Posterior Eye Shape in Myopia.

Purpose: To explore prevalence and associated factors of abnormalities of the posterior eye shape in dependence of axial length. Design: Population-based study. Participants: Of the participants (n = 3468) of the Beijing Eye Study, we included all eyes with an axial length of ≥25 mm, and a randomized sample of eyes with an axial length of <25 mm. Methods: Using 30°-wide, serial horizontal, and fovea-centered radial, OCT images, we examined location and depth of the most posterior point of the retinal pigment epithelium/Bruch's membrane line (PP-RPE/BML). Main Outcome Measures: Prevalence and depth of an extrafoveal PP-RPE/BML. Results: The study included 366 eyes (314 individuals). On the radial OCT scans, the PP-RPE/BML was located in the foveola in 190 (51.9%) eyes, in 121 (33.1%) eyes in the 6 o'clock part of the vertical meridian (distance to foveola: 1.73 ± 0.70 mm), and in 54 (14.8%) eyes in the 12 o'clock part of the vertical meridian (fovea distance: 2.01 ± 0.66 mm). On the horizontal OCT scans, the PP-RPE/BML was located in the foveola in 304 (83.1%) eyes, between foveola and optic disc in 36 (9.8%) eyes (fovea distance: 1.59 ± 0.76 mm), and temporal to the foveola in 26 (7.1%) eyes (fovea distance: 1.20 ± 0.60 mm). Higher prevalence of an extrafoveal PP-RPE/BML correlated with longer axial length (odds ratio [OR]: 1.55; 95% confidence interval [CI]: 1.28, 1.89), higher corneal astigmatism (OR: 1.78; 95% CI: 1.14, 2.79), and female sex (OR: 2.74; 95% CI: 1.30, 5.77). The curvature of the RPE/BML at the posterior pole was similar to the RPE/BML curvature outside of the posterior pole in 309 (84.4%) eyes, and it was steeper (i.e., smaller curvature radius) in 57 (15.6%) eyes. In these eyes, axial length was longer (24.41 ± 1.78 mm versus 27.74 ± 1.88 mm; P < 0.001). Conclusions: With longer axial length, the foveola is more often located outside of the geometrical posterior pole. It may be of importance for biometric axial length measurements. An extrafoveal location of the PP-RPE/BML may be due to an axial elongation-associated, meridionally asymmetric enlargement of Bruch's membrane in the fundus midperiphery. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Descemet's membrane transplantation for the treatment of recurrent high myopic macular hole associated with retinal detachment : Descemet's membrane for myopic macular hole.

PURPOSE: To report the efficacy of Descemet's Membrane (DM) transplantation over the macular hole in patients with recurrent high myopic macular hole (HMMH) associated with retinal detachment (RD). METHODS: Six eyes of six patients with wide posterior staphyloma including MH and recurrent HMMH associated with RD were included to this retrospective study. All patients underwent pars plana vitrectomy and DM obtained from eye bank was placed over the macular hole during the surgery. Silicone oil endotamponade was used as endotamponade and removed within 6 months following surgery. Pre-operative and post-operative ophthalmologic examination and optical coherence tomography findings were recorded. RESULTS: The mean follow-up time was 18.53 ± 7.36 months. Macular hole closure was achieved in all patients (100%). Best-corrected visual acuity was improved from 1.51 ± 0.55 logMAR to 1.08 ± 0.50 logMAR (p = 0.043). No complications due to surgery or DM during follow-up. No DM dislocation or hole re-opening occurred after surgery. CONCLUSION: DM transplantation during vitrectomy may be an effective treatment for the recurrent HMMH associated with RD. KEY MESSAGES: What is known Various surgical techniques have been tried for recurrent high myopic macular hole associated with retinal detachment, but satisfactory anatomical and functional success rates have still not been achieved. WHAT IS NEW: The study demonstrates that Descemet's membrane transplantation is a safe and effective option for treating recurrent high myopic macular hole associated with retinal detachment. This is a novel technique that may overcome the limitations of existing approaches. The findings suggest that Descemet's membrane transplantation could become a promising addition to the surgical options for recurrent high myopic macular hole associated with retinal detachment.

Proteomic analysis reveals key differences in pro-stromal corneal tissue between highly myopic males and females.

