A novel Lenslet-ARray-Integrated spectacle lenses for myopia control: a one-year randomized, double-masked, controlled trial.

PURPOSE: To investigate the myopia control efficacy of novel Lenslet-ARray-Integrated (LARI) spectacle lenses with positive (PLARI) and negative (NLARI) power lenslets worn for one year in myopic children. DESIGN: Randomized, double-masked, controlled clinical trial. PARTICIPANTS: A total of 240 children, aged 6 to 12 years, with spherical equivalent refraction (SER) between -4.00 and -1.00 diopter (D), astigmatism of 1.50 D or less, and anisometropia of 1.00 D or less. METHODS: Participants were assigned randomly in a 1:1:1 ratio to PLARI, NLARI, and a control (single-vision (SV)) groups. Cycloplegic autorefraction and axial length were measured at baseline and 6-month intervals after lens wear. MAIN OUTCOME MEASURES: Changes in SER, axial elongation (AE), and differences between groups. RESULTS: After 1-year, SER changes and AE in the PLARI and NLARI groups were significantly less than those in the SV group (SER: -0.30 ± 0.48 D, -0.21 ± 0.35 D, -0.66 ± 0.40 D; AE: 0.19 ± 0.20 mm, 0.17 ± 0.14 mm, 0.34 ± 0.18 mm, respectively) (all P < 0.001). There were no significant differences in SER changes and AE between PLARI and NLARI groups (P = 0.54 and P = 1.00, respectively). Younger age was associated with more rapid SER increase and larger AE in the SV (r = 0.40, P < 0.001 and r = -0.59, P < 0.001, respectively) and PLARI (r= 0.46, P < 0.001 and r = -0.52, P < 0.001, respectively) groups, but not in the NLARI group (r = -0.002, P = 0.98 and r = -0.08, P = 0.48, respectively). CONCLUSIONS: Compared with the SV group, both PLARI and NARI groups showed significantly slower myopia progression in terms of SER and axial elongation. Faster myopia progression, in terms of both SER and AE, was associated with younger age in the SV and PLARI groups, but not in the NLARI group.

Positions of the horizontal and vertical centre of rotation in eyes with different refractive errors.

PURPOSE: To determine how the position of the centre of rotation of the eyeball is related to axial length and refractive error when horizontal and vertical eye movements are performed. METHODS: A custom-built eye tracker was used that determined the centre of rotation of the eye (COR) from lateral displacements of the pupil centre. Horizontal and vertical eye movements were studied in the right eyes, and each measurement performed five times in 59 subjects (32 females) with an average age of 36.6 ± 9.1 years. Spherical equivalent refractive errors ranged from -9.7 to +6.8 D with an average error of -1.5 ± 2.9 D. Axial lengths were measured with the ZEISS IOL Master 500. RESULTS: The mean horizontal centre of rotation (COR) of the right eye for a saccade from 0° to ±11.9° was 15.3 ± 1.5 mm behind the corneal apex, while the average vertical COR for the same angle of eccentricity was 12.5 ± 1.4 mm, indicating that the horizontal COR was 2.8 ± 1.7 mm behind the vertical COR. In right eyes, horizontal COR was significantly correlated with axial length (r = 0.28, p = 0.02) but not with the spherical equivalent refractive error (r = 0.39, p = 0.90). Similarly, vertical COR was significantly correlated with axial length (r = 0.25, p = 0.03) but not with the spherical equivalent refractive error (r = 0.17, p = 0.90). CONCLUSIONS: While it might be expected that the COR is dependent on axial length, the correlation was not strong. Interestingly, the location of the COR was substantially different for horizontal and vertical eye movements which may relate to the flatter curvature of the eyeball in the vertical meridian, compared to the horizontal, as described in previous studies.

Effect of wearing peripheral focus-out glasses on emmetropization in Chinese children aged 6-8 years: study protocol for a 2-year randomized controlled intervention trial.

