Posterior Scleral Reinforcement to Prevent Progression of High Myopia

Collagen is crucial target protein for scleral remodeling and biomechanical change in myopia progression and control

In recent decades, the prevalence of myopia has been on the rise globally, attributed to changes in living environments and lifestyles. This increase in myopia has become a significant public health concern. High myopia can result in thinning of the sclera and localized ectasia of the posterior sclera, which is the primary risk factor for various eye diseases and significantly impacts patients' quality of life. Therefore, it is essential to explore effective prevention strategies and programs for individuals with myopia. Collagen serves as the principal molecule in the extracellular matrix (ECM) of scleral tissue, consisting of irregular collagen fibrils. Collagen plays a crucial role in myopia progression and control. During the development of myopia, the sclera undergoes a thinning process which is primarily influenced by collagen expression decreased and remodeled, thus leading to a decrease in its biomechanical properties. Improving collagen expression and promoting collagen crosslinking can slow down the progression of myopia. In light of the above, improving collagen expression or enhancing the mechanical properties of collagen fibers via medication or surgery represents a promising approach to control myopia.

Computational modelling of scleral photocrosslinking: from rat to minipig to human

Selective scleral crosslinking has been proposed as a novel treatment to increase scleral stiffness to counteract biomechanical changes associated with glaucoma and high myopia. Scleral stiffening has been shown by transpupillary peripapillary scleral photocrosslinking in rats, where the photosensitizer, methylene blue (MB), was injected retrobulbarly and red light initiated crosslinking reactions with collagen. Here, we adapted a computational model previously developed to model this treatment in rat eyes to additionally model MB photocrosslinking in minipigs and humans. Increased tissue length and subsequent diffusion and light penetration limitations were found to be barriers to achieving the same extent of crosslinking as in rats. Per cent inspired O2, injected MB concentration and laser fluence were simultaneously varied to overcome these limitations and used to determine optimal combinations of treatment parameters in rats, minipigs and humans. Increasing these three treatment parameters simultaneously resulted in maximum crosslinking, except in rats, where the highest MB concentrations decreased crosslinking. Additionally, the kinetics and diffusion of photocrosslinking reaction intermediates and unproductive side products were modelled across space and time. The model provides a mechanistic understanding of MB photocrosslinking in scleral tissue and a basis for adapting and screening treatment parameters in larger animal models and, eventually, human eyes.

Understanding Posterior Staphyloma in Pathologic Myopia: Current Overview, New Input, and Perspectives

Posterior staphyloma (PS) is considered the hallmark of pathologic myopia and is defined as an outpouching of a circumscribed portion of the eyeball with a radius of curvature smaller than that of the adjacent zone. Although more common in eyes with high myopia, it can affect those without it. The presence of PS is associated with a structurally and functionally worse course of high myopia that can lead to visual disability. Unfortunately, the pathogenesis of PS is unclear so far. Thus, due to the increasing prevalence of myopia which has been further exacerbated by the advent of COVID-19 lockdown, researchers are eager to elucidate the pathogenesis of pathologic myopia and that of its complications, especially PS, which will allow the development of preventive strategies. The aim of this work was to review the morphological characteristics of PS with emphasis on similarities with peripapillary staphyloma and to discuss the pathogenesis of PS considering recent suggestions about that of peripapillary staphyloma.

