A randomised clinical trial to assess the effect of a dual treatment on myopia progression: the Cambridge Anti-Myopia Study

Interventions for myopia control in children: a living systematic review and network meta-analysis

BACKGROUND

Myopia is a common refractive error, where elongation of the eyeball causes distant objects to appear blurred. The increasing prevalence of myopia is a growing global public health problem, in terms of rates of uncorrected refractive error and significantly, an increased risk of visual impairment due to myopia-related ocular morbidity. Since myopia is usually detected in children before 10 years of age and can progress rapidly, interventions to slow its progression need to be delivered in childhood.

OBJECTIVES

To assess the comparative efficacy of optical, pharmacological and environmental interventions for slowing myopia progression in children using network meta-analysis (NMA). To generate a relative ranking of myopia control interventions according to their efficacy. To produce a brief economic commentary, summarising the economic evaluations assessing myopia control interventions in children. To maintain the currency of the evidence using a living systematic review approach.  SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register), MEDLINE; Embase; and three trials registers. The search date was 26 February 2022.  SELECTION CRITERIA: We included randomised controlled trials (RCTs) of optical, pharmacological and environmental interventions for slowing myopia progression in children aged 18 years or younger. Critical outcomes were progression of myopia (defined as the difference in the change in spherical equivalent refraction (SER, dioptres (D)) and axial length (mm) in the intervention and control groups at one year or longer) and difference in the change in SER and axial length following cessation of treatment ('rebound').  DATA COLLECTION AND ANALYSIS: We followed standard Cochrane methods. We assessed bias using RoB 2 for parallel RCTs. We rated the certainty of evidence using the GRADE approach for the outcomes: change in SER and axial length at one and two years. Most comparisons were with inactive controls.

MAIN RESULTS

We included 64 studies that randomised 11,617 children, aged 4 to 18 years. Studies were mostly conducted in China or other Asian countries (39 studies, 60.9%) and North America (13 studies, 20.3%). Fifty-seven studies (89%) compared myopia control interventions (multifocal spectacles, peripheral plus spectacles (PPSL), undercorrected single vision spectacles (SVLs), multifocal soft contact lenses (MFSCL), orthokeratology, rigid gas-permeable contact lenses (RGP); or pharmacological interventions (including high- (HDA), moderate- (MDA) and low-dose (LDA) atropine, pirenzipine or 7-methylxanthine) against an inactive control. Study duration was 12 to 36 months. The overall certainty of the evidence ranged from very low to moderate. Since the networks in the NMA were poorly connected, most estimates versus control were as, or more, imprecise than the corresponding direct estimates. Consequently, we mostly report estimates based on direct (pairwise) comparisons below. At one year, in 38 studies (6525 participants analysed), the median change in SER for controls was -0.65 D. The following interventions may reduce SER progression compared to controls: HDA (mean difference (MD) 0.90 D, 95% confidence interval (CI) 0.62 to 1.18), MDA (MD 0.65 D, 95% CI 0.27 to 1.03), LDA (MD 0.38 D, 95% CI 0.10 to 0.66), pirenzipine (MD 0.32 D, 95% CI 0.15 to 0.49), MFSCL (MD 0.26 D, 95% CI 0.17 to 0.35), PPSLs (MD 0.51 D, 95% CI 0.19 to 0.82), and multifocal spectacles (MD 0.14 D, 95% CI 0.08 to 0.21). By contrast, there was little or no evidence that RGP (MD 0.02 D, 95% CI -0.05 to 0.10), 7-methylxanthine (MD 0.07 D, 95% CI -0.09 to 0.24) or undercorrected SVLs (MD -0.15 D, 95% CI -0.29 to 0.00) reduce progression.  At two years, in 26 studies (4949 participants), the median change in SER for controls was -1.02 D. The following interventions may reduce SER progression compared to controls: HDA (MD 1.26 D, 95% CI 1.17 to 1.36), MDA (MD 0.45 D, 95% CI 0.08 to 0.83), LDA (MD 0.24 D, 95% CI 0.17 to 0.31), pirenzipine (MD 0.41 D, 95% CI 0.13 to 0.69), MFSCL (MD 0.30 D, 95% CI 0.19 to 0.41), and multifocal spectacles  (MD 0.19 D, 95% CI 0.08 to 0.30). PPSLs (MD 0.34 D, 95% CI -0.08 to 0.76) may also reduce progression, but the results were inconsistent. For RGP, one study found a benefit and another found no difference with control. We found no difference in SER change for undercorrected SVLs (MD 0.02 D, 95% CI -0.05 to 0.09). At one year, in 36 studies (6263 participants), the median change in axial length for controls was 0.31 mm. The following interventions may reduce axial elongation compared to controls: HDA (MD -0.33 mm, 95% CI -0.35 to 0.30), MDA (MD -0.28 mm, 95% CI -0.38 to -0.17), LDA (MD -0.13 mm, 95% CI -0.21 to -0.05), orthokeratology (MD -0.19 mm, 95% CI -0.23 to -0.15), MFSCL (MD -0.11 mm, 95% CI -0.13 to -0.09), pirenzipine (MD -0.10 mm, 95% CI -0.18 to -0.02), PPSLs (MD -0.13 mm, 95% CI -0.24 to -0.03), and multifocal spectacles (MD -0.06 mm, 95% CI -0.09 to -0.04). We found little or no evidence that RGP (MD 0.02 mm, 95% CI -0.05 to 0.10), 7-methylxanthine (MD 0.03 mm, 95% CI -0.10 to 0.03) or undercorrected SVLs (MD 0.05 mm, 95% CI -0.01 to 0.11) reduce axial length. At two years, in 21 studies (4169 participants), the median change in axial length for controls was 0.56 mm. The following interventions may reduce axial elongation compared to controls: HDA (MD -0.47mm, 95% CI -0.61 to -0.34), MDA (MD -0.33 mm, 95% CI -0.46 to -0.20), orthokeratology (MD -0.28 mm, (95% CI -0.38 to -0.19), LDA (MD -0.16 mm, 95% CI -0.20 to  -0.12), MFSCL (MD -0.15 mm, 95% CI -0.19 to -0.12), and multifocal spectacles (MD -0.07 mm, 95% CI -0.12 to -0.03). PPSL may reduce progression (MD -0.20 mm, 95% CI -0.45 to 0.05) but results were inconsistent. We found little or no evidence that undercorrected SVLs (MD -0.01 mm, 95% CI -0.06 to 0.03) or RGP (MD 0.03 mm, 95% CI -0.05 to 0.12) reduce axial length. There was inconclusive evidence on whether treatment cessation increases myopia progression. Adverse events and treatment adherence were not consistently reported, and only one study reported quality of life. No studies reported environmental interventions reporting progression in children with myopia, and no economic evaluations assessed interventions for myopia control in children.