Background and purpose: Nowadays, myopia has become a highly prevalent disease globally, especially in East Asia. Epidemiological studies have found that there may be sex differences in the occurrence and progression of myopia, with females having a higher incidence of myopia and higher risk of myopia progression. The purpose of this study was to explore the sex differences in myopic cornea using corneal stroma removed by small incision lenticule extraction (SMILE) surgery. Methods: The corneal stroma of females with high myopia (FH) and males with high myopia (MH) were subjected to proteomic assays. Proteomic-related data were statistically analyzed using software such as MaxQuan, KAAS, Proteome Discovery, etc. The total number of proteins in the cornea and the proteins specifically expressed in the two groups were counted, and the differentially expressed proteins in the two groups were identified by expression fold change >2 and p-value <0.05, and volcano plots were constructed, and functional enrichment analysis, subcellular organelle analysis, and molecular interaction were implemented. Results: Ten samples from each group were analyzed. Twenty-seven proteins were down-regulated and 27 proteins were up-regulated in the FH group, of which 23 proteins were up-regulated in the range of 2-10-fold and 4 proteins were up-regulated in the range of >10-fold. Comparative proteomic analysis of the cornea of male and female patients with high myopia revealed that the expression of corneal extracellular matrix and collagen I, III, V, and VIII-associated proteins were increased in the cornea of female patients, and the transforming growth factor-ß (TGF-ß)/Smad pathway was an important pathway obtained by functional analysis. Conclusion: Comparative proteomic analysis of cornea from male and female patients with high myopia revealed increased expression of proteins related to extracellular matrix and collagen I, III, V, and VIII in female patients, and the TGF-ß/Smad pathway was an important pathway obtained from the functional analysis, suggesting that extracellular matrix remodeling and collagen fiber synthesis may be more active in the cornea of female patients.

Comparison of the IOL Master and Pentacam in the measurement of anterior segment parameters in patients with high myopia and cataracts.

PURPOSE: This study aimed to compare the differences between the Zeiss IOL Master and Oculus Pentacam in keratometry and central anterior chamber depth (ACD) measurements in patients with high myopia and cataracts. METHODS: Between January 2019 and December 2020, 89 patients (103 eyes) with cataracts and high myopia who underwent preoperative cataract evaluation at Nanchang First Hospital were selected for retrospective analysis. Keratometry (K1, K2) and ACD were measured with the IOL Master and Pentacam. Paired t-tests were performed to compare the differences, while the Bland-Altman method was used to evaluate the agreement. RESULTS: The K1 value was (43.15±2.44) D for the IOL Master and (42.98±2.47) D for the Pentacam, and the difference between the two instruments was statistically significant (P<0.01). The K2 value was (44.55±2.63) D for the IOL Master and (44.32±2.55) D for the Pentacam. The ACD was (3.44±0.33)mm for the IOL Master and (3.39±0.36)mm for the Pentacam. There were statistically significant differences between the two instruments in both keratometry and ACD (P<0.01). The absolute values of the maximum difference between the two instruments for K1 and K2 were 1.1 and 1.07; thus, the consistency of the two instruments with respect to this measurement was poor. However, the absolute value of the maximum difference between the two instruments for ACD was 0.34, so the consistency of the two instruments in relation to this measurement was good. CONCLUSIONS: Both the IOL Master and the Pentacam can be used in the measurement of keratometry and ACD in patients with high myopia and cataracts, but the keratometry measurements should be compared in clinical application.

Systemic Oxidative Stress Level as a Pathological and Prognostic Factor in Myopic Choroidal Neovascularization.

Purpose: To investigate the association of systemic oxidative stress level with myopic choroidal neovascularization (mCNV) and its clinical outcomes. Design: Retrospective case-control study. Participants: This retrospective study included 52 eyes of 52 healthy participants (mean age: 62.5 years), 30 eyes of 30 patients (mean age: 59.6 years) with high myopia (HM) but without mCNV, and 23 eyes of 23 patients (mean age: 61.8 years) with HM and mCNV who received intravitreal anti-VEGF antibody injections (IVIs) using a pro re nata regimen during the 6-month follow-up after the first IVI. Methods: Clinical findings, including oxidative stress parameters, such as diacron reactive oxygen metabolites (dROMs), biological antioxidant potential (BAP), and the BAP/dROM ratio (B/d ratio), were analyzed. Main Outcome Measures: Clinical features and oxidative stress parameters. Results: Both BAP and the B/d ratio were significantly lower in the HM/mCNV group than in the HM/no mCNV group (P = 0.002 and P = 0.012, respectively) and than in the control group (P = 0.001 and P = 0.026, respectively). In a multiple logistic regression analysis, axial length (odds ratio 1.878, P = 0.042) and the B/d ratio (odds ratio 0.470, P = 0.026) were significantly associated with mCNV. Dividing the patients into high and low B/d ratio groups (with a cutoff of 5.2) showed that subfoveal choroidal thickness (SFCT) was lower (P = 0.002) and the number of IVI treatments was higher (P = 0.029) in the low B/d ratio group than in the high B/d ratio group. In multiple regression analyses, only the B/d ratio was significantly associated with SFCT (ß = 0.684, P = 0.006). Conclusions: The oxidative stress level in eyes with HM differed according to mCNV, SFCT, and the number of IVI treatments. Measuring oxidative stress parameters might be useful in eyes with HM both for assessing the risk of developing mCNV and determining disease activity. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Choroidal vascular changes in early-stage myopic maculopathy from deep learning choroidal analysis: a hospital-based SS-OCT study.