Corneal metabolic biomarkers for moderate and high myopia in human

This study aimed to identify the corneal metabolic biomarkers for moderate and high myopia in human. We enrolled 221 eyes from 221 subjects with myopia to perform the femtosecond laser small incision lenticule extraction (SMILE) surgery. Among these, 71 eyes of 71 subjects were enrolled in the low myopic group, 75 eyes of 75 subjects in the moderate myopic group and 75 eyes of 75 subjects in the high myopic group. The untargeted metabolomics analysis was performed to analyze the corneal tissues extracted during the SMILE surgery using an ultra-high-performance liquid chromatography (UHPLC) coupled to a quadrupole time-of-flight (Q-TOF) mass spectrometry (MS). The one-way analysis of variance (ANOVA) was used to identify the different metabolites among the three myopic groups, the orthogonal partial least-squares discriminant analysis (OPLS-DA) model was used to reveal the different metabolites between moderate myopia and low myopia, and between high myopia and low myopia. The Venn gram was used to find the overlapped metabolites of the three datasets of the different metabolites. The stepwise multiple linear regression analysis was used to determine the metabolic molecules associated with manifest refractive spherical equivalents (MRSE). The Receiver Operating Characteristics (ROC) analysis was performed to reveal the corneal biomarkers for moderate and high myopia. The hub biomarker was further selected by the networks among different metabolites created by the Cytoscape software. A total of 1594 metabolites were identified in myopic corneas. 321 metabolites were different among the three myopic groups, 106 metabolites were different between high myopic corneas and low myopic corneas, 104 metabolites were different between moderate myopic corneas and low myopic corneas, and 30 metabolic molecules overlapped among the three datasets. The multivariate linear regression analysis revealed the myopic degree was significantly influenced by the corneal levels of azelaic acid, arginine-proline (Arg-Pro), 1-stearoyl-2-myristoyl-sn-glycero-3-phosphocholine, and hypoxanthine. The ROC curve analysis showed that azelaic acid, Arg-Pro and hypoxanthine were effective in discriminating low myopia from moderate to high myopia with the area under the curve (AUC) values as 0.982, 0.991 and 0.982 for azelaic acid, Arg-Pro and hypoxanthine respectively. The network analysis suggested that Arg-Pro had the maximum connections among these three biomarkers. Thus, this study identified azelaic acid, Arg-Pro and hypoxanthine as corneal biomarkers to discriminate low myopia from moderate to high myopia, with Arg-Pro serving as the hub biomarker for moderate and high myopia.

Observation of the effect of posterior scleral reinforcement combined with orthokeratology and 0.01% atropine in the treatment of congenital myopia: a case report

BACKGROUND

Myopia has recently emerged as a significant threat to global public health. The high and pathological myopia in children and adolescents could result in irreversible damage to eye tissues and severe impairment of visual function without timely control. Posterior scleral reinforcement (PSR) can effectively control the progression of high myopia by limiting posterior scleral expansion, improving retrobulbar vascular perfusion, thereby stabilizing the axial length and refraction of the eye. Moreover, orthokeratology and low concentrations of atropine are also effective in slowing myopia progression.

CASE PRESENTATION

A female child was diagnosed with binocular congenital myopia and amblyopia at the age of 3 and the patient's vision had never been rectified with spectacles at the first consultation. The patient's ophthalmological findings suggested, high refractive error with low best corrected visual acuity, longer axial length beyond the standard level of her age, and fundus examination suggesting posterior scleral staphyloma with weakened hemodynamics of the posterior ciliary artery. Thereby, PSR was performed to improve fundus health and the combination of orthokeratology and 0.01% atropine were performed to control the development of myopia. Following up to 8 years of clinical treatment and observations, the progression of myopia could be well controlled and fundus health was stable.

CONCLUSION

In this report, 8-year of clinical observation indicated that PSR could improve choroidal thickness and hemodynamic parameters of the retrobulbar vessels, postoperative orthokeratology combined with 0.01% atropine treatment strategy may be a good choice for myopia control effectively.

Evaluation of new robust silk fibroin hydrogels for posterior scleral reinforcement in rabbits

Background: Currently, there is no ideal material available for posterior scleral reinforcement (PSR) to prevent the progression of high myopia. In this study, we investigated robust regenerated silk fibroin (RSF) hydrogels as potential grafts for PSR in animal experiments to evaluate their safety and biological reactions. Methods: PSR surgery was performed on the right eye of twenty-eight adult New Zealand white rabbits, with the left eye serving as a self-control. Ten rabbits were observed for 3 months, while 18 rabbits were observed for 6 months. The rabbits were evaluated using intraocular pressure (IOP), anterior segment and fundus photography, A- and B-ultrasound, optical coherence tomography (OCT), histology, and biomechanical tests. Results: No complications such as significant IOP fluctuation, anterior chamber inflammation, vitreous opacity, retinal lesion, infection, or material exposure were observed. Furthermore, no evidence of pathological changes in the optic nerve and retina, or structural abnormalities on OCT, were found. The RSF grafts were appropriately located at the posterior sclera and enclosed in fibrous capsules. The scleral thickness and collagen fiber content of the treated eyes increased after surgery. The ultimate stress of the reinforced sclera increased by 30.7%, and the elastic modulus increased by 33.0% compared to those of the control eyes at 6 months after surgery. Conclusion: Robust RSF hydrogels exhibited good biocompatibility and promoted the formation of fibrous capsules at the posterior sclera in vivo. The biomechanical properties of the reinforced sclera were strengthened. These findings suggest that RSF hydrogel is a potential material for PSR.

