Posterior scleral reinforcement combined with patching therapy for pre-school children with unilateral high myopia

Posterior scleral reinforcement surgery effectively slows the rate of high myopic progression in children

PURPOSE

To investigate the rate of axial length elongation and high myopia progression in operated eyes before and after posterior scleral reinforcement (PSR) surgery.

METHODS

This was a retrospective study. Children with pathological myopia treated with PSR at Beijing Tongren Hospital between May 2013 and May 2020 were recruited into the PSR surgery group. Children matched for age and myopia were recruited into the control group. All children underwent comprehensive ophthalmologic examinations. The presurgical and postsurgical rates of axial length elongation and myopic (spherical equivalent) progression were calculated.

RESULTS

A total of 35 PSR patients were included in the study. The mean age was 6.5±3.0 years (range 2 to 14 years). Mean follow-up was 544 days (range 216 to 1657 days). The rate of axial length elongation was significantly less after posterior scleral reinforcement surgery (0.505±0.048mm per year prior to surgery; 0.382±0.045mm per year after surgery, P<0.001). The rate of myopic progression decreased after posterior scleral reinforcement surgery (1.162±0.118 D per year prior to surgery; 0.153±0.437 D per year after surgery, P=0.0239). There was no statistically significant difference in axial length elongation or myopic progression between pre-inclusion and post-inclusion in the control group. Moreover, the children's best-corrected visual acuity was significantly improved after posterior scleral reinforcement surgery (P<0.001).

CONCLUSION

Posterior scleral reinforcement surgery effectively decreased the rate of high myopic progression and axial length elongation in children.

3D printed fibroblast-loaded hydrogel for scleral remodeling to prevent the progression of myopia

Pathologic myopia has seriously jeopardized the visual health of adolescents in the past decades. The progression of high myopia is associated with a decrease in collagen aggregation and thinning of the sclera, which ultimately leads to longer eye axis length and image formation in front of the retina. Herein, we report a fibroblast-loaded hydrogel as a posterior scleral reinforcement (PSR) surgery implant for the prevention of myopia progression. The fibroblast-loaded gelatin methacrylate (GelMA)-poly(ethylene glycol) diacrylate (PEGDA) hydrogel was prepared through bioprinting with digital light processing (DLP). The introduction of the PEGDA component endowed the GelMA-PEGDA hydrogel with a high compression modulus for PRS surgery. The encapsulated fibroblasts could consistently maintain a high survival rate during 7 days of in vitro incubation, and could normally secrete collagen type I. Eventually, both the hydrogel and fibroblast-loaded hydrogel demonstrated an effective shortening of the myopic eye axis length in a guinea pig model of visual deprivation over three weeks after implantation, and the sclera thickness of myopic guinea pigs became significantly thicker after 4 weeks, verifying the success of sclera remodeling and showing that myopic progression was effectively controlled. In particular, the fibroblast-loaded hydrogel demonstrated the best therapeutic effect through the synergistic effect of cell therapy and PSR surgery.

Effect and safety posterior scleral reinforcement on controlling myopia in children: a meta-analysis

PURPOSE

The aim of this meta-analysis was to assess the efficacy of posterior scleral reinforcement (PSR) on the control of pediatric myopia. Electronic databases were systematically searched.

METHODS

Standardized mean differences (SMDs) of outcomes were calculated. Eight studies with 357 patients with pediatric myopia were included. The SMD for the increase in mean axial length (AL) in the PSR and control group was - 1.19 (95% CI - 1.71, - 0.68).

RESULTS

The SMD for decrease of best-corrected visual acuity (BCVA) LogMAR in the PSR and control group was 0.85 (95% CI 0.28, 1.43). The SMD for change in intraocular pressure (IOP) at the time of surgery and at the end of the follow-up period in the PSR group was - 0.01 (95% CI - 0.48, 0.47).

CONCLUSION

This meta-analysis indicates that PSR surgery may be an effective therapeutic strategy to control the progression of myopia in childhood with acceptable adverse effects.

Clinical and genetic risk factors underlying severe consequence identified in 75 families with unilateral high myopia

BACKGROUNDS

Unilateral high myopia (uHM), commonly observed in patients with retinal diseases or only with high myopia, is frequently associated with amblyopia with poor prognosis. This study aims to reveal the clinical and genetic spectrum of uHM in a large Chinese cohort.