BACKGROUND: Myopia is one of the most common eye diseases causing visual impairment and blindness, and the high prevalence in adolescents remains a major public health concern. Based on clinical studies using optical defocus to regulate ocular growth and refractive changes through visual feedback, we hypothesize that early wearing of peripheral myopic defocusing spectacles in children with high risk of myopia may slow the process of emmetropization and even prevent the onset of myopia by inducing more peripheral myopic defocus. The aim of this study is to investigate whether the wearing of peripheral focus-out glasses can be effective in delaying emmetropization in non-myopic children aged 6-8 years. METHODS: The study is a 2-year randomized controlled trial. A total of 160 subjects will be randomized into the experimental group or the control group. The experimental group will be fitted with direct emmetropia with focus-out glasses (DEFOG) to guide the emmetropization process. The control group will not receive any treatment and will serve as a blank control group. The primary aim is to determine whether non-myopic children wearing DEFOG lenses are superior to those who do not receive any intervention on the progression of cycloplegic objective refraction over 2 years. DISCUSSION: This is the first randomized controlled trial aiming at myopic prevention by non-invasive intervention in non-myopic children. This study aims to initially investigate whether wearing peripheral focus-out glasses can effectively delay the process of emmetropization in children aged 6-8 years with high risk of myopia, which might give potential clues for further exploration on early prevention of myopia. TRIAL REGISTRATION: ClinicalTrials.gov NCT05689567. Registered on 10 January 2023.

Overview on Defocus Incorporated Multiple Segments Lenses: A Novel Perspective in Myopia Progression Management.

Myopia is becoming more common across the world, affecting approximately two billion people and rising. Different kinds of therapies (optical, pharmaceutical, environmental, or behavioral) have been proposed to decrease myopia progression, but with variable results and a lack of standardization. The evidence that targeted myopic defocus inhibits eye length growth has paved the way for several contact and spectacle lense designs to induce a peripheral defocus, thus slowing myopia progression, but the perfect configuration has yet to be defined. One of the newest and more promising approaches in this field is the use of Defocus Incorporated Multiple Segments (DIMS) lenses. These lenses are built from the assumption that targeted myopic defocus, produced by 396 mid-peripheral lenslets with positive power, inhibits eye length growth. Recent studies have highlighted the effectiveness of these lenses compared to children who had worn single vision spectacle lenses, in terms of myopia control and tolerability. Despite the evidence that these lenses can help slow down the progression of myopia, the occasional mid-peripheral aberrations they can induce, as well as the overall eye strain that comes with wearing them, should not be overlooked. The aim of this review is to give attention to the advantages and the shortfalls of this new approach and to evaluate its effectiveness in clinical practice.

Effect of Defocus Incorporated Multiple Segments Spectacle Lens Wear on Visual Function in Myopic Chinese Children.

Purpose: To compare visual function of myopic children who had worn either defocus incorporated multiple segment (DIMS) spectacle lenses or single vision (SV) spectacle lenses over two years. Methods: We included 160 Chinese myopic (-1 diopter [D] to -5 D) children aged 8 to 13 years in a randomized clinical trial; they wore either DIMS lenses (DIMS; n = 79) or regular SV spectacles lenses (n = 81) full time for 2 years. Visual function, including high-contrast visual acuity (VA) and low-contrast VA at distance and near, binocular functions, and accommodation, before, during, and after 2 years of spectacle wear were assessed when both groups wore SV corrections. Changes of visual function between the two groups and within groups were compared. Results: There were no statistically significant differences in the 2-year visual function changes between DIMS and SV groups (repeated measures analysis of variance with group as factor; P > 0.05). Statistically significant improvement in the best-corrected distance high-contrast VA (P < 0.001) and stereoacuity score (P < 0.001) were found after DIMS lens wear over 2 years. Similar findings were observed after SV spectacle lens wear. For both the DIMS and SV groups, there were statistically significant decreases in accommodative lag, monocular and binocular amplitude of accommodation after two years (P < 0.01), but not in the changes in distance low-contrast VA, near high-contrast VA, near low-contrast VA, or phoria. Conclusions: Although changes in some visual function were shown during 2 years of DIMS lens wear, similar changes were found with SV lens wear. Wear of DIMS spectacle lenses for 2 years does not adversely affect major visual function when children return to SV corrections. Translational Relevance: DIMS spectacle lenses did not cause any adverse effects on visual function.

