The quality of life in patients with pathologic myopia

Retinal characteristics in eyes with pathologic myopia among individuals self-identifying as Black

OBJECTIVE

Investigate retinal characteristics of pathologic myopia (PM) among patients self-identifying as Black.

DESIGN

Retrospective cohort single-institution retrospective medical record review.

METHODS

Adult patients between January 2005 and December 2014 with International Classification of Diseases (ICD) codes consistent with PM and given 5-year follow-up were evaluated. The Study Group consisted of patients self-identifying as Black, and the Comparison Group consisted of those not self-identifying as Black. Ocular features at study baseline and 5-year follow-up visit were evaluated.

RESULTS

Among 428 patients with PM, 60 (14%) self-identified as Black and 18 (30%) had baseline and 5-year follow-up visits. Of the remaining 368 patients, 63 were in the Comparison Group. For the study (n = 18) and Comparison Group (n = 29), median (25th percentile, 75th percentile) baseline visual acuity was 20/40 (20/25, 20/50) and 20/32 (20/25, 20/50) in the better-seeing eye and 20/70 (20/50, 20/1400) and 20/100 (20/50, 20/200), respectively, in the worse-seeing eye. In the eyes that did not have choroidal neovascularization (CNV) in the study and Comparison Group, median study baseline optical coherence tomography central subfield thickness was 196 μm (169, 306 μm) and 225 μm (191, 280 μm), respectively, in the better-seeing eye and 208 μm (181, 260 μm) and 194 μm (171, 248 μm), respectively, in the worse-seeing eye. Baseline prevalence of CNV was 1 Study Group eye (3%) and 20 Comparison Group eyes (34%). By the 5-year visit, zero (0%) and 4 (15%) additional eyes had CNV in the study and Comparison Group, respectively.

CONCLUSION

These findings suggest that the prevalence and incidence of CNV may be lower in patients with PM self-identifying as Black when compared with individuals of other races.

Performance of artificial intelligence for the detection of pathological myopia from colour fundus images: a systematic review and meta-analysis

BACKGROUND

Pathological myopia (PM) is a major cause of worldwide blindness and represents a serious threat to eye health globally. Artificial intelligence (AI)-based methods are gaining traction in ophthalmology as highly sensitive and specific tools for screening and diagnosis of many eye diseases. However, there is currently a lack of high-quality evidence for their use in the diagnosis of PM.

METHODS

A systematic review and meta-analysis of studies evaluating the diagnostic performance of AI-based tools in PM was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance. Five electronic databases were searched, results were assessed against the inclusion criteria and a quality assessment was conducted for included studies. Model sensitivity and specificity were pooled using the DerSimonian and Laird (random-effects) model. Subgroup analysis and meta-regression were performed.

RESULTS

Of 1021 citations identified, 17 studies were included in the systematic review and 11 studies, evaluating 165,787 eyes, were included in the meta-analysis. The area under the summary receiver operator curve (SROC) was 0.9905. The pooled sensitivity was 95.9% [95.5%-96.2%], and the overall pooled specificity was 96.5% [96.3%-96.6%]. The pooled diagnostic odds ratio (DOR) for detection of PM was 841.26 [418.37-1691.61].

CONCLUSIONS

This systematic review and meta-analysis provides robust early evidence that AI-based, particularly deep-learning based, diagnostic tools are a highly specific and sensitive modality for the detection of PM. There is potential for such tools to be incorporated into ophthalmic public health screening programmes, particularly in resource-poor areas with a substantial prevalence of high myopia.

Prevalence of uncorrected distance refractive errors and associated risk factors in employees of an academic centre

BACKGROUND

Uncorrected refractive error (RE) may affect the work performance of adults in the workplace. The aim of current study was to determine the prevalence of corrected and uncorrected RE, and the determinants of uncorrected RE in adult employees of a university.

METHODS

This was a cross-sectional study of Tehran University Medical Sciences' staff. Besides demographic and some specific questionnaires, ophthalmic examinations including the measurement of uncorrected visual acuity (UCVA), best spectacles corrected visual acuity (BCVA), and presenting visual acuity were performed for all participants. The need for spectacles was defined as UCVA worse than 6/12 in the better eye that could be corrected to better than 6/12 with spectacles based on subjective refraction.

RESULTS

In total, 4460 individuals with mean age of 42.32 ± 8.80 were included in the study. The VA of the better eye was 0.01 ± 0.05 logMAR for BCVA, 0.13 ± 0.26 for UCVA, and 0.05 ± 0.12 for presenting VA. Prevalence of RE was 15.7%, including uncorrected RE of 5% and spectacles coverage (corrected RE) of 10.7%. The proportion of individuals with elementary education and poor-fair status of general health were 1.62 times higher in the uncorrected group. In the univariate analysis, type of occupation (office versus non-office workers), socioeconomic status, and insurance of employees were not related to uncorrected RE (all P > 0.4). Myopia was the only factor associated with uncorrected RE in logistic regression analysis (odds ratio = 2.73, 95%CI = 1.02-7.31, P = 0.04).