BACKGROUND: The objective of this study is to illustrate the changes in the choroidal vasculature in individuals with diffuse chorioretinal atrophy (DCA, early-stage myopic maculopathy) and investigate the association between them. METHODS: This study included 1418 highly myopic eyes from 720 participants aged 18 - 60 years from the Wenzhou High Myopia Cohort Study. These participants underwent comprehensive ophthalmic assessments. Myopic maculopathy classification followed the Meta-PM system, with pathological myopia defined as myopic maculopathy of DCA or severer. Eyes with myopic maculopathy categorized as no macular lesions (C0), tessellated fundus (C1), and DCA (C2) were enrolled in the analysis. Choroidal images were obtained from swept-source optical coherence tomography (SS-OCT), and the images were processed with a deep learning-based automatic segmentation algorithm and the Niblack auto-local threshold algorithm. RESULTS: DCA was detected in 247 eyes (17.4%). In comparison to eyes with C0, those with C2 exhibited significant reductions in choroidal thickness (ChT), luminal area (LA), and stromal area (SA) across all evaluated regions (all P < 0.001). An increase in choroidal vascular index (CVI) was observed in all regions, except for the nasal perifoveal (N2) and inferior perifoveal (I2) regions (all P < 0.01). Multivariable logistic regression analysis revealed a negative association between the presence of DCA and increases in choroidal LA and SA (odds ratio ≤ 0.099, P < 0.001). Multivariable linear regression analysis showed that the mean deviation of the visual field test was positively associated with LA and SA at the vertical meridian (B = 1.512, P < 0.001 for LA; B = 1.956, P < 0.001 for SA). Furthermore, the receiver operating characteristic curve analyses showed the optimal ChT to diagnose pathological myopia was 82.4 µm in the N2 region, the LA was 0.076 mm2 and the SA was 0.049 mm2, with area under the curves of 0.916, 0.908, and 0.895, respectively. CONCLUSIONS: The results of this study indicated that both the presence of DCA and visual function impairment were associated with reductions in choroidal perfusion and stromal components. Moreover, we established threshold values for choroidal parameters in diagnosing pathological myopia, offering valuable references for clinical diagnosis and management.

Tilt and decentration of the crystalline lens in ultra-high myopia with cataract and its influencing factors: A study based on CASIA2'.

OBJECTIVE: This study aims to examine the characteristics and influencing factors of crystalline lens tilt and decentration in ultra-high myopic cataract patients, as measured by the CASIA2. METHODS AND ANALYSIS: 60 eyes scheduled for cataract surgery with an axial length (AL) ≥ 28 mm were included. The IOLMaster700 was utilized to measure AL and the white-to-white (WTW) distance. The CASIA2 was employed to measure front curvature radius (FCR), crystalline lens tilt, and crystalline lens decentration. The relationships between lens tilt, decentration, and related factors were evaluated. RESULTS: The degree of lens tilt was 4.62 ± 2.44°, and the decentration was 0.20 (Q1 0.13, Q3 0.28) mm. Among the 60 eyes, 11 (18.3%) had a tilt ≥7°, and 6 (10%) had a decentratiolens tilt ≥7° (P = 0.038, P = 0.018). Eyes with AL >30.00 mm and FCR <8.45 mm had a higher degree of lens tilt. Additionally, a tilt ≥7° was associated with a greater decentration (P = 0.032), n. CONCLUSION: Preoperative crystalline lenses in eyes with ultra-high myopia and cataract exhibit certain degrees of tilt and decentration. An AL >30 mm is a risk factor for a lens tilt ≥7° and an decentration ≥0.4 mm. An FCR <8.45 mm is a risk factor for increased lens tilt, and a tilt ≥7° is a risk factor for increased lens decentrati ≥ 0.4 mm. An increase in AL and FCR <8.45 mm were risk factors for a and eyes with AL >30.00 mm had a higher degree of decentration (P = 0.005).

