightGlass Vision have demonstrated the ability to control the progression of myopia in children. These lenses contain a clear central area encircled by a treatment zone with light scattering micro-dots which are reported to reduce peripheral contrast. The primary objective of this study was to compare threshold CS between DOT myopia control and standard single vision (SV) spectacle lenses (optimal correction and +0.50 D induced blur) in the lens periphery and centrally.

Methods

Ten healthy subjects (5 male) 20-31 years of age (mean±SD, 23.9±3.5) were enrolled and optimally corrected to view a distance target at 4m through spectacle lenses with their right eye. FrACT contrast sensitivity (CS) threshold was measured at 3, 6, 12 and 18 cycles per degree (cpd) while subjects viewed through the central clear area and a peripheral portion with the pupil entirely outside central area of DOT lenses and SV lenses, as well as a SV lens with +0.50 D of blur. Equivalence testing was performed using an equivalence criterion based on published normative data.

Results: Mean logCS values for both SV and DOT lenses when viewing through the central clear optics were, as expected, generally higher for low spatial frequencies (SF) (3cpd: SV = 2.03±0.22; DOT = 2.02±0.19), and lower at the higher SF (18cpd: SV = 1.53±0.32; DOT = 1.52±0.28). LogCS through the peripheral section with DOT lenses was slightly lower but statistically equivalent (p>0.05) and not clinically different (<0.2 log unit) compared to SV (3cpd: SV = 2.05±0.18 and DOT = 1.90±0.18; 18cpd: SV = 1.59±0.17 and DOT = 1.42±0.32). LogCS was statistically equivalent through the central and peripheral lens sections of DOT and SV lenses. LogCS with +0.50 D of induced blur was statistically equivalent and not clinically different than that of the SV or DOT lenses in either the central or peripheral sections (central: 3cpd: 1.93±0.17, 18cpd: 1.48±0.29; peripheral: 3cpd: 1.96±0.19, 18cpd: 1.52±0.28).

Conclusions: DOT lenses provided CS statistically and clinically equivalent to standard SV and +0.50D blur through the central clear aperture and treatment zone. Thus, wearers of DOT lenses are not expected to notice substantial decreases in contrast when viewing through the clear lens center or when their eyes are turned to look through the treatment zone.

Authors: Francisco Javier Gantes-Nuñez¹, Dawn Meyer¹, Josh Richards¹, Ebrahim Aboualizadeh², Pete S. Kollbaum¹

1. School of Optometry, Indiana University, Bloomington, Indiana, United States
2. SightGlass Vision Inc, Los Altos, California, United States

The Point Spread Function (PSF) of the DOT lenses were measured and the modulation transfer function (MTF) was computed to evaluate imaging properties. These measures describe how an optical system transmits either a point source of light (PSF) or a variety of spatial frequencies (MTF). The results showed that the DOT lenses produced sharp PSFs through the treatment zone, similar to the clear central zone. Modulation values across the treatment zone were comparable to the clear central zone for clinically relevant spatial frequencies up to 18 cycles per degree (eg. relevant to reading text, acuity tasks and motion detection. However, slight contrast reduction was observed at very high spatial frequencies towards upper detectable limits,. Overall, the DOT lens design provides comparable image quality and visual performance to standard single vision lenses, with minimal impact on spatial details and visual performance.

Purpose: Novel spectacle lenses from SightGlass Vision^TM utilize Diffusion Optics Technology™ (DOT) to slow myopia progression by modulating contrast at the retina. These lenses contain a clear central area encircled by a treatment zone with light scattering micro-dots. Here, we evaluated the imaging properties of DOT lenses by optically measuring the Point Spread Function (PSF) followed by computing the modulation transfer function (MTF).

Methods: The PSF of a DOT lens was acquired from 10 different regions within the treatment zone and the clear central zone was used as a reference. The PSFs were measured using a custom-built 4f optical imaging system with a 636.8 nm laser diode and an 8 mm pupil. A CMOS sensor (SonyTM Exmor 1/2.3’) with a 1.55 um pitch and 12-bit digital output was used to capture the image of the PSF from which the MTF was computed. Relative image quality was assessed in each zone by dividing the area under the MTF curve (AUC) of the treatment zone by the clear central zone.