CONCLUSION

The prevalence of uncorrected RE and spectacle coverage were 5% and 10.7%, respectively. Myopia was almost three times more likely to be associated among employees with uncorrected RE.

Patient reported outcomes for phosphomannomutase 2 congenital disorder of glycosylation (PMM2-CDG): listening to what matters for the patients and health professionals

Background

Congenital disorders of glycosylation (CDG) are a growing group of rare genetic disorders. The most common CDG is phosphomannomutase 2 (PMM2)-CDG which often has a severe clinical presentation and life-limiting consequences. There are no approved therapies for this condition. Also, there are no validated disease-specific quality of life (QoL) scales to assess the heterogeneous clinical burden of PMM2-CDG which presents a challenge for the assessment of the disease severity and the impact of a certain treatment on the course of the disease.

Aim and methods

This study aimed to identify the most impactful clinical signs and symptoms of PMM2-CDG, and specific patient and observer reported outcome measures (PROMs and ObsROMs, respectively) that can adequately measure such impact on patients’ QoL. The most burdensome signs and symptoms were identified through input from the CDG community using a survey targeting PMM2-CDG families and experts, followed by family interviews to understand the real burden of these symptoms in daily life. The list of signs and symptoms was then verified and refined by patient representatives and medical experts in the field. Finally, a literature search for PROMs and ObsROMs used in other rare or common diseases with similar signs and symptoms to those of PMM2-CDG was performed.

Results

Twenty-four signs/symptoms were identified as the most impactful throughout PMM2-CDG patients’ lifetime. We found 239 articles that included tools to measure those community-selected PMM2-CDG symptoms. Among them, we identified 80 QoL scales that address those signs and symptoms and, subsequently, their psychometric quality was analysed. These scales could be applied directly to the PMM2-CDG population or adapted to create the first PMM2-CDG-specific QoL questionnaire.

Conclusion

Identifying the impactful clinical manifestations of PMM2-CDG, along with the collection of PROMs/ObsROMs assessing QoL using a creative and community-centric methodology are the first step towards the development of a new, tailored, and specific PMM2-CDG QoL questionnaire. These findings can be used to fill a gap in PMM2-CDG clinical development. Importantly, this methodology is transferable to other CDG and rare diseases with multiple signs and symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02551-y.

Coronavirus disease 2019 outbreak and associated public health measures increase the progression of myopia among children and adolescents: Evidence synthesis

Purpose

Although studies have suggested that the coronavirus disease 2019 (COVID‐19) outbreak increased myopia progression, they had different settings and analysis methods. This study compared myopia progression before and during the COVID‐19 outbreak using meta‐analysis.

Methods

Relevant literature was searched on EMBASE, PubMed, ClinEpiDB and Web of Science and reviewed until 8 October 2021. The Newcastle–Ottawa Scale was used to evaluate the quality of the original studies. The mean difference of change in spherical equivalent refraction (SER) was used for evaluation before and during the COVID‐19 pandemic.

Results

The meta‐analysis included eight studies with 773, 797 individuals aged 5–18 years. Pooled analysis indicated that the mean difference of annual myopia progression during the pandemic was 0.41 D higher (95% confidence interval [CI]: 0.35–0.48, p < 0.01) than before the pandemic. Subgroup analysis using cycloplegic (mean difference, 0.30 D; 95% CI, 0.22–0.38; p < 0.01) or noncycloplegic refraction (mean difference, 0.60 D; 95% CI, 0.27–0.93; p < 0.01) indicated that the mean difference of annual myopia progression during COVID‐19 significantly increased in both refractive measurements.

Conclusion

Our findings demonstrated that the COVID‐19 pandemic accelerated myopic progression compared to the past. Government policies are urgently required to prevent and control myopia progression.