Structural, blood flow and functional changes in the macular area and the expression of aqueous humor factors in myopia.

Objective: To compare the macular area parameters and aqueous humor factors between myopia and emmetropia. Methods: Convenience sampling was used to select patients who visited the Changzhi Aier Eye Hospital's department of ophthalmology from December 2018 to December 2022 as the study participants. They were divided into three groups according to whether they were diagnosed as mild myopia myopic, highly myopic or not as follows: the mild myopia group (60 cases, 108 eyes), the high myopia group (46 cases, 78 eyes) and the healthy emmetropia group (40 cases, 65 eyes). The differences in the macular integrity (MI) assessment, optical coherence tomography and optical coherence tomography angiography parameters and aqueous humor factors were compared between the three groups. Results: AL in high myopia group was the highest, and that in emmetropia group was the lowest. The BCVA of mild myopia group was the highest. The RS in the high myopia group were significantly lowest in the three groups (26.42 ± 1.04 vs. 28.34 ± 0.76 vs. 31.92 ± 0.77) (F = 5.374, p = 0.013). The 63% BCEA, 95% BCEA and MI in the high myopia group were significantly highest (p < 0.05). The mean RPE thickness, mean CT and mean RT in the high myopia group were lowest (p < 0.05). The blood flow density were lowest in the superficial fovea, paracentral fovea and different subdivisions of the paracentral fovea in the high myopia group (p < 0.05). The VEGF concentration in the aqueous humor of the high myopia group was lowest (25.62 ± 17.43 vs. 32.45 ± 24.67 vs. 64.37 ± 21.14) (F = 9.237, p < 0.001). The MMP-2 concentration was highest (483 ± 201.48 vs. 410 ± 142.37 vs. 386 ± 154.34) (F = 5.542, p = 0.018). The VEGF concentration in the aqueous humor factor was negatively correlated with the AL in the myopia group (r = -0.438, p = 0.002), the MMP-2 concentration was positively correlated with the AL (r = 0.484, p = 0.010). Conclusion: Patients with high myopia showed decreased retinal light sensitivity, fixation stability, superficial blood flow density and retinal thickness compared with people with emmetropia. A decreased VEGF concentration and increased MMP-2 concentration in the aqueous humor factor have potential associations with the development of high myopia.

Effect of magnification error and axial length on circumpapillary capillary density and retinal nerve fiber layer thickness.

This study aimed to evaluate the effect of magnification error and axial length (AL) on circumpapillary capillary density (cpCD) and circumpapillary retinal nerve fiber layer thickness (cpRNFLT) in healthy eyes. Seventy-two healthy eyes of 72 subjects with AL 24.7 ± 1.5 mm (range: 20.9-28.0 mm) were enrolled in this retrospective cross-sectional study and underwent optical coherence tomography angiography scanning. Magnification corrected measurement areas were obtained using AL upon which corrected cpCD, cpRNFLT values were determined. Relationships between AL and the percentage difference between corrected and uncorrected values (ΔcpCD, ΔcpRNFLT) as well as the effect of AL on magnification corrected cpCD, cpRNFLT were evaluated. ΔcpCD significantly increased with AL in the global, inferior nasal and superior nasal sectors (all p < 0.001). ΔcpRNFLT significantly increased with AL in global and all sectors (all p < 0.001) and the correlations were significantly stronger than that of ΔcpCD-AL in all sectors (all p < 0.001). Corrected cpCD did not associate with AL while corrected cpRNFLT demonstrated a significant positive association with AL in the global (p = 0.005) and temporal sector (p < 0.001). Magnification error led to a significant underestimation of cpCD in eyes with longer AL although its underestimation and the effect of AL was smaller in comparison to that of cpRNFLT.

Intraocular amphiregulin and axial elongation in non-human adolescent primates.