Difference in aqueous concentration and vitreous mass of cytokines in high myopias with and without choroidal neovascularization

PURPOSE

To investigate and compare the aqueous humor (AH) concentration and vitreous mass of cytokines in high myopias (HM) with and without myopic choroidal neovascularization (mCNV). And the correlations between cytokines and the size of CNVs on optical coherence tomography angiography (OCTA) images were also be analyzed.

METHODS

This observational study included 56 highly myopic eyes with and without CNV and 57 control eyes with cataracts. AH samples were obtained prior to the intravitreal injection of anti-VEGF and cataract surgery. This study measured multiple inflammatory cytokines including VEGF, interleukin (IL)-6, IL-8, IL-10, interferon-inducible protein-10 (IP-10), and monocyte chemotactic protein-1 (MCP-1) by multiplex bead assay. AH cytokine level, axial length, and vitreous volume were used to calculate the vitreous mass of cytokines.

RESULTS

The vitreous mass of VEGF in eyes with mCNV was significantly higher than that in control group. However, the difference in AH concentration of VEGF between high myopias with mCNV was not observed. Inflammatory cytokines were upregulated (IL-6, IL-10, and MCP-1) in highly myopic eyes both with and without mCNV (all P<0.05). There was also a significant difference in the vitreous mass of IL-8 and IP-10 among all three groups (P<0.05).

CONCLUSION

We confirmed the secretion of VEGF increased in eyes with mCNV from a new perspective. The development of both HM and mCNV were related to inflammatory cytokines and the upregulation of inflammatory cytokines may precede upregulation of VEGF. The vitreous mass might be tried as a more reliable potential biomarker in eyes with longer axial length.

Posterior scleral reinforcement for the treatment of myopic traction maculopathy

Background

This study aimed to investigate the clinical effectiveness of posterior scleral reinforcement(PSR) for the treatment of myopic traction maculopathy (MTM).

Methods

This was a prospective study of 32 eyes from 20 patients with MTM treated with PSR using genipin-cross-linked donor sclera. The length of the scleral strip used for the surgery was designed to be 1.5-times the axial length of the eye, whereas its width was 0.4-times the axial length of the eye. The optical coherence tomography images, spherical equivalent of refractive error, axial length, best corrected visual acuity, electroretinogram findings, and intraocular pressure of the patients were assessed postoperatively.

Results

The mean duration of follow-up was 17.80 ± 8.74 months. The differences between the spherical equivalent of refractive error, best corrected visual acuity, axial length, and electroretinogram findings recorded preoperatively and those measured postoperatively were statistically significant (p < 0.05). The final reduction in axial length was 1.64 ± 0.85 mm. At the end of the follow-up, optical coherence tomography showed essential foveal reattachment in 30 eyes (93.75%), partial reattachment in two eyes (6.25%), and closure of macular holes in seven eyes (77.78%). No retinal detachment, vitreous haemorrhage, or other serious complications occurred following the surgery.

Conclusions

Posterior scleral reinforcement with genipin-cross-linked sclera showed safe and effective outcomes for the treatment of MTM during a follow-up period of at least one year.

Trial registration

11\12\2018, ChiCTR1800020012.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02497-6.

Biomechanical Considerations of Patching Material for Posterior Scleral Reinforcement Surgery

Purpose

To characterize biomechanical properties of genipin-crosslinked human dura mater as reinforcing material for posterior scleral reinforcement (PSR) and to compare it with crosslinked human sclera.

Methods

Donor dura mater and sclera were crosslinked in the same optimized genipin solution. Resistance to enzyme degradation for both materials were investigated by exposing the materials to accelerated enzyme degrading. Elastic modulus and tensile strength were measured by biomechanics testing equipment. Crosslinked human dura mater was used as reinforcing patch in PSR on 57 adult pathologic myopic eyes. The patients were followed up for an average 3 years. The main outcome was eye globe axial length change and safety profile of the reinforcing material.