METHODS

A total of 75 probands with simplex uHM were included in our Pediatric and Genetic Eye Clinic. Patients with significant posterior anomalies other than myopic fundus changes were excluded. Variants were detected by exome sequencing and then analyzed through multiple-step bioinformatic and co-segregation analysis and finally confirmed by Sanger sequencing. Genetic findings were correlated with associated clinical data for analysis.

RESULTS

Among the 75 probands with a mean age of 6.21 ± 4.70 years at the presentation, myopic fundus of C1 and C2 was observed in 73 (97.3%) probands. Surprisingly, specific peripheral changes were identified in 63 eyes involving 36 (48.0%) probands after extensive examination, including peripheral retinal avascular zone (74.6%, 47/63 eyes), neovascularization (54.0%), fluorescein leakage (31.7%), peripheral pigmentary changes (31.7%), and others. Exome sequencing identified 21 potential pathogenic variants of 13 genes in 20 of 75 (26.7%) probands, including genes for Stickler syndrome (COL11A1 and COL2A1; 6/20), FEVR (FZD4, LRP5, and TSPAN12; 5/20), and others (FBN1, GPR179, ZEB2, PAX6, GPR143, OPN1LW, FRMD7, and CACNA1F; 9/20). For the peripheral retinal changes in the 20 probands, variants in Stickler syndrome-related genes were predominantly associated with retinal pigmentary changes, lattice degeneration, and retinal avascular region, while variants in genes related to FEVR were mainly associated with the avascular zone, neovascularization, and fluorescein leakage.

CONCLUSIONS

Genetic defects were identified in about one-fourth of simplex uHM patients in which significant consequences may be hidden under a classic myopic fundus in up to half. To our knowledge, this is the first systematic genetic study on simplex uHM to date. In addition to routine care of strabismus and amblyopia, careful examination of the peripheral retina and genetic screening is warranted for patients with uHM in order to identify signs of risk for retinal detachment and other complications and provide meaningful genetic counseling.

Analysis of morphological and quantitative changes in pathological myopia and perioperative changes in posterior scleral reinforcement using three-dimensional magnet resonance imaging

Objective: To compare the morphological and quantitative changes in pathological myopia (PM) and the perioperative changes in posterior scleral reinforcement (PSR) using three-dimensional magnetic resonance images (3D MRI). Methods: A total of 49 patients with high myopia (HM; 98 eyes), 15 with pathological myopia (PM; 19 eyes), and 10 without high myopia (NORM; 20 eyes) were recruited between September 2019 and July 2021. The patients underwent measurements of refractive error and axial length, as well as 3D MRI of the eyeball. Python was used to analyze the 3D MRI images, calculate the vitreous volume, establish a topography of the height of the eyeball posterior surface, and calculate the rate of change in height (H). For the PM group undergoing PSR, changes in vitreous volume and the highest point of the eyeball posterior surface in four quadrants (temporal, subtemporal, nasal, and subnasal) were compared before and after PSR. Results: The vitreous volume was smaller in the NORM group compared to the HM and PM groups (p < 0.01). The PM group had a larger volume than the HM group (p < 0.01). The H for the PM group was higher than that of the NORM and HM groups (p < 0.01). After PSR in the PM group, the total vitreous volume, as well as the volume in the subnasal and supratemporal quadrants, decreased (p < 0.05). Additionally, the highest point of the eyeball's posterior surface was generally shifted to the upper nasal side. Finally, the shape and position of the scleral band after PSR were plotted. Conclusion: 3D MRI is capable of a quantitative description of the eyeball morphology in PM and PSR. It allows for precise calculations of changes in vitreous volume and the H of the posterior surface. It also facilitates a meticulous analysis of the specific details of the scleral band following PSR.

An empirical study on the effect of outdoor illumination and exercise intervention on Children's vision

Objective

To explore the relationship between outdoor lighting and sports and the development of myopia, and to analyze the effects of outdoor lighting and exercise on the diopter of children with normal vision and myopia, so as to provide guidance for the prevention and treatment of myopia in children and adolescents in the future.