Pathologic myopia: advances in imaging and the potential role of artificial intelligence

Pathologic myopia is a severe form of myopia that can lead to permanent visual impairment. The recent global increase in the prevalence of myopia has been projected to lead to a higher incidence of pathologic myopia in the future. Thus, imaging myopic eyes to detect early pathological changes, or predict myopia progression to allow for early intervention, has become a key priority. Recent advances in optical coherence tomography (OCT) have contributed to the new grading system for myopic maculopathy and myopic traction maculopathy, which may improve phenotyping and thus, clinical management. Widefield fundus and OCT imaging has improved the detection of posterior staphyloma. Non-invasive OCT angiography has enabled depth-resolved imaging for myopic choroidal neovascularisation. Artificial intelligence (AI) has shown great performance in detecting pathologic myopia and the identification of myopia-associated complications. These advances in imaging with adjunctive AI analysis may lead to improvements in monitoring disease progression or guiding treatments. In this review, we provide an update on the classification of pathologic myopia, how imaging has improved clinical evaluation and management of myopia-associated complications, and the recent development of AI algorithms to aid the detection and classification of pathologic myopia.

IMI Pathologic Myopia

Pathologic myopia is a major cause of visual impairment worldwide. Pathologic myopia is distinctly different from high myopia. High myopia is a high degree of myopic refractive error, whereas pathologic myopia is defined by a presence of typical complications in the fundus (posterior staphyloma or myopic maculopathy equal to or more serious than diffuse choroidal atrophy). Pathologic myopia often occurs in eyes with high myopia, however its complications especially posterior staphyloma can also occur in eyes without high myopia.

Owing to a recent advance in ocular imaging, an objective and accurate diagnosis of pathologic myopia has become possible. Especially, optical coherence tomography has revealed novel lesions like dome-shaped macula and myopic traction maculopathy. Wide-field optical coherence tomography has succeeded in visualizing the entire extent of large staphylomas. The effectiveness of new therapies for complications have been shown, such as anti-VEGF therapies for myopic macular neovascularization and vitreoretinal surgery for myopic traction maculopathy.

Myopia, especially childhood myopia, has been increasing rapidly in the world. In parallel with an increase in myopia, the prevalence of high myopia has also been increasing. However, it remains unclear whether or not pathologic myopia will increase in parallel with an increase of myopia itself. In addition, it has remained unclear whether genes responsible for pathologic myopia are the same as those for myopia in general, or whether pathologic myopia is genetically different from other myopia.

Efficacy and safety of 0.01% atropine for prevention of childhood myopia in a 2-year randomized placebo-controlled study

PURPOSE

Atropine eye drops prevent the progression of myopia, but their use has not been tested in the Japanese schoolchildren population. Here, we evaluate the efficacy and safety of 0.01% atropine eye drops for myopia control in Japanese children.

STUDY DESIGN

Multicenter (7 university hospitals), randomized, double-masked, placebo-controlled trial.

METHODS

Participants were 171 Japanese schoolchildren aged 6 to 12 years, with progressive myopia, spherical equivalence (SE) of -1.00 to -6.00 diopters (D), and astigmatism of ≤1.5 D. They were randomized to receive either 0.01% atropine (n=85) or placebo (n=86) eye drops once nightly OU for 24 months. Primary and secondary efficacy endpoints were changes in SE and axial length (AL), respectively, from baseline to month 24.

RESULTS

Data from 168 subjects were analyzed. At month 24, compliance was similar in both groups (atropine: 83.3%; placebo: 85.7%). The least squares mean change in SE and AL from baseline were, respectively, -1.26 D (95% confidence interval [CI]: -1.35, -1.17) and 0.63 mm (0.59, 0.67) for atropine and -1.48 D (- 1.57, -1.39) and 0.77 mm (0.73, 0.81) for placebo. Inter-group differences were 0.22 D (95% CI: 0.09, 0.35; P < 0.001) for SE and - 0.14 mm (-0.20, -0.08; P < 0.001) for AL. Three patients experienced mild allergic conjunctivitis side effects, with no inter-group difference in incidence (atropine: 2.4%; 2/84 patients; placebo: 1.4%; 1/84 patients).

CONCLUSION

With good compliance, 0.01% atropine is effective and safe for preventing the progression of childhood myopia.

Reducing the Global Burden of Myopia by Delaying the Onset of Myopia and Reducing Myopic Progression in Children: The Academy's Task Force on Myopia

In 2019, the American Academy of Ophthalmology (AAO) created the Task Force on Myopia in recognition of the substantial global increases in myopia prevalence and its associated complications. The Task Force, led by Richard L. Abbott, MD, and Donald Tan, MD, comprised recognized experts in myopia prevention and treatment, public health experts from around the world, and organization representatives from the American Academy of Family Physicians, American Academy of Optometry, and American Academy of Pediatrics. The Academy's Board of Trustees believes that myopia is a high-priority cause of visual impairment, warranting a timely evaluation and synthesis of the scientific literature and formulation of an action plan to address the issue from different perspectives. This includes education of physicians and other health care providers, patients and their families, schools, and local and national public health agencies; defining health policies to ameliorate patients' access to appropriate therapy and to promote effective public health interventions; and fostering promising avenues of research.

