Effects of Atropine Treatment on Choroidal Thickness in Myopic Children

The Short-term Effect of Atropine 0.1% on the Axial Length and Choroid of Children Treated for Myopia Progression Prevention, Measured by Optical Coherence Tomography Angiography

PURPOSE

To investigate the short-term effect of atropine to better understand its mechanism of action in myopia prevention. The current study investigates whether atropine's effect on the axial length arises from an increase in choroidal thickness using swept-source optical coherence tomography angiography (OCTA).

METHODS

Twenty-five myopic children (25 eyes) (9 boys and 16 girls; mean age: 11.8 years, range: 7 to 15 years) were enrolled following documented myopia progression and axial length increase in the preceding 6 months. Using swept-source OCTA, choroidal thickness and choroidal stromal volume (CSV) were measured at baseline and after 1 month of daily atropine 0.1% use. Axial length measurements were taken on the same days.

RESULTS

Following 1 month of daily atropine 0.1% instillation, choroidal thickness increased from 284.24 ± 65.05 to 308.04 ± 70.65 µm (Δ 22.41 ± 4.20 µm, P < .01), CSV increased from 11.88 ± 5.20 to 12.96 ± 5.86 mm3 (Δ 1.08 ± 1.02 mm3, P < .01), and axial length decreased from 25.37 ± 1.21 to 25.33 ± 1.21 mm (Δ 0.044 ± 0.016 mm, P < .05). The CSV and choroidal thickness increase show a negative correlation with the axial length decrease of -0.462 and -0.374, respectively, demonstrating a weak to moderate correlation.

CONCLUSIONS

One month of daily atropine 0.1% eye drop administration results in an acute decrease in axial length concurrent with an increase in choroidal thickness and CSV. A direct cause-and-effect relationship between these two parameters is plausible. [J Pediatr Ophthalmol Strabismus. 20XX;X(X):XXXXXX.].

Short-term effectiveness and safety of photobiomodulation on low-to-moderate myopia

To find and assess the effectiveness and safety of short-term Photobiomodulation (PBM) treatment in children with low-to-moderate myopia. Children with low-to-moderate myopia were recruited and divided into PBM or control groups based on whether they received PBM treatment. The PBM group underwent a three-month treatment with a 650 nm low-energy semiconductor laser, while the control group did not receive any therapeutic intervention. At the end of the trial, the changes in spherical equivalent refractive (SER) and axial length (AL) before and after treatment were compared between the PBM group and the control group to evaluate the effectiveness of PBM in preventing myopia. The best corrected visual acuity (BCVA), nerve fiber layer thickness (RNFLT), ganglion cell layer thickness (GCLT), central point retinal thickness (CPRT), 3-mm subfield central retinal thickness (3 mm-CRT), superficial retinal vascular density (SCP), and central choroid thickness (CCT) were self-compared to assess the safety of PBM. A total of 57 subjects were prospectively followed from October 2020 to September 2021, comprising 28 participants (56 eyes) in the PBM group and 29 participants (58 eyes) in the control group. After three months of treatment, the AL decreased by 0.07 ± 0.11 mm, and the SER decreased by -0.12 ± 0.39 D in the PBM group. However, both SER and AL increased in the control group. Furthermore, there were statistically significant differences between the PBM and control groups (p < 0.01). The BCVA, RNFLT, GCLT, CPRT, and 3 mm-CRT remained almost unchanged in the PBM group; The SCP decreased from 0.37 ± 0.03 to 0.35 ± 0.02 in the PBM group with a statistically significant difference before and after treatment (p = 0.045). The CCT increased from 255 ± 41 µm to 274 ± 29 µm in the PBM group without any significant difference before and after treatment. The administration of PBM significantly suppresses the elevation of AL and SER following a three-month duration. No significant adverse effects were observed on visual function and retinal morphology.Trial Registration: This study is registered at https://clinicaltrials.gov/ (registration number: NCT04604405).

Fundus vascular arcades angle reflects choroidal thickness in highly myopic children and adolescents

OBJECTIVES

To identify the role of fundus vascular arcades angle (VAA) in reflecting choroidal thickness (ChT) of highly myopic children and adolescents.

METHODS

Participants aged 5 to 18 yrs with high myopia (spherical equivalent, SE ≤ -5.0 D) were enrolled and followed up for one year from the Shanghai Child and Adolescent Large-scale Eye Study. The VAA in the range of one papillary diameter (PD) as well as 2PD away from the central point of optic disc was recognized and measured by artificial intelligence from fundus photographs.

RESULTS

Finally, 277 highly myopic participants were included in the analysis. The mean VAA (1PD) was 128.38 ± 9.56°, and the mean VAA (2PD) was 110.25 ± 11.97°. For those with larger VAA, the choroidal thickness around macula (mChT) or papillary (pChT) was thicker (P for trend < 0.05). After adjusting for age and gender, thinner ChT was independently associated with smaller VAA (P < 0.001). For those with more decrease of VAA, the thinning of ChT was more remarkable (P < 0.05). In the regression analysis, more change of pChT was independently associated with more change of VAA (P < 0.01). After adjusting for other related parameters, 1°change of VAA (1PD) or VAA (2PD) accounted for 0.855 mm or 0.719 mm change of pChT.

CONCLUSIONS

Fundus VAA was closely associated with choroidal thickness in highly myopic paediatric population. It could serve as an alternative indicator of choroid thickness in the fundus screening for evaluating the risk of pathological changes of high myopia.

Choroidal thickness under pilocarpine versus cyclopentolate

Bruch´s membrane (BM) is firmly connected posteriorly to the optic nerve head through the peripapillary choroidal border tissue, and anteriorly through the longitudinal ciliary muscle to the scleral spur. We assessed, whether a difference in the contractile state of the ciliary muscle influences the position of the posterior BM by lifting the posterior BM pole, i.e., induces changes in the subfoveal choroidal thickness (SFCT). Healthy young adult individuals received one drop of cyclopentolate 1% into their right eyes and one drop of pilocarpine 1% into their left eyes. Using optical coherence tomography (OCT), three examiners measured independently SFCT and choroidal thickness in the fundus midperiphery at baseline and 30 min after eye drop instillation. The study included 21 healthy individuals (age:21.9 ± 2.6 years; range:15.7-25.8 years; axial length:24.4 ± 1.2 mm). In the right eyes, SFCT changed by 8.7 ± 34.9 μm (examiner 1), -2.9 ± 18.6 μm (examiner 2), and 10.5 ± 21.8 μm (examiner 3), respectively, and the midperipheral choroidal thickness changed by -10.6 ± 25.9 μm (examiner 1), 0.9 ± 17.5 μm (examiner 2), and 4.2 ± 24.7 μm (examiner 3), respectively, without significant differences between the measurements taken before and after eye drop application (all P > 0.05). In the left eyes, SFCT changed by 5.8 ± 22.2 μm (examiner 1), 5.5 ± 36.5 μm (examiner 2), and 3.9 ± 29.5 μm (examiner 3), respectively, and the midperipheral choroidal thickness changed by -6.9 ± 47.9 μm (examiner 1), -3.5 ± 28.7 μm (examiner 2), and 16.0 ± 28.2 μm (examiner3), respectively, without significant differences between baseline and study end (all P > 0.05). Application of cyclopentolate 1% and of pilocarpine 1% did not result in a statistically significant change in choroidal thickness in young healthy adults.