Results

Crosslinked dura mater demonstrated similar percentage weight loss to crosslinked sclera when exposed to enzymatic solution. Dura mater has higher density than sclera. The retaining elastic modulus after enzyme exposure was 72.02 MPa for crosslinked dura mater while 53.88 MPa for crosslinked sclera, 34% greater for crosslinked dura mater, P = 0.0186). At the end of 3 years follow-up, the mean globe axis of the surgery eyes was reduced by 1.29 mm (from 30.81 to 29.51 mm, P < 0.0001, paired t-test). Visual acuity (BCVA logMar) improved by 0.10 logMar unit which is an improvement of five letters (P = 0.0184, paired t-test). No material specific complication was noted.

Conclusion

Crosslinked human dura mater may be superior to crosslinked human sclera as reinforcing material for PSR to manage progression of high myopia. This material was well tolerated on human eye.

Clinical effect of rigid gas permeable (RGP) contact lens in improving vision and controlling myopia progression of unilateral high myopic children

BACKGROUND

The aim of this study was to explore the clinical effect of the RGP contact lens in improving vision and controlling myopia progression of the unilateral high myopic children.

METHODS

In this retrospective analysis case series study, we analyzed the clinical data for 23 subjects with unilateral high myopic children under 6 years old, with the spherical equivalent refractive error of the myopic eye from -5.0 D to -12.0 D, who were enrolled from the outpatient clinic at Beijing Tongren Hospital, China. Fourteen subjects could successfully fit the RGP contact lens, and nine subjects used the spectacle lens. Complete ocular examination was performed at the first visit at the clinic and every three months during the follow-up period.

RESULTS

In the RGP group, the change of axial length (AL) of the high myopic eye was from 25.62 ± 1.31 mm to 25.69 ± 1.31 mm after 12 months. The change of spherical equivalent (SE) was from -8.73 ± 2.54 D to -8.48 ± 2.77 D. The best corrected visual acuity (BCVA) improved from 0.24 ± 0.18 to 0.78 ± 0.26. In the spectacle group, the change of AL was from 24.76 ± 0.56 mm to 24.94 ± 0.71 mm. The change of SE was from -6.16 ± 2.86 D to -9.45 ± 2.06 D. The improvement of BCVA was from 0.52 ± 0.15 to 0.72 ± 0.23.

CONCLUSIONS

Wearing RGP lens in the children with unilateral high myopia is a safe, convenient and effective method to improve the best corrected vision and controlling myopia progression.

One-year analysis of the refractive stability, axial elongation and related factors in a high myopia population after Implantable Collamer Lens implantation

PURPOSE

To investigate the refractive stability, axial length (AL) changes and their related factors in a high myopia population after Implantable Collamer Lens (ICL) implantation.

METHODS

This prospective study included 116 eyes of 116 patients divided into several groups based on the spherical equivalent refractive error (SE)-SE > - 6 D, - 12 ≤ SE < - 6 D and SE < - 12 D groups-and AL-AL < 28 mm and AL ≥ 28 mm groups. The uncorrected and corrected distance visual acuity, refraction, AL and intraocular pressure were followed for 1 year.

RESULTS

SE changed from - 11.53 ± 5.25 D preoperatively to - 0.33 ± 0.70 D at 1 week, and further changed to - 0.48 ± 0.77 D at 1 year after ICL implantation, with average progression being - 0.15 ± 0.37 D from 1 week to 1 year after surgery. AL changed from 27.95 ± 2.33 mm preoperatively to 27.98 ± 2.36 mm 1 year after surgery, with an average axial elongation of 0.03 ± 0.12 mm. The mean axial elongation rate was 0.05 mm/year in the SE < - 12 D group, being significantly faster than the other refractive groups (P < 0.05); it was 0.06 mm/year in the AL ≥ 28 mm group, being significantly faster than the AL < 28 mm group (P < 0.05).

CONCLUSION

Patients with high myopia and long AL showed a continuous myopic progression and axial elongation at an adult age one year after ICL surgery, especially in those with myopia higher than - 12.00 D and AL longer than 28.00 mm.

Scleral Cross-Linking in Form-Deprivation Myopic Guinea Pig Eyes Leads to Glaucomatous Changes

Purpose

To investigate the potential glaucomatous changes caused by scleral cross-linking (CXL) in a guinea pig form-deprivation (FD) myopia model.

Methods

Eighty 4-week-old tricolor guinea pigs were divided into four groups: FD only, genipin CXL only, FD plus CXL, and control. Refractive error, axial length (AL), intraocular pressure (IOP), and structural and vasculature optic disc changes in optical coherence tomography (OCT) and OCT angiography (OCTA) were measured at baseline and day 21. CXL efficacy was evaluated by scleral rigidity Young's modulus values. Histological and molecular changes in the anterior chamber angle, retina, and sclera were assessed.