Evaluating the myopia progression control efficacy of defocus incorporated multiple segments (DIMS) lenses and Apollo progressive addition spectacle lenses (PALs) in 6- to 12-year-old children: study protocol for a prospective, multicenter, randomized controlled trial.

BACKGROUND: Myopia is increasing in prevalence and is currently recognized as a significant public health issue worldwide, particularly in China. Once myopia develops, appropriate clinical interventions need to be prescribed to slow its progression. Currently, several publications indicate that myopic defocus (MD) retards eye growth and myopia progression. However, no clinical trials have compared the outcomes of different MD spectacle lenses in the same observational group, especially in mainland China. The aim of the present study is to compare the myopia control efficiency of two different MD spectacle lenses: defocus incorporated multiple segments (DIMS) lenses and Apollo progressive addition lenses (PALs). METHODS: The trial is designed as a 3-year, prospective, randomized, multicenter clinical trial of schoolchildren treated with DIMS lenses and PALs. A total of 600 Chinese primary school children aged 6-12 years will be recruited, and each group is intended to include 300 subjects. The inclusion criteria are myopia between - 1.00 and - 5.00 diopters and astigmatism ≤ 1.50 diopters. The follow-up time points will be 1 month (m), 3 m, 6 m, 12 m, 18 m, 24 m, 30 m, and 36 m. The primary outcome will be determined by the difference between the two groups in cycloplegic spherical equivalent refraction between baseline and the last follow-up visit. The secondary outcome is the axial length, and the exploratory outcomes include ocular biometric measures, peripheral refraction, binocular vision, accommodation, compliance, and the results of questionnaires related to wearing experiences. DISCUSSION: The present study will be the first randomized controlled trial in myopic primary school children treated with DIMS lenses and PALs in China. The results will indicate whether and how much different MD mechanisms retard myopia progression and axial elongation. In addition, the comparison will provide information on the clinical efficacy and safety of DIMS lenses and PALs, including information related to wearing experiences and visual function. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR), ChiCTR1900025645. Registered on 3 September 2019. http://www.chictr.org.cn/showproj.aspx?proj=42927.

Defocus Incorporated Multiple Segments (DIMS) spectacle lenses slow myopia progression: a 2-year randomised clinical trial.

AIM: To determine if 'Defocus Incorporated Multiple Segments' (DIMS) spectacle lenses slow childhood myopia progression. METHODS: A 2-year double-masked randomised controlled trial was carried out in 183 Chinese children aged 8-13 years, with myopia between -1.00 and -5.00 D and astigmatism ≤1.50 D. Children were randomly assigned to wear DIMS (n=93) or single vision (SV) spectacle lenses (n=90). DIMS lens incorporated multiple segments with myopic defocus of +3.50 D. Refractive error (cycloplegic autorefraction) and axial length were measured at 6month intervals. RESULTS: 160 children completed the study, n=79 in the DIMS group and n=81 in the SV group. Average (SE) myopic progressions over 2 years were -0.41±0.06 D in the DIMS group and -0.85±0.08 D in the SV group. Mean (SE) axial elongation was 0.21±0.02 mm and 0.55±0.02 mm in the DIMS and SV groups, respectively. Myopia progressed 52% more slowly for children in the DIMS group compared with those in the SV group (mean difference -0.44±0.09 D, 95% CI -0.73 to -0.37, p<0.0001). Likewise, children in the DIMS group had less axial elongation by 62% than those in the SV group (mean difference 0.34±0.04 mm, 95% CI 0.22 to 0.37, p<0.0001). 21.5% children who wore DIMS lenses had no myopia progression over 2 years, but only 7.4% for those who wore SV lenses. CONCLUSIONS: Daily wear of the DIMS lens significantly retarded myopia progression and axial elongation in myopic children. Our results demonstrated simultaneous clear vision with constant myopic defocus can slow myopia progression. TRIAL REGISTRATION NUMBER: NCT02206217.

Historical Development, Applications and Advances in Materials Used in Spectacle Lenses and Contact Lenses.