Methods

A total of 201 children were divided into two groups according to myopia or not. Each group was randomly divided into 4 groups: outdoor exercise group, outdoor control group, indoor exercise group and indoor control group. Among them, the outdoor exercise group and indoor exercise group received moderate and high intensity aerobic exercise 3 times a week for 60 min each time for 12 months, while the outdoor control group and indoor control group had normal study and life during the corresponding period of time. No additional exercise intervention. At the end of the experiment, the diopter of each group was compared.

Results

The diopter of all groups with normal vision and myopia decreased significantly after the experiment (p < 0.01). There were significant differences in diopter between outdoor exercise group and indoor control group (p < 0.01), between outdoor exercise group and indoor control group (p < 0.05), and between indoor exercise group and indoor control group (p < 0.01). There were significant differences in diopter between indoor exercise group and indoor control group (p < 0.01). The differences among myopic children after the experiment showed that there was significant difference in diopter between outdoor exercise group and indoor exercise group (p < 0.05), between outdoor exercise group and indoor control group (p < 0.01), and between outdoor control group and indoor control group (p < 0.05). There were significant differences in the changes of diopter between the outdoor control group and the indoor exercise group with normal vision and myopia before and after the experiment (p < 0.05).

Conclusion

Outdoor light and exercise intervention can have a beneficial effect on children's vision, but because of whether children are myopic or not, the effect is different, outdoor light and exercise have a better effect on reducing the diopter of children with normal vision.

Clinical observation of posterior scleral reinforcement in the treatment of progressive high myopia in Chinese children: a retrospective study

Objective

To observe the efficacy and safety of posterior sclera reinforcement over time.

Methods

This retrospective single-arm cohort study included children with high myopia who underwent the modified Snyder-Thompson type posterior sclera reinforcement surgery from 03/2015 to 08/2018 at Fuzhou Children’s Hospital of Fujian Medical University. Axial length (AL), corneal radius of curvature (CRC), AL/CRC, refractive error, and best-corrected visual acuity (BCVA) were observed from 1 year before the operation to 2 years after.

Results

Nineteen children (33 eyes) with high myopia were included. The patients were 4.9 ± 2.7 (range, 2–10) years of age (three patients were 10 years old, all others were ≤ 7 years old). AL increased from 1 year before surgery to 2 years after surgery (from 25.31 ± 1.59 to 26.76 ± 1.52, P < 0.001). The refractive error was smaller 1 year before surgery than at the other timepoints (all P < 0.05). BCVA improved over time (P < 0.001). Changes over time were also observed in horizontal CRC (hCRC), AL/hCRC, AL/vertical CRC (vCRC), and AL/CRC (all P < 0.001), but not in vCRC (P = 0.304). The increase of AL at 2 years after surgery was smaller than at 1 year before surgery and 1 year after surgery (both P < 0.001). The increase of AL/CRC at 2 years after surgery was smaller than at 1 year before surgery (0.04 ± 0.04 vs. 0.07 ± 0.04; P = 0.008).

Conclusion

In the short term, posterior scleral reinforcement surgery can delay the increase of AL of progressive high myopia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02375-1.

Investigation of Macular Choroidal Thickness and Blood Flow Change by Optical Coherence Tomography Angiography After Posterior Scleral Reinforcement

Purpose: This work aimed to study the effect of posterior scleral reinforcement (PSR) on choroidal thickness (CT) and blood flow.

Methods: This study included 25 eyes of 24 patients with high myopia ( ≤ -6.0 dioptres or axial length ≥ 26.0 mm) who underwent PSR surgery. All patients completed the 1-month follow-up visit. Myopic macular degeneration (MMD) was graded according to the International Meta-Analysis for Pathologic Myopia (META-PM) classification based on color fundus photographs. Swept-source optical coherence tomography angiography (SSOCTA) was performed to investigate CT, choroidal perfusion area (CPA), and choriocapillaris perfusion area (CCPA) change following PSR surgery.