The purpose of the experimental interventional study was to examine the influence of intraocularly applied amphiregulin, a member of the epidermal growth factor (EGF) family, on axial length in young non-human primates. It included three non-human primates (Macaca mulatta), aged 4-6 years. The left eyes received three intravitreal injections of amphiregulin (400ng/50 µl) in intervals of 4 weeks, while the right eyes received three intravitreal injections of phosphate buffered solution (50 µl) at the same time points. Ocular biometry was performed in weekly intervals. At baseline, the left eyes (study eyes) were shorter than the right (control) eyes (20.69 ± 0.21 mm versus 20.79 ± 0.24 mm; P < 0.001), with an inter-eye axial length (AL) difference (left minus right eye) of -0.10 ± 0.23 mm. Inter-eye AL difference increased (P < 0.001) to 0.15 ± 0.18 mm at study end, at 12 weeks after baseline. Axial elongation during the study was higher (P < 0.001) in the left eyes (20.69 ± 0.21 mm to 21.05 ± 0.29 mm or 0.36 ± 0.30 mm) than in the right eyes (20.79 ± 0.24 mm to 20.90 ± 0.31 mm or 0.11 ± 0.17 mm). In a parallel manner, inter-eye difference in vitreous cavity depth combined with lens thickness (left eye minus right eye) increased from -0.04 ± 0.17 mm at baseline to -0.02 ± 0.21 mm (P = 0.02), 0.04 ± 0.10 mm (P = 0.002), and to 0.42 ± 0.67 mm (P < 0.001) at 5, 6, and 12 weeks after baseline, respectively. The results suggest that intravitreally applied amphiregulin as EGF family member led to an increase in axial length in adolescent non-human primates. It supports the hypothesis of amphiregulin as EGF family member being involved in the process of axial elongation.

Analyzing the topological properties of resting-state brain function network connectivity based on graph theoretical methods in patients with high myopia.

AIM: Recent imaging studies have found significant abnormalities in the brain's functional or structural connectivity among patients with high myopia (HM), indicating a heightened risk of cognitive impairment and other behavioral changes. However, there is a lack of research on the topological characteristics and connectivity changes of the functional networks in HM patients. In this study, we employed graph theoretical analysis to investigate the topological structure and regional connectivity of the brain function network in HM patients. METHODS: We conducted rs-fMRI scans on 82 individuals with HM and 59 healthy controls (HC), ensuring that the two groups were matched for age and education level. Through graph theoretical analysis, we studied the topological structure of whole-brain functional networks among participants, exploring the topological properties and differences between the two groups. RESULTS: In the range of 0.05 to 0.50 of sparsity, both groups demonstrated a small-world architecture of the brain network. Compared to the control group, HM patients showed significantly lower values of normalized clustering coefficient (γ) (P = 0.0101) and small-worldness (σ) (P = 0.0168). Additionally, the HM group showed lower nodal centrality in the right Amygdala (P < 0.001, Bonferroni-corrected). Notably, there is an increase in functional connectivity (FC) between the saliency network (SN) and Sensorimotor Network (SMN) in the HM group, while the strength of FC between the basal ganglia is relatively weaker (P < 0.01). CONCLUSION: HM Patients exhibit reduced small-world characteristics in their brain networks, with significant drops in γ and σ values indicating weakened global interregional information transfer ability. Not only that, the topological properties of the amygdala nodes in HM patients significantly decline, indicating dysfunction within the brain network. In addition, there are abnormalities in the FC between the SN, SMN, and basal ganglia networks in HM patients, which is related to attention regulation, motor impairment, emotions, and cognitive performance. These findings may provide a new mechanism for central pathology in HM patients.

Complications of high myopia: An update from clinical manifestations to underlying mechanisms.

Background: High myopia is one of the major causes of visual impairment and has an ever-increasing prevalence, especially in East Asia. It is characterized by excessive axial elongation, leading to various blinding complications that extend beyond mere refractive errors and persist immovably after refractive surgery, presenting substantial public health challenge. Main text: High myopia-related complications include lens pathologies, atrophic and tractional maculopathy, choroidal neovascularization, peripheral retinal degenerations and retinal detachment, and glaucoma and heightened susceptibility to intraocular pressure (IOP) elevation. Pathological lens changes characteristic of high myopia include early cataractogenesis, overgrowth of lens, weakened zonules, and postoperative capsular contraction syndrome, possibly driven by inflammatory pathogenesis, etc. Dome-shaped macula and cilioretinal arteries are two newly identified protective factors for central vision of highly myopic patients. These patients also face risks of open-angle glaucoma and IOP spike following intraocular surgery. Morphologic alternations of optic nerve in high myopia can complicate early glaucoma detection, necessitating comprehensive examinations and close follow-up. Anatomically, thinner trabecular meshwork increases this risk; conversely lamina cribrosa defects may offer a fluid outlet, potentially mitigating the pressure. Notably, anxiety has emerged as the first recognized extra-ocular complication in high myopia, with an underlying inflammatory pathogenesis that connects visual stimulus, blood and brain. Conclusions: High myopia induces multiple ocular and potential mental health complications, underscoring the need to develop more effective strategies to improve both physical and emotional well-being of these patients, among which anti-inflammation might possibly represent a promising new target.