Efficacy in myopia control-The impact of rebound

PURPOSE

When myopia control treatment is discontinued, progression will increase, but does it revert to expected values based on the age and race of the child or does it accelerate further? The latter scenario is considered a rebound.

METHODS

A PubMed search was conducted with the words 'rebound' and 'myopia control', identifying further papers from reviews. Inclusion was limited to prospective studies with ≥6 months of treatment, ≥3 months of data following cessation and with axial length data, which allowed calculation of rebound. Nineteen studies were identified, comprising 24 treatment groups. In 10 studies, untreated control children were followed both throughout the treatment and cessation periods, allowing for a concurrent comparison group. In three studies, a control group was followed for 1 or 2 years and thereafter received the treatment under evaluation. Later, treatment ceased in the originally treated children. Finally, six studies were cross-over designs. For these latter two study designs, initial axial elongation and myopia progression in the control group were extrapolated to the cessation period, accounting for annual slowing. Values from durations of <1 year were annualised.

RESULTS

The mean annualised rebound was +0.05 ± 0.10 mm and -0.09 ± 0.24 D for axial length and myopia progression, respectively, and these were correlated (r2 = 0.59, p < 0.001). Rebound was associated with 1-year treatment efficacy (r2 = 0.43, p < 0.001). The mean annualised rebound with optical corrections was -0.01 ± 0.03 mm. Five of the six highest rebound values (≥0.14 mm) were from red light therapy and atropine studies. Rebound ranged from +0.03 to +0.14 mm for overnight orthokeratology.

CONCLUSIONS

Consistent with previous statements, no evidence for rebound was found for myopia control spectacles and soft contact lenses. Future research should explore the influence of age and magnitude of treatment efficacy on rebound.

Efficacy of defocus incorporated multiple segments (DIMS) lenses and low-dose atropine on retarding myopic shift among premyopic preschoolers: Protocol for a prospective, multicenter, randomized controlled trial

BACKGROUND

Myopia has been a rising problem globally. Early-onset myopia significantly increases the risk of high myopia later in life. Despite the proven benefits of increased outdoor time, optimal strategies for preventing early-onset myopia in premyopic children need further investigation.

METHODS

This randomized controlled trial aims to evaluate the efficacy of optical (Defocus Incorporated Multiple Segments [DIMS] spectacle lenses) and pharmacological (0.01% atropine eye drops) interventions in preventing myopia among premyopic preschoolers. We will recruit 234 premyopic, asymptomatic 5-to-6-year-old children who will have received cycloplegic autorefraction examination in a countywide kindergarten eye care program in Yilan County, Taiwan. Eligible participants will be randomly assigned to DIMS spectacles (n = 78), 0.01% atropine (n = 78), or usual care (n = 78). In the DIMS group, preschoolers will be instructed to wear spectacles at home before entering elementary school but to wear them all the time after school entry. In the atropine group, subjects will be given 0.01% atropine eyedrops nightly throughout the study period. All participants will be encouraged to spend time outdoors for 2 hours every day. During the 18-month study period, cycloplegic spherical equivalent (SE) refraction, axial length, and subfoveal choroidal thickness will be measured every three months, and parents-administered questionnaires regarding risk factors for myopia will be performed every nine months.

PRIMARY OUTCOME

The change in mean cycloplegic SE.

SECONDARY OUTCOMES

The cumulative percentage of incident myopia, the cumulative percentage of a fast myopic shift of SE, and the changes in mean axial length.

OTHER PRE-SPECIFIED OUTCOMES

The time to myopia onset, alteration in subfoveal choroidal thickness, and levels of near work/outdoor activities.

TRIAL REGISTRATION

This study is registered at www.clinicaltrials.gov as NCT06200194.

CONCLUSION

This trial will provide insights into myopia prevention strategies and inform new eye care policies for early identification and intervention in premyopic preschoolers.

Effects of computer-generated patterns with different temporal and spatial frequencies on choroidal thickness, retinal dopamine and candidate genes in chickens wearing lenses

Purpose

Changes in choroidal thickness (ChT) are proposed to predict myopia development but evidence is mixed. We investigated time courses of choroidal responses, following different types of dynamic artificial stimulation in chicks with and without spectacle lenses, as well as changes in retinal dopamine metabolism and expression of candidate genes.

Methods

Chicks were kept in an arena surrounded by computer monitors presenting dynamic checkerboard fields of small, medium and large size. Fields were displayed with different cycle frequencies, as ON (rapid rise, slow decay) or OFF (slow rise, rapid decay) temporal luminance profile. Refractive errors, ocular biometry and ChT were assessed. Dopamine metabolism and candidate gene expression levels were also measured. Stimuli were applied for (1) 3 h with no lens, (2) 3 h and monocular treatment with -7D or +7D lenses, (3) 3 or 7 days.

Results

(1) The smallest fields caused the largest decrease in ChT. (2) Negative lens treatment induced on average 11.7 μm thinner choroids. ChT thinning was enhanced by 10 Hz-ON medium field size flicker which also reduced choroidal thickening with positive lenses. (3) With prolonged treatment, the choroid recovered from initial thinning in all groups although to varying degrees which were dependent on stimulus parameters. Relative ChT changes were positively correlated with the vitreal level of dopamine metabolites. Retinal EGR-1 mRNA level was positively correlated with choroidal thickness. Retinal melanopsin mRNA was increased by 10 Hz-ON stimulation and choroidal BMPR1A mRNA increased with 10 Hz-OFF stimulation. On average, early choroidal thinning did not predict the amount of negative lens-induced eye growth changes after 7 days, whereas later ChT changes showed a weak association.