Subjective Happiness and Sleep in University Students with High Myopia

Purpose: Recent investigations described a host of disadvantageous myopia comorbidities including decreased QOL, depression, and sleep problems. The present study evaluated mental status and habitual sleep in young subjects with myopia based on the reported association between myopic error and psychiatric profiles. Methods: This cross-sectional study surveyed 153 university students using a questionnaire containing the Pittsburgh Sleep Quality Index (PSQI), Subjective Happiness Scale (SHS), short morningness/eveningness questionnaire, and Hospital Anxiety and Depression Scale (HADS). Results: Participants were classified as having high myopia (n = 44), mild myopia (n = 86), or no myopia (n = 23). The SHS and HADS scores in this cohort were significantly worse in the high myopia group than in the other two groups (p < 0.05, t-test). PSQI values were not significantly different among the three groups. Regression analysis correlated myopic error with poor SHS (p = 0.003), eveningness chronotype (p = 0.032), late wake-up time (p = 0.024), and late bedtime (p = 0.019). Conclusions: University students with myopia tended to be unhappy, have an eveningness chronotype, wake up late, and go to bed late compared to less myopic subjects. Optimal correction might, therefore, be beneficial to myopic students in addition to preventing progression to high myopia in early childhood to potentially avoid related negative effects on mental health and sleep habits in adolescence.

IMI - Industry Guidelines and Ethical Considerations for Myopia Control Report

Purpose

To discuss guidelines and ethical considerations associated with the development and prescription of treatments intended for myopia control (MC).

Methods

Critical review of published papers and guidance documents was undertaken, with a view to carefully considering the ethical standards associated with the investigation, development, registration, marketing, prescription, and use of MC treatments.

Results

The roles and responsibilities of regulatory bodies, manufacturers, academics, eye care practitioners, and patients in the use of MC treatments are explored. Particular attention is given to the ethical considerations for deciding whether to implement a MC strategy and how to implement this within a clinical trial or practice setting. Finally, the responsibilities in marketing, support, and education required to transfer required knowledge and skills to eye care practitioners and academics are discussed.

Conclusions

Undertaking MC treatment in minors creates an ethical challenge for a wide variety of stakeholders. Regulatory bodies, manufacturers, academics, and clinicians all share an ethical responsibility to ensure that the products used for MC are safe and efficacious and that patients understand the benefits and potential risks of such products. This International Myopia Institute report highlights these ethical challenges and provides stakeholders with recommendations and guidelines in the development, financial support, prescribing, and advertising of such treatments.

Prevention and Management of Myopia and Myopic Pathology

Myopia is fast becoming a global public health burden with its increasing prevalence, particularly in developed countries. Globally, the prevalence of myopia and high myopia (HM) is 28.3% and 4.0%, respectively, and these numbers are estimated to increase to 49.8% for myopia and 9.8% for HM by 2050 (myopia defined as -0.50 diopter [D] or less, and HM defined as -5.00 D or less). The burden of myopia is tremendous, as adults with HM are more likely to develop pathologic myopia (PM) changes that can lead to blindness. Accordingly, preventive measures are necessary for each step of myopia progression toward vision loss. Approaches to prevent myopia-related blindness should therefore attempt to prevent or delay the onset of myopia among children by increased outdoor time; retard progression from low/mild myopia to HM, through optical (e.g., defocus incorporated soft contact lens, orthokeratology, and progressive-additional lenses) and pharmacological (e.g., low dose of atropine) interventions; and/or retard progression from HM to PM through medical/surgical treatments (e.g., anti-VEGF therapies, macula buckling, and scleral crosslinking). Recent clinical trials aiming for retarding myopia progression have shown encouraging results. In this article, we highlight recent findings on preventive and early interventional measures to retard myopia, and current and novel treatments for PM.

The penetration and distribution of topical atropine in animal ocular tissues

PURPOSE

To conduct a multi-tissue investigation on the penetration and distribution of topical atropine in myopia treatment, and determine if atropine is detectable in the untreated contralateral eye after uniocular instillation.

METHODS

Nine mature New Zealand white rabbits were evenly divided into three groups. Each group was killed at 5, 24 and 72 hr, respectively, following uniocular instillation of 0.05 ml of 1% atropine. Tissues were sampled after enucleation: conjunctiva, sclera, cornea, iris, ciliary body, lens, retina, aqueous, and vitreous humors. The assay for atropine was performed using liquid chromatography-mass spectrometry (LC-MS), and molecular tissue distribution was illustrated using matrix-assisted laser desorption ionization-imaging mass spectrometry (MALDI-IMS) via an independent experiment on murine eyes.

