Prevention of Progression in Myopia: A Systematic Review

Slowing of Greater Axial Length Elongation Stemming from the Coronavirus Disease 2019 Pandemic with Increasing Time Outdoors: The Tokyo Myopia Study

Purpose

To investigate the changes in axial length (AL) elongation and other ocular parameters before and during the coronavirus disease 2019 pandemic.

Design

A longitudinal school-based study.

Participants

Public elementary schoolchildren in Tokyo (grades 1-6; age, 6-12 years) participated in this study from 2018 to 2021.

Methods

All participants underwent eye examinations and provided written consent to measurements of the noncycloplegic refraction and ocular biometry including AL, among others. The students' parents also completed a questionnaire about the students' lifestyles. We included the right eye in our analysis and compared the changes in the ocular parameters among the periods using a linear mixed-effects model for repeated measures and examined the univariate and step-wise multiple regression analyses to evaluate the associations between myopia and other covariates.

Main Outcome Measures

Changes in AL elongation and other ocular parameters from 2018 to 2019 (prepandemic), that of 2019 to 2020 (immediately after the pandemic onset), and that of 2020 to 2021 (during the pandemic).

Results

A total of 578 students before the pandemic period, 432 immediately after the pandemic onset, and 457 during the pandemic period were evaluated. The changes in the ALs and spherical equivalents (SEs) a year before, immediately after onset, and during the pandemic were 0.31 mm/-0.20 diopter, 0.38 mm/-0.27 diopter, and 0.28 mm/-0.47 diopter, respectively (ALs, P < 0.001; SEs, P = 0.014). The results of the questionnaire showed that time spent outdoors daily had changed during the 3 years to 79, 63, and 77 minutes/day, respectively (P < 0.001). Time spent using smartphones or tablets increased year by year to 41, 52, and 62 minutes/day (P < 0.001). The greatest AL elongation occurred during the period when the shortest amount of time was spent outdoors during the 3 years.

Conclusions

These results suggested that the school closures and decreasing time spent outdoors might have caused greater AL elongation among schoolchildren in Tokyo; however, it is possible that, although the time spent in near work still increased, the return to the time spent outdoors to the prepandemic levels may have affected the slowing of AL elongation after lockdown.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Low-level red-light therapy for myopia control in children: A systematic review and meta-analysis

INTRODUCTION

Low-Level Red-Light (LLRL) Therapy is a safe and natural way to promote healing and reduce inflammation in the body. When it comes to treating myopia in children, LLRL therapy is recent, and its efficacy and safety still are not clear.

METHODS

A systematic review and meta-analysis of the literature for LLRL was conducted in accordance with the PRISMA guidelines on November 5, 2022. Databases, including PUBMED, Cochrane Library, Web of Science, and Embase were queried. A meta-analysis of random effects was conducted. Inclusion criteria included Randomized Controlled Trials (RCTs) or observational studies where LLRL therapy was used in children (3‒15 years old) with myopia. Exclusion criteria were studies with other ocular abnormalities. Efficacy was evaluated through the mean change in Axial Length (AL) and cycloplegic Spherical Equivalent Error (SER), while safety was evaluated by monitoring adverse effects.

RESULTS

A total of 5 final studies were included (4 RCTs, and 1 observational), in which 685 total patients were analyzed. The mean age was 9.7 ± 0.66 years, with 48,2% female patients. The number of eyes in the LRLL arm is 714 and, in the control, arm is 656. LLRL showed better results in SER and AL mean change (OR = 0.58; 95% CI 0.33 to 0.83; p < 0.00001, and MD -0.33; 95% CI -0.52 to -0.13; p = 0.001, respectively), in comparison to the control group. There was no significant difference in adverse effects between groups (MD = 5.76; 95% CI 0.66 to 50.14; p = 0.11).

CONCLUSION

LLRL therapy is a non-invasive, effective, and safe short-term treatment option; however, long-term evaluation, particularly in comparison to other therapies, requires additional investigation.

Could Children's Myopization Have Been Avoided during the Pandemic Confinement? The Conjunctival Ultraviolet Autofluorescence (CUVAF) Biomarker as an Answer

BACKGROUND

The objective of this study was to evaluate the association of the presence of conjunctival ultraviolet autofluorescence (CUVAF) with the level and progression of myopia and the impact of reduced sunlight exposure during the COVID-19 pandemic confinement (PC).

METHODS

A retrospective observational study was carried out using three cohorts, children (9-17 years old), young adults (18-25 years old), and adults (>40 years old) with myopia (≤0.75D) and at least three annual eye examinations (before and after PC). All participants underwent an automatic objective refraction and CUVAF area analysis. All the participants filled out a questionnaire regarding lifestyle and myopia history.