Conclusion

Negative lenses caused long-lasting choroidal thinning, with some recovery during lens wear, especially after stimulation with 10 Hz. The dynamic stimuli modulated choroidal thinning but effects were small. There was little difference between ON and OFF stimulation, perhaps because the checkerboard patterns were too coarse. 10 Hz cycle frequency increased dopamine release. Less dopamine was correlated with thinner choroids. Result do not exclude a predictive value of choroidal thickening for future refractive development since we almost exclusively tested choroidal thinning effects.

Blue light stimulation of the blind spot in human: from melanopsin to clinically relevant biomarkers of myopia

The protective effects of time spent outdoors emphasize the major role of daylight in myopia. Based on the pathophysiology of myopia, the impact of blue light stimulation on the signaling cascade, from melanopsin at the blind spot to clinically relevant biomarkers for myopia, was investigated. Parameters and site of light stimulation are mainly defined by the photopigment melanopsin, that is sensitive to blue light with a peak wavelength of 480 nm and localized on the intrinsically photosensitive retinal ganglion cells (ipRGC) whose axons converge to the optic disc, corresponding to the physiological blind spot. Blue light at the blind spot (BluSpot) stimulation provides the opportunity to activate the vast majority of ipRGC and avoids additional involvement of rods and cones which may exert incalculable effects on the signaling cascade.Experimental studies have applied anatomical, histochemical, electrophysiological, imaging, and psychophysical methods to unravel the mode of action of BluSpot stimulation. Results indicate activation of melanopsin, improvement of contrast sensitivity, gain in electrical retinal activity, and increase of choroidal thickness following BluSpot stimulation. Short-term changes of clinically relevant biomarkers lead to the hypothesis that BluSpot stimulation may exert antimyopic effects with long-term application.

Effects of atropine on choroidal thickness in myopic children: a meta-analysis

Background

Atropine is an effective medicine for myopia prevention and control. This meta-analysis was conducted to investigate the effects of atropine on choroidal thickness (ChT) in children with myopia.

Methods

Between its inception and 1 June 2023, Medline, Embase, and Web of Science were all searched, and only English literature was included. The choroidal thickness was the primary study outcome. Axial length, standardized equivalent refraction were examined as secondary outcomes. STATA 12.0 was used for data extraction and analysis.

Results

A total of 307 eyes were involved in this study to evaluate the effect of atropine on ChT, axial length (AL) and standardized equivalent refraction (SER) in myopic children. Choroidal thickening was significantly higher in the atropine group than in the control group at 1 month (WMD, 6.87 mm, 95% CI, 0.04 to 13.10, P = 0.049), whereas it was significantly higher in the atropine group than in the control group at months 6 (WMD, 10.37 mm, 95% CI, -3.21 to 23.95, P = 0.135), 12 (WMD, 15.10 mm, 95% CI, -5.08 to 35.27, P = 0.143) and at final follow-up (WMD, 11.52 mm, 95% CI, -3.26 to 26.31, P = 0.127), the differences were not statistically significant. At months 1 (WMD, -0.03 mm, 95% CI, -0.04 to -0.01, P = 0.003), 6 (WMD, -0.07 mm, 95% CI, -0.01 to -0.03, P = 0.000), 12 (WMD, -0.13mm, 95% CI, -0.15 to -0.11, P = 0.843), and at final follow-up (WMD, -0.08 mm, 95% CI, -0.16 to -0.01, P = 0.127), atropine treatment was able to delay the axial elongation. At 1-month follow-up, there was no significant difference in the effect of atropine on SER in myopic children compared with the control group (WMD, 0.01D, 95% CI, -0.07 to 26.31, P = 0.127), whereas it was able to control the progression of refractive status at final follow-up (WMD, 11.52 mm, 95% CI, -3.26 to 26.31, P = 0.127).

Conclusion

Limited evidence suggests that 0.01% atropine causes choroidal thickening in myopic children at 1 month of treatment. In the short term, choroidal thickness may be a predictor of the effectiveness of atropine in controlling myopia in children. 0.01% atropine is effective in controlling myopic progression in terms of SER and AL.

Systematic Review Registration

http://www.crd.york.ac.uk/prospero, identifier, CRD42022381195.

Key role for inflammation-related signaling in the pathogenesis of myopia based on evidence from proteomics analysis

The mechanisms underlying myopia pathogenesis are not well understood. Using publicly-available human and animal datasets, we expound on the roles of known, implicated proteins, and new myopia-related signaling pathways were hypothesized. Proteins identified from human serum or ocular fluids, and from ocular tissues in myopic animal models, were uploaded and analyzed with the QIAGEN Ingenuity Pathway Analysis (IPA) software (March 2023). With each IPA database update, more potentially-relevant proteins and signaling pathways previously unavailable during data acquisition are added, allowing extraction of novel conclusions from existing data. Canonical pathway analysis was used to analyze these data and calculate an IPA activation z-score-which indicates not only whether an association is significant, but also whether the pathway is likely activated or inhibited. Cellular immune response and cytokine signaling were frequently found to be affected in both human and animal myopia studies. Analysis of two publicly-available proteomic datasets highlighted a potential role of the innate immune system and inflammation in myopia development, detailing specific signaling pathways involved such as Granzyme A (GzmA) and S100 family signaling in the retina, and activation of myofibroblast trans-differentiation in the sclera. This perspective in myopia research may facilitate development of more effective and targeted therapeutic agents.

Choroidal Changes During and After Discontinuing Long-Term 0.01% Atropine Treatment for Myopia Control

Purpose

Few studies have explored choroidal changes after cessation of myopia control. This study evaluated the choroidal thickness (ChT) and choroidal vascularity index (CVI) during and after discontinuing long-term low-concentration atropine eye drops use for myopia control.

Methods

Children with progressive myopia (6-16 years; n = 153) were randomized to receive 0.01% atropine eye drops or a placebo (2:1 ratio) instilled daily over 2 years, followed by a 1-year washout (no eye drop use). Optical coherence tomography imaging of the choroid was conducted at the baseline, 2-year (end of treatment phase), and 3-year (end of washout phase) visits. The main outcome measure was the subfoveal ChT. Secondary measures include the CVI.

