Continued Increase of Axial Length and Its Risk Factors in Adults With High Myopia

Eight Years and Beyond Longitudinal Changes of Peripapillary Structures on OCT in Adult Myopia

PURPOSE

To investigate the long-term changes of peripapillary structures detected by enhanced depth imaging of optical coherence tomography (OCT) in adult myopia.

DESIGN

Observational case series.

METHODS

Myopic participants who had undergone a full baseline ophthalmologic examination and had been followed up for a minimum of 8 years were included. Using enhanced depth imaging of OCT, scans around the optic disc in the Spectralis software Follow-up mode, which enabled capturing of the same positions, were performed in 65 eyes. The peripapillary parameters including the size of border tissue, Bruch membrane opening (BMO), peripapillary choroidal thickness, and the angle between peripapillary Bruch membrane (BM) and anterior sclera were manually delineated and measured.

RESULTS

The axial length showed a significant elongation after a mean follow-up of 9.46 ± 0.92 years. The rates of changes were 0.015 ± 0.011 mm/y in the medium myopia group and 0.057 ± 0.039 mm/y in the high myopia group. At the last visit, the average border tissue length and BMO diameter were increased. The angle between peripapillary BM did not show significant change, while the angle between the peripapillary sclera showed a significant rise. On multivariate analysis, the border tissue elongation, BMO enlargement, and increased sclera angle were all associated with a change in axial length. The development of a BM defect and inward protrusion of sclera in the temporal peripapillary region was observed on 8 eyes (34.8%) in the high myopia group, along with an extreme thinning or disappearing of the peripapillary choroid.

CONCLUSION

Marked longitudinal changes in peripapillary structures including border tissue, BM, choroid, and sclera could be observed in adult myopic eyes, which may impact the biomechanical environment around the optic nerve head.

Enhanced Intrusion of Exogenous Airborne Fine Particles toward Eyes in Humans and Animals: Where Damaged Blood-Ocular Barrier Plays a Crucial Role

Emerging data suggest a close correlation between ambient fine particle (AFP) exposure and eye disorders and pinpoint potential threats of AFPs to eye health in humans. However, the possible passage (including direct intrusion) and the interactions of AFPs with the eye microenvironment in addition to morphological and physiological injuries remain elusive. To this end, the likely transport of AFPs into the eyes via blood-ocular barrier (BOB) in humans and animals was investigated herein. Exogenous particles were recognized inside human eyes with detailed structural and chemical fingerprints. Importantly, comparable AFPs were found in sera with constant structural and chemical fingerprints, hinting at the translocation pathway from blood circulation into the eye. Furthermore, we found that the particle concentrations in human eyes from patients with diabetic retinopathy were much higher than those from patients with no fundus pathological changes (i.e., myopia), indicating that the damaged BOB increased the possibility of particle entrance. Our diseased animal model further corroborated these findings. Collectively, our results offer a new piece of evidence on the intrusion of exogenous particles into human eyes and provide an explanation for AFP-induced eye disorders, with substantially increased risk in susceptible individuals with BOB injuries.

Long-term observation of V4c implantable collamer lenses implantation for moderate to extreme high myopia correction: five years follow-up

BACKGROUND

This study aims to assess the long term effectiveness, safety, predictability and stability of V4c implantable collamer lenses (ICL) for correction of moderate to extreme high myopia.

METHODS

We reviewed 125 eyes from 64 patients who implanted V4c ICL at the Refractive Surgery Center of West China Hospital in Chengdu, China, between May 2015 and January 2017. The median spherical equivalent was -11.50 D (interquartile range [IQR]: -13.00 to -9.00 D). We followed up with the patients over five years and evaluated several parameters, including uncorrected visual acuity (UDVA), corrected visual acuity (CDVA), axial length, refractive error, endothelial cell density (ECD), intraocular pressure (IOP), white-to-white distance (WTW), and vault. We performed a correlation analysis to explore the potential impacts on vault following implantation.

RESULTS

The median safety index (postoperative CDVA/preoperative CDVA) during the last follow-up was 1.00 (interquartile range [IQR]: 1.00-1.20), and the efficacy indices (postoperative UDVA/preoperative CDVA) were 1.20 (IQR: 1.00-1.25), 1.20 (IQR: 1.00-1.33), and 0.8 (IQR: 0.65-1.00) at postoperative 1 week, 1 month, and 5 years, respectively. At the five-year mark, 16% of the eyes were within ±0.50 D of expected correction, and 73% were within ±2.00 D. No significant difference in ECD was observed between pre-operative and post-operative measurements. Compared to baseline, we observed a significant increase in IOP at the one-week follow-up, which decreased significantly at the one-month visit. Furthermore, we identified ICL size and spherical equivalent (SE) as independent variables in a multiple linear regression model that accurately predicted the five-year vault after surgery.

CONCLUSION

In conclusion, V4c ICL implantation is an effective and safe treatment for moderate to extreme high myopia with good predictability and stability over the long-term.

Ocular biometric characteristics of Han ethnicity in Tianjin and Uyghur ethnicity in Xinjiang undergoing cataract surgery

AIM

To analyze and compare the differences among ocular biometric parameters in Han and Uyghur populations undergoing cataract surgery.

METHODS

In this hospital-based prospective study, 410 patients undergoing cataract surgery (226 Han patients in Tianjin and 184 Uyghur patients in Xinjiang) were enrolled. The differences in axial length (AL), anterior chamber depth (ACD), keratometry [steep K (Ks) and flat K (Kf)], and corneal astigmatism (CA) measured using IOL Master 700 were compared between Han and Uyghur patients.

RESULTS

The average age of Han patients was higher than that of Uyghur patients (70.22±8.54 vs 63.04±9.56y, P<0.001). After adjusting for age factors, Han patients had longer AL (23.51±1.05 vs 22.86±0.92 mm, P<0.001), deeper ACD (3.06±0.44 vs 2.97±0.37 mm, P=0.001), greater Kf (43.95±1.40 vs 43.42±1.69 D, P=0.001), steeper Ks (45.00±1.47 vs 44.26±1.71 D, P=0.001), and higher CA (1.04±0.68 vs 0.79±0.65, P=0.025) than Uyghur patients. Intra-ethnic male patients had longer AL, deeper ACD, and lower keratometry than female patients; however, CA between the sexes was almost similar. In the correlation analysis, we observed a positive correlation between AL and ACD in patients of both ethnicities (rHan =0.48, rUyghur =0.44, P<0.001), while AL was negatively correlated with Kf (rHan =-0.42, rUyghur =-0.64, P<0.001) and Ks (rHan =-0.38, rUyghur =-0.66, P<0.001). Additionally, Kf was positively correlated with Ks (rHan =0.89, rUyghur =0.93, P<0.001).

CONCLUSION

There are differences in ocular biometric parameters between individuals of Han ethnicity in Tianjin and those of Uyghur ethnicity in Xinjiang undergoing cataract surgery. These ethnic variances can enhance our understanding of ocular diseases related to these parameters and provide guidance for surgical procedures.

Repeated Low-Level Red Light Therapy for Myopia Control in High Myopia Children and Adolescents: A Randomized Clinical Trial

PURPOSE

To assess the effectiveness and safety of repeated low-level red light (RLRL), which is a newly available treatment for myopia control in children and adolescents with high myopia.

DESIGN

Multicenter, randomized, parallel-group, single-blind clinical trial (randomized controlled trial; NCT05184621).

PARTICIPANTS

Between February 2021 and April 2022, 192 children aged 6 to 16 years were enrolled. Each child had at least 1 eye with myopia of cycloplegic spherical equivalent refraction (SER) at least -4.0 diopters (D), astigmatism of ≤2.0 D, anisometropia of ≤3.0 D, and best-corrected visual acuity (BCVA) of 0.2 logarithm of the minimum angle of resolution or better. Follow-up was completed by April 2023.

METHODS

Participants were randomly assigned at a 1:1 ratio to intervention (RLRL treatment plus single-vision spectacles) or control (single-vision spectacles) groups. The RLRL treatment was administered for 3 minutes per session, twice daily with a minimum interval of 4 hours, 7 days per week.

MEAN OUTCOME MEASURES

The primary outcome and key secondary outcome were changes in axial length (AL) and cycloplegic SER measured at baseline and the 12-month follow-up visit. Participants who had at least 1 postrandomization follow-up visit were analyzed for treatment efficacy.

RESULTS

Among 192 randomized participants, 188 (97.91%) were included in the analyses (96 in the RLRL group and 92 in the control group). After 12 months, the adjusted mean change in AL was -0.06 mm (95% confidence interval [CI], -0.10 to -0.02 mm) and 0.34 mm (95% CI, 0.30 to 0.39 mm) in the intervention and control groups, respectively. A total of 48 participants (53.3%) in the intervention group were still experiencing axial shortening >0.05 mm at the 12-month follow-up. The mean SER change after 12 months was 0.11 D (95% CI, 0.02to 0.19 D) and -0.75 D (95% CI, -0.88 to -0.62 D) in the intervention and control groups, respectively.