RESULTS

The 298 recruited participants showed that during the PC, children's and young adults' myopia progression rate increased on average by -0.50 and -0.30 D/year, respectively, compared with the pre-pandemic level (p < 0.0001 and p < 0.01). A significantly greater progression was observed in those with low baseline myopia compared to those with moderate or high myopia (p < 0.01). CUVAF shows its protective effect associated with outdoor activity (OA) with regard to the age of onset of myopia and mean diopters (p < 0.01). In fact, although there were no differences in the increase in diopters between children with and without CUVAF during the PC, those who had CUVAF started with lower gains (-0.3 D/year) compared to those who did not (-0.5 D/year; p < 0.05). The myopia treatments (atropine drops, Ortho-K, and MiSight® contact lenses) showed a reduction effect in myopic progression rate post-PC in comparison with non-treated children (p < 0.0001, p < 0.0001 and p < 0.01, respectively).

CONCLUSIONS

The strict restriction of OA during PC led to the rate of myopia progression doubling among children and young adults. This progression occurred mainly in children with previously low myopia, and CUVAF, as a biomarker of OA, reflects its potential to provide benefits in the form of recommended behavioral changes to protect against the development of myopia.

Topical Application of Bunazosin Hydrochloride Suppresses Myopia Progression With an Increase in Choroidal Blood Perfusion

Purpose

The incidence of myopia has rapidly increased in recent decades, making it a growing public health concern worldwide. Interventions to suppress the progression of myopia are needed; one suggested strategy is the prevention of choroidal thinning, which can improve choroidal blood perfusion (ChBP). Bunazosin hydrochloride (BH) is an alpha1-adrenergic blocker and commercialized glaucoma eye drop that increases in blood circulation in the eye. In this study, we evaluated the efficacy of BH in suppressing the progression of myopia in a lens-induced murine model.

Methods

Lens-induced myopia was induced in 3-week-old C57BL/6 J mice with -30 diopter (D) lenses for three weeks. Refractive error, axial length, and choroidal thickness were evaluated at three and six weeks of age using an infrared photorefractor and a spectral domain optical coherence tomography (OCT) system. Moreover, ChBP and scleral thickness were evaluated using swept-source OCT and histological analysis.

Results

Compared with the controls, the administration of BH eye drops suppressed the myopic shift of refractive error (mean difference ± standard error in the eye with -30 D lens, -13.65 ± 5.69 D vs. 2.55 ± 4.30 D; P < 0.001), axial elongation (0.226 ± 0.013 mm vs. 0.183 ± 0.023 mm; P < 0.05), choroidal thinning (-2.01 ± 1.80 µm vs. 1.88 ± 1.27 µm; P < 0.001), and scleral thinning (11.41 ± 3.91 µm vs. 19.72 ± 4.01 µm; P < 0.01) with myopia progression and increased ChBP (52.0% ± 4.1% vs. 59.5% ± 6.3%; P < 0.05). The suppressive effect of BH eye drops was dose-dependent and higher than that of other glaucoma eye drops and alpha1 blockers.

Conclusions

These results demonstrate the potential of BH eye drops in the treatment of myopia and support further investigation of their efficacy in humans. Further studies are needed to determine the mechanism of action and long-term safety of this treatment.

Prevalence of myopia in school-age children in Ethiopia: A systematic review and meta-analysis

Objective

This study aimed to estimate the pooled prevalence of myopia among school-age children in Ethiopia.

Methods

Eligible articles were searched from PubMed, Embase, and Web of Science databases. In addition, Google Scholar and reference lists of the retrieved articles were searched from 30 July 2022 to 02 January 2023. The preferred reporting of items for systematic reviews and meta-analysis was used to report the search results. Microsoft Excel was used to keep the data. The qualities of eligible studies were checked using the Joanna Briggs Institute critical appraisal checklist for prevalence studies. Analysis was held using STATA Version 11. The degree of heterogeneity was checked using I² statistics. The possible sources of heterogeneity were examined using meta-regression and subgroup analyses. The funnel plot and Egger's test were used to assess the potential publication bias. A correction was made for publication bias using Duval and Twee Die's trim-and-fill analysis. The systematic review registration number is PROSPERO (#CRD42022330541).

Results

We identified 21 eligible articles including 20,757 subjects. Of those participants, 10,601 (51.1%) and 10,156 (48.9%) were males and females, respectively. A total of 15,152 (73%) participants were urban residents. The estimated prevalence of myopia among school-age children in Ethiopia was found to be 5.26% (95% confidence interval: 4.09-6.42).