AUTHORS' CONCLUSIONS

Studies mostly compared pharmacological and optical treatments to slow the progression of myopia with an inactive comparator. Effects at one year provided evidence that these interventions may slow refractive change and reduce axial elongation, although results were often heterogeneous. A smaller body of evidence is available at two or three years, and uncertainty remains about the sustained effect of these interventions. Longer-term and better-quality studies comparing myopia control interventions used alone or in combination are needed, and improved methods for monitoring and reporting adverse effects.

Update and guidance on management of myopia. European Society of Ophthalmology in cooperation with International Myopia Institute

The prevalence of myopia is increasing extensively worldwide. The number of people with myopia in 2020 is predicted to be 2.6 billion globally, which is expected to rise up to 4.9 billion by 2050, unless preventive actions and interventions are taken. The number of individuals with high myopia is also increasing substantially and pathological myopia is predicted to become the most common cause of irreversible vision impairment and blindness worldwide and also in Europe. These prevalence estimates indicate the importance of reducing the burden of myopia by means of myopia control interventions to prevent myopia onset and to slow down myopia progression. Due to the urgency of the situation, the European Society of Ophthalmology decided to publish this update of the current information and guidance on management of myopia. The pathogenesis and genetics of myopia are also summarized and epidemiology, risk factors, preventive and treatment options are discussed in details.

Visual Performance with Spherical and Multifocal Contact Lenses in a Pediatric Population

SIGNIFICANCE

This pilot study compared subjective and objective vision of children wearing single-vision and +2.00, +3.00, and +4.00 D add power soft multifocal contact lenses to determine whether the higher add power-thought to provide better myopia control-resulted in visual compromise.

PURPOSE

This study aimed to determine the maximum add power children wearing center-distance soft multifocal contact lenses could accept objectively and subjectively.

METHODS

Myopic children were assigned in random order to wear omafilcon A single-vision or multifocal "D" contact lenses with +2.00, +3.00, or +4.00 D add power for 1 week each. High-contrast distance and near visual acuity, low-contrast distance visual acuity, and contrast sensitivity were measured at each visit along with a quality of vision questionnaire to assess their vision. The Friedman test was performed to evaluate the impact of add power on all outcome measures.

RESULTS

Eleven subjects were enrolled, and nine subjects completed the study. The median age of completed subjects was 11 years. Median logMAR low-contrast distance visual acuity was reduced in the +3.00 (+0.20) and +4.00 (+0.28) D add lenses compared with the +2.00 (+0.16) D add and single-vision lenses (+0.10, P < .001). All three multifocal lenses resulted in reduced contrast sensitivity (+1.35 to +1.40) compared with single-vision lenses (+1.60, P < .001). In general, +3.00 and +4.00 D add lenses resulted in worse glare/starbursts, ghost images, computer vision, changing fixation distance, and overall vision, but results varied. There were no differences among the lenses with respect to subjective assessments of distance vision, near vision, strain or tiredness, contact lens comfort, or sporting activities.