Lenses used in vision correction have evolved from the initial glass reading stone of the 10th century to the currently anticipated planar metalens made from "nanopillars" of titanium dioxide. With ideas from early scientific minds being translated into reality, and military commissioned concepts adapted for civilian use, spectacle lens and contact lens materials have progressed significantly over the last century, with the expectation of further lens material innovations ahead. The purpose of this article is a review of literature on the historical developments and advances in spectacle lens and contact lens materials.

An investigation of low power convex lenses (adds) for eyestrain in the digital age (CLEDA).

INTRODUCTION: Digital eye strain (DES; computer vision syndrome) is a common cause of symptoms when viewing digital devices. Low-powered convex lenses (adds) have been recommended for the condition and "accommodative support" designs developed on this premise. The present research reports the extent to which dry eye is present in this population and the effect of convex lenses on symptoms and visual performance. METHODS: The CVS-Q instrument was used to select pre-presbyopic adults with the symptoms of DES. Participants received a full eye examination including an assessment of dry eye with a modified SANDE questionnaire and using DEWS I criteria. The immediate effect of low-powered convex lenses (low adds: +0.50D, +0.75D, +1.25D) was investigated using subjective preference and a double-masked comparison with plano lenses with the Wilkins Rate of Reading Test (WRRT). Throughout this testing, participants wore their full distance refractive correction, based on non-cycloplegic retinoscopy and subjective refraction. RESULTS: The signs and symptoms of dry eye were frequently present. Most participants reported a subjective preference for low adds, with +0.75D the most commonly preferred lens. Low adds (+0.50D and +0.75D; but not +1.25D) were associated with significantly improved performance at the WRRT. One quarter of participants read more than 10% faster with these additional convex lenses. CONCLUSIONS: The study population was aged 20-40y and mostly worked on desktop computers. It is possible that +1.25D add may be more advantageous for people who are older or work more at closer viewing distances. Many symptomatic users of digital devices report a preference for low adds and use of these lenses is often associated with an improvement in reading performance.

Integration of defocus by dual power Fresnel lenses inhibits myopia in the mammalian eye.

PURPOSE: Eye growth compensates in opposite directions to single vision (SV) negative and positive lenses. We evaluated the response of the guinea pig eye to Fresnel-type lenses incorporating two different powers. METHODS: A total of 114 guinea pigs (10 groups with 9-14 in each) wore a lens over one eye and interocular differences in refractive error and ocular dimensions were measured in each of three experiments. First, the effects of three Fresnel designs with various diopter (D) combinations (-5D/0D; +5D/0D or -5D/+5D dual power) were compared to three SV lenses (-5D, +5D, or 0D). Second, the ratio of -5D and +5D power in a Fresnel lens was varied (50:50 compared with 60:40). Third, myopia was induced by 4 days of exposure to a SV -5D lens, which was then exchanged for a Fresnel lens (-5D/+5D) or one of two SV lenses (+5D or -5D) and ocular parameters tracked for a further 3 weeks. RESULTS: Dual power lenses induced an intermediate response between that to the two constituent powers (lenses +5D, +5D/0D, 0D, -5D/+5D, -5D/0D and -5D induced +2.1 D, +0.7 D, +0.1 D, -0.3 D, -1.6 D and -5.1 D in mean intraocular differences in refractive error, respectively), and changing the ratio of powers induced responses equal to their weighted average. In already myopic animals, continued treatment with SV negative lenses increased their myopia (from -3.3 D to -4.2 D), while switching to SV positive lenses or -5D/+5D Fresnel lenses reduced their myopia (by 2.9 D and 2.3 D, respectively). CONCLUSIONS: The mammalian eye integrates competing defocus to guide its refractive development and eye growth. Fresnel lenses, incorporating positive or plano power with negative power, can slow ocular growth, suggesting that such designs may control myopia progression in humans.