CONCLUSIONS

Repeated low-level red light demonstrates stronger treatment efficacy among those with high myopia, with 53.3% experiencing substantial axial shortening. Repeated low-level red light provides an excellent solution for the management of high myopia progression, a significant challenge in ophthalmology practice.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Effect of intraocular pressure reduction on progressive high myopia (PHM study): study protocol of a randomised controlled trial

BACKGROUND

In adult patients with high myopia (HM), progressive axial elongation poses a significant risk for the development of subsequent ocular complications that may lead to visual impairment. Effective strategies to reduce or prevent further axial elongation in highly myopic adult patients have not been available so far. Recent studies suggested that medically lowering intraocular pressure (IOP) may reduce axial elongation.

OBJECTIVE

This clinical randomised controlled trial (RCT) aims to evaluate the efficacy of medical IOP reduction in adult patients with progressive HM (PHM).

TRIAL DESIGN

Single-centre, open-label, prospective RCT.

METHODS

This RCT will recruit 152 participants with PHM at the Zhongshan Ophthalmic Center (ZOC). Randomised in a ratio of 1:1, participants will receive IOP-lowering eyedrops (intervention group) or will be followed without treatment (control group) for 12 months. Follow-up visits will be conducted at 1, 6 and 12 months after baseline. Only one eye per eligible participant will be included for analysis. The primary outcome is the change in axial length (AL) within the study period of 12 months. Secondary outcomes include the incidence and progression of visual field (VF) defects, changes in optic disc morphology and incidence and progression of myopic maculopathy. Difference in AL changes between the two groups will be analysed using linear regression analysis. For the secondary outcomes, a multifactor Poisson regression within a generalised linear model will be used to estimate the relative risk of progression in VF defects and myopic maculopathy, and the rate of thinning in retinal nerve fibre layer and ganglion cell-inner plexiform will be assessed through Kaplan-Meier curves and log-rank tests.

ETHICS AND DISSEMINATION

Full ethics approval for this trial has been obtained from the Ethics Committee of ZOC, Sun Yat-sen University, China (ID: 2023KYPJ110). Results of this trial will be disseminated through peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05850936.

Intravitreal panitumumab and myopic macular degeneration

BACKGROUND

In experimental studies, intravitreally applied antibodies against epidermal growth factor (EGF), EGF family members (amphiregulin, neuregulin-1, betacellulin, epigen, epiregulin) and against the EGF receptor (EGFR) were associated with a reduction in lens-induced axial elongation and decrease in physiological eye elongation in guinea pigs and in non-human primates. Here, we investigated the intraocular tolerability and safety of a fully human monoclonal IgG2-antibody against EGFR, already in clinical use in oncology, as a potential future therapeutic approach for axial elongation in adult eyes with pathological myopia.

METHODS

The clinical, monocentre, open-label, multiple-dose, phase-1 study included patients with myopic macular degeneration of stage 4, who received intravitreal injections of panitumumab in various doses and in intervals ranging between 2.1 months and 6.3 months.

RESULTS

The study included 11 patients (age:66.8±6.3 years), receiving panitumumab injections in doses of 0.6 mg (4 eyes; 1×1 injection, 3×2 injections), 1.2 mg (4 eyes; 1×1 injection, 2×2 injections, 1×3 injections) and 1.8 mg (3 eyes; 1×1 injection, 2×2 injections), respectively. None of the participants showed treatment-emergent systemic adverse events or intraocular inflammatory reactions. Best-corrected visual acuity (1.62±0.47 logarithm of the minimal angle of resolution (logMAR) vs 1.28±0.59 logMAR; p=0.08) and intraocular pressure (13.8±2.4 mm Hg vs 14.3±2.6 mm Hg; p=0.20) remained unchanged. In nine patients with a follow-up of >3 months (mean:6.7±2.7 months), axial length did not change significantly (30.73±1.03 mm vs 30.77±1.19 mm; p=0.56).

CONCLUSIONS

In this open-labelled, phase-1 study with a mean follow-up of 6.7 months, panitumumab repeatedly administered intravitreally up to a dose of 1.8 mg was not associated with intraocular or systemic adverse effects. During the study period, axial length remained unchanged.

TRIAL REGISTRATION NUMBER

DRKS00027302.

Ciliary muscles contraction leads to axial length extension--The possible initiating factor for myopia

PURPOSE

This study aimed to investigate the underlying factors driving the onset of myopia, specifically the role of the ciliary muscle's contraction in the elongation of the axial length of the eye.

METHODS

The retrospective study was conducted utilizing data from three ophthalmic centers in Shanghai and Beijing. Both Chinese and Caucasian children were involved. The axial length of the subjects' eyes was measured in both relaxed and contracted state of the ciliary muscle. A comprehensive mechanical model was also developed to observe the influence of ciliary muscle contraction on the axial length.

RESULTS

This study included a sample of 198 right eyes of 198 myopic children. Of these, 97 were male and 101 were female, 126 were of Chinese ethnicity and 72 were Caucasian. The age of onset for myopia ranged from 5.9 to 16.9 years old. The axial length of the eye decreased 0.028 ± 0.007mm following dilation, indicating relaxation of the ciliary muscle (t paired student = 15.16, p = 6.72 x 10-35). In contrast, ciliary muscle contraction resulted in an increase in axial length. Considering proportionality, a significant 90.4% (179 eyes) exhibited a reduced axial length, while a minor 9.6% (19 eyes) demonstrated an increase post-mydriasis. Finite element modeling demonstrated that muscle contraction caused a tension force that transmits towards the posterior pole of the eye, causing it to extend posteriorly.

CONCLUSION

The contraction of the ciliary muscle leads to an extension of the axial length. This could potentially be the initiating factor for myopia.

The effect of axial length on pseudophakic retinal detachment

PURPOSE

The purpose of the study was to analyse the surgical management and outcome regarding axial length in the population affected by pseudophakic retinal detachment (PRD) 2015-2020.

METHOD

The patients included were from an observational cohort study of patients undergoing cataract surgery in the region of Skåne during 2015-2017. Data were retrieved from the Swedish National Cataract Register and cross-referenced with cases of PRD in the same region from 2015 to 2020. The surgical method used and findings at follow-up were recorded. The patients were stratified according to axial length (AL) to <25 mm, 25 ≤ n < 26.5 mm and ≥26.5 mm. The main outcome was primary success with one surgery apart from silicone oil removal. The secondary outcome was postoperative visual acuity.

RESULTS

In the whole study group of 58 624 cases, complete follow-up data were available for 288 eyes. The median follow-up time was 324 days, and primary operation was successful in 82.9% of these cases. The median visual acuity was 0.31 (LogMAR). In the stratification those with AL < 25 mm had a primary success of 75.8%, AL 25 ≤ n < 26.5 mm of 87.9% and ≥26.5 mm of 95.8%.

CONCLUSIONS

The primary anatomical success was 82.9% in the whole group of PRD but with stratification they had an increasing number of primary success with longer AL.

Evaluation and comparison of optical coherence tomography angiography (OCTA) parameters in normal and moderate myopic individuals

OBJECTIVE

The objective of this study was to evaluate and compare Optical Coherence Tomography Angiography (OCTA) parameters in patients with moderate myopia and healthy individuals retrospectively.

METHODS

A total of 80 male individuals aged 18-20 years were included in the study with 40 moderate myopic and 40 healthy persons. All participants underwent detailed ocular examination including refraction, intraocular pressure (IOP), visual acuity, biomicroscopy, OCTA measurement and optic biometry measurement. Retinal, retinal nerve fiber layer and choroidal layer thicknesses were evaluated in µm with the help of the software available in the OCTA device.

RESULTS

The mean axial length (24.32 ± 0.53 mm) was statistically significantly higher in the moderate myopic group (24.32 mm) compared to the healthy group (23.33 ± 0.61 mm) (p < 0.001). Spherical equivalent (SE) was found as -3.79 ± 0.91 D in the moderate myopic group and -0.22 ± 0.32 D in the healthy group (p < 0.05). The mean superficial foveal mean density (FovSupMVD) and the mean deep foveal mean density (FovDepMVD) were statistically significantly lower in the moderate myopic group than in the healthy group (both, p < 0.001). The mean retinal temporal thickness (RTt) was statistically significantly lower in the moderate myopic group (p = 0.017). There was a mild negative correlation between axial length and FovSupMVD, FovDepMVD in myopes. In axial length ROC analysis, the cutoff value for moderate myopes was found to be 24.15 mm. Mean superficial foveal mean density (FovSupMVD) and mean deep foveal mean density (FovDepMVD), mean retinal temporal thickness (RTt) were significantly lower in the group above 24.15 mm axial length compared to the group below 24.15 mm axial length (all three, p < 0.001). Foveal avascular zone was significantly higher in the group above 24.15 mm axial length (p = 0.016) CONCLUSION: The results of our study indicate that the mean axial length and spherical equivalent were significantly higher, while retinal temporal thickness, the mean superficial foveal mean density and the mean deep foveal mean density were significantly lower in patients with myopia up to -6.0 D compared to the healthy individuals.