Conclusions

The prevalence of myopia among school-age children in Ethiopia is considerable, affecting one in 20 school-age children. Therefore, the authors recommend the stakeholders take extra steps to speed up the implementation of the school vision screening program and its integration plan into the existing school nutrition program.

Comparison of Three Different Devices for the Evaluation of Axial Length, Refractive Error, and Keratometry

SIGNIFICANCE

Myopia prevalence is increasing worldwide. Axial length, refractive error, and keratometry are important outcome measures in myopia management. Precise measurement methods are required for myopia management. Various devices are used to measure these three parameters, and it is not known whether their results can be used interchangeably.

PURPOSE

The aim of this study was to compare three different devices to evaluate axial length, refractive error, and keratometry.

METHODS

A total of 120 subjects (37.7 ± 15.5 years) were enrolled in this prospective study. All subjects were measured with DNEye Scanner 2 (Rodenstock GmbH, Munich, Germany), Myopia Master (Oculus Optikgeräte GmbH, Wetzlar, Germany), and IOLMaster 700 (Carl Zeiss Meditec AG, Jena, Germany). Myopia Master and IOLMaster 700 use interferometry to measure axial length. Rodenstock Consulting software (Rodenstock GmbH, Munich, Germany) was used to calculate axial length from DNEye Scanner 2 measurement. Differences were analyzed using Bland-Altman 95% limits of agreement.

RESULTS

Differences for axial length were as follows: DNEye Scanner 2 versus Myopia Master, 0.67 ± 0.46 mm; DNEye Scanner 2 versus IOLMaster 700, 0.64 ± 0.46 mm; and Myopia Master versus IOLMaster 700, -0.02 ± 0.02 mm. Differences for mean corneal curvature were as follows: DNEye Scanner 2 versus Myopia Master, -0.20 ± 0.36 mm; DNEye Scanner 2 versus IOLMaster 700, -0.40 ± 0.35 mm; and Myopia Master versus IOLMaster 700, -0.20 ± 0.13 mm. The difference in noncycloplegic spherical equivalent between DNEye Scanner 2 and Myopia Master was 0.05 ± 0.25 D.

CONCLUSIONS

The results for axial length and keratometry from Myopia Master and IOLMaster were comparable. The axial length calculated by DNEye Scanner 2 was significantly different from interferometry devices and is not appropriate for myopia management. The differences in keratometry readings were clinically not significant. All refractive outcomes were comparable.

Influence of overnight orthokeratology on tear film and meibomian glands in myopic children: a prospective study

BACKGROUND

Orthokeratology lenses, which are worn overnight, are recommended for reducing myopia progression. They lie on the cornea and can influence the ocular surface by temporarily reshaping the corneal surface through a reverse geometry design. This study investigated the effect of overnight orthokeratology lenses on tear film stability and meibomian gland status in children aged 8-15 years.

METHODS

This prospective, self-controlled study included 33 children with monocular myopia who were prescribed orthokeratology lenses for at least one year. The experimental group (ortho-k group) comprised 33 myopic eyes. The control group comprised the emmetropic eyes of the same participants. Tear film stability and meibomian gland status were measured using a Keratograph 5M (Oculus, Wetzlar, Germany). Paired t-tests and Wilcoxon signed-rank tests were used to compare the data between the two groups.

RESULTS

At the one-year visit, the non-invasive first tear film break-up time (NIBUTf) values were 6.15 ± 2.56 s and 6.18 ± 2.61 s in the experimental and control groups, respectively. The lower tear meniscus height was 18.74 ± 0.05 μm and 18.65 ± 0.04 μm in these groups, respectively. No significant difference was observed in loss of meibomian glands or non-invasive average tear film break-up time between the experimental and control groups using Wilcoxon signed-rank tests.

CONCLUSIONS

The stability of the tear film and meibomian gland status were not significantly affected by wearing orthokeratology lenses overnight, indicating that continuous use of orthokeratology lenses for 12 months has a minimal effect on the ocular surface. This finding can help guide the clinical management of tear film quality with respect to the use of orthokeratology contact lenses.

A comparison of myopia control in European children and adolescents with defocus incorporated multiple segments (DIMS) spectacles, atropine, and combined DIMS/atropine

PURPOSE

To evaluate the efficacy of a myopia control spectacle lens (DIMS) at slowing the progression of myopia in a population of European children in comparison with 0.01% atropine and combined DIMS and atropine.