Results: The distribution of MMD categories was 9 (36.0%) in category 1, 10 (40.0%) in category 2, and 6 (24.0%) in category 3 or 4. MMD severity was strongly correlated with CT (all P < 0.01) and CPA (all P < 0.04). Postoperative CT at each sector increased significantly at 1 week's follow-up, compared to preoperative measures (all P < 0.05). Postoperative CPA at subfoveal, superior, inferior, and nasal sectors also increased significantly 1 week after PSR surgery (all P < 0.05). Moreover, the increased CT, CPA, and CCPA remain after PSR surgery at 1 month's follow-up, but the difference was not statistically significant.

Conclusions: We demonstrated that the CT and choroidal blood flow increased significantly in patients with high myopia who underwent PSR surgery in a short period of time. In addition, the CT and CPA were independently associated with MMD. However, whether the transient improvement of the choroidal circulation could prevent long-term progression of high myopia warrants further study in the future.

Treatment effect of posterior scleral reinforcement on controlling myopia progression: A systematic review and meta-analysis

Background

High myopia is a sight-threatening disease that causes axial length elongation and severe complications. Data on the benefits of posterior scleral reinforcement surgery in myopia control have been conflicting. The purpose of this study was to explore the treatment effect and complications of posterior scleral reinforcement in the treatment of myopia.

Methods

Articles were retrieved for relevant studies from inception to July 24, 2019, by PubMed, EMBASE, and Ovid. Analyses were conducted to compare the treatment effects of controlling spherical equivalent refraction and axial length elongation. The weighted mean difference and Hedges’ adjusted g were used to evaluate the treatment effects, with a random-effects model. Heterogeneity was quantified using I² statistic and explored by subgroup analysis. Publication bias was addressed by funnel plots and Egger’s test.

Results

A total of 11 articles were included in this meta-analysis. On estimating the treatment effect, the mean differences of myopia progression and axial length changes between surgery and control groups were 0.41 diopters per year (95% CI 0.21 to 0.61; P < .001) and −0.17 mm per year (95% CI −0.22 to −0.11; P < .001). Subgroup analysis showed significant treatment effects of the single wide strip operation. Single-arm meta-analysis showed less annual axial elongation in children subgroup. These results were robust by sensitivity analysis. The incidence of some major complications in the operation group were significantly greater (5.8% vs 2.7% for myopic degeneration; 2.3% vs 1.6% for macular hemorrhage; 0.8% vs 0 for retinal detachment).

Conclusion

Posterior scleral reinforcement may be an effective surgery on controlling myopia progression by slowing both refraction and axial length change. However, frequent surgical complications should be considered. Further well-designed studies are needed to determine the long-term safety and efficacy.

The efficacy of modified posterior scleral reinforcement with round scleral patches in Chinese children with high myopia

PURPOSE

To observe the efficacy of modified Snyder-Thompson posterior scleral reinforcement with round scleral patches in Chinese children with high myopia.

METHODS

This retrospective study included 46 Chinese children with high myopia (72 eyes) who underwent modified Snyder-Thompson posterior scleral reinforcement (PSR) with round scleral patches and 43 Chinese children with high myopia (67 eyes) who wore only spectacles as a control group. Both groups attended a follow-up at 3 years. Axial length (AL), spherical equivalent (SE), best-corrected visual acuity (BCVA), and full ocular assessment results were evaluated at the initial and final visits. Complications were recorded.

RESULTS

AL had increased by 0.29 ± 0.33 mm in the PSR group and 0.82 ± 0.33 mm in the control group (P < 0.0001) at the final follow-up. The change in the SE was 0.31 ± 0.81 D in the PSR group and 2.25 ± 1.02 D in the control group (P < 0.0001). A decrease of 0.02 ± 0.11 LogMAR was found in the control group, and a change of 0.22 ± 0.35 LogMAR was found in the PSR group. No serious complications due to PSR surgery occurred.

CONCLUSIONS

Modified Snyder-Thompson PSR surgery with round scleral patches can effectively limit the progression of axial elongation in Chinese children with high myopia. The operation is safe, causes little damage, and can be customized.

Pathogenesis and Prevention of Worsening Axial Elongation in Pathological Myopia

PURPOSE

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

Posterior Scleral Reinforcement to Prevent Progression of High Myopia

BACKGROUND

Myopia has become a global public health problem. High myopia is linked to pathologic myopia (PM). As the severity of myopia increases, excessive axial elongation of the globe exerts a biomechanical stretch on the posterior pole, followed by a series of retinopathy which can lead to marked visual impairment. Posterior scleral reinforcement (PSR) is the only way that may have the potential to prevent the progression of axial elongation. Some scholars expressed satisfaction with the efficacy and safety of PSR. In contrast, other surgeons had negative conclusions on the outcomes for the surgery.