Prevalence of Myopic Maculopathy Among the Very Old: The Ural Very Old Study

Purpose

To assess the prevalence of myopic macular degeneration (MMD) in very old individuals.

Methods

The population-based Ural Very Old Study (UVOS) included 1526 (81.1%) of 1882 eligible inhabitants aged ≥85 years. Assessable fundus images were available for 930 (60.9%) individuals (mean age, 88.6 ± 2.7 years). MMD was defined by macular patchy atrophies (i.e., MMD stage 3 and 4 as defined by the Pathologic Myopia Study Group).

Results

MMD prevalence was 21 of 930 (2.3%; 95% CI, 1.3-3.3), with 10 individuals (1.1%; 95% CI, 0.4-1.7) having MMD stage 3 and 11 participants (1.2%; 95% CI, 0.5-1.9) MMD stage 4 disease. Within MMD stage 3 and 4, prevalence of binocular moderate to severe vision impairment was 4 of 10 (40%; 95% CI, 31-77) and 7 of 11 (64%; 95% CI, 30-98), respectively, and the prevalence of binocular blindness was 2 of 10 (20%; 95% CI, 0-50) and 3 of 11 (27%; 95% CI, 0-59), respectively. In minor myopia (axial length, 24.0 to <24.5 mm), moderate myopia (axial length, 24.5 to <26.5 mm), and high myopia (axial length, ≥26.5 mm), MMD prevalence in the right eyes was 0 of 46 eyes (0%), 3 of 40 eyes (8%; 95% CI, 0-16), and 7 of 9 (78%; 95% CI, 44-100), respectively; MMD prevalence in the left eyes was 1 in 48 eyes (2%; 95% CI, 0-6), 4 of 36 eyes (11%; 95% CI, 0-22), and 3 of 4 eyes (75%; 95% CI, 0-100), respectively. In multivariable analysis, a higher MMD prevalence (odds ratio, 8.89; 95% CI, 3.43-23.0; P < 0.001) and higher MMD stage (beta, 0.45; B, 19; 95% CI, 0.16-0.22; P < 0.001) were correlated with longer axial length but not with any other ocular or systemic parameter.

Conclusions

MMD prevalence (stages 3 and 4) in very old individuals increased 8.89-fold for each mm axial length increase, with a prevalence of ≥75% in highly myopic eyes. In old age, highly myopic individuals have a high risk of eventually developing MMD with marked vision impairment.

PREVALENCE AND CLINICAL FEATURES OF RADIAL FUNDUS AUTOFLUORESCENCE IN HIGH MYOPIC WOMEN

PURPOSE

To determine the prevalence and characteristics of radial fundus autofluorescence (FAF) in highly myopic women.

METHODS

This was a retrospective, observational case study to determine the prevalence of radial FAF in the ultra-widefield FAF images in women. The clinical characteristics of these patients were evaluated.

RESULTS

Fifteen of 1,935 (0.78%) highly myopic women were found to have radial FAF. Their mean age was 36.6 ± 25.6 years, and their mean best-corrected visual acuity was 0.3 ± 0.42 logMAR units. The mean axial length (AL) was 28.8 ± 2.8 mm. Among the 15 cases, eight did not have pigmentary changes and seven had pigmentary changes in the ultra-widefield FAF images. The women with the pigmentary changes were significantly older ( P = 0.021), had poorer BCVA ( P = 0.001), and had longer ALs ( P = 0.002). The visual fields and electroretinograms were worse in the eyes with pigmentary changes.

CONCLUSION

The prevalence of radial FAF was 0.78% in women with high myopia. These patients might have mutations in the RPGR or RP2 genes and can develop high myopia and retinitis pigmentosa. Ultra-widefield FAF images should be examined in all highly myopic patients for early detection of radial FAF, and myopia prevention and genetic counseling for possible genetic therapy are recommended.

A wireless battery-free eye modulation patch for high myopia therapy

The proper axial length of the eye is crucial for achieving emmetropia. In this study, we present a wireless battery-free eye modulation patch designed to correct high myopia and prevent relapse. The patch consists of piezoelectric transducers, an electrochemical micro-actuator, a drug microneedle array, μ-LEDs, a flexible circuit, and biocompatible encapsulation. The system can be wirelessly powered and controlled using external ultrasound. The electrochemical micro-actuator plays a key role in precisely shortening the axial length by driving the posterior sclera inward. This ensures accurate scene imaging on the retina for myopia eye. The drug microneedle array delivers riboflavin to the posterior sclera, and μ-LEDs' blue light induces collagen cross-linking, reinforcing sclera strength. In vivo experiments demonstrate that the patch successfully reduces the rabbit eye's axial length by ~1217 μm and increases sclera strength by 387%. The system operates effectively within the body without the need for batteries. Here, we show that the patch offers a promising avenue for clinically treating high myopia.

Axial Elongation Trajectories in Chinese Children and Adults With High Myopia

Importance

Understanding the long-term axial elongation trajectory in high myopia is important to prevent blindness.

Objective

To evaluate axial elongation trajectories and related visual outcomes in children and adults with high myopia.

Design, Setting, and Participants

In this cohort study, participants in the Zhongshan Ophthalmic Centre-Brien Holden Vision Institute high myopia cohort were followed up every other year for 8 years. Participants with axial length measurements at baseline (2011 or 2012) and at least 1 follow-up visit were included. Participants were grouped according to baseline age as children and adolescents (7 to <18 years), young adults (18 to <40 years), and older adults (≥40 to 70 years). Data were analyzed from November 1, 2022, to June 1, 2023.

Exposure

High myopia (spherical power ≤-6.00 diopters).

Main Outcomes and Measures

Longitudinal axial elongation trajectories were identified by cluster analysis. Axial elongation rates were calculated by linear mixed-effects models. A 2-sided P < .05 was defined as statistically significant.

Results

A total of 793 participants (median [range] age, 17.8 [6.8-69.7] years; 418 females [52.7%]) and 1586 eyes were included in the analyses. Mean axial elongation rates were 0.46 mm/y (95% CI, 0.44-0.48 mm/y) for children and adolescents, 0.07 mm/y (95% CI, 0.06-0.09 mm/y) for young adults, and 0.13 mm/y (95% CI, 0.07-0.19 mm/y) for older adults. Cluster analysis identified 3 axial elongation trajectories, with the stable, moderate, and rapid progression trajectories having mean axial elongation rates of 0.02 mm/y (95% CI, 0.01-0.02 mm/y), 0.12 mm/y (95% CI, 0.11-0.13 mm/y), and 0.38 mm/y (95% CI, 0.35-0.42 mm/y), respectively. At 8 years of follow-up, compared with the stable progression trajectory, the rapid progression trajectory was associated with a 6.92 times higher risk of developing pathological myopic macular degeneration (defined as diffuse or patchy chorioretinal atrophy or macular atrophy; odds ratio, 6.92 [95% CI, 1.07-44.60]; P = .04), and it was associated with a 0.032 logMAR decrease in best-corrected visual acuity (β = 0.032 [95% CI, 0.001-0.063]; P = .04).

Conclusions and Relevance

The findings of this 8-year follow-up study suggest that axial length in high myopia continues to increase from childhood to late adulthood following 3 distinct trajectories. At 8 years of follow-up, the rapid progression trajectory was associated with a higher risk of developing pathological myopic macular degeneration and poorer best-corrected visual acuity compared with the stable progression trajectory. These distinct axial elongation trajectories could prove valuable for early identification and intervention for high-risk individuals.

Influence of posterior staphyloma in myopic maculopathy and visual prognosis

BACKGROUND/OBJECTIVES

Posterior staphyloma is a hallmark of high myopia and its presence associates to greater degrees of myopic maculopathy. Nonetheless, its development, repercussion on visual function and relationship with maculopathy components, is still unclear. The objective was to analyze the impact of posterior staphyloma on the incidence and severity of myopic maculopathy and its repercussion on visual prognosis.