METHODS

The study was a non-randomised experimenter-masked prospective controlled observational study of individuals aged 6-18 years with progressing myopia but no ocular pathology. Participants were allocated, according to patient/parent choice, to receive 0.01% atropine eyedrops, DIMS (Hoya® MiyoSmart®) spectacles, combined atropine+DIMS or single vision spectacle lenses (control group). The key outcome variables, cycloplegic autorefraction spherical equivalent refraction (SER) and axial length (AL), were measured at baseline and after three, six, and 12 months.

RESULTS

Of the 146 participants (mean age 10.3y ±3.2), 53 received atropine, 30 DIMS spectacles, 31 atropine+DIMS, and 32 single vision control spectacles. Generalized linear mixed model analysis revealed for SER, whilst controlling for age and SER at baseline, at each stage all treatment groups had significantly reduced progression compared with the control group (p<0.016). For AL, whilst controlling for baseline age and AL, at 6 and 12 months all treatment groups had significantly less progression than the control group (p<0.005). For SER only, in pairwise comparisons at 12 months the atropine+DIMS group had significantly reduced progression compared with the DIMS only and Atropine only groups (p<0.001).

CONCLUSION

In a European population, DIMS and atropine are effective at reducing myopia progression and axial elongation in progressing myopia and are most successful at reducing myopia progression when used in combination.

Akanthamöbenkeratitiden in Jugendlichen mit Orthokeratologielinsen

Hintergrund

Durch die rasant steigende Prävalenz der Myopie kommen zunehmend progressionshemmende Verfahren zum Einsatz. Auch die Orthokeratologie, basierend auf dem Ansatz des peripheren Defokus, erlebt eine Renaissance. Die gefährlichste Nebenwirkung der Orthokeratologie ist die mikrobielle Keratitis, unter ihnen eine Infektion mit Akanthamöben, welche oft spät diagnostiziert wird und potenziell visusbedrohende Verläufe nehmen kann.

Material und Methode

Diese Fallserie beschreibt die Diagnosefindung und den Behandlungsverlauf der Akanthamöbenkeratitis bei jugendlichen Patient*innen mit Orthokeratologielinsen, welche an der Spezialambulanz für Hornhauterkrankungen der Universitätsklinik für Augenheilkunde und Optometrie an der Medizinischen Universität Wien im Zeitraum eines Jahres betreut wurden.

Resultate

Vier Fälle von orthokeratologieassoziierten Akanthamöbenkeratitiden wurden mittels kornealer Konfokalmikroskopie und mikrobiologischer Verfahren zwischen August 2021 und August 2022 diagnostiziert. Die intensive Stufentherapie umfasste ein hochdosiertes, topisches Biguanid in Kombination mit einem Diamidinderivat, welches in der ersten Therapiephase mit antibakteriellen und antifungalen Augentropfen kombiniert wurde. Der Therapieverlauf und -erfolg wurde mittels der kornealen Konfokalmikroskopie beurteilt, und entsprechend angepasst.

Schlussfolgerung

Die Akanthamöbenkeratitis ist ein ernst zu nehmendes Erkrankungsbild im Zusammenhang mit Orthokeratologielinsen. Im Hinblick auf das Alter der Zielgruppe dieser myopieprogressionshemmenden Therapie sollte, neben sorgfältiger Patientenselektion, auf eine detaillierte Schulung der Kontaktlinsenträger in der Handhabung der Linsen sowie auf ein erhöhtes Bewusstsein für Zeichen einer frühen Infektion besonderes Augenmerk gelegt werden. Da alternative Möglichkeiten zur Myopieprophylaxe bestehen, müssen PatentInnen auf das Risiko der jeweiligen Methode hingewiesen werden.

Piperidine Derivatives: Recent Advances in Synthesis and Pharmacological Applications

Piperidines are among the most important synthetic fragments for designing drugs and play a significant role in the pharmaceutical industry. Their derivatives are present in more than twenty classes of pharmaceuticals, as well as alkaloids. The current review summarizes recent scientific literature on intra- and intermolecular reactions leading to the formation of various piperidine derivatives: substituted piperidines, spiropiperidines, condensed piperidines, and piperidinones. Moreover, the pharmaceutical applications of synthetic and natural piperidines were covered, as well as the latest scientific advances in the discovery and biological evaluation of potential drugs containing piperidine moiety. This review is designed to help both novice researchers taking their first steps in this field and experienced scientists looking for suitable substrates for the synthesis of biologically active piperidines.