Results

During the treatment phase, the subfoveal choroids in both treatment and control groups thickened by 12-14 µm (group difference P = 0.56). During the washout phase, the subfoveal choroids in the placebo group continued to thicken by 6.6 µm (95% confidence interval [CI] = 1.7 to 11.6), but those in the atropine group did not change (estimate = -0.04 µm; 95% CI = -3.2 to 3.1). Participants with good axial eye growth control had greater choroidal thickening than the fast-progressors during the treatment phase regardless of the treatment group (P < 0.001), but choroidal thickening in the atropine group's fast-progressors was not sustained after stopping eye drops. CVI decreased in both groups during the treatment phase, but increased in the placebo group after treatment cessation.

Conclusions

On average, compared to placebo, 0.01% atropine eye drop treatment did not cause a differential rate of change in ChT during treatment, but abrupt cessation of long-term 0.01% atropine eye drops may disrupt normal choroidal thickening in children.

Comparison of Changes in Retinal Vascular Density and Thickness After Using Low-Level Red Light and 0.01% Atropine in Premyopic Children

Purpose

To compare changes in superficial retinal vascular density (SRVD), deep retinal vascular density (DRVD), and retinal thickness (RT) of the macular zone after repeated low-level red light (RLRL) and 0.01% atropine exposure in premyopic schoolchildren.

Methods

Prospective randomized trial. Sixty-nine schoolchildren with cycloplegic refraction >-0.75 D and ≤0.50 D were randomly assigned to RLRL and 0.01% atropine groups. SRVD, DRVD, and RT were measured using swept-source optical coherence tomography at baseline and six months. The macular zone was divided into three concentric rings (fovea, parafovea, and perifovea) using the Early Treatment Diabetic Retinopathy Study.

Results

After six months, the whole, parafoveal, and perifoveal SRVD significantly increased in the two groups (all P < 0.05). Multivariate regression analyses showed that none of these changes varied significantly between the two groups (all P > 0.05), whereas foveal SRVD remained stable in both groups (all P > 0.05). In the RLRL group, the whole and perifoveal DRVD increased significantly (all P < 0.05), whereas no statistical difference was observed in the foveal and parafoveal DRVD. DRVD remained stable in the 0.01% atropine group (all P > 0.05). No significant differences were observed in RT changes between the two groups (all P > 0.05). In comparison, there were no significant changes in SRVD, DRVD, or RT after six months in the placebo group in our previous study.

Conclusions

SRVD increased similarly in the RLRL and 0.01% atropine groups, whereas DRVD increased only in the former group. There were no significant RT changes in either group after six months of treatment in premyopic schoolchildren.

Translational Relevance

This research observed the effects of low-level red light and 0.01% atropine on retinal vasculature, offering valuable insights into myopia progression prevention.

Increase in choroidal thickness after blue light stimulation of the blind spot in young adults

BACKGROUND

Blue light activates melanopsin, a photopigment that is expressed in intrinsically photosensitive retinal ganglion cells (ipRGCs). The axons of ipRGCs converge on the optic disc, which corresponds to the physiological blind spot in the visual field. Thus, a blue light stimulus aligned with the blind spot captures the ipRGCs axons at the optic disc. This study examined the potential changes in choroidal thickness and axial length associated with blue light stimulation of melanopsin-expressing ipRGCs at the blind spot. It was hypothesized that blue light stimulation at the blind spot in adults increases choroidal thickness.

METHODS

The blind spots of both eyes of 10 emmetropes and 10 myopes, with a mean age of 28 ± 6 years (SD), were stimulated locally for 1-minute with blue flickering light with a 460 nm peak wavelength. Measurements of choroidal thickness and axial length were collected from the left eye before stimulation and over a 60-minute poststimulation period. At a similar time of day, choroidal thickness and axial length were measured under sham control condition in all participants, while a subset of 3 emmetropes and 3 myopes were measured after 1-minute of red flickering light stimulation of the blind spot with a peak wavelength of 620 nm. Linear mixed model analyses were performed to examine the light-induced changes in choroidal thickness and axial length over time and between refractive groups.

RESULTS

Compared with sham control (2 ± 1 μm, n = 20) and red light (-1 ± 2 μm, n = 6) stimulation, subfoveal choroidal thickness increased within 60 min after blue light stimulation of the blind spot (7 ± 1 μm, n = 20; main effect of light, p < 0.001). Significant choroidal thickening after blue light stimulation occurred in emmetropes (10 ± 2 μm, p < 0.001) but not in myopes (4 ± 2 μm, p > 0.05). Choroidal thickening after blue light stimulation was greater in the fovea, diminishing in the parafoveal and perifoveal regions. There was no significant main effect of light, or light by refractive error interaction on the axial length after blind spot stimulation.

CONCLUSIONS

These findings demonstrate that stimulating melanopsin-expressing axons of ipRGCs at the blind spot with blue light increases choroidal thickness in young adults. This has potential implications for regulating eye growth.

Assessment of the effects of myopic and hyperopic anisometropia on choroidal vascular structure in children using SS-OCTA

OBJECTIVE

To compare large- and medium-sized choroidal vascularity and the choriocapillaris (CC) flow area in children with different refractive errors using swept-source optical coherence tomography angiography (SS-OCTA).

METHODS

Forty-two anisometropic children were enrolled and divided into hyperopic anisometropia (HA) and myopic anisometropia (MA) groups. SS-OCTA was performed to analyse choroidal vascularity. Mean choroidal thickness (CT), choroidal vascularity volume (CVV), choroidal vascularity index (CVI) and CC flow area were compared between the two eyes. The inter-ocular differences between the two groups were also determined.

RESULTS

Mean CT and CVV were highest in eyes with shorter axial lengths in both refractive groups, and the difference between the two eyes was positively correlated with the difference in axial length at the foveal region. Significant differences in the CVI in the MA group were only found in the parafoveal region. Inter-ocular differences in the CC were significantly reduced in eyes with longer axial lengths in the foveal and parafoveal regions of the HA and MA groups, respectively. Comparing inter-ocular differences, CC was significantly greater in the parafoveal region of the MA group than the HA group.

CONCLUSIONS

All layers of choroidal vasculature were thinner in eyes with longer axial lengths in all groups. The inter-ocular CC difference was greater in the MA than in the HA group, with similar differences in axial length. This suggests that both medium-to-large choroidal vascular and choroidal capillaries may play a role in myopia development.