SUBJECTS/METHODS

Cross-sectional study conducted on 473 consecutive eyes of 259 highly myopic patients examined at Puerta de Hierro-Majadahonda University Hospital (Madrid, Spain). All patients underwent complete ophthalmologic examination including best corrected visual acuity (BCVA), axial length (AL), myopic maculopathy classification according to ATN system (atrophic/traction/neovascularization), determined the presence of posterior staphyloma, pathologic myopia (PM) and severe PM. Multimodal imaging were performed including fundus photography, optical coherence tomography (OCT), OCT-angiography, fundus autofluorescence and/ or fluorescein angiography.

RESULTS

Out of the total, 70.65% were female patients (n = 173/259), mean BCVA was 0.41 ± 0.54 logMAR units and mean AL was 29.3 ± 2.6 mm (26-37.6). Posterior staphyloma was present in 69.4% of eyes. Eyes with posterior staphyloma compared to non-staphyloma were older (p < 0.05), had greater AL (p < 0.01), worse BCVA (p < 0.01) and higher stage in ATN components (p < 0.01). Moreover, compound subgroup showed worse BCVA (p < 0.01) and greater stage in each of the ATN components (p < 0.01). Staphylomas with macular involvement presented worse BCVA (p < 0.01), higher AL (p < 0.01), and greater ATN (p < 0.05). The risk of posterior staphyloma presence in eyes with PM and severe PM eyes was 89.8% and 96.7%, respectively. Posterior staphyloma was the best predictor for BCVA in myopic patients (p < 0.01).

CONCLUSIONS

Posterior staphyloma's presence determines high risk of myopic maculopathy and therefore worse visual prognosis, especially those with macular involvement. Posterior staphyloma represented the best predictor for BCVA in highly myopic patients.

The SNTB1 and ZFHX1B gene have susceptibility in northern Han Chinese populations with high myopia

The aim of this study was to explore the association between SNTB1 and ZFHX1B polymorphisms and high myopia (HM) in a Northern Han Chinese population. This case-control study included 457 HM and 860 healthy subjects from the Northern Han Chinese population. Four single nucleotide polymorphisms (SNPs) (rs7839488, rs4395927, rs4455882, and rs6469937) in SNTB1 and one SNP in ZFHX1B (rs13382811)were selected based on two previous genome-wide association study (GWAS) studies. The allele and genotype distributions of SNPs in SNTB1 and ZFHX1B were compared between the two groups using the chi-square test. The allele results were adjusted for age and sex using Plink software (Plink 1.9). Pairwise linkage disequilibrium (LD) and haplotype analyses were performed using SHEsis software. For HM subjects, the mean age was 44.80 ± 17.11 years, and for the control subjects, it was 44.41 ± 14.26 years. For rs7839488 of the SNTB1 gene, the A allele is a risk allele and the G allele is a wild allele. The A allele had no statistical significance with the HM cases and controls (OR = 0.90, 95% CI = 0.74-1.09, aP = 0.273, Pc = NS). There was a LD in SNTB1 (rs7839488, rs4395927, rs4455882, and rs6469937). The G-C-A-G haplotype frequency was higher in HM subjects than that of the controls (OR = 1.31, 95% CI = 1.07-1.60, P = 0.008). Meanwhile, the A-T-G-A haplotype frequency was slightly lower in the HM group (OR = 0.81, 95% CI = 0.66-0.99, P = 0.048). In the ZFHX1B gene, the frequency of the minor T allele of rs13382811 was significant higher in the HM group than in the control group (OR = 1.34, 95% CI = 1.11-1.61, aP = 0.001, Pc = 0.009). Furthermore, compared to the CC genotype, there were significant differences in the CT genotype (OR = 1.57, 95% CI = 1.23-2.00, aP < 0.001, Pc = 0.002). In conclusion, G-C-A-G is a risk haplotype from the SNTB1 gene in high myopia patients. The minor T-allele of ZFHX1B rs13382811 is a risk factor for high myopia. SNTB1 and ZFHX1B are both risk genes associated with increased susceptibility to high myopia in the Northern Han Chinese population.

Quantitative analysis of optic disc changes in school-age children with ametropia based on artificial intelligence

AIM

To explore changes in the optic disc and peripapillary atrophy (PPA) in school-age children with ametropia using color fundus photography combined with artificial intelligence (AI) technology.

METHODS

Based on the retrospective case-controlled study, 226 eyes of 113 children aged aged 6-12y were enrolled from October 2021 to May 2022. According to the results of spherical equivalent (SE), the children were divided into four groups: low myopia group (66 eyes), moderate myopia group (60 eyes), high myopia group (50 eyes) and emmetropia control group (50 eyes). All subjects underwent un-aided visual acuity, dilated pupil optometry, best-corrected visual acuity (BCVA), intraocular pressure, ocular axis measurement and color fundus photography.

RESULTS

The width of PPA, horizontal diameter ratio of PPA to the optic disc and area ratio of PPA to the optic disc were significantly different among the four groups (P<0.05). The width of the nasal and temporal neuroretinal rim, the roundness of the optic disc, the height of PPA, the vertical diameter ratio of PPA to the optic disc, and the average density of PPA in the high myopia group were significantly different compared with the other three groups (P<0.05). There were strong negative correlations between SE and area ratio of PPA to the optic disc (r=-0.812, P<0.001) and strong positive correlation between axial length (AL) and area ratio of PPA to the optic disc (r=0.736, P<0.001).

CONCLUSION

In school-age children with high myopia, the nasal and temporal neuroretinal rims are narrowed and even lost, which have high sensitivity. The area ratio of the PPA to the optic disc could be used as an early predictor of myopia progression, which is of great significance for the development prevention and management of myopia.

High myopia is protective against diabetic retinopathy in the participants of the National Health and Nutrition Examination Survey

PURPOSE

To investigate the association of subjects with refractive error and diabetic retinopathy (DR) in the United States comparing results between different race groups.

METHODS

All data were derived from National Health and Nutrition Examination Survey (NHANES) from 2005 to 2008. The data were divided into four groups (emmetropia, mild myopia, high myopia, hypertropia) according to the spherical equivalent (SE), and those who met the enrollment conditions were selected as the study subjects. Multivariable logistic regression analysis was used to evaluate the relationship between refractive error and diabetic retinopathy risk.

RESULTS

A total of 1317 participants were included in the study, including 331 participants with diabetic retinopathy, and 986 without diabetic retinopathy. After adjustment for potential confounders, subjects with high myopia were associated with a lower risk of diabetic retinopathy. The odds ratio (OR) was 0.44, 95% confidence interval (CI): (0.20-0.96), P-value = 0.040 in the multivariate regression analysis. Subgroup analyses showed that subjects with high myopia in the non-Hispanic Black group were associated with decreased odds of diabetic retinopathy. (OR was 0.20, and 95% CI: 0.04-0.95, P-value = 0.042).

CONCLUSION

The results show that high myopia is associated with diabetic retinopathy in diabetic patients.

Incidence and its risk factors of high myopia in Chinese rural adults: A population-based six-year cohort study

BACKGROUND

To investigate the incidence rate of high myopia and its risk factors in adults.

METHODS

This was a population-based cohort study, 4582 adults aged ≥ 30 years from rural area of China were included. The follow-up duration was six years. Objective refraction (sphere, cylinder, and axis) was measured using an autorefractor. Multivariable Logistic regression was used to explore risk factors of high myopia, odds ratio (OR) with 95% confidence interval (CI) were reported.

RESULTS

During the six-year follow-up, 25 participants developed high myopia. The incidence rate was 0.55% (95%CI: 0.44% to 0.66%), and were 0.54% (11/2035) in males and 0.55% (14/2547) in females. The age-gender standardized annual incidence rate was 0.11%. The median changes in spherical equivalent (SE) of all participants was 0.25D (IQR: -0.125 to 0.625). For the baseline myopic adults and non-myopic adults, the median changes in SE were 0.125D (IQR: -0.375 to 0.5), and 0.25D (IQR: -0.125 to 0.625). The difference was significant (p < 0.001). Of the two subgroups, 1.52% (21/1383) and 0.13% (4/3199) developed high myopia during six years. The risk of developing high myopia in baseline myopic adults was 11.7 times higher than that of the baseline non-myopic adults (p < 0.001). Age (OR = 1.061, 95%CI: 1.022 to 1.103, p = 0.002), and baseline myopia (OR = 1.007, 95%CI: 1.001 to 1.012, p < 0.001) were risk factors for high myopia.

CONCLUSION

The age-gender standardized annual incidence rate of high myopia in Chinese rural adults is 0.11%. More than 30% of adults still have myopia progression. Myopia control is of great significance for high myopia prevention.

Time trends in myopia and high myopia prevalence in young university adults in China

AIM

To investigate time trends in myopia and high myopia prevalence over 6y among young university adults in China.