OBJECTIVES

The aims of this review are to provide an update on the current knowledge of posterior scleral reinforcement to prevent progression of high myopia and to discuss clinical trials examining the potential utility of PSR in treating this disease.

METHODS

We searched Ovid MEDLINE, Embase, PubMed and China National Knowledge Infrastructure (CNKI) (all years to 1 July 2019). We also conducted a gray literature search and handsearched reference lists of included studies and pertinent review articles.

RESULTS

26 clinical trials were included. 20 trials were designed as only one eye of each patient had posterior scleral reinforcement surgery. After 3 to 5 years of follow-up, the results are very satisfactory. 6 randomized controlled trials, which have conservatively treated groups, showed statistically significant differences between the eyeball axial length progression in the study group and the control group, where surgery was not performed. Most clinical trials reached a positive influence. But the efficacy of different clinical trials varies greatly.

CONCLUSIONS

PSR, is safe and effective to slowdown myopia progression, especially for high myopia.

IMI - Interventions Myopia Institute: Interventions for Controlling Myopia Onset and Progression Report

Myopia has been predicted to affect approximately 50% of the world's population based on trending myopia prevalence figures. Critical to minimizing the associated adverse visual consequences of complicating ocular pathologies are interventions to prevent or delay the onset of myopia, slow its progression, and to address the problem of mechanical instability of highly myopic eyes. Although treatment approaches are growing in number, evidence of treatment efficacy is variable. This article reviews research behind such interventions under four categories: optical, pharmacological, environmental (behavioral), and surgical. In summarizing the evidence of efficacy, results from randomized controlled trials have been given most weight, although such data are very limited for some treatments. The overall conclusion of this review is that there are multiple avenues for intervention worthy of exploration in all categories, although in the case of optical, pharmacological, and behavioral interventions for preventing or slowing progression of myopia, treatment efficacy at an individual level appears quite variable, with no one treatment being 100% effective in all patients. Further research is critical to understanding the factors underlying such variability and underlying mechanisms, to guide recommendations for combined treatments. There is also room for research into novel treatment options.

Scleral structure and biomechanics

As the eye's main load-bearing connective tissue, the sclera is centrally important to vision. In addition to cooperatively maintaining refractive status with the cornea, the sclera must also provide stable mechanical support to vulnerable internal ocular structures such as the retina and optic nerve head. Moreover, it must achieve this under complex, dynamic loading conditions imposed by eye movements and fluid pressures. Recent years have seen significant advances in our knowledge of scleral biomechanics, its modulation with ageing and disease, and their relationship to the hierarchical structure of the collagen-rich scleral extracellular matrix (ECM) and its resident cells. This review focuses on notable recent structural and biomechanical studies, setting their findings in the context of the wider scleral literature. It reviews recent progress in the development of scattering and bioimaging methods to resolve scleral ECM structure at multiple scales. In vivo and ex vivo experimental methods to characterise scleral biomechanics are explored, along with computational techniques that combine structural and biomechanical data to simulate ocular behaviour and extract tissue material properties. Studies into alterations of scleral structure and biomechanics in myopia and glaucoma are presented, and their results reconciled with associated findings on changes in the ageing eye. Finally, new developments in scleral surgery and emerging minimally invasive therapies are highlighted that could offer new hope in the fight against escalating scleral-related vision disorder worldwide.