Factors Related to Axial Length Elongation in Myopic Children Who Received 0.05% Atropine Treatment

Purpose: To evaluate the longitudinal changes of axial length (AL) and factors associated with AL growth in myopic children receiving 0.05% atropine. Methods: This single-center retrospective study included children aged 4-13 years with myopia of at least -0.5 diopters (D) treated with 0.05% atropine eye drops from November 2016 to May 2021. Predictive factors for AL change were evaluated using linear mixed models. Results: Among 109 patients (218 eyes), 58 (53.2%) were male and the mean age at treatment was 8.5 ± 2.0 years. At baseline measurement, the mean spherical equivalent was -4.05 ± 2.34 diopters (D), and AL was 25.00 ± 0.97 mm. The mean follow-up duration was 25.4 (12-58) months, and the mean AL elongation was 0.23 ± 0.17 mm/year during the follow-up periods. AL shortening of ≥0.05 mm at subsequent visit occurred in 18 patients (26 eyes). The mean AL change in the group without initial AL shortening was statistically larger than that in the group with initial AL shortening (0.26 ± 0.16 mm/year vs. 0.02 ± 0.17 mm/year, P < 0.001). In linear mixed model, the age at atropine treatment and initial AL shortening were significantly associated with respect to AL growth (beta coefficient: -0.032 and -0.122, respectively, P < 0.001 for both). Conclusions: Our study found that older age and initial AL shortening are predictors of favorable response after 0.05% atropine treatment. Children with AL shortening at initial subsequent visit may be associated with good long-term response, and younger children may require higher concentration of atropine for optimal response.

Axial length growth difference between eyes after monocular laser refractive surgery: eight patients who underwent myopic laser ablation for both eyes at intervals of several years

Background

Myopia is a global public health issue. Controlling myopia progression is a primary focus of myopia studies today. Peripheral retinal myopic defocus is considered the mechanism for reduced myopia progression in orthokeratology studies. The topographic change in the front corneal surface after laser refractive surgery and orthokeratology procedures may appear similar. The purpose of this study was to explore the role of myopic laser ablation on axial length (AL) growth.

Methods

Myopic patients who underwent monocular excimer laser refractive surgery first in one eye and then in another eye several years later because of myopia occurrence or myopia progression were recruited. The axial length elongation and refraction (spherical equivalent) between the two eyes were observed and compared.

Results

A total of 8 myopic patients were enrolled in the study. The AL increased from 24.52 ± 0.96 mm to 24.68 ± 1.03 mm but without significance (T = 1.49, P > 0.05) in the ablated eyes. The AL increased significantly from 23.73 ± 0.91 mm to 24.26 ± 0.95 mm in the nonablated eyes (T = 6.76, P < 0.001). The AL elongation of the ablated eyes with 0.16 ± 0.30 mm growth was significantly lower than that of the nonablated eyes with 0.53 ± 0.32 mm growth (T = 8.98, P < 0.001). The spherical equivalent (SE) increased significantly in the ablated eyes (− 0.59 ± 0.21 (D), T = 6.36, P < 0.001) and in the nonablated eyes (− 0.97 ± 0.55 (D), T = 4.91, P < 0.01), and the difference between the two eyes was significant (T = 3.05, P < 0.05).

Conclusions

The inhibitory effect of myopic laser ablation on AL elongation reported in the limited case studies argues for animal research on its efficacy as a new intervention for myopia progression.

Analysis of treatment response about low-dose (0.01%) atropine eye-drops in myopic children

INTRODUCTION

Myopia usually commences during primary school and progresses until the mean age of 16 years. Topical low-dose (0.01%) atropine eye-drop appears to be safe and efficacious for myopia control in children. However, in some cases, a higher concentration of atropine is required in some cases because low-dose atropine treatment is not effective.

METHODS

This is a retrospective study among young myopic children between 5 and 15 years with myopia progression > 0.50 D/year. We selected patients treated with low-dose atropine (0.01%) eye-drops for 12 months and conducted a comparative analysis of the group with good responder and poor responder. Patients were classified as good responders if spherical equivalent refractive error (SE) progression was ⩽ 0.50 D after 12 months of treatment and poor responders if SE progression > 0.50 D. The prognostic factors before and after treatment were analyzed in two groups.

RESULTS

A total of 68 eyes were included. Low-dose (0.01%) atropine eye-drops have a good treatment response in 54% of patients. In the good responder group (n = 37), the mean rate of myopia progression after 12 months of treatment (0.36 ± 0.17 D) was significantly slower compared with the baseline progression (p < 0.001). Good responders have smaller changes in axial length (AL) elongation and SE than poor responders (p < 0.001). The only adverse event was temporary near vision difficulty (10%), photophobia (10%), and mild pupil dilation (30%).