CONCLUSIONS

The +3.00 D and higher add powers result in more objective and subjective vision-related issues than single-vision lenses, but the +2.00 D add multifocal lenses were well tolerated.

Manipulation of Front-Surface Profile of Scleral Contact Lenses to Alter Peripheral Refraction

SIGNIFICANCE

The front optic zone diameter of scleral contact lenses was manipulated to mimic the central treatment zone induced by orthokeratology contact lens wear, to explore potential effects on the peripheral refraction profile.

PURPOSE

The purpose of this study was to investigate effects on the peripheral refraction profile of changing front optic zone diameters of scleral contact lenses.

METHODS

Twelve young adults were fitted with scleral contact lenses (diameter, 16.5 mm) with two front optic zone diameters (6 and 4 mm) on one eye only on 2 separate days. Both lenses were fabricated with front optic zone power of -3.00 D and plano power outside the optic zone to mimic the orthokeratology treatment effect. All lenses had the same spherical back-surface design with a toric lens periphery. Peripheral refraction was measured at 10° increments along horizontal (±35°) and vertical (±30°) meridians before lens insertion and after 10 minutes of lens wear. Mixed-model analysis and post hoc t tests with Bonferroni correction were performed.

RESULTS

Compared with baseline, no significant change in relative spherical equivalent refraction M was observed with 6-mm optic zone lenses along the horizontal meridian. However, a significant difference in relative M profile was found with 4-mm optic zone lenses (P = .009). M became myopic at all locations in the nasal visual field (P < .05) except at 35°. In contrast, compared with baseline, no significant changes in relative M were found with either 6- or 4-mm optic zone lenses along the vertical meridian.

CONCLUSIONS

The greater myopic shift in relative peripheral refraction with 4-mm compared with 6-mm front optic zone lenses suggests that a reduced treatment zone diameter in orthokeratology may induce more myopic peripheral refraction changes. This may guide us toward novel orthokeratology lens designs for more effective myopia control.

The Impact of Overnight Orthokeratology on Accommodative Response in Myopic Subjects

This study aimed to evaluate the effects of two months of orthokeratology (OK) treatment in the accommodative response of young adult myopes. Twenty eyes (21.8 ± 1.8 years) were fitted with the Paragon CRT^® 100 LENS to treat myopia between −1.00 and −2.00 D. Low- and high-contrast visual acuity (LCDVA and HCDVA), central objective refraction, light disturbance (LD), and objective accommodative response (using the Grand Seiko WAM-5500 open-field autorefractometer coupled with a Badal system) were measured at baseline (BL) before lens wear and after 1, 15, 30, and 60 nights of OK. Refractive error correction was achieved during the first fifty days of OK lens wear, with minimal changes afterwards. LD analysis showed a transient increase followed by a reduction to baseline levels over the first 30 nights of treatment. The accommodative response was lower than expected for all target vergences in all visits (BL: 0.61 D at 1.00 D to 0.96 D at 5.00 D; 60 N: 0.36 D at 1.00 D to 0.79 D at 5.00 D). On average, the accommodative lag decreases over time with OK lens wear. However, these differences were not statistically significant (p > 0.050, repeated-measures ANOVA and Friedman test). This shows that overnight OK treatment does not affect objectively measured the accommodative response of young, low myopic eyes after two months of treatment stabilization.

Effect of High Add Power, Medium Add Power, or Single-Vision Contact Lenses on Myopia Progression in Children: The BLINK Randomized Clinical Trial

IMPORTANCE

Slowing myopia progression could decrease the risk of sight-threatening complications.

OBJECTIVE

To determine whether soft multifocal contact lenses slow myopia progression in children, and whether high add power (+2.50 D) slows myopia progression more than medium (+1.50 D) add power lenses.

DESIGN, SETTING, AND PARTICIPANTS

A double-masked randomized clinical trial that took place at 2 optometry schools located in Columbus, Ohio, and Houston, Texas. A total of 294 consecutive eligible children aged 7 to 11 years with -0.75 D to -5.00 D of spherical component myopia and less than 1.00 D astigmatism were enrolled between September 22, 2014, and June 20, 2016. Follow-up was completed June 24, 2019.

INTERVENTIONS

Participants were randomly assigned to wear high add power (n = 98), medium add power (n = 98), or single-vision (n = 98) contact lenses.

MAIN OUTCOMES AND MEASURES

The primary outcome was the 3-year change in cycloplegic spherical equivalent autorefraction, as measured by the mean of 10 autorefraction readings. There were 11 secondary end points, 4 of which were analyzed for this study, including 3-year eye growth.