RESULTS

At 5 hr, the highest (mean ± SEM) concentration of atropine was detected in the conjunctiva (19.05 ± 5.57 ng/mg, p < 0.05) with a concentration gradient established anteriorly to posteriorly, as supported by MALDI-IMS. At 24 hr, preferential binding of atropine to posterior ocular tissues occurred, demonstrating a reversal of the initial concentration gradient. Atropine has good ocular bioavailability with concentrations of two magnitudes higher than its binding affinity in most tissues at 3 days. Crossing-over of atropine to the untreated eye occurred within 5 hr post-administration.

CONCLUSION

Both transcorneal and transconjunctival-scleral routes are key in atropine absorption. Posterior ocular tissues could be important sites of action by atropine in myopic reduction. In uniocular atropine trials, cross-over effects on the placebo eye should be adjusted to enhance results reliability. Combining the use of LC-MS and MALDI-IMS can be a viable approach in the study of the ocular pharmacokinetics of atropine.

A Review of Current Concepts of the Etiology and Treatment of Myopia

Myopia occurs in more than 50% of the population in many industrialized countries and is expected to increase; complications associated with axial elongation from myopia are the sixth leading cause of blindness. Thus, understanding its etiology, epidemiology, and the results of various treatment regiments may modify current care and result in a reduction in morbidity from progressive myopia. This rapid increase cannot be explained by genetics alone. Current animal and human research demonstrates that myopia development is a result of the interplay between genetic and the environmental factors. The prevalence of myopia is higher in individuals whose both parents are myopic, suggesting that genetic factors are clearly involved in myopia development. At the same time, population studies suggest that development of myopia is associated with education and the amount time spent doing near work; hence, activities increase the exposure to optical blur. Recently, there has been an increase in efforts to slow the progression of myopia because of its relationship to the development of serious pathological conditions such as macular degeneration, retinal detachments, glaucoma, and cataracts. We reviewed meta-analysis and other of current treatments that include: atropine, progressive addition spectacle lenses, orthokeratology, and multifocal contact lenses.

Patient-reported Outcomes for Assessment of Quality of Life in Refractive Error: A Systematic Review

SIGNIFICANCE

This review has identified the best existing patient-reported outcome (PRO) instruments in refractive error. The article highlights the limitations of the existing instruments and discusses the way forward.

PURPOSE

A systematic review was conducted to identify the types of PROs used in refractive error, to determine the quality of the existing PRO instruments in terms of their psychometric properties, and to determine the limitations in the content of the existing PRO instruments.

METHODS

Articles describing a PRO instrument measuring 1 or more domains of quality of life in people with refractive error were identified by electronic searches on the MEDLINE, PubMed, Scopus, Web of Science, and Cochrane databases. The information on content development, psychometric properties, validity, reliability, and responsiveness of those PRO instruments was extracted from the selected articles. The analysis was done based on a comprehensive set of assessment criteria.

RESULTS

One hundred forty-eight articles describing 47 PRO instruments in refractive error were included in the review. Most of the articles (99 [66.9%]) used refractive error-specific PRO instruments. The PRO instruments comprised 19 refractive, 12 vision but nonrefractive, and 16 generic PRO instruments. Only 17 PRO instruments were validated in refractive error populations; six of them were developed using Rasch analysis. None of the PRO instruments has items across all domains of quality of life. The Quality of Life Impact of Refractive Correction, the Quality of Vision, and the Contact Lens Impact on Quality of Life have comparatively better quality with some limitations, compared with the other PRO instruments.

CONCLUSIONS

This review describes the PRO instruments and informs the choice of an appropriate measure in refractive error. We identified need of a comprehensive and scientifically robust refractive error-specific PRO instrument. Item banking and computer-adaptive testing system can be the way to provide such an instrument.

Retinal and Choroidal Thickness in Patients with High Myopia without Maculopathy

Objective

To evaluate macular choroidal thickness (CT) and retinal thickness in Turkish patients with high myopia without maculopathy and in normal subjects and to examine the association with age, axial length (AL), best corrected visual acuity (BCVA), cycloplegic refraction, and spherical equivalent (SE).

Methods

This prospective study was performed between January 2015 and June 2016 in the Department of Ophthalmology, Duzce University Medical Faculty. It had 65 individuals (30 patients with high myopia, 35 healthy subjects). Retinal and choroidal images were obtained using spectral-domain optical coherence tomography (OCT). Measurements (one subfoveal, three temporal, three nasal) were taken at 500 μm intervals up to 1,500 μm using the caliper system. Only the right eye was used for subsequent analysis.