A New Model of a Macular Buckle and a Refined Surgical Technique for the Treatment of Myopic Traction Maculopathy.

Myopic traction maculopathy (MTM) affects 20% of eyes with pathologic myopia (PM). The MTM Staging System (MSS), published in 2020, describes the nomenclature of MTM as well as a proposal of pathogenesis, natural evolution, and prognosis. A study of customized treatment for each stage of MTM has been published previously and suggested to treat maculoschisis and detachment by placing a macular buckle (MB) behind the macula to push the sclera towards the retina, selecting pars plana vitrectomy (PPV) only in cases where a macular hole is associated with MTM. We hereby describe a new model of a macular buckle, known as NPB, and an NPB loading device, with the aim to standardize the surgical technique and render it more user friendly, efficient, and safe. Macular buckle is an effective and safe procedure to treat maculoschisis and macular detachment in MTM. We recommend using it as a unique and first-line treatment.

Early changes in corneal densitometry after FS-LASIK combined with accelerated corneal cross-linking for correction of high myopia.

AIM: To observe the effects of femtosecond laser-assisted excimer laser in situ keratomileusis combined with accelerated corneal cross-linking (FS-LASIK Xtra) on corneal densitometry after correcting for high myopia. METHODS: In this prospectively study, 130 patients underwent FS-LASIK or FS-LASIK Xtra for high myopia. Their right eyes were selected for inclusion in the study, of which 65 cases of 65 eyes in the FS-LASIK group, 65 patients with 65 eyes in the FS-LASIK Xtra group. Patients were evaluated for corneal densitometry at 1, 3, and 6mo postoperatively using Pentacam Scheimpflug imaging. RESULTS: Preoperative differences in corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups in different ranges were not statistically significant (P>0.05). Layer-by-layer analysis revealed statistically significant differences in the anterior (120 µm), central, and total layer corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups at 1 and 3mo postoperatively (all P<0.05), the FS-LASIK Xtra group is higher than that of the FS-LASIK group. Analysis of different diameter ranges showed statistically significant differences between the FS-LASIK group and the FS-LASIK Xtra group at 1mo postoperatively in the ranges of 0-2, 2-6, and 6-10 mm (both P<0.05); At 3mo postoperatively, the FS-LASIK Xtra group is higher than that of the FS-LASIK group in the ranges of 0-2 and 2-6 mm (P<0.05). At 6mo postoperatively, there were no statistically significant differences in corneal densitometry between the FS-LASIK group and the FS-LASIK Xtra group in different diameter ranges (all P>0.05). CONCLUSION: There is an increase in internal corneal densitometry during the early postoperative period after FS-LASIK Xtra for correction of high myopia. However, the densitometry values decreased to the level of conventional FS-LASIK at 6mo after surgery, with the most significant changes observed in the superficial central zone.

High myopia: Reviews of myopia control strategies and myopia complications.

BACKGROUND: Myopia and especially high myopia are recognised as major public health concerns. Although the prevalence of high myopia in young children is low, 10-20% of high school children in Asia have high myopia, with many still progressing, and one in three patients with high myopia develop visual impairment with age. Most participants in myopia control studies have low and moderate myopia; relatively little is known about myopia control in high myopia. METHOD: Literature searches were undertaken in MEDLINE and EMBASE to identify publications in English, investigating (Aim 1) the efficacy of myopia control strategies (environmental, pharmacological and optical) in high myopia (≤-6.00 D) and (Aim 2) the complications of high myopia using keywords. Outcomes included change in spherical equivalent refractive error (SE) and/or axial length (AL) to evaluate progression in high myopia. RESULTS: Aim 1: Twelve studies were identified that reported the efficacy of optical and pharmacological (none on environmental) interventions on AL and SE for high myopia control. A statistically significant reduction in progression of SE and AL in high myopes was reported with 1% and 0.5% atropine. Defocus Incorporated Multiple Segment spectacle lenses had lower efficacy in slowing high myopia progression compared to moderate and low myopia. Ortho-K lenses were equally effective in reducing myopia progression in low, moderate and high myopia. Aim 2: Myopic patients have an increased risk of myopic macular degeneration, retinal detachment, cataract and glaucoma, with the risk increasing with the level of myopia. CONCLUSIONS: High myopia has significant effects on quality of life, risk of pathological complications and vision impairment. Young children, excluding those with some syndromic associations, who are fast progressing moderate and high myopes require early intervention and close monitoring. Further research investigating the efficacy of myopia control strategies in highly myopic patients, both independently and through combination treatments, are necessary.