RESULTS

Among 294 randomized participants, 292 (99%) were included in the analyses (mean [SD] age, 10.3 [1.2] years; 177 [60.2%] were female; mean [SD] spherical equivalent refractive error, -2.39 [1.00] D). Adjusted 3-year myopia progression was -0.60 D for high add power, -0.89 D for medium add power, and -1.05 D for single-vision contact lenses. The difference in progression was 0.46 D (95% CI, 0.29-0.63) for high add power vs single vision, 0.30 D (95% CI, 0.13-0.47) for high add vs medium add power, and 0.16 D (95% CI, -0.01 to 0.33) for medium add power vs single vision. Of the 4 secondary end points, there were no statistically significant differences between the groups for 3 of the end points. Adjusted mean eye growth was 0.42 mm for high add power, 0.58 mm for medium add power, and 0.66 mm for single vision. The difference in eye growth was -0.23 mm (95% CI, -0.30 to -0.17) for high add power vs single vision, -0.16 mm (95% CI, -0.23 to -0.09) for high add vs medium add power, and -0.07 mm (95% CI, -0.14 to -0.01) for medium add power vs single vision.

CONCLUSIONS AND RELEVANCE

Among children with myopia, treatment with high add power multifocal contact lenses significantly reduced the rate of myopia progression over 3 years compared with medium add power multifocal and single-vision contact lenses. However, further research is needed to understand the clinical importance of the observed differences.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02255474.

Accommodation is unrelated to myopia progression in Chinese myopic children

This study shows accommodative accuracy and distance accommodation facility in myopic children do not play a role in myopia progression. In 144 subjects, the monocular distance accommodative facility (DAF) and continuous accommodative stimulus-response curves (ASRCs) were measured at the enrolment. Retrospective and prospective refraction with regard to the enrolment visit were obtained from the outpatient database system based on noncycloplegic subjective spherical equivalent refraction (SER). The rate of myopic progression at enrolment was the first derivative of the Gompertz function, which was fitted with each subject's longitudinal refractive error data, including at least four records of SER with an interval of more than 6 months between each visit. A mixed linear model for multilevel repeated-measures data was used to explore the associations between the rate of myopia progression and accommodative parameters. The mean rate of myopia progression at enrolment was -0.61 ± 0.31 D/y with a mean age of 12.27 ± 1.61 years. By adjusting for age and SER, it was shown that the myopic progression rate was not associated with the accommodative lag (F = 0.269, P = 0.604), accommodative lag area (F = 0.086, P = 0.354), slope of ASRC (F = 0.711, P = 0.399), and DAF (F = 0.619, P = 0.432).

Higher-Order Aberrations and Axial Elongation in Myopic Children Treated With Orthokeratology

Purpose

This retrospective longitudinal study aimed to examine the relationship between ocular higher-order aberrations (HOA) and axial eye growth in young myopic children undergoing orthokeratology (ortho-k) treatment.

Methods

Axial length and ocular HOA, measured under cycloplegia annually over a 2-year period from the right eyes of myopic children, who previously completed ortho-k clinical trials, were retrieved. Linear mixed model analyses were applied to determine the association between ocular HOA, other known confounding variables (age, sex, and refractive error), and axial eye growth.

Results

Data from 103 subjects were analyzed. The root-mean square (RMS) values of total ocular HOA (third to sixth orders combined), spherical (Z40 and Z60 combined), and comatic (Z3-1, Z31, Z5-1, and Z51 combined) aberrations increased by approximately 3, 9, and 2 times, respectively, after 2 years of ortho-k treatment. After adjusting for age, sex, and refractive error, higher RMS values of total HOA and spherical aberrations were associated with both longer axial length and slower axial elongation (all P < 0.01). For individual Zernike term coefficients, a higher level of positive spherical aberration (Z40) was also associated with longer axial length and slower axial elongation (both P < 0.01), after adjusting for baseline HOA.

Conclusions

Ortho-k for myopia control significantly increases the Zernike coefficients and therefore the RMS values for a range of total ocular HOA terms or metrics in children. These findings suggest the potential role of HOA, particularly spherical aberration, as the possible mechanism of slowing axial elongation in ortho-k treatment.

Bifocal and Multifocal Contact Lenses for Presbyopia and Myopia Control

Bifocal and multifocal optical devices are intended to get images into focus from objects placed at different distances from the observer. Spectacles, contact lenses, and intraocular lenses can meet the requirements to provide such a solution. Contact lenses provide unique characteristics as a platform for implementing bifocality and multifocality. Compared to spectacles, they are closer to the eye, providing a wider field of view, less distortion, and their use is more consistent as they are not so easily removed along the day. In addition, contact lenses are also minimally invasive, can be easily exchangeable, and, therefore, suitable for conditions in which surgical procedures are not indicated. Contact lenses can remain centered with the eye despite eye movements, providing the possibility for simultaneous imaging from different object distances. The main current indications for bifocal and multifocal contact lenses include presbyopia correction in adult population and myopia control in children. Considering the large numbers of potential candidates for optical correction of presbyopia and the demographic trends in myopia, the potential impact of contact lenses for presbyopia and myopia applications is undoubtedly tremendous. However, the ocular characteristics and expectations vary significantly between young and older candidates and impose different challenges in fitting bifocal and multifocal contact lenses for the correction of presbyopia and myopia control. This review presents the recent developments in material platforms, optical designs, simulated visual performance, and the clinical performance assessment of bifocal and multifocal contact lenses for presbyopia correction and/or myopia progression control.