Results

The mean age was 29.5 ± 14.5 years and 25.6 ± 7.0 in the high myopia and control groups, respectively. The subfoveal CT was significantly lower in the high myopia group (mean, 218.3 ± 102.25 mm) than the control group (mean, 331.83 ± 99.06 mm; p < 0.001). In both groups, the choroid was thinnest at the nasal 1,500 μm location, being 158.40 ± 90.8 μm and 301 ± 103.59 μm, respectively. Retinal thickness in both groups was thickest at the nasal 1,500 μm location and thinnest in the subfoveal region. In patients with high myopia, CT was negatively correlated with AL (r=-0.490, p=0.006) and age (r=-0.455, p=0.012).

Conclusions

Highly myopic eyes have a thinner choroid, which may be secondary to longer AL but is not an independent factor. Further studies in the field of OCT are important to exploring the pathology of high myopia.

Epidemiology of Pathologic Myopia in Asia and Worldwide

The myopia epidemic in Asia is evident because the prevalence of high myopia among young adults is higher among Asian (6.8%-21.6%) compared with non-Asian populations (2.0%-2.3%). High myopia is linked to pathologic myopia (PM), which may cause irreversible visual impairment (VI). This review will highlight updates on the prevalence of PM and the associated VI from PM. The prevalence of PM among the middle-aged and elderly (0.9%-3.1%) is higher than the prevalence among children and adolescents (<0.2%). The PM lesions detected among older adults include advanced lesions, such as posterior staphyloma, chorioretinal atrophy, lacquer cracks, and Fuchs spot (in descending frequency of occurrence). A relatively high prevalence of PM (8%) was recently reported among highly myopic young adults. As young individuals grow older, the early grades of PM lesions are likely to progress to advanced grades. Two longitudinal changes that occur frequently in PM include the enlargement of beta peripapillary atrophy and the development of chorioretinal atrophy. The lack of longitudinal changes in PM limits the causal inferences of PM. The prevalence of VI attributed to PM seems to be higher among Asian populations compared with Western and European populations. Pathologic myopia is ranked as a more important cause of blindness and low vision in Asian populations compared with Western and European populations. With the lack of effective treatment strategies and poor prognosis, PM threatens the vision health of populations in Asia and worldwide. To control this future epidemic, the prevention of myopia onset and progression is necessary.

APLP2 Regulates Refractive Error and Myopia Development in Mice and Humans

Myopia is the most common vision disorder and the leading cause of visual impairment worldwide. However, gene variants identified to date explain less than 10% of the variance in refractive error, leaving the majority of heritability unexplained (“missing heritability”). Previously, we reported that expression of APLP2 was strongly associated with myopia in a primate model. Here, we found that low-frequency variants near the 5’-end of APLP2 were associated with refractive error in a prospective UK birth cohort (n = 3,819 children; top SNP rs188663068, p = 5.0 × 10⁻⁴) and a CREAM consortium panel (n = 45,756 adults; top SNP rs7127037, p = 6.6 × 10⁻³). These variants showed evidence of differential effect on childhood longitudinal refractive error trajectories depending on time spent reading (gene x time spent reading x age interaction, p = 4.0 × 10⁻³). Furthermore, Aplp2 knockout mice developed high degrees of hyperopia (+11.5 ± 2.2 D, p < 1.0 × 10⁻⁴) compared to both heterozygous (-0.8 ± 2.0 D, p < 1.0 × 10⁻⁴) and wild-type (+0.3 ± 2.2 D, p < 1.0 × 10⁻⁴) littermates and exhibited a dose-dependent reduction in susceptibility to environmentally induced myopia (F(2, 33) = 191.0, p < 1.0 × 10⁻⁴). This phenotype was associated with reduced contrast sensitivity (F(12, 120) = 3.6, p = 1.5 × 10⁻⁴) and changes in the electrophysiological properties of retinal amacrine cells, which expressed Aplp2. This work identifies APLP2 as one of the “missing” myopia genes, demonstrating the importance of a low-frequency gene variant in the development of human myopia. It also demonstrates an important role for APLP2 in refractive development in mice and humans, suggesting a high level of evolutionary conservation of the signaling pathways underlying refractive eye development.