Results: Sharp PSF’s are seen through the DOT treatment area, resembling those seen through the clear central zone. Modulation values across the 10 areas within the treatment zone describe a similar trend over most of the spatial frequencies (SFs) (Figure 1). When comparing to the central clear zone, the DOT treatment areas demonstrated minimal contrast reduction at low frequencies (<18 cycles per degree (cpd)), however, some slight contrast reduction is observed for very high SFs (>30 cpd). At clinically relevant contrast sensitivity SFs of 3, 6, 12, and 18 cpd, the mean modulation values across the 10 regions covered by the micro-dots were similar to that of the clear central zone (Table 1).

Conclusions: The PSF-imaging method and MTF analysis reveals that DOT lens design can generate comparable image quality and visual performance to SV lenses when looking through the treatment zone, up to 18 cycles per degree. However, some reduction is present at higher SFs toward the upper detectable limits of human vision. This finding suggests that contrast reduction introduced by the micro-dots in the DOT lens does not limit its ability to provide high quality spatial details and good visual performance.

Authors: Asiya Jabeen¹, Doerte Luensmann¹, Jill Woods¹, Jennifer Hill², Lyndon Jones¹

1. School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
2. SightGlass Vision Inc, Los Altos, California, United States

DOT lenses were tested in 30 participants aged 7 to 17 years of age with ±1.00 diopters prescription or less to evaluate accommodation which historically is less accurate in myopes when contrast is altered. Participants wore DOT lenses with no central clear zone to ascertain that they are looking through the DOT pattern and single vision lenses, autorefraction was then measured for targets at 6m and 40cm. The mean lag of accommodation was 0.60D in the dominant eye wearing DOT lenses; in single vision, it was 0.68D. This indicates that short-term wear of DOT lenses had no significant effect on lag of accommodation compared to single vision lenses. Hence, although the treatment zone of the DOT lenses slightly reduces contrast, this does not necessarily reduce accommodative accuracy. 

Purpose: Alterations in contrast have shown to impact the accommodative accuracy in myopes. This study investigated whether the Diffusion Optics Technology™ (DOT) spectacles that are designed to reduce the contrast on peripheral retina, have an impact on the lag of accommodation (LOA) in emmetropic children after short-term wear.

Methods: This was a single visit, prospective, randomized, subject-masked study. Participants were eligible if they had ±1.00 diopters prescription or less and they had no history of previous myopia control treatment. The logMAR visual acuity was measured and ocular dominance was tested using the sighting method. Participants then wore a pair of plano DOT spectacles (not featuring a central clear zone) and standard plano spectacles (control) in a randomized order and, after 5 minutes adaptation to the lenses, ten open-field autorefraction measurements (Grand Seiko 5500) were taken for each eye, with the target at 6m and 40cm. Analysis was conducted on the mean auto-refraction to determine differences in LOA between lens types for the right eye and also for the dominant eye.

Results: A total of 30 participants (20 female:10 male) with a mean (± SD) age of 10.4 ± 2.8 years (range 7 to 17) completed the study. The mean ± SD LOA was 0.57 ± 0.39D for the right eye and 0.60 ± 0.40D for the dominant eye whilst wearing DOT spectacles and similarly, 0.62 ± 0.34D for the right eye and 0.68 ± 0.33D for the dominant eye while wearing control spectacles. Mann Whitney U test results indicated no statistically significant difference between DOT and control spectacles for the right eye data (p=0.64) or for the dominant eye data (p=0.25). Similarly, no difference was observed in the mean LOA when compared between males and females, and between the younger (6-11) and older (12-17) age groups for both right eye and dominant eye with DOT and control spectacles (all p>0.05).

Conclusions: DOT lenses have no significant effect on the lag of accommodation compared to single vision spectacles after short-term wear. The study counters the supposition that reduced contrast may influence accommodative accuracy.