DISCUSSION

The AL elongation is an important indicator for monitoring the treatment response. Children with a family history of myopia at a young age may not respond well to low-dose (0.01%) atropine eye-drops. In these cases, increasing the concentration of atropine eye-drops should be considered.

Evaluation of retinal vascular density and related factors in youth myopia without maculopathy using OCTA

To evaluate the retinal vascular flow density changes of myopic eyes of young adults using optical coherence tomography angiography and the factors affecting these changes. In this cross-sectional study, 90 eyes of 45 participants were analyzed and divided into three groups: mild, moderate, and high myopia (without pathological changes). Macular and radial peripapillary capillary flow densities were measured using optical coherence tomography angiography. Their relationships with the axial length, the spherical equivalent of the refractive error, and age were analyzed using analysis of variance, Pearson's correlation coefficient, and multivariate linear regression analysis. Superficial and deep macular vascular densities were significantly decreased in the high myopia group compared to the other groups. In the high myopia group, the nasal peripapillary flow density decreased, whereas the flow density inside the disc increased. The axial length negatively correlated with the superficial and deep macular vascular density, but positively correlated with the vascular density inside the disc. The spherical equivalent of the refractive error negatively correlated with the macular vascular density. The retinal vascular density decreased in the high myopia group. Hence, the microvascular network inside the disc may have a compensatory action in the hypoxic setting of high myopia.

The Association between Fourier Parameters and Clinical Parameters in Myopic Children Undergoing Orthokeratology

Purpose: To explore how Fourier parameters are associated with axial length growth (ALG) and clinical parameters in children who underwent orthokeratology.Materials and Methods: A total of 267 children received orthokeratology. Baseline cycloplegic autorefraction was performed. Axial length was measured at baseline and one year after the lens dispatch, and the difference was defined as ALG. Corneal topography was performed at the same two visits. Central treatment zone (CTZ) was identified from the difference between the two tangential maps, and its center distance to corneal center was defined as decentration. A relative refractive corneal power (RCRP) map was derived by subtracting the center value from every point on the one-year axial map. It was decomposed into 3 Fourier components: a mean (F0), a single-cycle sinewave (F1), and a double-cycle sinewave (F2). Linear regressions were used to reveal the association between ALG and these parameters.Results: At baseline, the age was 10.18 ± 1.48 year, spherical equivalent (SE) was - 3.10 ± 1.15D, astigmatism was 1.17 ± 0.58D, and axial length was 24.69 ± 0.81 mm. The mean ALG was 0.181 ± 0.22 mm. In multiple regression, ALG was negatively associated with F1 (p < .001), not F0 and F2. Amplitude-wise, F0 and F1 were correlated with decentration (p < .01) and SE (p < .01), and F2 was associated with astigmatism (p < .001). Direction-wise, F1 was correlated with decentration (p < .001) and F2 was associated with astigmatism (p < .001).Conclusions: Among Fourier parameters, F0 and F1 were negatively associated with ALG in myopic children undergoing orthokeratology. Their associations to SE and CTZ decentration may partially explain the effect on ALG retardation.

Regulation of Retinal Melanopsin on Lens-induced Myopia in Guinea Pigs

SIGNIFICANCE

Investigation of the mechanism and the role of melanopsin in lens-induced myopia is necessary to find out potential targets in the prevention of myopia development.

PURPOSE

We aimed to study the effect and mechanism of retinal melanopsin on lens-induced myopia in guinea pigs, as well as the interactions between melanopsin and other myopic regulation neurotransmitters such as dopamine and melatonin, and to explore the possible role of melanopsin in the prevention of myopia development.

METHODS

Twenty-day-old tricolor guinea pigs were randomly divided into four groups: control group, defocus group, defocus + AA92593 group, and defocus + dimethyl sulfoxide (DMSO) group. The defocus eyes wore -6.00 D lens. In the defocus + AA92593 group, the vitreous cavities were injected with melanopsin antagonist AA92593. In the defocus + DMSO group, the vitreous cavities were injected with 5% DMSO as the administration control. The expression of retinal melanopsin protein was measured with immunofluorescence staining and Western blot. The content of dopamine and melatonin in the retina was determined by the high-performance liquid chromatography electrochemical method.