A 3-year Randomized Clinical Trial of MiSight Lenses for Myopia Control

SIGNIFICANCE

Results of this randomized, double-masked clinical trial demonstrate the effectiveness of the MiSight soft contact lens in slowing myopia progression over multiple years.

PURPOSE

The purpose of this study was to quantify the effectiveness of MiSight daily disposable soft contact lens in slowing the progression of juvenile-onset myopia.

METHODS

Myopic children (spherical equivalent refraction, -0.75 to -4.00 D; astigmatism, <1.00 D) aged 8 to 12 years with no prior contact lens experience were enrolled in a 3-year, double-masked, randomized clinical trial at four investigational sites in four countries. Subjects in each group were matched for age, sex, and ethnicity and were randomized to either a MiSight 1-day contact lens (test) or Proclear 1-day (control; omafilcon A) and worn on a daily disposable basis. Primary outcome measures were the change in cycloplegic spherical equivalent refraction and axial length.

RESULTS

Of the subjects enrolled, 75.5% (109/144) completed the clinical trial (53 test, 56 control). Unadjusted change in spherical equivalent refraction was -0.73 D (59%) less in the test group than in the control group (-0.51 ± 0.64 vs. -1.24 ± 0.61 D, P < .001). Mean change in axial length was 0.32 mm (52%) less in the test group than in the control group (0.30 ± 0.27 vs. 0.62 ± 0.30 mm, P < .001). Changes in spherical equivalent refraction and axial length were highly correlated (r = -0.90, P < .001). Over the course of the study, there were no cases of serious ocular adverse events reported. Four asymptomatic corneal infiltrative (one test, three control) events were observed at scheduled study visits.

CONCLUSIONS

Results of this clinical trial demonstrate the effectiveness of the MiSight daily disposable soft contact lens in slowing change in spherical equivalent refraction and axial length.

Interventions to slow progression of myopia in children

BACKGROUND

Nearsightedness (myopia) causes blurry vision when one is looking at distant objects. Interventions to slow the progression of myopia in children include multifocal spectacles, contact lenses, and pharmaceutical agents.

OBJECTIVES

To assess the effects of interventions, including spectacles, contact lenses, and pharmaceutical agents in slowing myopia progression in children.

SEARCH METHODS

We searched CENTRAL; Ovid MEDLINE; Embase.com; PubMed; the LILACS Database; and two trial registrations up to February 2018. A top up search was done in February 2019.

SELECTION CRITERIA

We included randomized controlled trials (RCTs). We excluded studies when most participants were older than 18 years at baseline. We also excluded studies when participants had less than -0.25 diopters (D) spherical equivalent myopia.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods.