Macular retinal thickness and flow density change by optical coherence tomography angiography after posterior scleral reinforcement

Optical coherence tomography angiography (Angio-OCT) has introduced a new non-invasive, quantitative method to assess superficial and deep capillary networks of the retina. In this study, we investigated macular retinal thickness and flow density change following posterior scleral reinforcement (PSR) surgery, using an RTVue XR Avanti Angio-OCT (A2016.2.0.35, Optovue, Fremont, CA), in patients with pathological myopia. A total of 13 patients with pathological myopia were recruited and all patients completed the 6 months follow-up visit. Data from 22 eyes were used in this study. The mean age was 36.23±15.29 years, and 43% (n=6) were men. Spherical equivalent refractive error (SE) ranged from -8.0 to -24.0 D. Post-operative axial length, best-corrected visual acuity and SE did not change significantly at each follow-up, compared with preoperative measure (all P>0.05). Postoperative flow density of superficial and deep retinal layers at each sector did not change significantly at each follow-up, compared to pre-operative measure (all P>0.05). However, we found significant decrease in retinal thickness of parafovea-inferior sector after PSR surgery (P<0.01), indicating potential relaxation of vitreofoveal traction after PSR surgery.

Modified Posterior Scleral Reinforcement as a Treatment for High Myopia in Children and Its Therapeutic Effect

PURPOSE

To investigate the safety and therapeutic effect of a modified posterior scleral reinforcement (PSR) in treating high myopia.

METHODS

A total of 85 highly myopic eyes in 47 children (6.3±3.6 years of age, range from 3 years to 15 years) who underwent this modified PSR were included in this study. Axial length, refractive error, best-corrected visual acuity (BCVA), macular scans, and adverse events were recorded before the operation (as a baseline) and in postoperative reviews taken yearly for 5 years.

RESULTS

This was a 5-year research: 50% of the children (20 children, 40 eyes) participated in the 6-month review, 41% of the children (17 children, 33 eyes) participated in the 1-year review, 26% of the children (11 children, 21 eyes) participated in the 2-year review, 16% of the children (7 children, 13 eyes) participated in the 3-year review, 13% of the children (5.3 children, 11 eyes) participated in the 4-year review, and 8% of the children (3.3 children, 7 eyes) participated in the 5-year review. Compared with the baseline, axial elongation was significantly changed (P<0.05) over the 5-year period in all of the children: 6-month (P=0.003), 1-year (P=0), 2-year (P=0), 3-year (P=0), 4-year (P=0), and 5-year (P=0). The axial length was extended. No significant difference was found in refractive error between measurements taken at baseline and at the 5-year postoperative visit in all of the children: 6-month (P=0.51), 1-year (P=0.50), 2-year (P=0.46), 3-year (P=0.56), 4-year (P=0.30), and 5-year (P=0.16). There were significant differences in BCVA between measurements taken at baseline and at the postoperative 5-year visit in all the children: 6-month (P=0), 1-year (P=0), 2-year (P=0), 3-year (P=0), 4-year (P=0), and 5-year (P=0). BCVA improved in 71 eyes (83.52%), remained stable in 14 eyes (16.47%), and declined in none of the children. No serious adverse events occurred before the operation and during the 5-year follow-up period.

CONCLUSION

This modified PSR could be a therapeutic treatment for high myopia.

Effects of posterior scleral reinforcement in pathological myopia: a 3-year follow-up study

PURPOSE

To assess the effects of posterior sclera reinforcement (PSR) in refractive outcomes, choroidal thickness (CT), and retinal thickness (RT) during a 3-year follow-up in eyes with pathological myopia.

METHODS

Thirty-eight eyes of 26 adults with pathological myopia who underwent PSR (the PSR group) and 30 eyes of 18 adults with matched age and myopia who did not receive PSR treatment (the control group) were followed up with measurements of axial length (AL), spherical equivalent (SE), best corrected visual acuity (BCVA), CT, and RT at baseline, 1 and 3 months, and 1, 2, and 3 years postoperatively. Data were analyzed by repeated measures analysis of variance and independent-samples t test.

RESULTS

In the PSR group, AL, SE, BCVA, and CT were tending to be relatively stable and no statistically significant changes were found during the follow-up (all P > 0.05). In contrast, in the control group, compared with the measurements taken at baseline, AL, SE, BCVA, and CT altered gradually from 1 month onward to 3 years postoperatively. At 2-year and 3-year follow-ups, significant differences in AL, SE, BCVA, and CT were noted between the PSR group and the control group (all P < 0.05). RTs of the center subfield and the inner ring were equal to the baseline in the control group; however, RTs of the center subfield at 1 year, 2 years, and 3 years postoperatively significantly slightly reduced compared with those at the baseline in the PSR group (all P < 0.05).