METHODS

This is a 6-year series cross-sectional study from 2016 to 2021. Totally 4910 freshmen were enrolled and completed a questionnaire concerning age, gender, and disease history. Students with eye diseases were excluded after a detailed eye examination. The refractive status was measured by non-cycloplegic objective refraction and ocular parameters were measured by Lenstar 900. The examination followed the same protocol each year. Trends over time in myopia and high myopia prevalence, as well as ocular biometry parameters, were analyzed.

RESULTS

From 2016 to 2021, the axial length (AL) and corneal radius (CR) increased significantly (P=0.002 for AL; P=0.04 for CR). However, the spherical equivalent (SE) and the ratio of axial length to the corneal radius (AL/CR) did not change significantly (P=0.59 for SE; P=0.24 for AL/CR). The frequency of AL ≥26.0 mm increased from 26.6% in 2016 to 29.3% in 2021 (P=0.05 for trend). The prevalence of myopia and high myopia did not change significantly in our study (P≥0.18). Compared to a similar cross-sectional study conducted 10 years ago, the prevalence of myopia decreased significantly (94.9% vs 91.8%, P<0.001). Whereas the prevalence of high myopia increased largely (18.12% vs 27.6%, P<0.001).

CONCLUSION

The prevalence of high myopia increases in young university adults during 10y period. Myopia control should begin earlier in childhood. However, these interventions are still needed for high myopia even in young adulthood.

Six-month repeated irradiation of 650 nm low-level red light reduces the risk of myopia in children: a randomized controlled trial

PURPOSE

To evaluate whether the six-month repeated irradiation of 650 nm low-level red light (LLRL) decreases the risk of myopia onset in children.

METHODS

This was a single-masked, randomized controlled trial. A total of 112 children (aged 6-12 years) were enrolled and randomized to the treatment group or control group in a 1:1 ratio. The cycloplegic spherical equivalent error (SER) of children at baseline was -0.5 diopter (D) to 3D. Children in the treatment group were irradiated with the 650 nm LLRL for 6 min daily. No intervention was given to the control. The primary outcomes are myopia incidence, change in cycloplegic SER, and change in axial length (AL).

RESULTS

For the treatment group and control group, the six-month myopia incidence rates were 1.8% (95% confidence interval, CI: 0.2-4.9%) and 12.5% (95% CI: 5.5-21.9%), respectively. The difference was significant (p = 0.028). The median changes in AL for the treatment group and control group were -0.02 (interquartile range, IQR: -0.12 to 0.06) mm, and 0.09 (IQR: 0-0.18) mm, respectively. The difference was significant (p < 0.001). The median changes in cycloplegic SER for the treatment group and control group were 0 (IQR: 0-0.25) D, and -0.125 (IQR: -0.375 to 0) D, respectively. The difference was significant (p < 0.001). There was no adverse event.

CONCLUSION

The repeated irradiation of 650 nm LLRL may have a strong effect for myopia prevention in children, without risk of adverse events.

TRIAL REGISTRATION

this trial is retrospectively registered in the Chinese Clinical Trial Registry ( http://www.chictr.org.cn/ ), the registration number is ChiCTR2200058963.

Predictors of myopic macular degeneration in a 12-year longitudinal study of Singapore adults with myopia

PURPOSE

To investigate the predictive factors for myopic macular degeneration (MMD) and progression in adults with myopia.

METHODS

We examined 828 Malay and Indian adults (1579 myopic eyes) with myopia (spherical equivalent (SE) ≤-0.5 dioptres) at baseline who participated in both baseline and 12-year follow-up visits of the Singapore Malay Eye Study and the Singapore Indian Eye Study. Eye examinations, including subjective refraction and axial length (AL) measurements, were performed. MMD was graded from fundus photographs following the Meta-Analysis for Pathologic Myopia classification. The predictive factors for MMD development and progression were assessed in adults without and with MMD at baseline, respectively as risk ratios (RR) using multivariable modified Poisson regression models. The receiver operating characteristic curve was used to visualise the performance of the predictive models for the development of MMD, with performance quantified by the area under the curve (AUC).

RESULTS

The 12-year cumulative MMD incidence was 10.3% (95% CI 8.9% to 12.0%) among 1504 myopic eyes without MMD at baseline. Tessellated fundus was a major predictor of MMD (RR=2.50, p<0.001), among other factors including age, worse SE and longer AL (all p<0.001). The AUC for prediction of MMD development was found to be 0.78 (95% CI 0.76 to 0.80) for tessellated fundus and increased significantly to an AUC of 0.86 (95% CI 0.84 to 0.88) with the combination of tessellated fundus with age, race, gender and SE (p<0.001). Older age (p=0.02), worse SE (p<0.001) and longer AL (p<0.001) were found to be predictors of MMD progression.

CONCLUSIONS

In adults with myopia without MMD, tessellated fundus, age, SE and AL had good predictive value for incident MMD. In adults with MMD, 1 in 10 eyes experienced progression over the same period. Older age, more severe myopia and longer AL were independent risk factors for progression.

Longitudinal Changes in Axial Length and Spherical Equivalent in Children and Adolescents With High Myopia

Purpose

To investigate longitudinal changes in axial length (AL) and spherical equivalent (SE) in children and adolescents with high myopia and to explore associated risk factors.

Methods

This was a longitudinal, observational cohort study of highly myopic participants (aged 7-17 years) to evaluate the mean rates of change in AL and SE. Mixed effects regression models were used to explore the risk factors.

Results

The sample consisted of 293 participants (mean age at the baseline, 13.63 ± 2.66 years; mean AL, 27.03 ± 1.30 mm diopters; mean SE, -8.99 ± 2.30 diopters) who were followed for 7.09 ± 1.64 years. Pathological myopia (PM) was present in 11.95% of the participants at the baseline. Over the follow-up period, the mean AL and SE progression rates were 0.13 mm/y (95% CI, 0.12-0.14) and -0.36 diopters/y (95% CI, -0.39 to -0.34). The multivariate analysis showed that the AL elongation and myopic SE progression decreased significantly after age 11 (β = -0.080, P < 0.001; β = 0.146, P < 0.001), increased with a greater baseline SE (β = -0.006, P = 0.014; β = 0.017, P = 0.005), and accelerated in children and adolescents who had PM at the baseline (β = 0.043, P = 0.011; β = -0.097, P = 0.025).

Conclusions

A significant association was found between acceleration of AL elongation and myopic SE progression among the children and adolescents with age, especially those younger than 11 years, and the presence of PM.

Microvasculature and microstructure alteration in dry-type high myopia

BACKGROUND

To investigate the alterations in the retinal vasculature and microstructure in dry-type high myopia.

METHODS

One hundred and eighty-nine dry-type high myopia eyes were classified into three groups. Group 1 consisted of 86 eyes with no myopic retinal degenerative lesion (C0). Group 2 consisted of 71 eyes with tessellated fundus (C1). Group 3 consisted of 32 eyes with diffuse chorioretinal atrophy (C2). Retinal vascular density and retinal thickness were measured with optical coherence tomography angiography. The scanning area was a 3 × 3 mm2 ring with the fovea of the macular. All data were analyzed with the SPSS 23.0 by one-way ANOVA test among comparison groups. Pearson's correlation analysis was used to determine the relations among measurements. Univariate linear regression showed a correlation between the vascular densities and retinal thicknesses.

RESULTS

The microvessel density significantly decreased and significant thinning of the superior and temporal macular thickness in the C2 group. The vascular densities of macular decreased significantly with the increase of axial length (AL) and refractive diopter in the C2 group. The retinal thicknesses of the macular fovea increased significantly with the increase of vascular densities in the C0 group and C1 group.

CONCLUSIONS

The impairment of retinal microstructure is more likely related to reduced oxygen and nutrients due to microvessel density decreases.

Myopia: Histology, clinical features, and potential implications for the etiology of axial elongation

Myopic axial elongation is associated with various non-pathological changes. These include a decrease in photoreceptor cell and retinal pigment epithelium (RPE) cell density and retinal layer thickness, mainly in the retro-equatorial to equatorial regions; choroidal and scleral thinning pronounced at the posterior pole and least marked at the ora serrata; and a shift in Bruch's membrane opening (BMO) occurring in moderately myopic eyes and typically in the temporal/inferior direction. The BMO shift leads to an overhang of Bruch's membrane (BM) into the nasal intrapapillary compartment and BM absence in the temporal region (i.e., parapapillary gamma zone), optic disc ovalization due to shortening of the ophthalmoscopically visible horizontal disc diameter, fovea-optic disc distance elongation, reduction in angle kappa, and straightening/stretching of the papillomacular retinal blood vessels and retinal nerve fibers. Highly myopic eyes additionally show an enlargement of all layers of the optic nerve canal, elongation and thinning of the lamina cribrosa, peripapillary scleral flange (i.e., parapapillary delta zone) and peripapillary choroidal border tissue, and development of circular parapapillary beta, gamma, and delta zone. Pathological features of high myopia include development of macular linear RPE defects (lacquer cracks), which widen to round RPE defects (patchy atrophies) with central BM defects, macular neovascularization, myopic macular retinoschisis, and glaucomatous/glaucoma-like and non-glaucomatous optic neuropathy. BM thickness is unrelated to axial length. Including the change in eye shape from a sphere in emmetropia to a prolate (rotational) ellipsoid in myopia, the features may be explained by a primary BM enlargement in the retro-equatorial/equatorial region leading to axial elongation.