MAIN RESULTS

We included 41 studies (6772 participants). Twenty-one studies contributed data to at least one meta-analysis. Interventions included spectacles, contact lenses, pharmaceutical agents, and combination treatments. Most studies were conducted in Asia or in the United States. Except one, all studies included children 18 years or younger. Many studies were at high risk of performance and attrition bias. Spectacle lenses: undercorrection of myopia increased myopia progression slightly in two studies; children whose vision was undercorrected progressed on average -0.15 D (95% confidence interval [CI] -0.29 to 0.00; n = 142; low-certainty evidence) more than those wearing fully corrected single vision lenses (SVLs). In one study, axial length increased 0.05 mm (95% CI -0.01 to 0.11) more in the undercorrected group than in the fully corrected group (n = 94; low-certainty evidence). Multifocal lenses (bifocal spectacles or progressive addition lenses) yielded small effect in slowing myopia progression; children wearing multifocal lenses progressed on average 0.14 D (95% CI 0.08 to 0.21; n = 1463; moderate-certainty evidence) less than children wearing SVLs. In four studies, axial elongation was less for multifocal lens wearers than for SVL wearers (-0.06 mm, 95% CI -0.09 to -0.04; n = 896; moderate-certainty evidence). Three studies evaluating different peripheral plus spectacle lenses versus SVLs reported inconsistent results for refractive error and axial length outcomes (n = 597; low-certainty evidence). Contact lenses: there may be little or no difference between vision of children wearing bifocal soft contact lenses (SCLs) and children wearing single vision SCLs (mean difference (MD) 0.20D, 95% CI -0.06 to 0.47; n = 300; low-certainty evidence). Axial elongation was less for bifocal SCL wearers than for single vision SCL wearers (MD -0.11 mm, 95% CI -0.14 to -0.08; n = 300; low-certainty evidence). Two studies investigating rigid gas permeable contact lenses (RGPCLs) showed inconsistent results in myopia progression; these two studies also found no evidence of difference in axial elongation (MD 0.02mm, 95% CI -0.05 to 0.10; n = 415; very low-certainty evidence). Orthokeratology contact lenses were more effective than SVLs in slowing axial elongation (MD -0.28 mm, 95% CI -0.38 to -0.19; n = 106; moderate-certainty evidence). Two studies comparing spherical aberration SCLs with single vision SCLs reported no difference in myopia progression nor in axial length (n = 209; low-certainty evidence). Pharmaceutical agents: at one year, children receiving atropine eye drops (3 studies; n = 629), pirenzepine gel (2 studies; n = 326), or cyclopentolate eye drops (1 study; n = 64) showed significantly less myopic progression compared with children receiving placebo: MD 1.00 D (95% CI 0.93 to 1.07), 0.31 D (95% CI 0.17 to 0.44), and 0.34 (95% CI 0.08 to 0.60), respectively (moderate-certainty evidence). Axial elongation was less for children treated with atropine (MD -0.35 mm, 95% CI -0.38 to -0.31; n = 502) and pirenzepine (MD -0.13 mm, 95% CI -0.14 to -0.12; n = 326) than for those treated with placebo (moderate-certainty evidence) in two studies. Another study showed favorable results for three different doses of atropine eye drops compared with tropicamide eye drops (MD 0.78 D, 95% CI 0.49 to 1.07 for 0.1% atropine; MD 0.81 D, 95% CI 0.57 to 1.05 for 0.25% atropine; and MD 1.01 D, 95% CI 0.74 to 1.28 for 0.5% atropine; n = 196; low-certainty evidence) but did not report axial length. Systemic 7-methylxanthine had little to no effect on myopic progression (MD 0.07 D, 95% CI -0.09 to 0.24) nor on axial elongation (MD -0.03 mm, 95% CI -0.10 to 0.03) compared with placebo in one study (n = 77; moderate-certainty evidence). One study did not find slowed myopia progression when comparing timolol eye drops with no drops (MD -0.05 D, 95% CI -0.21 to 0.11; n = 95; low-certainty evidence). Combinations of interventions: two studies found that children treated with atropine plus multifocal spectacles progressed 0.78 D (95% CI 0.54 to 1.02) less than children treated with placebo plus SVLs (n = 191; moderate-certainty evidence). One study reported -0.37 mm (95% CI -0.47 to -0.27) axial elongation for atropine and multifocal spectacles when compared with placebo plus SVLs (n = 127; moderate-certainty evidence). Compared with children treated with cyclopentolate plus SVLs, those treated with atropine plus multifocal spectacles progressed 0.36 D less (95% CI 0.11 to 0.61; n = 64; moderate-certainty evidence). Bifocal spectacles showed small or negligible effect compared with SVLs plus timolol drops in one study (MD 0.19 D, 95% CI 0.06 to 0.32; n = 97; moderate-certainty evidence). One study comparing tropicamide plus bifocal spectacles versus SVLs reported no statistically significant differences between groups without quantitative results. No serious adverse events were reported across all interventions. Participants receiving antimuscarinic topical medications were more likely to experience accommodation difficulties (Risk Ratio [RR] 9.05, 95% CI 4.09 to 20.01) and papillae and follicles (RR 3.22, 95% CI 2.11 to 4.90) than participants receiving placebo (n=387; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Antimuscarinic topical medication is effective in slowing myopia progression in children. Multifocal lenses, either spectacles or contact lenses, may also confer a small benefit. Orthokeratology contact lenses, although not intended to modify refractive error, were more effective than SVLs in slowing axial elongation. We found only low or very low-certainty evidence to support RGPCLs and sperical aberration SCLs.

Effect of Vision Therapy on Accommodative Lag in Myopic Children: A Randomized Clinical Trial

SIGNIFICANCE

Accommodative dysfunction has been suggested to be related to the development and progression of myopia. Office-based accommodative/vergence therapy (OBAVT) improved accommodative facility in Chinese myopic children, but it is unclear if such improvement has a role in decreasing myopic progression.

PURPOSE

The purpose of this study was to compare the effects of OBAVT with home reinforcement and office-based placebo therapy (OBPT) as a treatment to improve accommodative functions (i.e., lag, amplitude, and facility) in myopic children with poor accommodative accuracy.

METHODS

This was a prospective, single-masked, randomized clinical trial. Thirty-four Chinese children 8 to 12 years old with myopia and at least 1 diopter of lag of accommodation measured by autorefraction were enrolled. The participants were randomly assigned to the OBAVT or OBPT group. The primary outcome measure was the change in the monocular lag of accommodation from the baseline visit to the 13-week visit measured by a Shin-Nippon open-field autorefractor. Secondary outcome measures were changes in accommodative amplitude and monocular accommodative facility.