CONCLUSIONS

The effects of PSR in restraining eyeball elongation, stabilizing vision, and strengthening the structure of posterior pole are more prominent 2 years or more postoperatively compared with the natural progression of pathological myopia.

Scleral Cross-Linking Using Glyceraldehyde for the Prevention of Axial Elongation in the Rabbit: Blocked Axial Elongation and Altered Scleral Microstructure

BACKGROUND

This study aims to assess the efficacy of the scleral collagen cross-linking method using glyceraldehyde solution for prevention of lens-induced axial elongation in New Zealand rabbits and investigate the biochemical and microstructural changes that occur.

METHODS

The right eyes of New Zealand rabbits aged seven weeks were randomly divided into three groups: the cross-linking group (n = 6), non-crosslinking group (n = 5), and untreated control group (n = 5). Eyes in cross-linking and non-crosslinking groups were treated with a -8.00 Diopter spherical lens over the course of two weeks. The cross-linking effects were achieved by a sub-Tenon's injection of 0.15 ml 0.5 M glyceraldehyde to eyes in the CL group. Ocular parameters were measured on the 1st, 7^th, and 14th days. Biomechanical testing, light and electronic microscopy were used.

RESULTS

Following the cross-linking treatment, eyes in the cross-linking group had a shorter axial length compared to those in the non-crosslinking group (p = 0.006). Collagen fibrils larger than 240 nm were observed in the scleral stroma of cross-linking group, which were absent in the scleral stroma of the non-crosslinking and untreated control group. The mean ultimate stress and Young's modulus was significantly greater in the cross-linking group compared to those in the non-crosslinking and untreated control group (p < 0.05). No histological damage observed in the retina or choroid.

CONCLUSIONS

This study demonstrates that lens-induced axial elongation in rabbits can be effectively blocked by cross-linking using glyceraldehyde, with anatomical and mechanical modification and no deleterious effects.

Axial Length/Corneal Radius of Curvature Ratio Assessment of Posterior Sclera Reinforcement for Pathologic Myopia

PURPOSE

The aim of this study was to assess the axial length/corneal radius of curvature ratio changes after posterior scleral reinforcement (PSR) for pathologic myopia.

PROCEDURES

This study enrolled 32 pathologically myopic eyes treated with PSR and 35 untreated pathologically myopic eyes. Axial length, refractive error, best corrected visual acuity, corneal radius of curvature, and the axial length/corneal radius of curvature ratio were evaluated during the 1-year follow-up.

RESULTS

There were no statistical differences in each parameter between the 2 groups at baseline. Significant differences were found between the 2 groups in both axial elongation and best corrected visual acuity improvement. The average axial length/horizontal corneal radius of curvature ratio significantly decreased in the PSR group.

CONCLUSION

The PSR surgery can effectively delay the axial elongation in pathological myopia. Axial length/horizontal corneal radius of curvature ratio significantly decreased, which may indicate less myopic progression after surgery.

Effectiveness of combined macular buckle under direct vision and vitrectomy with ILM peeling in refractory macular hole retinal detachment with extreme high axial myopia: a 24-month comparative study

Purpose

To evaluate the efficacy of a combined macular buckle under direct vision and 23-gauge pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling in refractory macular hole retinal detachment (MHRD) with extreme high axial myopia.

Design

Prospective, randomised controlled study.

Participants

The study included 98 eyes of 98 patients of MHRD with extreme high axial (>30 mm) myopia.

Intervention

Patients were randomly assigned to undergo PPV with ILM peeling (group 1, n=52) or PPV with ILM peeling combined with macular buckle under direct vision (group 2, n=46).

Main outcome measures

Complete ocular examination included best-corrected visual acuity (BCVA) (LogMAR), applanation tonometry, optical biometry, slit-lamp biomicroscopy, colour fundus photography, ultrasound examination and optical coherence tomography at baseline and every follow-up visit.