Results

Baseline parameters were similar among groups (P > 0.05). The FD plus CXL group at day 21 had the least increase of AL (0.14 ± 0.08 mm) and highest IOP elevation (31.5 ± 3.6 mmHg) compared with the FD-only group (AL: 0.68 ± 0.17 mm; IOP: 22.2 ± 2.6 mmHg) and the control group (AL: 0.24 ± 0.09 mm; IOP: 17.4 ± 1.8 mmHg) (all P < 0.001). OCT and OCTA parameters of the optic disc in the FD plus CXL group at day 21 showed glaucomatous changes and decreased blood flow signals. Sclera rigidity increased in the CXL and FD plus CXL groups. Advanced glycation end products deposited extensively in the retina, choroid, and sclera of FD plus CXL eyes.

Conclusions

CXL causes increased IOP and subsequent optic disc, anterior segment, and scleral changes while inhibiting myopic progression and axial elongation in FD guinea pig eyes. Therefore, applying CXL to control myopia raises safety concerns.

Shaping Eyeballs by Scleral Collagen Cross-Linking: A Hypothesis for Myopia Treatment

The global prevalence of myopia has brought to the attention of the different eye and vision specialists, who make way to control its progression. Evidence have shown that a proactive reshaping of the eyeball is the core point of myopia developing process, which particularly includes the weakening, thinning, and expanding of the sclera. Thus, the sclera is considered to be a prime target for therapeutic manipulation in halting progressive myopia. In the past decades, corneal collagen cross-linking has been applied in clinical practice for treating aberrant corneal remodeling diseases. In this article, we hypothesize that scleral collagen cross-linking (SXL) has a huge potential in stabilizing myopic process by shaping the eyeball and preventing the aberrant scleral remodeling. In contrast with the current methods of optometry correction, such as physiotherapy, pharmacotherapy, spectacles, contact lenses, refractive surgeries, etc., eyeball-shaping method using SXL is a fundamental intervention which aims at the pathogenesis of progressive visual loss of myopia. Compared with the current posterior scleral reinforcement, the most advantage of SXL is that there is no allotransplant into the myopic eye, which means less expenditure, lower risk, and easier to handle in operating.

Longitudinal Changes in Macular Optical Coherence Tomography Angiography Metrics in Primary Open-Angle Glaucoma With High Myopia: A Prospective Study

Purpose

To characterize longitudinal changes in macular microvasculature as quantified from optical coherence tomography angiography (OCTA) metrics in primary open-angle glaucoma (POAG) eyes with and without high myopia.

Methods

In total, 63 and 61 POAG eyes with and without high myopia, respectively, underwent swept-source OCTA imaging in at least four follow-up visits at an ophthalmic center, with a scanning protocol of 3- × 3-mm centered at the fovea. The foveal avascular zone (FAZ) area, FAZ circularity, and vessel density (VD) in both the superficial (SCP) and deep capillary plexuses (DCP) were measured. The rate of change in macular OCTA metrics over time was estimated using linear mixed-effects models in both groups of POAG eyes.

Results

The mean follow-up time and number of visits were 27.72 ± 8.57 months and 8.5 (8 to 13) times, and 30.95 ± 10.19 months and 10 (8‒13) times in POAG eyes with and without high myopia, respectively. VD in the DCP reduced significantly more quickly in POAG eyes with high myopia than in those without high myopia (−5.14%/year vs. −3.71%/year, P = 0.008). Moreover, lower baseline VD in the DCP was significantly associated with faster VD reduction in POAG with high myopia eyes (P < 0.001). Conversely, the VD reduction rate in the SCP, FAZ area, and FAZ circularity in both the SCP and DCP were similar in both groups (all Ps > 0.05).

Conclusions

VD in DCP reduced significantly more quickly in POAG eyes with high myopia over time. Density in the DCP reduced more quickly when baseline VD was low.

Association of Aberrant Posterior Vitreous Detachment and Pathologic Tractional Forces With Myopic Macular Degeneration

Purpose

The purpose of this study was to assess whether the tractional elements of pathologic myopia (PM; e.g. myopic traction maculopathy [MTM], posterior staphyloma [PS], and aberrant posterior vitreous detachment [PVD]) are associated with myopic macular degeneration (MMD) independent of age and axial length, among highly myopic (HM) eyes.