Biomarker Signature in Aqueous Humor Mirrors Lens Epithelial Cell Activation: New Biomolecular Aspects from Cataractogenic Myopia

Inflammatory, vasculogenic, and profibrogenic factors have been previously reported in vitreous (VH) and aqueous (AH) humors in myopic patients who underwent cataract surgery. In light of this, we selected some mediators for AH and anterior-capsule-bearing lens epithelial cell (AC/LEC) analysis, and AH expression was correlated with LEC activation (epithelial-mesenchymal transition and EMT differentiation) and axial length (AL) elongation. In this study, AH (97; 41M/56F) and AC/LEC samples (78; 35M/43F) were collected from 102 patients who underwent surgery, and biosamples were grouped according to AL elongation. Biomolecular analyses were carried out for AH and LECs, while microscopical analyses were restricted to whole flattened AC/LECs. The results showed increased levels of interleukin (IL)-6, IL-8, and angiopoietin-2 (ANG)-2 and decreased levels of vascular endothelium growth factor (VEGF)-A were detected in AH depending on AL elongation. LECs showed EMT differentiation as confirmed by the expression of smooth muscle actin (α-SMA) and transforming growth factor (TGF)-βR1/TGFβ isoforms. A differential expression of IL-6R/IL-6, IL-8R/IL-8, and VEGF-R1/VEGF was observed in the LECs, and this expression correlated with AL elongation. The higher VEGF-A and lower VEGF-D transcript expressions were detected in highly myopic LECs, while no significant changes were monitored for VEGF-R transcripts. In conclusion, these findings provide a strong link between the AH protein signature and the EMT phenotype. Furthermore, the low VEGF-A/ANG-2 and the high VEGF-A/VEGF-D ratios in myopic AH might suggest a specific inflammatory and profibrogenic pattern in high myopia. The highly myopic AH profile might be a potential candidate for rating anterior chamber inflammation and predicting retinal distress at the time of cataract surgery.

Distribution of Axial Length in Australians of Different Age Groups, Ethnicities, and Refractive Errors

Purpose

Treatments are available to slow myopic axial elongation. Understanding normal axial length (AL) distributions will assist clinicians in choosing appropriate treatment for myopia. We report the distribution of AL in Australians of different age groups and refractive errors.

Methods

Retrospectively collected spherical equivalent refraction (SER) and AL data of 5938 individuals aged 5 to 89 years from 8 Australian studies were included. Based on the SER, participants were classified as emmetropes, myopes, and hyperopes. Two regression model parameterizations (piece-wise and restricted cubic splines [RCS]) were applied to the cross-sectional data to analyze the association between age and AL. These results were compared with longitudinal data from the Raine Study where the AL was measured at age 20 (baseline) and 28 years.

Results

A piece-wise regression model (with 1 knot) showed that myopes had a greater increase in AL before 18 years by 0.119 mm/year (P < 0.001) and after 18 years by 0.011 mm/year (P < 0.001) compared to emmetropes and hyperopes, with the RCS model (with 3 knots) showing similar results. The longitudinal data from the Raine Study revealed that, when compared to emmetropes, only myopes showed a significant change in the AL in young adulthood (by 0.016 mm/year, P < 0.001).

Conclusions

The AL of myopic eyes increases more rapidly in childhood and slightly in early adulthood. Further studies of longitudinal changes in AL, particularly in childhood, are required to guide myopia interventions.

Translational Relevance

The axial length of myopic eyes increases rapidly in childhood, and there is a minimal increase in the axial length in non-myopic eyes after 18 years of age.

Influencing factors associated with high myopia in Chinese college students

Background

High myopia (HM) may elicit irreversible pathological changes in the fundus and severely impair visual quality, thereby becoming a major public health issue in China. However, the influencing factors associated with HM remain unknown in Chinese college students, whose visual quality is crucial to country development.

Methods

This is a cross-sectional observational study. Two thousand three hundred and fifteen undergraduate and graduate students were initially recruited from various majors in 3 universities in Tianjin, China. Under the principle of voluntary participation and informed consent, simple random sampling was conducted in the recruited subjects while maintaining balanced number of subjects from each major. After screening with inclusion and exclusion criteria, 96 undergraduate and graduate students (186 eyes) were finally included and divided into non-HM and HM groups. The eyes of subjects were examined by optical coherence tomography angiography (OCTA) for vessel density and structure thickness at the macula and optic disc, and the subjects were surveyed by an itemized questionnaire on lifestyles and study habits.

Results

The OCTA and questionnaire results revealed 10 factors, including hemodynamic and anatomic parameters and lifestyle metrics, with statistical significance between the non-HM and HM groups. Receiver operating characteristic curve analysis showed that vessel density of the inner retina at the macula, vessel density of the radial peripapillary capillary at the optic disc, smartphone usage time, continuous near work time, and sleeping after midnight had superior values of area under the curve (AUC > 0.700). Therefore, these 5 factors were selected for univariant and multivariant logistic regression analyses. A prediction model comprising the 5 influencing factors had an AUC of 0.940 and 95% CI of 0.908-0.972.

Conclusion

This study for the first time identified the vessel density of the inner retina at the macula, the vessel density of the radial peripapillary capillary at the optic disc, smartphone usage time, continuous near work time, and sleeping after midnight as influencing factors associated with HM in Chinese college students. A prediction model comprising the 5 influencing factors was proposed for calculating likelihood of a Chinese college student developing HM, based on which lifestyle improvement and medical intervention might be recommended.

Predicting axial length in patients with Marfan syndrome and ectopia lentis after modified capsular tension ring and intraocular lens implantation

PURPOSE

To predict the growth of axial length (AL) in patients with Marfan syndrome (MFS) and ectopia lentis (EL).

SETTING

Eye and ENT Hospital of Fudan University, Shanghai, China.

DESIGN

Consecutive retrospective case series.

METHODS

Eyes were evaluated that had modified capsular tension ring and intraocular lens (IOL) implantation. The rate of AL growth (RALG) was calculated using AL divided by log10-transformed age. A multivariate linear regression model of RALG was developed after validation.

RESULTS

128 patients with MFS and EL were enrolled with a median follow-up duration of about 3 years. RALG was independent of age between 3 years and 15 years old ( P = .799) and decreased to 0 thereafter ( P = .878). Preoperative AL was associated with RALG in patients under 15 years old ( P = .003). Beta values for the final model of RALG were as below: intercept (-9.794) and preoperative AL (0.664). The postoperative AL was predicted as: postAL = preAL + RALG × log 10 ([postAge + 0.6]/[preAge + 0.6]). The mean prediction error was -0.003 (95% CI, -0.386 to 0.3791) mm and the mean absolute percentage error was 1.93% (95% CI, 0.73% to 3.14%). A Python-based calculator was developed to use the predicted AL in selecting IOL power and setting undercorrection.

CONCLUSIONS

The AL growth of patients with MFS followed a logarithmic pattern and ceased at about age 15. A prediction model of postoperative AL was established for individual MFS patients between 3 and 15 years old, which could potentially optimize the IOL power selection.

Prevalence and associated health and lifestyle factors of myopic maculopathy in northern China: the Kailuan eye study

BACKGROUND

To evaluate the prevalence and associated health and lifestyle factors of myopic maculopathy (MM) in a northern Chinese industrial city.

METHODS

The cross-sectional Kailuan Eye Study included subjects who participated in the longitudinal Kailuan Study in 2016. Ophthalmologic and general examinations were performed on all the participants. MM was graded based on fundus photographs using the International Photographic Classification and Grading System. The prevalence of MM was evaluated. Univariate and multiple logistic regression were adopted to evaluated risk factors of MM.

RESULTS

The study included 8330 participants with gradable fundus photographs for MM and ocular biometry data. The prevalence of MM was 1.11% (93/8330; 95% confidence interval [CI] 0.89-1.33%). Diffuse chorioretinal atrophy, patchy chorioretinal atrophy, macular atrophy, and plus lesions were observed in 72 (0.9%), 15 (0.2%), 6 (0.007%), and 32 eyes (0.4%), respectively. MM was more common in eyes with longer axial length (OR 4.517; 95%CI 3.273 to 6.235) and in participants with hypertension (OR 3.460; 95%CI 1.152 to 10.391), and older age (OR 1.084; 95%CI 1.036 to 1.134).