Choroidal vascularity features of fundus tessellation in adults with high myopia.

BACKGROUND: To investigate alterations in choroidal vascularity index among highly myopic adults with fundus tessellation, utilizing optical coherence tomography. METHODS: Total of 143 highly myopic adults (234 eyes) with fundus tessellation were collected in this cross-sectional study, which was stratified into different lesion groups based on the novel tessellated fundus classification. Subfoveal choroidal thickness (SFCT), choroidal luminal area (LA), stromal area (SA), total choroidal area (TCA), and choroidal vascularity index (CVI) were analyzed utilizing optical coherence tomography (OCT) with enhanced depth imaging (EDI) mode, enabling precise quantification of these parameters. RESULTS: Comparison analysis demonstrated notable distinctions in spherical equivalent (SE), axial length (AL), and SFCT across the four tessellation grades (p < 0.001). Analysis of the choroidal vascularity parameters, including LA, TCA, and CVI, demonstrated notable disparities across the four groups (p < 0.001), while no significant variations were observed in SA when comparing Grade 1 versus Grade 2, as well as Grade 2 versus Grade 3 (p > 0.05). Logistic regression analyses illustrated that the higher grade of tessellated exhibited a positive association with AL (OR = 1.701, p = 0.027), while negatively associated with SFCT (OR = 0.416, p = 0.007), LA (OR = 0.438, p = 0.010) and CVI (OR = 0.529, p = 0.004). Multiple regression analyses demonstrated a significant negative association between CVI and both SE and AL after adjusting for age, while positively associated with SFCT (p < 0.05). CONCLUSION: Subtle choroidal vascularity changes may have a meaningful contribution to the development and progression of fundus tessellation. CVI and LA dramatically decreased during the early stages of tessellation development and maintained a relatively stable status when in the severe tessellated grades.

Nasal loop myopexy for management of exotropia-hypotropia complex associated with high myopia.

INTRODUCTION: Exotropia-hypotropia complex is an uncommon phenomenon associated with high myopia. However, some literature reports cases of the exotropia-hypotropia complex where residual hypotropia is managed through a secondary surgery following the conventional recession-resection of the lateral rectus (LR) and medial rectus (MR). Nasal Loop myopexy as a primary surgical procedure for the management of exotropia-hypotropia complex has been rarely reported in the literature. METHODS: A 24-year-old male with unilateral high myopia presented with a large angle exotropia-hypotropia complex with limitation of elevation in abduction in his left eye. His ocular deviation was successfully managed through a nasal loop myopexy of the superior rectus (SR) and MR using a non-absorbable suture, combined with large LR recession and MR resection. RESULTS: Postoperatively, the patient had satisfactory ocular alignment with improved hypotropia and normal elevation in abduction, contributing to enhanced binocular vision and better cosmesis. DISCUSSION: Managing the exotropia-hypotropia complex in the context of high myopia demands a comprehensive approach that addresses both vertical and horizontal deviations. The surgical strategy employed in this case, which included loop myopexy of SR and MR along with LR recession and MR resection, achieved positive outcomes regarding alignment, elevation, and binocular vision. The case supports variations in muscle path and the potential benefits of tailored surgical strategies for complex strabismus cases associated with high myopia.

Clinical outcomes of posterior scleral reinforcement in Chinese high myopia children.