RESULTS

Compared with the defocus group, intravitreal injection of AA92593 resulted in increased axial length of the defocus eyes (defocus, 8.05 ± 0.09 mm; defocus + AA92593, 8.15 ± 0.11 mm; P = .008), lower refractive degree (defocus, -1.98 ± 0.82 D; defocus + AA92593, -2.59 ± 0.97 D; P = .05), decreased relative expression of retinal melanopsin protein (defocus, 0.67 ± 0.11; defocus + AA92593, 0.20 ± 0.06; P < .0001), and increased melatonin content in the defocus eyes (defocus, 0.38 ± 0.09 ng/mg; defocus + AA92593, 0.55 ± 0.13 ng/mg; P = .01), but it had no obvious effect on dopamine content (defocus, 0.64 ± 0.18 ng/mg; defocus + AA9259, 0.61 ± 0.17 ng/mg; P > .99). The melatonin content of retina in the defocus + AA92593 group was correlated with refractive error (Pearson correlation coefficient = -0.68, P = .006) and eye axis length (Pearson correlation coefficient = 0.74, P = .02).

CONCLUSIONS

Retinal melanopsin has inhibitory effect on lens-induced myopia development in guinea pigs, and such effect may be related to retinal melatonin.

Atropine in topical formulations for the management of anterior and posterior segment ocular diseases

INTRODUCTION

Atropine is an old-known drug which is gaining increasing attention due to the myriad of therapeutic effects it may trigger on eye structures. Nevertheless, novel applications may require more adequate topical formulations.

AREAS COVERED

This review aims to gather the existing knowledge about atropine and its clinical applications in the ophthalmological field when administered topically. Atropine ocular pharmacokinetics is paid a special attention, including recent evidences of the capability of the drug to access to the posterior segment. Ocular bioavailability and systemic bioavailability are counterbalanced. Finally, limitations of traditional dosage forms and potential advantages of under investigation delivery systems are analyzed.

EXPERT OPINION

Mydriasis and cyclopegia have been widely exploited for eye examination, management of anterior segment diseases, and more recently as antidotes of chemical weapons. Improved knowledge on drug receptors and related pathways explains atropine repositioning as an outstanding tool to prevent myopia. The ease with which atropine penetrates ocular tissues is a double edged sword, that is, while it ensures therapeutic levels in the posterior segment, the unspecific distribution causes a wide variety of untoward effects. The design of formulations that can selectively deliver atropine to the target tissue for each specific application is an urgent unmet need.

Orthokeratology lens-related Acanthamoeba keratitis: case report and analytical review

Acanthamoeba keratitis (AK) is a rare but severe ocular infection with a significant risk of vision loss. Contact lens use is the main risk factor for AK. The orthokeratology (OK) lens, a specially designed contact lens, has been used worldwide as an effective method of myopia control. However, the OK lens is associated with an increased risk of Acanthamoeba infection. Many primary practitioners are concerned about this infection because of its relative rarity, the lack of promising therapeutic medications, and the need for referral. We herein report two cases of AK associated with OK lenses, present a systematic review of such cases, and discuss the possible reasons for the higher incidence rate of this infection in patients who wear OK lenses. We combined the clinical knowledge and skills of corneal specialists and lens experts with the sole objective of addressing these OK lens-related AK cases. We found that the most common risk factors were rinsing the lenses or lens cases with tap water. Prompt and accurate diagnosis along with adequate amoebicidal treatment are essential to ensure desirable outcomes for OK lens wearers who develop AK. Appropriate OK lens parameters and regular checkups are also important.

Efficacy and safety of 0.01% atropine for prevention of childhood myopia in a 2-year randomized placebo-controlled study

PURPOSE

Atropine eye drops prevent the progression of myopia, but their use has not been tested in the Japanese schoolchildren population. Here, we evaluate the efficacy and safety of 0.01% atropine eye drops for myopia control in Japanese children.

STUDY DESIGN

Multicenter (7 university hospitals), randomized, double-masked, placebo-controlled trial.

METHODS

Participants were 171 Japanese schoolchildren aged 6 to 12 years, with progressive myopia, spherical equivalence (SE) of -1.00 to -6.00 diopters (D), and astigmatism of ≤1.5 D. They were randomized to receive either 0.01% atropine (n=85) or placebo (n=86) eye drops once nightly OU for 24 months. Primary and secondary efficacy endpoints were changes in SE and axial length (AL), respectively, from baseline to month 24.

RESULTS

Data from 168 subjects were analyzed. At month 24, compliance was similar in both groups (atropine: 83.3%; placebo: 85.7%). The least squares mean change in SE and AL from baseline were, respectively, -1.26 D (95% confidence interval [CI]: -1.35, -1.17) and 0.63 mm (0.59, 0.67) for atropine and -1.48 D (- 1.57, -1.39) and 0.77 mm (0.73, 0.81) for placebo. Inter-group differences were 0.22 D (95% CI: 0.09, 0.35; P < 0.001) for SE and - 0.14 mm (-0.20, -0.08; P < 0.001) for AL. Three patients experienced mild allergic conjunctivitis side effects, with no inter-group difference in incidence (atropine: 2.4%; 2/84 patients; placebo: 1.4%; 1/84 patients).