Eye Diseases: When the Solution Comes from Plant Alkaloids

Plants are an incredible source of metabolites showing a wide range of biological activities. Among these, there are the alkaloids, which have been exploited for medical purposes since ancient times. Nowadays, many plant-derived alkaloids are the main components of drugs used as therapy for different human diseases. This review deals with providing an overview of the alkaloids used to treat eye diseases, describing the historical outline, the plants from which they are extracted, and the clinical and molecular data supporting their therapeutic activity. Among the different alkaloids that have found application in medicine so far, atropine and pilocarpine are the most characterized ones. Conversely, caffeine and berberine have been proposed for the treatment of different eye disorders, but further studies are still necessary to fully understand their clinical value. Lastly, the alkaloid used for managing hypertension, reserpine, has been recently identified as a potential drug for ameliorating retinal disorders. Other important aspects discussed in this review are different solutions for alkaloid production. Given that the industrial production of many of the plant-derived alkaloids still relies on extraction from plants, and the chemical synthesis can be highly expensive and poorly efficient, alternative methods need to be found. Biotechnologies offer a multitude of possibilities to overcome these issues, spanning from genetic engineering to synthetic biology for microorganisms and bioreactors for plant cell cultures. However, further efforts are needed to completely satisfy the pharmaceutical demand.

Myopia progression after cessation of atropine in children: a systematic review and meta-analysis

Purpose: To comprehensively assess rebound effects by comparing myopia progression during atropine treatment and after discontinuation. Methods: A systematic search of PubMed, EMBASE, Cochrane CENTRAL, and ClinicalTrials.gov was conducted up to 20 September 2023, using the keywords "myopia," "rebound," and "discontinue." Language restrictions were not applied, and reference lists were scrutinized for relevant studies. Our study selection criteria focused on randomized control trials and interventional studies involving children with myopia, specifically those treated with atropine or combination therapies for a minimum of 6 months, followed by a cessation period of at least 1 month. The analysis centered on reporting annual rates of myopia progression, considering changes in spherical equivalent (SE) or axial length (AL). Data extraction was performed by three independent reviewers, and heterogeneity was assessed using I2 statistics. A random-effects model was applied, and effect sizes were determined through weighted mean differences with 95% confidence intervals Our primary outcome was the evaluation of rebound effects on spherical equivalent or axial length. Subgroup analyses were conducted based on cessation and treatment durations, dosage levels, age, and baseline SE to provide a nuanced understanding of the data. Results: The analysis included 13 studies involving 2060 children. Rebound effects on SE were significantly higher at 6 months (WMD, 0.926 D/y; 95%CI, 0.288-1.563 D/y; p = .004) compared to 12 months (WMD, 0.268 D/y; 95%CI, 0.077-0.460 D/y; p = .006) after discontinuation of atropine. AL showed similar trends, with higher rebound effects at 6 months (WMD, 0.328 mm/y; 95%CI, 0.165-0.492 mm/y; p < .001) compared to 12 months (WMD, 0.121 mm/y; 95%CI, 0.02-0.217 mm/y; p = .014). Sensitivity analyses confirmed consistent results. Shorter treatment durations, younger age, and higher baseline SE levels were associated with more pronounced rebound effects. Transitioning or stepwise cessation still caused rebound effects but combining optical therapy with atropine seemed to prevent the rebound effects. Conclusion: Our meta-analysis highlights the temporal and dose-dependent rebound effects after discontinuing atropine. Individuals with shorter treatment durations, younger age, and higher baseline SE tend to experience more significant rebound effects. Further research on the rebound effect is warranted. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=463093], identifier [registration number].

Incidence of Adverse Events Induced by Atropine in Myopic Children: A Meta-Analysis

A large number of studies have evaluated the efficacy of low-dose atropine in preventing or slowing myopic progression. However, it is challenging to evaluate the ocular safety from these studies. We aimed to evaluate the incidence of adverse events induced by atropine in children with myopia. We performed a systematic literature search in several databases for studies published until November 2022. The incidence of adverse events induced by atropine was pooled by a common-effect (fixed-effect) or random-effects model. Subgroup analyses were conducted according to drug doses, types of adverse events, and ethnicity. A total of 31 articles were ultimately included in the study. The overall incidence of adverse events for atropine was 5.9%, and the incidence of severe adverse events was 0.0%. The most commonly reported adverse events were photophobia (9.1%) and blurred near vision (2.9%). Other adverse events including eye irritation/discomfort, allergic reactions, headache, stye/chalazion, glare, and dizziness occurred in less than 1% of the patients. The incidence of atropine-induced adverse events varied depending on the drug doses. A lower dose of atropine was associated with a lower incidence of adverse events. There was no significant difference in the incidence of adverse events for low-dose atropine between Asian and White children. Our study suggests photophobia and blurred near vision are the most frequently reported adverse events induced by atropine. Low-dose atropine is safer than moderate- and high-dose atropine. Our study could provide a safe reference for ophthalmologists to prescribe atropine for myopic children.

Efficacy of Repeated Low-Level Red-Light Therapy for Slowing the Progression of Childhood Myopia: A Systematic Review and Meta-analysis

PURPOSE

To evaluate the long-term efficacy and safety of repeated low-intensity red light (RLRL) treatment for childhood myopia.

DESIGN

Systematic review and meta-analysis METHODS: We searched PubMed, Web of Science, CNKI, and Wanfang from inception to February 8, 2023. We used the RoB 2.0 and ROBINS-I tools to assess the risk of bias and then used a random-effect model to calculate the weighted mean difference (WMD) and 95% CIs. The primary outcomes were WMD in spherical equivalent refractive error (SER), WMD in axial length (AL), and WMD in subfoveal choroid thickness (SFChT). Subgroup analyses were performed to investigate the sources of heterogeneity based on variation in follow-up and study design. The Egger and Begg tests were used to assess publication bias. Sensitivity analysis was used to verify the stability.

RESULTS

This analysis included 13 studies (8 randomized controlled trials, 3 non-randomized controlled trials, and 2 cohort studies) involving 1857 children and adolescents. Eight studies met the meta-analysis criteria, and the WMD for myopia progression between RLRL and the control group was 0.68 diopters (D) per 6 months (95% CI = 0.38 to 0.97 D; I2 = 97.7%; P < .001) for SER change; -0.35 mm per 6 months (95% CI = -0.51 to -0.19 mm; I2 = 98.0%; P < .001) for AL elongation; and 36.04 µm per 6 months (95% CI = 19.61 to 52.48 µm; I2 = 89.6%; P < .001) for SFChT change.

CONCLUSIONS

Our meta-analysis shows that RLRL therapy may be effective for delaying the progression of myopia. The evidence is low certainty, and larger and better randomized clinical trials with 2-year follow-ups are needed to improve the existing state of knowledge to inform medical guidelines more comprehensively.