Methods

One hundred twenty-nine individuals with 239 HM eyes from the Myopic and Pathologic Eyes in Singapore (MyoPES) cohort underwent ocular biometry, fundus photography, swept-source optical coherence tomography, and ocular B-scan ultrasound. Images were analyzed for PVD grade, and presence of MTM, PS, and MMD. The χ² test was done to determine the difference in prevalence of MMD between eyes with and without PVD, PS, and MTM. Multivariate probit regression analyses were performed to ascertain the relationship between the potential predictors (PVD, PS, and MTM) and outcome variable (MMD), after accounting for possible confounders (e.g. age and axial length). Marginal effects were reported.

Results

Controlling for potential confounders, eyes with MTM have a 29.92 percentage point higher likelihood of having MMD (P = 0.003), and eyes with PS have a 25.72 percentage point higher likelihood of having MMD (P = 0.002). The likelihood of MMD increases by 10.61 percentage points per 1 mm increase in axial length (P < 0.001). Subanalysis revealed that eyes with incomplete PVD have a 22.54 percentage point higher likelihood of having MMD than eyes with early PVD (P = 0.04).

Conclusions

Our study demonstrated an association between tractional (MTM, PS, and persistently incomplete PVD) and degenerative elements of PM independent of age and axial length. These data provide further insights into the pathogenesis of MMD.

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

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

Review on current concepts of myopia and its control strategies

Myopia poses a significant burden on the healthcare system, economy and quality of life. It is an emerging global public health challenge and requires interventions to delay or stop onset and progression. With changing times and evidence, the concepts of myopia are changing along with the treatment and control strategies. Behavioural modifications including increased outdoors time and reduced near work, optical and pharmaceutical management options are reviewed. This paper presents a current overview on the concepts of myopia, and is expected to summarize updates on myopia control methods.

Long-term progression of myopic maculopathy in degenerative myopia as imaged by SD-OCT and IR imaging

CLINICAL RELEVANCE

Clinicians can benefit from developing an understanding of the natural disease progression of myopic maculopathy in degenerative myopia using optical coherence tomography (OCT).

BACKGROUND

The prevalence of high myopia is constantly increasing. In this work, infrared imaging and OCT is used to study the natural course of the disease.

METHODS

This is a retrospective longitudinal study. Medical records of 72 patients with high myopia (< 6.00 D) and a minimum five-year follow-up period were analysed. Collected data on all enrolled patients included demographic characteristics and medical history, as well as recordings on best-corrected visual acuity, slitlamp examination, OCT, and fluorescein angiography in cases of suspected myopic choroidal neovascularisation. Images were independently marked by two graders.

RESULTS

The mean age of patients was 54.6 ± 14.4 years (59.72% female) with baseline logMAR best-corrected visual acuity of 0.22 ± 0.28. At baseline examination, 70.83% of the study group showed signs of maculopathy and 62.5% diffuse or patchy atrophy. During follow-up, 22.2% of patients with any type of atrophy showed enlarged affected areas. Two patients with baseline lacquer cracks developed new lesions. There was a weak correlation between patient age and maculopathy progression (r = 0.233; p = 0.03). While central retinal thickness was not associated with maculopathy progression (p = 0.203), a moderate correlation was found between choroidal thickness and maculopathy progression (r = -0.516; p < 0.001).

CONCLUSION

Lesion characteristics in myopic degeneration have been elucidated, taking advantage of the ongoing technological advances in retinal imaging. The understanding of disease patterns and progression is essential for appropriate management of patients, while discovering biomarkers which lead to choroidal neovascularisation development is of urgent importance to establish international diagnostic criteria and treatment protocols.

Efficacy and safety of Bu Jing Yi Shi tables for high myopia: A protocol of systematic review and meta-analysis

BACKGROUND

High myopia is a kind of ametropia with diopter more than -6.00D or axial length ≥26 mm. With the change of the modern environment, the incidence rate is increasing year by year. At present, the pathogenesis of high myopia is not clear. Some current studies indicate that it may be related to the environment and genetics. A Chinese patent medicine named Bu Jing Yi Shi Tablets (BJYST) has many functions including anti-oxidation, expansion of blood vessels, anti-inflammatory, immune regulation, inhibition of retinal photoreceptor cell apoptosis, and promotion of retinal repair. A large number of existing studies have shown that this prescription can relieve the clinical manifestations of high myopia and its complications, but its true efficacy and safety are still unclear. To certify this point, a protocol for a systematic review and meta-analysis of BJYST for high myopia will be performed.