CONCLUSIONS

The MM was present in 1.11% of the northern Chinese individuals 21 years or older and the associate factors include longer axial length, older age, and hypertension.

Axial Shortening in Myopic Children after Repeated Low-Level Red-Light Therapy: Post Hoc Analysis of a Randomized Trial

INTRODUCTION

Axial length (AL) elongation in myopia is considered irreversible. We aimed to systemically report unexpected AL shortening observed in a randomized clinical trial (RCT) after repeated low-level red-light (RLRL) therapy.

METHODS

This is a post hoc analysis of a multicenter, single-masked RCT. Two hundred sixty-four myopic children aged 8-13 years allocated to RLRL treatment (intervention group) or a single vision spectacle (SVS, control group) were included. AL was measured using an IOL-master 500 at baseline, 1-, 3-, 6-, and 12-month follow-up visits. AL shortening was defined as AL reduction from baseline to follow-up visits at three cutoffs: > 0.05 mm, > 0.10 mm, and > 0.20 mm. Frequency of AL shortening at different cutoffs was calculated. Analysis was done with intent to treat (ITT).

RESULTS

At 12-months follow up, frequency of AL shortening > 0.05 mm was 26/119 (21.85%) and 2/145 (1.38%) for the RLRL group versus the control group, respectively. The frequency was 18/119 (15.13%) versus 0/145 (0%) for AL shortening > 0.10 mm, and 7/119 (5.88%) versus 0/145 (0%), for AL shortening > 0.20 mm, respectively (p < 0.001). Mean AL shortening after 12 months (SD) was -0.156 (0.086) mm in the RLRL group and -0.06 mm in the control group. Age was significantly associated with AL shortening in the multivariable analysis. For the RLRL group that exhibited AL shortening (n = 56), choroidal thickness (ChT) thickening (0.056 mm) could only explain 28.3% of AL shortening (-0.20 mm).

CONCLUSION

Nearly a quarter of children had > 0.05 mm AL shortening following 12 months of RLRL therapy, whereas AL shortening rarely occurred among controls.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04073238).

Effects of Myopia on Rates of Change in Optical Coherence Tomography Measured Retinal Layer Thicknesses in People with Multiple Sclerosis and Healthy Controls

PURPOSE

To quantify the associations of myopia with longitudinal changes in retinal layer thicknesses in people with multiple sclerosis (PwMS) and healthy controls (HC).

METHODS

A cohort of PwMS and HC with recorded refractive error (RE) prospectively scanned on Cirrus HD-OCT at the Johns Hopkins MS Center was assessed for inclusion. Exclusion criteria included OCT follow-up < 6 months, ocular comorbidities, incidental OCT pathologies, and inadequate scan quality. Eyes were classified as having high myopia (HM) (RE≤ -6 diopters), low myopia (LM) (RE> -6 and ≤ -3 diopters), or no myopia (NM) (RE> -3 and ≤ +2.75). Linear mixed-effects regression models were used in analyses.

RESULTS

A total of 213 PwMS (eyes: 67 HM, 98 LM, 207 NM) and 80 HC (eyes: 26 HM, 37 LM, 93 NM) were included. Baseline average ganglion cell/inner plexiform (GCIPL) and peri-papillary retinal nerve fiber layer (pRNFL) thicknesses were lower in MS HM compared with MS NM (diff: -3.2 µm, 95% CI: -5.5 to -0.8, p = 0.008 and -5.3 µm, 95% CI: -9.0 to -1.7, p = 0.004, respectively), and similarly in HC HM, as compared with HC NM. Baseline superior, inferior, and nasal pRNFL thicknesses were lower in HM compared with NM, while temporal pRNFL thickness was higher, both in MS and HC (MS: 7.1 µm, 95% CI: 2.7-11.6, p = 0.002; HC: 4.7 µm, 95% CI: -0.3 to 9.7, p = 0.07). No longitudinal differences in rates of GCIPL change were noted between HM and LM vs. NM, either in MS or HC.

CONCLUSION

Cross-sectional differences in average GCIPL and pRNFL thicknesses are commonly seen in people with HM as compared to reference normative values from people with NM and can lead to false attribution of pathology if RE is not taken into account. However, our study suggests that longitudinal changes in average GCIPL thickness in PwMS with myopia are similar in magnitude to PwMS with NM, and therefore are appropriate for monitoring disease-related pathology.

Exploration of static functional connectivity and dynamic functional connectivity alterations in the primary visual cortex among patients with high myopia via seed-based functional connectivity analysis

Aim

This study was conducted to explore differences in static functional connectivity (sFC) and dynamic functional connectivity (dFC) alteration patterns in the primary visual area (V1) among high myopia (HM) patients and healthy controls (HCs) via seed-based functional connectivity (FC) analysis.

Methods

Resting-state functional magnetic resonance imaging (fMRI) scans were performed on 82 HM patients and 59 HCs who were closely matched for age, sex, and weight. Seed-based FC analysis was performed to identify alterations in the sFC and dFC patterns of the V1 in HM patients and HCs. Associations between mean sFC and dFC signal values and clinical symptoms in distinct brain areas among HM patients were identified via correlation analysis. Static and dynamic changes in brain activity in HM patients were investigated by assessments of sFC and dFC via calculation of the total time series mean and sliding-window analysis.

Results

In the left anterior cingulate gyrus (L-ACG)/left superior parietal gyrus (L-SPG) and left V1, sFC values were significantly greater in HM patients than in HCs. In the L-ACG and right V1, sFC values were also significantly greater in HM patients than in HCs [two-tailed, voxel-level P < 0.01, Gaussian random field (GRF) correction, cluster-level P < 0.05]. In the left calcarine cortex (L-CAL) and left V1, dFC values were significantly lower in HM patients than in HCs. In the right lingual gyrus (R-LING) and right V1, dFC values were also significantly lower in HM patients than in HCs (two-tailed, voxel-level P < 0.01, GRF correction, cluster-level P < 0.05).

Conclusion

Patients with HM exhibited significantly disturbed FC between the V1 and various brain regions, including L-ACG, L-SPG, L-CAL, and R-LING. This disturbance suggests that patients with HM could exhibit impaired cognitive and emotional processing functions, top-down control of visual attention, and visual information processing functions. HM patients and HCs could be distinguished from each other with high accuracy using sFC and dFC variabilities. These findings may help to identify the neural mechanism of decreased visual performance in HM patients.

Topical Review: Studies on Management of Myopia Progression from 2019 to 2021

SIGNIFICANCE

Myopia is a common eye condition that increases the risk of sight-threatening complications. Each additional diopter increases the chance of complications. The purpose of this review was to make an overview of myopia control treatment options for children with myopia progression.In this nonsystematic review, we searched PubMed and Cochrane databases for English-language studies published from 2019 to September 2021. Emphasis was given to selection of randomized controlled trials. Nineteen randomized controlled trials and two retrospective studies were included. Topical atropine and orthokeratology remain the most used treatments, whereas lenses with novel designs are emerging treatments. Overall myopia progression in the treatment groups for low-dose atropine and orthokeratology was lower than in the control groups, and their efficacy was reported in several randomized controlled trials and confirmed by various systematic reviews and meta-analysis. The findings of myopia progression and axial elongation for the MiSight, defocus incorporated multiple segment spectacle lens, highly aspherical lenslets, and diffusion optics technology spectacle lens were comparable. Public health interventions to optimize environmental influences may also be important strategies to control myopia. Optimal choice of management of myopia depends on treatment availability, acceptability to child and parents, and specific patient features such as age, baseline myopia, and lifestyle. Eye care providers need to understand the advantages and disadvantages of each therapy to best counsel parents of children with myopia.

Higher Circulating Levels of Neutrophils and Basophils Are Linked to Myopic Retinopathy

This retrospective study investigated circulating immune cell alteration in patients with myopic retinopathy. Blood test results and demographic and ocular information of 392 myopic patients and 129 emmetropia controls who attended Changsha Aier Eye Hospital from May 2017 to April 2022 were used in this study. Compared with emmetropia, the percentages of neutrophils and basophils and neutrophil/lymphocyte ratio were significantly higher in myopic patients, whereas the percentages of monocytes and lymphocytes and the counts of lymphocytes and eosinophils were significantly lower in myopic patients. After adjusting for age and hypertension/diabetes, the difference remained. Interestingly, the platelet counts were significantly lower in myopic patients after the adjustments. Further subgroup analysis using multivariable linear regression showed that higher levels of neutrophils, neutrophil/lymphocyte ratio, and platelet/lymphocyte ratio, lower levels of monocytes, eosinophils, lymphocytes, and platelets, were related to myopic peripheral retinal degeneration (mPRD) and posterior staphyloma (PS). A higher level of basophils was linked to myopic choroidal neovascularization (mCNV). Our results suggest that higher levels of circulating neutrophils and neutrophil/lymphocyte ratio, lower monocytes, eosinophils, lymphocytes, and platelets are related to mild myopic retinopathy. A higher level of circulating basophils is related to the severe form of myopic retinopathy, such as mCNV.