The efficacy and safety of 0.01% atropine alone or combined with orthokeratology for children with myopia: A meta-analysis

OBJECTIVE

To evaluate the efficacy and safety of 0.01% atropine alone and in combination with orthokeratology for myopia control using a meta-analysis.

METHODS

PubMed, Cochrane Library, and EMBASE were searched. We included eligible randomized controlled trials (RCTs), non-RCTs, and retrospective cohort studies, published up to August 1, 2022. We calculated the weighted mean difference (WMD) and 95% confidence interval (CI) for all outcomes and plotted them in forest plots.

RESULTS

Fourteen studies were included; 4 and 11 in the 0.01% atropine monotherapy and atropine-orthokeratology (AOK) groups, respectively. Compared with orthokeratology (OK) alone, 0.01% atropine alone had similar effects on slowing the axial elongation (WMD: -0.00 mm; 95% CI: -0.05-0.04, p<0.31), while AOK significantly lowered axial growth. Moreover, the baseline myopic degree and duration of treatment were influential for the change in axial elongation (WMD: -0.12 mm; 95% CI: -0.17--0.07, p = 0.00001 and WMD: -0.11 mm; 95% CI: -0.15--0.108, p<0.00001, respectively). Additionally, the AOK may reduce the change rate of the spherical equivalent refraction and the accommodation amplitude (WMD: -0.13 D; 95% CI: 0.07-0.19, p<0.001 and WMD: -1.08 mm; 95% CI: -1.73--0.43, p<0.0001, respectively), and cause a slight increase in the diameter of the pupil (WMD: 0.56 mm; 95% CI: 0.43-0.70, p = 0.007). No significant differences in the uncorrected distant visual acuity, best corrected visual acuity, intraocular pressure, tear film break-up time, lipid layer thickness, and corneal endothelial cell density were found between the OK and AOK groups.

CONCLUSION

In slowing the axial elongation, 0.01% atropine alone and OK alone have similar effects, while AOK is more effective than OK alone in slowing down the axial elongation. Furthermore, the baseline degree of myopia and treatment duration may affect changes in axial elongation.

Longitudinal Changes and Predictive Value of Choroidal Thickness for Myopia Control after Repeated Low-Level Red-Light Therapy

PURPOSE

To evaluate longitudinal changes in macular choroidal thickness (mCT) in myopic children treated for 1 year with repeated low-level red-light (RLRL) therapy and their predictive value for treatment efficacy on myopia control.

DESIGN

A secondary analysis of data from a multicenter, randomized controlled trial (RCT; NCT04073238).

PARTICIPANTS

Myopic children aged 8-13 years who participated in the RCT at 2 of 5 sites where mCT measurements were available.

METHODS

Repeated low-level red-light therapy was delivered using a home-use desktop light device that emitted red-light at 650 nm. Choroidal thickness was measured by SS-OCT at baseline and 1-, 3-, 6-, and 12-month follow-ups. Visual acuity, axial length (AL), cycloplegic spherical equivalent refraction (SER), and treatment compliance were measured.

MAIN OUTCOME MEASURES

Changes in mCT at 1, 3, 6, and 12 months relative to baseline, and their associations with myopia control.

RESULTS

A total of 120 children were included in the analysis (RLRL group: n = 60; single-vision spectacle [SVS] group: n = 60). Baseline characteristics were well balanced between the 2 groups. In the RLRL group, changes in mCT from baseline remained positive over 1 year, with a maximal increase of 14.755 μm at 1 month and gradually decreasing from 5.286 μm at 3 months to 1.543 μm at 6 months, finally reaching 9.089 μm at 12 months. In the SVS group, mCT thinning was observed, with changes from baseline of -1.111, -8.212, -10.190, and -10.407 μm at 1, 3, 6, and 12 months, respectively. Satisfactory myopia control was defined as annual progression rates of less than 0, 0.05, or 0.10 mm for AL and less than 0, 0.25, or 0.50 diopters for SER. Models that included mCT changes at 3 months alone had acceptable predictive discrimination of satisfactory myopia control over 12 months, with areas under the curve of 0.710-0.786. The predictive performance of the models did not significantly improve after adding age, gender, and baseline AL or SER.

CONCLUSIONS

This analysis from a multicenter RCT found RLRL induced sustained choroidal thickening over the full course of treatment. Macular choroidal thickness changes at 3 months alone can predict 12-month myopia control efficacy with reasonable accuracy.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Rates of Choroidal and Neurodegenerative Changes Over Time in Diabetic Patients Without Retinopathy: A 3-Year Prospective Study

PURPOSE

To evaluate the longitudinal changes of retinal neurodegeneration and choroidal thickness in diabetic patients with and without diabetic retinopathy (DR).

DESIGN

Prospective observational cohort study.

METHODS

This prospective observational cohort study recruited type 2 diabetic patients from a community registry in Guangzhou. All participants underwent annual ocular examinations via swept-source optical coherence tomography that obtained choroid thickness (CT), retinal thickness (RT), and ganglion cell-inner plexiform layer (GC-IPL) thickness. The changes in GC-IPL, CT, and RT between patients who developed incident DR (IDR) or remained non-DR (NDR) were compared during a 3-year follow-up.

RESULTS

Among 924 patients, 159 (17.2%) patients developed IDR within the 3-year follow-up. A reduction in GC-IPL, RT, and CT was observed in NDR and IDR; however, CT thinning in patients with IDR was significantly accelerated, with an average CT reduction of -6.98 (95% CI: -8.26, -5.71) μm/y in patients with IDR and -3.98 (95% CI: -4.60, -3.36) μm/y in NDR patients (P < .001). Reductions in average GC-IPL thickness over 3 years were -0.97 (95% CI: -1.24, -0.70) μm/y in patients with IDR and -0.76 (95% CI: -0.82, -0.70) μm/y in NDR patients (P = .025). After adjusting for confounding factors, the average CT and GC-IPL thinning were significantly faster in patients with IDR compared with those who remained NDR by 2.09 μm/y (95% CI: 1.01, 3.16; P = .004) and -0.29 μm/y (95% CI: -0.49, -0.09; P = .004), respectively. The RT in the IDR group increased, whereas the RT in the NDR group decreased over time, with the adjusted difference of 2.09 μm/y (95% CI: 1.01, 3.16; P < .001) for central field RT.

CONCLUSIONS

The rate of retinal neurodegeneration and CT thinning were significantly different between the eyes that developed IDR and remained NDR during the 3-year follow-up, but both groups observed thickness reduction. This indicates that GC-IPL and CTs may decrease before the clinical manifestations of DR.