Gene variants identified by GWAS studies to date explain only a small fraction of myopia cases because myopia represents a complex disorder thought to be controlled by dozens or even hundreds of genes. The majority of genetic variants underlying myopia seems to be of small effect and/or low frequency, which makes them difficult to identify using classical genetic approaches, such as GWAS, alone. Here, we combined gene expression profiling in a monkey model of myopia, human GWAS, and a gene-targeted mouse model of myopia to identify one of the “missing” myopia genes, APLP2. We found that a low-frequency risk allele of APLP2 confers susceptibility to myopia only in children exposed to large amounts of daily reading, thus, providing an experimental example of the long-hypothesized gene-environment interaction between nearwork and genes underlying myopia. Functional analysis of APLP2 using an APLP2 knockout mouse model confirmed functional significance of APLP2 in refractive development and implicated a potential role of synaptic transmission at the level of glycinergic amacrine cells of the retina for the development of myopia. Furthermore, mouse studies revealed that lack of Aplp2 has a dose-dependent suppressive effect on susceptibility to form-deprivation myopia, providing a potential gene-specific target for therapeutic intervention to treat myopia.

Treatment Satisfaction and Well-Being in Patients with Myopic Choroidal Neovascularization Treated with Ranibizumab in the REPAIR Study

The Ranibizumab for the Treatment of Choroidal Neovascularisation (CNV) Secondary to Pathological Myopia (PM): an Individualized Regimen (REPAIR) trial was a prospective study exploring the efficacy and safety of intravitreal ranibizumab 0.5 mg using an individualized treatment regimen over 12 months. The current study investigated the impact of treatment with ranibizumab as needed (pro re nata [PRN]) on individuals with myopic choroidal neovascularization (mCNV) in the REPAIR study, using patient-reported outcome measures (PROMs) for treatment satisfaction and well-being. This study included 65 adults with mCNV and a best-corrected visual acuity (BCVA) letter score of 24-78 in the study eye. Patients completed the Macular Disease Treatment Satisfaction Questionnaire (MacTSQ) at months 1, 6 and 12, and the 12-item Well-Being Questionnaire (W-BQ12) at baseline and months 1, 6 and 12. Subgroup analyses investigated the relationship between PROM scores and treatment in the better- or worse-seeing eye (BSE/WSE), number of injections received, baseline BCVA, BCVA improvement and age. Pearson correlations between change in BCVA, MacTSQ scores and W-BQ12 scores were calculated. The main outcome measures were treatment satisfaction measured with the MacTSQ (score 0-72) and well-being measured with the W-BQ12 (score 0-36). Treatment satisfaction significantly increased over the study period (p = 0.0001). Mean MacTSQ scores increased by 9.7 and 10.0 in patients treated in their WSE and BSE, respectively. Treatment satisfaction was highest in individuals receiving only one injection at month 1; however, by month 12, scores were similar across injection subgroups. Patients aged 68 years or older had the highest MacTSQ scores. Well-being scores also significantly increased over the study period (p = 0.03). Mean W-BQ12 scores increased by 1.7 in patients treated in their WSE and by 2.1 in patients treated in their BSE. Individuals aged 40 years or younger had the greatest increases in general well-being. Patients who experienced stable or improved BCVA at month 12 had greater increases in W-BQ12 scores than those who experienced a decrease. Correlations between BCVA, MacTSQ scores and W-BQ12 scores were largely non-significant. In conclusion, treatment satisfaction and well-being increased during treatment with ranibizumab PRN. Although directly comparable data are limited for the MacTSQ and W-BQ12 in mCNV, these results complement PROM outcomes reported in related studies.

Involvement of GABA transporters in atropine-treated myopic retina as revealed by iTRAQ quantitative proteomics

Atropine, a muscarinic antagonist, is known to inhibit myopia progression in several animal models and humans. However, the mode of action is not established yet. In this study, we compared quantitative iTRAQ proteomic analysis in the retinas collected from control and lens-induced myopic (LIM) mouse eyes treated with atropine. The myopic group received a (−15D) spectacle lens over the right eye on postnatal day 10 with or without atropine eye drops starting on postnatal day 24. Axial length was measured by optical low coherence interferometry (OLCI), AC-Master, and refraction was measured by automated infrared photorefractor at postnatal 24, 38, and 52 days. Retinal tissue samples were pooled from six eyes for each group. The experiments were repeated twice, and technical replicates were also performed for liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis. MetaCore was used to perform protein profiling for pathway analysis. We identified a total of 3882 unique proteins with <1% FDR by analyzing the samples in replicates for two independent experiments. This is the largest number of mouse retina proteome reported to date. Thirty proteins were found to be up-regulated (ratio for myopia/control > global mean ratio + 1 standard deviation), and 28 proteins were down-regulated (ratio for myopia/control < global mean ratio - 1 standard deviation) in myopic eyes as compared with control retinas. Pathway analysis using MetaCore revealed regulation of γ-aminobutyric acid (GABA) levels in the myopic eyes. Detailed analysis of the quantitative proteomics data showed that the levels of GABA transporter 1 (GAT-1) were elevated in myopic retina and significantly reduced after atropine treatment. These results were further validated with immunohistochemistry and Western blot analysis. In conclusion, this study provides a comprehensive quantitative proteomic analysis of atropine-treated mouse retina and suggests the involvement of GABAergic signaling in the antimyopic effects of atropine in mouse eyes. The GABAergic transmission in the neural retina plays a pivotal role in the maintenance of axial eye growth in mammals.