We aim to observe the posterior scleral reinforcement (PSR) clinical outcomes of children with high myopia and analyze the retinal vessel alteration before and after PSR by using angiography optical coherence tomography (angio-OCT). Fifty-six pediatric participants (112 eyes) clinically diagnosed high myopia were recruited and were treated by PSR in Shanghai Children's Hospital from June 1, 2021 to May 1, 2023. The average age ranged from 5.42 to 14.83 years (mean 8.83 years) and mean follow up duration was 8.7 months (3-24 months). The axial length (AL) was significantly shortened after PSR (p < 0.05). The spherical equivalent (SE) and the best-corrected visual acuity (BCVA) were also improved without severe rejection in the follow-up. Compared with baseline, angio-OCT parafoveal vessel indices including vascular area density (VAD) and vascular skeleton density (VSD) on the superficial capillary plexus layer (SCPL), as well as VAD and vessel perimeter index (VPI) on the deep capillary plexus layer (DCPL), were significantly increased after PSR surgery (p < 0.05). VPI on the SCPL, vascular diameter index (VDI) and VSD on the DCPL were also improved without statistical difference after PSR. The VSD on SCPL, VAD on DCPL of the right eyes and the VPI on SCPL of the left eyes were significantly increased after PSR (p < 0.05). PSR surgery can shorten the AL and can stable BCVA and SE in high myopia children. The angio-OCT parameters indicated that the retinal microcirculation supply was significantly improved after PSR.

Deep Learning-Enabled Vasculometry Depicts Phased Lesion Patterns in High Myopia Progression.

PURPOSE: To investigate the potential phases in myopic retinal vascular alterations for further elucidating the mechanisms underlying the progression of high myopia (HM). METHODS: For this retrospective study, participants diagnosed with high myopia at Beijing Tongren Hospital were recruited. Based on bionic mechanisms of human vision, an intelligent image processing model was developed and utilized to extract and quantify the morphological characteristics of retinal vasculatures in different regions measured by papilla-diameter (PD), including vascular caliber, arteriole-to-venule ratio (AVR), tortuosity, the angle of the vascular arch (AVA), the distance of the vascular arch (DVA), density, fractal dimension, and venular length. In addition, the optic disc and the area of peripapillary atrophy (PPA) were also quantified. The characteristics of the overall population, as well as patients aged less than 25 years old, were compared by different genders. Univariate and multiple linear regression analyses were conducted to investigate the correlation of retinal vasculature parameters with PPA width, and detailed trends of the vascular indicators were analyzed to explore the potential existence of staged morphological changes. FINDINGS: The study included 14,066 fundus photographs of 5775 patients (aged 41.2 ± 18.6 years), of whom 7379 (61.2 %) were female. The study included 12,067 fundus photographs of 5320 patients (aged 41.2 ± 18.6 years). Significant variations in the morphological parameters of retinal vessels were observed between males and females. After adjusting for age and sex, multiple linear regression analysis showed that an increased PPA width ratio was associated with lower AVA (1PD), DVA (1PD), vascular caliber (0.5-1.0 PD), tortuosity (0.5-1.0 PD), density and fractal dimension (all P < 0.001, Spearman's ρ < 0). Overall, the changes in retinal vascular morphology showed two phases: tortuosity (0.5-1.0PD) and AVA (1PD) decreased rapidly in the first stage but significantly more slowly in the second stage, while vascular density and fractal dimension showed a completely opposite trend with an initial slow decline followed by a rapid decrease. CONCLUSIONS: This study identified two distinct phases of retinal vascular morphological changes during the progression of HM. Traction lesions were predominant in the initial stage, while atrophic lesions were predominant in the later stage. These findings provide further insight into the development mechanism of HM from the perspective of retinal vasculature.

The anterior scleral thickness in primary open-angle glaucoma with high myopia.

Purpose: This study aimed to investigate and compare the anterior scleral thickness (AST) among high myopia (HM), primary open-angle glaucoma (POAG), and POAG with HM (HMPOAG) groups. Methods: Thirty-two HM eyes, 30 POAG eyes, and 31 HMPOAG eyes were included. The Schlemm's canal (SC) area, trabecular meshwork (TM) thickness, scleral spur (SS) length, and AST were measured using swept-source optical coherence tomography. AST was measured at 0 mm (AST0), 1 mm (AST1), 2 mm (AST2), and 3 mm (AST3) from SS. Results: The HMPOAG group had significantly thinner AST, SS length, and TM thickness than the HM and POAG groups (all p < 0.05). In addition, the SC area of the HMPOAG group was also significantly smaller than that of the HM group (p < 0.001). Conclusion: The HMPOAG group had the thinnest AST, shortest SS, thinnest TM, and smallest SC. The thinnest AST might contribute to the shortest SS, and further to the thinnest TM and smallest SC in the HMPOAG group. AST might be a novel clinical indicator in the prediction and evaluation of POAG.