Choroidal thickness, myopia, and myopia control interventions in children: a Meta-analysis and systemic review

AIM

To investigate changes of choroidal thickness (ChT) in children with myopia and the effect of current myopia control interventions on ChT.

METHODS

Major literature databases were searched for studies relevant to myopia in children. All studies used swept-source optical coherence tomography (SS-OCT) or enhanced depth imaging optical coherence tomography (EDI-OCT) to measure the ChT value. The weighted mean difference (WMD) and 95% confidence interval (CI) were pooled to evaluate ChT in myopia children.

RESULTS

A total of 11 eligible articles, including 1693 myopic and 1132 non-myopic eyes, were included in the first Meta-analysis. The sub-foveal choroidal thickness (SFCT; WMD=-40.06, 95%CI, -59.36 to -20.75, P<0.001) and ChT at other sectors were significantly thinner in myopic eyes compared with the non-myopic eyes. The Meta-analysis revealed that the ChT decreased horizontally from the temporal sector toward the nasal sector in the pediatric myopia population. Another 11 studies reporting the effect of myopia control interventions were included in the second Meta-analysis for the relationship between myopia control treatments and ChT. SFCT significantly increased after orthokeratology (OK) treatment and OK combined with 0.01% atropine (OKA) treatment (WMD=19.47, 95%CI, 15.96 to 22.98, P<0.001; WMD=21.81, 95%CI, 12.92 to 29.70, P<0.001, respectively). The forest plots showed that SFCT changed little in myopic children receiving 0.01% atropine (P=0.30). Furthermore, the Meta-analysis showed that OK treatment had a stronger effect on the value of SFCT in myopic children as compared with 0.01% atropine (WMD=9.86; 95%CI, -0.21 to 19.93, P=0.05). There is no difference between the treatment with OK and OKA treatment in ChT in myopic children (P=0.37).

CONCLUSION

The ChT in myopic eyes is thinner than that in non-myopic eyes in pediatric population. Myopia control interventions including OK and OKA lead to ChT thickening, but other treatments such as 0.01% atropine did not show an increase in ChT.

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.

Changes of Choroidal Thickness in Children after Short-Term Application of 1% Atropine Gel

INTRODUCTION

The aim of the study was to assess changes in choroidal thickness (ChT) after administration of 1% atropine for 1 week in myopic, emmetropic, and hyperopic children.

METHODS

A total of 235 children aged 4-8 years, which included 46 myopia, 34 emmetropia, and 155 hyperopia patients, were recruited and divided into three groups according to the spherical equivalent with the use of 1% atropine twice a day for 1 week. The ChT was measured at baseline and 1 week.

RESULTS

In the myopia and emmetropia groups, following administration of 1% atropine gel, the ChT thickened significantly under the fovea (i.e., from 278.29 ± 53.01 μm to 308.24 ± 57.3 μm, p < 0.05; from 336.10 ± 78.60 μm to 353.46 ± 70.22 μm, p < 0.05, respectively), and at all intervals from the fovea, while in the hyperopia group, there was no significant difference in the ChT except the nasal side (p < 0.05).

CONCLUSION

Topical administration of 1% atropine gel for 1 week significantly increased the subfoveal and parafoveal ChT in children with myopia and emmetropia. Atropine did not increase the ChT in hyperopic children, except on the nasal side.

Efficacy and Safety of Consecutive Use of 1% and 0.01% Atropine for Myopia Control in Chinese Children: The Atropine for Children and Adolescent Myopia Progression Study

INTRODUCTION

The purpose of this study was to investigate the efficacy and safety of consecutive use of 1% and 0.01% atropine compared with 0.01% atropine alone over 1 year.

METHODS

A total of 207 participants aged 6-12 years with myopia of - 0.50 to - 6.00 D in both eyes were enrolled in this randomized, controlled, non-masked trial and randomly assigned (1:1) to groups A and B. Group A received 1% atropine weekly and were tapered to 0.01% atropine daily at the 6-month visit, and group B received 0.01% atropine daily for 1 year.

RESULTS

Of the 207 participants, 109 were female (52.7%) and the mean (± standard deviation) age was 8.92 ± 1.61 years. Ninety-one participants (87.5%) in group A and 80 participants (77.7%) in group B completed the 1-year treatment. Group A exhibited less refraction progression (- 0.53 ± 0.49 D vs. - 0.74 ± 0.52 D; P = 0.01) and axial elongation (0.26 ± 0.17 mm vs. 0.36 ± 0.21 mm; P < 0.001) over 1 year compared with group B. The changes in refraction (- 0.82 ± 0.45 D vs. - 0.46 ± 0.35 D; P < 0.001) and axial length (0.29 ± 0.12 mm vs. 0.17 ± 0.11 mm; P < 0.001) during the second 6 months in group A were greater than those in group B, with 72.5% of participants presenting refraction rebound. No serious adverse events were reported.

CONCLUSIONS

The 1-year results preliminarily suggest that consecutive use of 1% and 0.01% atropine confers an overall better effect in slowing myopia progression than 0.01% atropine alone, despite myopia rebound after the concentration switch. Both regimens were well tolerated. The long-term efficacy and rebound after the concentration switch and regimen optimization warrant future studies to determine.

TRIAL REGISTRATION NUMBER

Clinical Trials.gov PRS (Registration No. NCT03949101).

Personalized Predictive Modeling of Subfoveal Choroidal Thickness Changes for Myopic Adolescents after Overnight Orthokeratology

The changes in subfoveal choroidal thickness after orthokeratology are crucial in myopia retardation; this study aimed to identify the risk factors that could be incorporated into a predictive model for subfoveal choroidal thickness (SFChT) that would provide further personalized and clinically specific information for myopia control. A one-year prospective study was conducted in the West China Hospital, Sichuan University. Basic information (age, gender, and height) was collected from all subjects. Initial spherical equivalent, axial length, intraocular pressure, central corneal thickness, and subfoveal choroidal thickness were measured, and the ocular environmental factors were also collected. All the measured parameters were recorded in the follow-up period for one year. After the analysis of univariate analysis, statistically significant factors were substituted into the multivariate three-level model. Thirty-three adolescents aged 8−14 years old were enrolled in this study; the results show that the subfoveal choroidal thickness in both eyes changed significantly after 12 months of lens wearing (pR < 0.0001, pL < 0.0001). The axial length was negatively correlated with the change in the SFChT after 12 months of lens wearing (r = −0.511, p = 0.002). After multilevel model analysis, the statistically significant factor was shown to have an important influence on the changes in the subfoveal choroidal thickness, which was the average near-work time. This suggested that the SFChT personal predictions can be made regarding changes in myopic adolescents after orthokeratology using the factor of daily average near-work time. Clinical practitioners will benefit from the results by obtaining a better understanding of the effects of orthokeratology on choroid and myopia progression.