Effect on visual parameters in myopic children wearing spectacle lens designed to reduce peripheral hyperopic defocus / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To study the efficacy of AMSPL on myopia control, and confirm the security of wearing AMSPL, through comparing the impacts on visual parameters between myopic children wearing spectacle lens designed to reduce peripheral hyperopic defocus(AMSPL)and myopic children wearing the standard design control lens(SPL).<p>METHODS: Totally 50 children aged 8 to 14 years wearing spectacle lens designed to reduce peripheral hyperopic defocus(AMSPL)were collected into the AMSPL group, and other 50 children in the same age, the same degree of myopia and the same glasses time wearing standard design control lens(SPL)were selected into normal control group randomly(SPL group). We reviewed their documents and exam all patients. The examination include intraocular pressure, refraction under cycloplegia, distant strabismus and near strabismus, AC/A ratio. <p>RESULTS: The children wearing spectacle lens designed to reduce peripheral hyperopic defocus(AMSPL)had lower feeling of comfort than SPL group, mainly in peripheral vision confused, but no difference between them 1mo later. The AMSPL group's average growth of refractive error is -0.62±0.50D, the SPL group's average growth of refractive error is -0.77±0.48D(<i>P</i>=0.072). In myopic children aged 8 to 10 years, the AMSPL group's average development of refractive error is -0.71±0.41D, lower than the SPL group that of -1.05±0.39D, the difference was significant(<i>t</i>=2.164, <i>P</i>=0.041). Between the two groups, there was no significant difference(<i>P</i>>0.05)in visual parameters of distant strabismus, near strabismus, AC/A ratio.<p>CONCLUSION: Wearing spectacle lens designed to reduce peripheral hyperopic defocus(AMSPL)can delay the progression of myopia to a certain extent, especially for myopic children aged 8 to 10 years. It suggests that wearing AMSPL has the same safety with SPL for myopic children.

Effect of progressive addition lens on peripheral refraction in adolescent myopic eye / 中华实验眼科杂志

Background Peripheral refraction of retina brings about influence on myopia development,and different corrective methods will play different roles on the peripheral refraction.Objective This study was to measure the peripheral refraction with progressive addition lenses (PALs) and single-vision spectacle lenses (SVLs) corrected in adolescent myopic eyes and to investigate the difference between them.Methods This was a selfcontrolled cross-sectional study.Forty corrected myopic eyes with PALs were recruited for the study.Twenty-three male and seventeen female subjects aged 10-15 years (mean 12.54 years±1.45 years) enrolled in this study.The refractive errors of the subjects ranged form-1.50 D to-6.00 D (mean-3.74 D±1.09 D) and the astigmatism was less than-1.50 D with the corrected visual acuity at least 20/25.1％ Tropicamide eye drops was topically administered for the cycloplegia and then Grand Seiko WAM-5500 Auto-refractor was used to measure the peripheral refraction.The measured points were determined follows as:fovea (0°),peripheral temporal (T30°,T20°,T10°) and nasal (N30°,N20°,N10°) visual fields from the right eyes.The mean of the six measuring points for each position was calculated.Peripheral refraction was measured from each subject under the wearing of PALs or SVLs (randomly in succession),and the statistic analyse perimeters included M value,relative peripheral refractive error (RPRE),J45,J180.Written informed consent was obtained from each subject before examination.Results The corrected visual acuity was 4.98 ± 0.65 and 4.97 ± 0.53 under the PALs and SVLs conditions respectively,showing in significant difference between them (t =0.222,P =0.639).Hypermetropic shift in peripheral M value and RPRE value were found with the increase of visual angle field,in contrast,the peripheral J180 showed a myopic shift,and significant difference was found among the six peripheral points with all of the above three perimeters (P＜0.05).Negative J45 values in the temporal visual filed and positive J45 values in the nasal filed showed less shift.Some peripheral angles of the peripheral refractions in M value,RPRE value,J180,J45 showed significantly difference from the fovea refraction(P＜0.05).Compared with SVLs correction,PALs induced relatively myopic shifts in M value and RPRE value in all of the peripheral angle fields,showing significant differences(P＜0.05).Conclusions PALs causes relatively myopic shift at the peripheral retina in adolescent myopic eyes in comparison with SVLs,and the important parameters are M value and RPRE value.The effect of PALs on controlling the onset and progression of myopia may be interpreted by peripheral refraction.