RESULTS

A total of 33 participants completed the study. After 12 weeks of treatment, there were significant improvements in the lag of accommodation in both the OBAVT and OBPT groups (OBAVT: -0.30 ± 0.29 diopters [P < .001; Cohen's d effect size, 1.29]; OBPT: -0.24 ± 0.30 diopters [P = .005; Cohen's d effect size, 1.24]). There was no statistically significant difference between the improvements in the two groups (P = .50). There was statistically significant improvement in monocular accommodative facility only in the OBAVT group (OBAVT: 7.7 ± 4.7 cycles per minute [P < .001; Cohen's d effect size, 2.20]; OBPT: 1.9 ± 4.4 cycles per minute [P = .072]). The change in the OBAVT group was statistically significantly larger than that in the OBPT group (P < .001).

CONCLUSIONS

Office-based accommodative/vergence therapy was no more effective than OBPT in reducing the lag of accommodation in children 8 to 12 years old with low to moderate myopia. It did improve accommodative facility in Chinese myopic children, but it is unclear if such an improvement has a role in decreasing myopic progression.

Advances and challenges of soft contact lens design for myopia control

Myopia has shown a rapid increase during the past decades around the world, posing great threat to ocular health. Myopia is mostly attributed to an overgrowth of the axial length of the eye, which is an abnormal growth of the sclera that is attributed to a series of environmental and genetic factors and their interactions. Soft contact lenses have the potential to be an ideal method of correction for slowing myopic progression. This paper serves as a comprehensive review of the state of the art in the field of soft contact lens design for myopia control. The knowledge gaps are identified in designing the contact lenses and potential challenges are also presented that could be faced in future development.

Repeatability of Wavefront Aberration Measurements With a Placido-Based Topographer in Normal and Keratoconic Eyes

PURPOSE

To determine and compare the repeatability of anterior corneal higher order aberrations (HOAs) using a Placido-based topographer (Allegro Topolyzer; WaveLight Technologie AG, Alcon Laboratories, Erlangen, Germany) in a sample of normal and keratoconic eyes.

METHODS

Three repeated measurements of each cornea of normal and keratoconic eyes were taken with the Allegro Topolyzer. Repeatability of the HOAs (3rd- and 4th-order individual values and normalized polar Zernike coefficients, coma-like, root mean square (RMS) up to 8th-order values, HOA RMS, and total RMS for 6-mm pupil diameter) and central corneal power (3-mm pupil) were analyzed. Within-subject standard deviation (Sw), precision, repeatability, coefficient of variation (CV), and the intraclass correlation coefficient (ICC) were calculated.

RESULTS

Zernike coefficients were significantly different between the normal (36 eyes of 36 patients) and keratoconus (36 eyes of 36 patients) groups (P ≤ .03) except in Z(+1) 3, Z(+3) 3, Z(-4) 4, and Z(+4) 4. In the normal group, Sw was 0.031 µm or less, CV ranged from 6.49% (spherical aberration) to 37.18% (secondary astigmatism), and ICC values ranged from 0.227 to 0.982. In the keratoconus group, Sw was 0.059 µm or less, CV ranged from 2.06% (total RMS) to 25.82% (tetrafoil), and ICC values ranged from 0.839 to 0.996. In analyzing the keratoconus stages (Amsler-Krumeich classification), the repeatability of the Zernike coefficients tended to improve with increasing keratoconus stage.

CONCLUSIONS

The repeatability of corneal wavefront aberration provided by the Allegro Topolyzer was better in keratoconic eyes (good and moderate repeatability) than in normal eyes (moderate and poor repeatability). These results are important to eye care practitioners and refractive surgeons during refractive surgery planning or keratoconus detection, classification, and management. [J Refract Surg. 2016;32(5):338-344.].

Effect of Vision Therapy on Accommodation in Myopic Chinese Children

Introduction. We evaluated the effectiveness of office-based accommodative/vergence therapy (OBAVT) with home reinforcement to improve accommodative function in myopic children with poor accommodative response. Methods. This was a prospective unmasked pilot study. 14 Chinese myopic children aged 8 to 12 years with at least 1 D of lag of accommodation were enrolled. All subjects received 12 weeks of 60-minute office-based accommodative/vergence therapy (OBAVT) with home reinforcement. Primary outcome measure was the change in monocular lag of accommodation from baseline visit to 12-week visit measured by Shinnipon open-field autorefractor. Secondary outcome measures were the changes in accommodative amplitude and monocular accommodative facility. Results. All participants completed the study. The lag of accommodation at baseline visit was 1.29 ± 0.21 D and it was reduced to 0.84 ± 0.19 D at 12-week visit. This difference (−0.46 ± 0.22 D; 95% confidence interval: −0.33 to −0.58 D) is statistically significant (p < 0.0001). OBAVT also increased the amplitude and facility by 3.66 ± 3.36 D (p = 0.0013; 95% confidence interval: 1.72 to 5.60 D) and 10.9 ± 4.8 cpm (p < 0.0001; 95% confidence interval: 8.1 to 13.6 cpm), respectively. Conclusion. Standardized 12 weeks of OBAVT with home reinforcement is able to significantly reduce monocular lag of accommodation and increase monocular accommodative amplitude and facility. A randomized clinical trial designed to investigate the effect of vision therapy on myopia progression is warranted.