Lipidomic analysis revealed n-3 polyunsaturated fatty acids suppressed choroidal thinning and myopia progression in mice

Myopia is increasing worldwide and its preventable measure should urgently be pursued. N-3 polyunsaturated fatty acids (PUFAs) have been reported to have various effects such as vasodilative and anti-inflammatory, which myopia may be involved in. This study is to investigate the inhibitory effect of PUFAs on myopia progression. A lens-induced myopia (LIM) model was prepared using C57B L6/J 3-week-old mice, which were equipped with a -30 diopter lens to the right eye. Chows containing two different ratios of n-3/n-6 PUFA were administered to the mice, and myopic shifts were confirmed in choroidal thickness, refraction, and axial length in the n-3 PUFA-enriched chow group after 5 weeks. To exclude the possibility that the other ingredients in the chow may have taken the suppressive effect, fat-1 transgenic mice, which can produce n-3 PUFAs endogenously, demonstrated significant suppression of myopia. To identify what elements in n-3 PUFAs took effects on myopia suppression, enucleated eyes were used for targeted lipidomic analysis, and eicosapentaenoic acid (EPA) were characteristically distributed. Administration of EPA to the LIM model confirmed the inhibitory effect on choroidal thinning and myopia progression. Subsequently, to identify the elements and the metabolites of fatty acids effective on myopia suppression, targeted lipidomic analysis was performed and it demonstrated that metabolites of EPA were involved in myopia suppression, whereas prostaglandin E2 and 14,15-dihydrotestosterone were associated with progression of myopia. In conclusion, EPA and its metabolites are related to myopia suppression and inhibition of choroidal thinning.

The Association of Choroidal Thickening by Atropine With Treatment Effects for Myopia: Two-Year Clinical Trial of the Low-concentration Atropine for Myopia Progression (LAMP) Study

PURPOSE

To evaluate longitudinal changes in subfoveal choroidal thickness (SFChT) among children receiving atropine 0.05%, 0.025%, or 0.01% over 2 years and their associations with treatment outcomes in myopia control.

DESIGN

Double-blinded randomized controlled trial.

METHODS

SFChT was measured at 4-month intervals using spectral domain optical coherence tomography. Cycloplegic spherical equivalent (SE), axial length (AL), best-corrected visual acuity, parental SE, outdoor time, near work diopter hours, and treatment compliance were also measured.

RESULTS

314 children were included with qualified choroidal data. The 2-year changes in SFChT from baseline were 21.15 ± 32.99 µm, 3.34 ± 25.30 µm, and -0.30 ± 27.15 µm for the atropine 0.05%, 0.025%, and 0.01% groups, respectively (P < .001). A concentration-dependent response was observed, with thicker choroids at higher atropine concentrations (β = 0.89, P < .001). Mean SFChT thickness significantly increased at 4 months in the atropine 0.025% (P = .001) and 0.05% groups (P < .001) and then remained stable until the end of the second year (P > .05 for all groups). Over 2 years, an increase in SFChT was associated with slower SE progression (β = 0.074, P < .001) and reduced AL elongation (β = -0.045, P < .001). In the mediation analysis, 18.45% of the effect on SE progression from atropine 0.05% was mediated via its choroidal thickening.

CONCLUSIONS

Low concentration atropine induced a choroidal thickening effect along a concentration-dependent response throughout the treatment period. The choroidal thickening was associated with a slower SE progression and AL elongation among all the treatment groups. Choroidal response can be used for assessment of long-term treatment outcomes and as a guide for concentration titrations of atropine.

The Role of Atropine in Preventing Myopia Progression: An Update

Several approaches have been investigated for preventing myopia progression in children and teenagers. Among them, topical atropine has shown promising results and it is being adopted in clinical practice more and more frequently. However, the optimal formulation and treatment algorithm are still to be determined. We discuss the pharmacokinetic, pharmacodynamic, clinical, and tolerability profile revealed first by the multicenter, randomized ATOM 1 and 2 trials and, more recently, by the LAMP Study. Results from these trials confirmed the efficacy of low-concentration atropine with a concentration-dependent response. Although atropine at 0.025% and 0.05% concentrations has shown the most encouraging results in large-scale studies, these formulations are not yet commonplace in worldwide clinical practice. Moreover, their rebound effect and the possibility of reaching a stabilization effect have not been fully investigated with real-life studies. Thus, further larger-scale studies should better characterize the clinical efficacy of atropine over longer follow-up periods, in order to define the optimal dosage and treatment regimen.

Short-Term Effects of Atropine 0.01% on the Structure and Vasculature of the Choroid and Retina in Myopic Chinese Children

Introduction

To explore the short-term effects of atropine 0.01% on the structure and vasculature of the choroid and retina in myopic Chinese children.

Methods

This study was a single-center randomized clinical trial. A total of 40 subjects with myopia < − 6.0 D were enrolled and randomized to receive atropine 0.01% once nightly with regular single-vision lenses or to simply wear regular single-vision lenses at an allocation ratio of 1:1. Follow-up visits were planned at 1 month and 3 months. Choroidal thickness (ChT) was obtained by optical coherence tomography (OCT). Retinal vessel density (RVD), retinal thickness (RT), foveal avascular zone (FAZ) and choriocapillaris flow (CCF) were measured by optical coherence tomography angiography (OCTA). The RVD and RT were measured at fovea, parafovea and perifovea area and four quadrants.

Results

Twenty-one subjects were allocated into the atropine group and 19 subjects into the control group. Over 3 months, the control group showed greater progression of myopia than those in the atropine group. ChT in the atropine group increased 11.12 ± 13.96 μm, which was not significant compared with that of the control group. None of the retinal sectors in atropine-treated eyes showed significant changes of RT and RVD compared with the control group. Besides, FAZ and CCF of the atropine group were not affected by atropine use over time, and there was no difference between the two groups.

Conclusion

Administration of atropine 0.01% eye drops demonstrated no effect on RVD, FAZ and CCF over 3 months, while a modest increase of ChT was observed in atropine-treated eyes.

Trial Registration Number

ChiCTR1800017154.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-022-00476-0.