Assessment of changes in optic disc parameters and peripapillary retinal nerve fiber layer thickness in myopic patients and its correlation with axial length and degree of myopia

Purpose

The present study aimed to assess the changes in optic disc and peripapillary retinal nerve fiber layer (RNFL) parameters in myopic patients and its correlation with axial length (AL) and spherical equivalent (SE) using optical coherence tomography (OCT).

Methods

This was a cross-sectional study carried out from August 2019 to September 2021 in the ophthalmology department of a tertiary care hospital in eastern India. Myopic patients in the age group of 20-40 years and SE between - 0.5 to - 10 Diopters (D) were included in the study. Patients were divided into two groups on the basis of degree of myopia and AL. Appropriate statistical analysis was done at the end of the study period.

Results

The study included 307 eyes of 307 myopic patients. There were 181 females (58.96%) and 126 males (41.04%). The mean age of the patients enrolled for the study was 28.78 ± 5.76 years. Statistically significant difference (P < 0.001) was found between SE and AL in between the subgroups of A and B. With every 1 D increase in SE, the average peripapillary RNFL thickness decreased by 0.61 μ while with every 1 mm increase in AL, the average peripapillary RNFL thickness was found to reduce by 1.03 μ.

Conclusion

Analysis of optic nerve head parameters and RNFL thickness by OCT for the diagnosis should be compared with a normative control group that has been matched for refractive error and AL instead of comparison with a normative database that has only been age matched.

Hospital-Based Study of Risk Factors Associated with Development of Myopic Macular Neovascularization in Highly Myopic Eyes

INTRODUCTION

Myopic macular neovascularization (MNV) is the most common cause of a reduction of central vision in eyes with pathologic myopia, and it can progress to macular atrophy in the long term. The aim of this study was to determine the risk factors associated with the development of MNVs.

METHODS

There were 17,198 follow-up records from 5,409 eyes of 2,784 highly myopic patients that were reviewed. The general information and ophthalmic information in the records were studied. The significance of the correlations of factors associated with the development and predicting the development of myopic MNV were determined.

RESULTS

Being a woman (odds ratio [OR] = 0.727, p < 0.001), having a longer axial length (OR = 0.948, p < 0.001), having a poorer baseline best-correct visual acuity (BCVA, OR = 2.098, p < 0.001), having severe myopic maculopathy (overall: p < 0.001), prior myopic MNV in the fellow eye (OR = 4.105, p < 0.001), presence of patchy atrophy (overall p < 0.001), lacquer cracks (OR = 1.718, p < 0.001), prior foveal retinal detachment (RD, OR = 3.269, p < 0.001), prior macular hole (MH, OR = 0.641, p < 0.001), prior macular retinoschisis (OR = 1.533, p < 0.001), and prior macular edema (OR = 1.508, p < 0.001) were significantly correlated with the development of myopic MNV. Eyes with MNV and patchy atrophy would require an intensive follow-up examination for myopic patients as the fellow eye would have a risk of >70% for the development of myopic MNV in 3 years and nearly 80% in 5 years.

CONCLUSIONS

Clinicians need to pay special attention to eyes with severe grades of myopic maculopathy, prior myopic MNV in the fellow eye, presence of patchy atrophy, and prior foveal retinal detachment to determine the onset of myopic MNV.

Intraocular Amphiregulin antibody and axial elongation in nonhuman primates

Purpose

To examine the effect of intraocularly applied amphiregulin antibody on physiological axial elongation in young nonhuman primates.

Methods

The experimental study included six male 12-months-old macaque nonhuman primates (body weight:2.46 ± 0.25kg;range:2.20-2.90kg). In the experimental group (n=3 animals), three intravitreal injections of amphiregulin antibody (100μg/50μl) were applied to the left eyes at intervals of 4-6 weeks, and injections of phosphate buffered solution (50μl) were applied to the right eyes. Three other animals were assigned to a blank control group.

Results

During the study period of 23.6 weeks, axial length in the experimental group did not change in the left eyes (18.91 ± 0.37mm to 18.94 ± 0.67mm;P=0.90), while it linearly increased in the right eyes (18.87 ± 0.38mm to 19.24 ± 0.53mm;P=0.056) and in the control group (left eyes:19.15 ± 0.22mm to 19.48 ± 0.22mm;P=0.009; right eyes:19.17 ± 0.15 mm to 19.46 ± 0.23 mm;P=0.024). The interocular difference in axial elongation increased in the experimental group from -0.11 ± 0.12mm at 4 weeks after baseline to -0.34 ± 0.15mm at the study end, while in the control group, the interocular side difference did not change significantly (from 0.01 ± 0.10 mm to 0.03 ± 0.08 mm;P=0.38). The difference in the interocular difference in axial elongation between the two groups was significant at 8 weeks (P=0.01), 15 weeks (P=0.007), and at study end (P=0.02). The interocular difference in axial length correlated with the interocular difference in vitreous cavity length (standardized regression coefficient beta:0.85;P<0.001). The interocular axial length difference was inversely associated with the interocular refractive error difference (beta:-0.49;P<0.001).

Conclusions

Intraocularly applied amphiregulin antibody (100μg) reduced the physiological ocular axial elongation in juvenile nonhuman primates.

Safety and tolerability of intravitreal cetuximab in young and adult rabbits

To assess safety and tolerability of intraocularly applied cetuximab as epidermal growth factor receptor antibody, we conducted the experimental study which consisted of groups of adult rabbits (body weight: 2.4 kg) and young rabbits (body weight: 1.6 kg). All animals received three intravitreal injections of 0.5 mg cetuximab (Erbitux) (0.10 mL; 5 mg cetuximab/mL) into their right eyes in 4-week intervals, while the contralateral eyes received intravitreal injections of Ringer's solution. All animals underwent regular ophthalmological examinations at baseline and two-week intervals. Four weeks after the last injection, the animals were sacrificed, and the eyes were enucleated, fixed and examined by light microscopy. The study included 10 adult rabbits (age: 18 weeks; range: 17–19 weeks) and 8 young rabbits (age: 8 weeks; range: 7–10 weeks). Biometric measurements of axial length, anterior chamber depth and lens thickness and intraocular pressure readings did not differ significantly (all P > 0.05, Bonferroni corrected) between the right (study) eyes and the left (control) eyes, neither in the young nor in the adult rabbit group. Signs of intraocular inflammation or fundus peculiarities were not detected. Thickness of the outer nuclear layer, inner nuclear layer, combined outer and inner nuclear layer and outer plexiform layer, and total retina, measured at the posterior pole, posterior pole/equator midpoint, equator, and ora serrata region, did not vary significantly between study eyes and control eyes (all P > 0.05, Bonferroni corrected). The results suggest that repeated intravitreal application of cetuximab did not result in any detected intraocular toxic or destructive effect in young and adult rabbits, concurring with the notion of an intraocular tolerability of cetuximab.

Higher-order aberrations and their association with axial elongation in highly myopic children and adolescents

BACKGROUND

Vision-dependent mechanisms play a role in myopia progression in childhood. Thus, we investigated the distribution of ocular and corneal higher-order aberrations (HOAs) in highly myopic Chinese children and adolescents and the relationship between HOA components and 1-year axial eye growth.

METHODS

Baseline cycloplegic ocular and corneal HOAs, axial length (AL), spherical equivalent (SE), astigmatism and interpupillary distance (IPD) were determined for the right eyes of 458 highly myopic (SE ≤-5.0D) subjects. HOAs were compared among baseline age groups (≤12 years, 13-15 years and 16-18 years). Ninety-nine subjects completed the 1-year follow-up. Linear mixed model analyses were applied to determine the association between HOA components, other known confounding variables (age, gender, SE, astigmatism and IPD) and axial growth. A comparison with data from an early study of moderate myopia were conducted.

RESULTS

Almost all ocular HOAs and few corneal HOAs exhibited significant differences between different age groups (all p<0.05). After 1 year, only ocular HOA components was significantly negative associated with a longer AL, including secondary horizontal comatic aberration (p=0.019), primary spherical aberration (p<0.001) and spherical HOA (p=0.026). Comparing with the moderate myopia data, the association of comatic aberration with AL growth was only found in high myopia.

CONCLUSION

In highly myopic children and adolescents, lower levels of annual ocular secondary horizontal comatic aberration changes, besides spherical aberrations, were associated with axial elongation. This suggests that ocular HOA plays a potential role in refractive development in high myopia.