METHODS AND ANALYSIS

Articles that have been identified by electronically searching of 9 English and 5 Chinese databases from their inception to December 4, 2020 will be incorporated into the study. This study only adopts Chinese and English. Two researchers will take charge of completing the selection of research, the extraction of data as well as the assessment of research quality independently. The primary outcomes will be an average change in refractive error measured in diopters and an average change in axial length measured in millimeters. Data analysis will be performed via the RevMan 5.3 software, and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) will help to assess the evidence level.

RESULTS

The results of this study will be published in a peer-reviewed journal.

CONCLUSION

This study will conclude whether BJYST is safe and effective in treating high myopia on the basis of evidence-based medicine.

REGISTRATION

The Open Science Framework (OSF) registration number is osf.io/dpk5b.

Results with Posterior Scleral Reinforcement for Progressive Highly Myopic Children in Hungary

PURPOSE

We have been performing posterior scleral reinforcement in our ophthalmological department since 1992 on progressive highly myopic eyes. Here, we report on our results with this technique in the foregoing 7 years in a retrospective comparative design.

METHODS

Thirty-eight eyes of 32 patients, operated according to Snyder-Thompson's method, were enrolled in this study, and a control group of 9 age- and myopia-matched children's 14 eyes was built for comparison. Pre- and postoperative best-corrected visual acuity, subjective refractive error (spherical equivalent of spectacle dioptres), and axial length were recorded. Changes within groups were calculated, as well as baseline parameters and their changes during follow-up, and compared between the groups. Correlation analysis was performed to identify factors that could influence myopia progression.

RESULTS

Myopic progression was significantly lower in the operated than in the nonoperated group, both in terms of mean annual axial length as well as refractive error changes (0.21 ± 0.08 mm versus 0.49 ± 0.19 mm and 0.18 ± 0.29 D versus 0.6 ± 0.33 D, respectively). Mean overall visual improvement was more explicit in operated eyes as compared to those left untreated (0.15 ± 0.09 versus 0.01 ± 0.1). No association of any factor with myopia progression could be identified. We encountered no serious or lasting complications.

CONCLUSION

In our clinical practice, posterior scleral reinforcement according to Snyder-Thompson proved to be a safely applicable and effective surgical method to stop or significantly retard pathological increases in axial length and dioptres, and thus can help prevent the onset of myopic degenerative lesions, and irreversible visual impairment in the long run.

[Myopia in children]

Myopia is a refractive anomaly, a global public health issue, mainly due to an increase in axial length of the eyeball. Myopia is increasing worldwide with the appearance of a "myopia global growing epidemic". In children under 6 years old, 20 % have abnormalities, the most common of which are primarily refractive abnormalities, followed by strabismus and amblyopia. Myopia presents a major risk of complications, correlated with its severity, such as retinal detachment, retinal neovascularization, early cataracts and glaucoma. In children with high myopia, syndromic myopia must be explored. Early detection of myopia onset and progression is essential to myopia control strategies. The most promising treatments include outdoor activities, defocusing corrective lenses, defocusing contact lenses, orthokeratology and pharmacological treatments with low-dose atropine.

Effect of 0.01% atropine eye drops on choroidal thickness in myopic children

PURPOSE

To examine the effects of low-dose atropine on the choroidal thickness (CT) of young children in Shanghai, China, as well as the ocular biometrics of myopic patients.

METHODS

A total of 59 eyes of 35 myopic children had subfoveal CT and ocular biometry measurements taken before and after 2weeks, 4weeks, and 8weeks of treatment with 0.01% atropine. All eyes were measured using swept-source optical coherence tomography. CT and changes in it were also recorded.

RESULTS

The choroid exhibited significant and continuous thickening under the fovea after patients were treated with 0.01% atropine. The magnitude of change in CT varied with the location and with the duration of treatment. The greatest change was observed in the fovea. There was no significant relationship between changes in subfoveal CT and axial length.

CONCLUSIONS

Using 0.01% atropine eye drops significantly increased CT in eyes of young myopic children, by variable magnitude depending upon location.