Near work-induced transient myopia in Indian subjects

PURPOSE

The aim was to determine the characteristics of near work-induced transient myopia (NITM) in asymptomatic Indian subjects and the influence of target size and contrast.

METHODS

Two studies were conducted: First, 24 myopes and 24 emmetropes viewed four targets (N8 and N12 with 50 and 90 per cent contrasts) placed at 0.2 m for five minutes. The refractive status was assessed objectively, before and after carrying out the near task, with the Grand Seiko WAM-5500 open-field autorefractor under monocular viewing conditions. Second, a different group of 24 myopes and 24 emmetropes viewed a N12 target with 90 per cent contrast for 60 minutes with pre- and post-refractive state measurements repeated as above. NITM was defined as the difference between pre-task and post-task distance refraction.

RESULTS

In the first study, myopes demonstrated an initial post-task myopic shift of 0.21 D, whereas emmetropes demonstrated a small hyperopic shift of 0.07 D (p < 0.001). The myopes demonstrated a decay time constant of 6.07 seconds. There was no effect of target size or contrast on the magnitude of the NITM or the decay time constant (p > 0.05). In the second study, myopes showed a NITM of 0.31 D, which was significantly greater than emmetropes (p < 0.001). The myopes demonstrated a decay time constant of 8.16 seconds.

CONCLUSION

The magnitude of the NITM was higher in myopes compared to emmetropes for both five minute and 60 minute viewing time. The NITM decayed slightly faster than that found in previous literature for some other ethnic groups. Potential reasons for these findings are discussed.

Rate of change and predictive factors for increasing minus contact lens powers in young myopes

BACKGROUND

Understanding the factors associated with myopic progression is critical to properly recruit subjects into clinical trials for control of myopia. The purpose of this study is to describe the rate of change in soft contact lens (SCL) power and the associated predictive factors in a young clinical population from the Contact Lens Assessment in Youth study.

METHODS

Data from a retrospective chart review of myopic SCL wearers aged eight to 22 years were analysed for rate of progression of myopia and associated characteristics using multivariate methods.

RESULTS

Myopic subjects (n = 912) with at least six months of follow-up were observed (4,341 visits, mean follow-up 25 months, 37 per cent hydrogel and 63 per cent silicone hydrogel SCLs). During observation, 36 per cent of subjects experienced a change in soft contact lens power of -0.50 D or more. Significant predictors of future increase in minus lens power were: ages eight to 13 years, shorter time to the first increase in minus power and hydrogel soft contact lens material. The mean annualised increase in minus decreased with age (-0.31D per year for eight to 13 year olds to -0.10 D per year for 20 to 22 year olds, p < 0.0001). Increases in minus were less common among users of silicone hydrogel materials than hydrogel daily disposable lenses after controlling for age (p = 0.039).

CONCLUSION

In this retrospective chart review of young soft contact lens wearers, the mean annualised rate of increase in minus soft contact lens power decreased with age, longer time to first increase in power and was greater with hydrogel soft contact lenses. The rates observed were similar to progression rates in prospective myopia clinical trials that employed cylcoplegic autorefraction.

The Cambridge Anti-myopia Study: variables associated with myopia progression

PURPOSE

To identify variables associated with myopia progression and to identify any interaction between accommodative function, myopia progression, age, and treatment effect in the Cambridge Anti-Myopia Study.

METHODS

Contact lenses were used to improve static accommodation by altering ocular spherical aberration, and vision training was performed to improve dynamic accommodation. One hundred forty-two subjects, aged 14-21 years, were recruited who had a minimum of -0.75D of myopia. Subjects were assigned to contact lens treatment only, vision training only, contact lens treatment and vision training, or control group. Spherical aberration, lag of accommodation, accommodative convergence/accommodation (AC/A) ratio, accommodative facility, ocular biometry, and refractive error were measured at regular intervals throughout the 2-year trial.

RESULTS

Ninety-five subjects completed the 24-month trial period. There was no significant difference in myopia progression between the four treatment groups at 24 months. Age, lag of accommodation, and AC/A ratio were significantly associated with myopia progression. There was a significant treatment effect at 12 months in the contact lens treatment group in younger subjects, based on a median split, aged under 16.9 years (p = 0.005). This treatment effect was not maintained over the second year of the trial. Younger subjects experienced a greater reduction in lag of accommodation with the treatment contact lens at 3 months (p = 0.03), compared to older contact lens treatment and control groups. There was no interaction between AC/A ratio and contact lens treatment effect.

CONCLUSIONS

Age, lag of accommodation, and AC/A ratio were significantly associated with myopia progression. Although there was no significant treatment effect at 24 months, an interaction between age and contact lens treatment suggests younger subjects may be more amenable, at least in the short term, to alteration of the visual system using optical treatments.