Results

Initial retinal reattachment rate was significantly higher in group 2 than in group 1 at 12-month postoperatively (χ² test, p=0.020). Macular hole closure rate in group 2 was significantly higher than that in group 1 at 3, 12, 18 and 24 months postoperatively (Fisher's exact test, p<0.05). In initial retinal reattachment cases, the mean BCVA decreased significantly in group 2 than in group 1 at 3 months postoperatively (Wilcoxon matched pairs signed rank test, p=0.036), and had increased significantly in group 2 than in group 1 since 6 months postoperatively (Wilcoxon matched pairs signed rank test, p<0.05). Mean axial lengths in group 2 were significantly shorter than that of group 1 at each follow-up time point (Wilcoxon matched pairs signed rank test, p<0.05).

Conclusions

Combined macular buckle under direct vision and PPV with ILM peeling is more effective in treatment of MHRD with extreme high axial (>30 mm) myopia.

Posterior scleral reinforcement for the treatment of pathological myopia

AIM

To investigate the effects of posterior scleral reinforcement (PSR) in the treatment of pathological myopia.

METHODS

The study included 52 eyes in 43 patients with pathological myopia who underwent PSR (PSR group), and 52 eyes in 36 age- and myopia-matched patients who did not undergo such treatment as control group. Axial length, refraction error, best corrected visual acuity (BCVA), and macular scans by optical coherence tomography (OCT) were recorded at baseline, 6mo, 1, 3 and 5y after the surgery, and the complications were noted.

RESULTS

There were no statistical differences in axial length, refractive error, or BCVA between the PSR group and the control group at baseline. At the end of the follow-up, the mean axial length was 29.79±1.26 mm in the PSR group, which was significantly shorter than that in the control group (30.78±1.30 mm) (P<0.01), and the mean refractive error was -16.86±2.53 D in the PSR group, which was significantly lower than that in the control group (-19.18±2.12 D) (P<0.01). A statistically significant difference in BCVA was found between the PSR group (0.51±0.25 logMAR) and the control group (0.62±0.26 logMAR) at the postoperative 5-year follow-up (P<0.01). There were no serious complications during the 5-year follow-up period.

CONCLUSION

PSR can prevent axial elongation and myopia progression in eyes with pathological myopia.

The efficacy and safety of a novel posterior scleral reinforcement device in rabbits

PURPOSE

To evaluate the efficacy and safety of posterior scleral reinforcement (PSR) device for myopia suppression in rabbits' eyes.

METHODS

PSR surgery was performed on the normal 12 8-week-old New Zealand white rabbits' right eyes. To determine efficacy of the device, ophthalmic examination would be taken at pre-operation and post-operation (1 week, 1 month, 3 months, 6 months, and 1 year), such as A-ultrasound, diopter and B-ultrasound. Evaluation of safety were based on the following indicators: intraocular pressure (IOP), slit lamp, fundus photography, fundus fluorescein angiography and pathological examination after surgery. The efficacy and safety of PSR device were evaluated by comparison (treated eyes and contralateral eyes) of pre and post-operation.

RESULTS

The novel PSR device could significantly shorten axial length (preoperative axial length: 16.36 ± 0.14 mm, postoperative 1 week, 1 month, 3 months, 6 months and 1 year axial lengths: 15.03 ± 0.28 mm, 15.23 ± 0.32 mm, 15.39 ± 0.31 mm, 15.45 ± 0.22 mm and 15.45 ± 0.22 mm; P=0.00037<0.001) in the treated eyes (right eyes) after surgery. At different postoperative time points, the B-ultrasound images showed that the PSR located in appropriate position and supported the posterior sclera very well. At the same time, IOP of treated eyes kept a relatively stable level (preoperative IOP: 12.56 ± 2.01 mmHg, postoperative IOP: ranging from 11.33 ± 1.23 mmHg to 13.44 ± 2.19 mmHg, P>0.05) post-operation 1 year. During observation period, there was no significant inflammatory reaction and complications such as anterior chamber flare, empyema, endophthalmitis, vitreous hemorrhage, retina detachment and retinal choroid neovascularization by slit lamp, fundus photography and fundus fluorescein angiography. In addition, there were no pathologic changes be found by comparison treated eyes group and contralateral group eyes based on pathological examinations.

CONCLUSIONS

In vivo study, effectively and safely, the novel PSR device can inhibit rabbits' axial length elongation during postoperative 1 year. This study demonstrates that this novel PSR could be a potential treatment approach for myopia.