CONCLUSION

With good compliance, 0.01% atropine is effective and safe for preventing the progression of childhood myopia.

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.

Atropine Differentially Modulates ECM Production by Ocular Fibroblasts, and Its Ocular Surface Toxicity Is Blunted by Colostrum

Background: The etiology and the mechanism behind atropine treatment of progressive myopia are still poorly understood. Our study addressed the role of scleral and choroidal fibroblasts in myopia development and atropine function. Methods: Fibroblasts treated in vitro with atropine or 7-methylxanthine were tested for ECM production by Western blotting. Corneal epithelial cells were treated with atropine in the presence or absence of colostrum or fucosyl-lactose, and cell survival was evaluated by the MTT metabolic test. Results: Atropine and 7-methyl-xanthine stimulated collagen I and fibronectin production in scleral fibroblasts, while they inhibited their production in choroidal fibroblasts. Four days of treatment with atropine of corneal epithelial cells significantly decreased cell viability, which could be prevented by the presence of colostrum or fucosyl-lactose. Conclusions: Our results show that atropine may function in different ways in different eye districts, strengthening the scleral ECM and increasing permeability in the choroid. The finding that colostrum or fucosyl-lactose attenuate the corneal epithelial toxicity after long-term atropine treatment suggests the possibility that both compounds can efficiently blunt its toxicity in children subjected to chronic atropine treatment.

Pathogenesis and Prevention of Worsening Axial Elongation in Pathological Myopia

PURPOSE

This review discusses the etiology and pathogenesis of myopia, prevention of disease progression and worsening axial elongation, and emerging myopia treatment modalities.

INTRODUCTION

Pediatric myopia is a public health concern that impacts young children worldwide and is associated with numerous future ocular diseases such as cataract, glaucoma, retinal detachment and other chorioretinal abnormalities. While the exact mechanism of myopia of the human eye remains obscure, several studies have reported on the role of environmental and genetic factors in the disease development.

METHODS

A review of literature was conducted. PubMed and Medline were searched for combinations and derivatives of the keywords including, but not limited to, "pediatric myopia", "axial elongation", "scleral remodeling" or "atropine." The PubMed and Medline database search were performed for randomized control trials, systematic reviews and meta-analyses using the same keyword combinations.

RESULTS

Studies have reported that detection of genetic correlations and modification of environmental influences may have a significant impact in myopia progression, axial elongation and future myopic ocular complications. The conventional pharmacotherapy of pediatric myopia addresses the improvement in visual acuity and prevention of amblyopia but does not affect axial elongation or myopia progression. Several studies have published varying treatments, including optical, pharmacological and surgical management, which show great promise for a more precise control of myopia and preservation of ocular health.

DISCUSSION

Understanding the role of factors influencing the onset and progression of pediatric myopia will facilitate the development of successful treatments, reduction of disease burden, arrest of progression and improvement in future of the management of myopia.

Cerebral Blood Flow Alterations in High Myopia: An Arterial Spin Labeling Study

Objective

The aim of this study was to explore cerebral blood flow (CBF) alterations in subjects with high myopia (HM) using three-dimensional pseudocontinuous arterial spin labeling (3D-pcASL).

Methods

A total of sixteen patients with bilateral HM and sixteen age- and sex-matched healthy controls (HCs) were recruited. All subjects were right-handed. Image data preprocessing was performed using SPM8 and the DPABI toolbox. Clinical parameters were acquired in the HM group. Two-sample t-tests and Pearson correlation analysis were applied in this study.

Results

Compared to HCs, patients with HM exhibited significantly increased CBF in the bilateral cerebellum, and no decreases in CBF were detected in the brain. However, no relationship was found between the mean CBF values in the different brain areas and the disease duration (P > 0.05).

Conclusions

Using ASL analysis, we detected aberrant blood perfusion in the cerebellum in HM patients, contributing to a better understanding of brain abnormalities and brain plasticity through a different perspective.

Update on Myopia Risk Factors and Microenvironmental Changes

The focus of this update is to emphasize the recent advances in the pathogenesis and various molecular key approaches associated with myopia in order to reveal new potential therapeutic targets. We review the current evidence for its complex genetics and evaluate the known or candidate genes and loci. In addition, we discuss recent investigations regarding the role of environmental factors. This paper also covers current research aimed at elucidating the signaling pathways involved in the pathogenesis of myopia.