Utility values among myopic patients in mainland China

PURPOSE

To elicit utility values of adult myopic patients in mainland China.

METHODS

A valid sample of 442 myopia patients (spherical equivalent at least -0.5 diopters) aged 17 to 44 years who were scheduled to undergo refractive surgery were recruited. Information on time trade-off ([TTO] years of life willing to sacrifice for treatment of myopia) and standard gamble (SG) for blindness (risk of blindness from therapy, willing to sacrifice for treatment of myopia) utility values and sociodemographic and clinical data were obtained.

RESULTS

The mean utility values based on TTO and SG were 0.96 ± 0.05 (95% confidence interval [CI], 0.95 to 0.96; median, 0.98) and 0.93 ± 0.09 (95% CI, 0.92 to 0.94; median, 0.97), respectively. Myopic patients using contact lens had significantly higher TTO utility values than those wearing glasses (p < 0.001). There was no significant difference in the TTO and SG utility values by age, sex, occupation, educational levels, residence, reasons for refractive surgery, and severity and duration of myopia (p > 0.05).

CONCLUSIONS

The TTO and SG produce similar mean utility values, but there is poor agreement between results for individuals from the two methods. Utility values associated with myopic patients obtained in this study or reported in the literature seem to be higher than those obtained for other ophthalmic conditions.

Epidemiology of myopia

Myopia is one of the most prevalent disorders of the eye. Higher myopia is associated with comorbidities that increase risks of severe and irreversible loss of vision, such as retinal detachment, subretinal neovascularization, dense cataract, and glaucoma. In recent years, reports from population-based prevalence studies carried out in various geographical areas now give a clear picture of the current distribution of refractive error. The scarcity of data from well-designed longitudinal cohort studies is still yet to be addressed. These studies have confirmed the previous data indicating that prevalence of refractive error varies according to ethnicity and geographic regions, and also point to an increase in myopia prevalence over the past half-century. The problem is particularly pronounced in affluent, industrialised areas of East Asia. Environmental risk factors for myopia related to socioeconomic status and lifestyle have been identified. The past decade has seen a greater understanding of the molecular biological mechanisms that determine refractive error, giving further support to the belief that myopia is the result of a complex interaction between genetic predisposition and environmental exposures. This review summarizes data on the prevalence, incidence, progression, associations, risk factors, and impact from recent epidemiological studies on myopia.

Predictive factors for comorbid psychiatric disorders and their impact on vision-related quality of life in patients with high myopia

To determine the incidence of depression and anxiety disorders in patients with high myopia as well as the factors that would predict the development of psychiatric complications and their impact on vision-related quality of life (VR-QoL). Two hundred and five patients with pathologic myopia (axial length ≥26.50 mm) were studied. Incidence of depression and anxiety disorders was determined using the Hospital Anxiety and Depression Scale (HADS). VR-QoL was determined by the 25-item National Eye Institute Visual Function Questionnaire. Incidence of depression was 22.0 % and incidence of anxiety disorder was 25.9 %. Absence of children was the only factor significantly associated with the presence of depression, and a past history of cataract surgery was the only factor significantly associated with the presence of anxiety disorder. Factors which decreased the VR-QoL were in order of importance--anxiety disorder, decreased visual acuity in the best eye, depression, and being female. Responses of the subjects to two HADS statements 'I can laugh and see the funny side of things' and 'I can enjoy a good book or radio or television program' identified 82.2 % of depressed patients, and 'I get sudden feelings of panic' and 'I can sit at ease and feel relaxed' identified 71.7 % of patients with anxiety disorder. Twenty-two to 26 % of highly myopic patients had psychiatric disorders which had a strong negative impact on their VR-QoL. Two statements from the HADS questionnaire can be used to screen highly myopic patients for depression or anxiety disorders.

Choroidal thickness and visual acuity in highly myopic eyes. Retina. 2012;32:1229-1236. [PMID: 22466466 DOI: 10.1097/iae.0b013e318242b990]

PURPOSE

To examine predictive factors for visual acuity in highly myopic eyes.

METHODS

Consecutive patients with high myopia (≥6 diopters [D]) with no other pathology such as lacquer cracks in the fovea, choroidal neovascularization, or myopic macular schisis, were evaluated. The study was performed in 2 retina centers, one in the United States and the other in Japan. Enhanced depth imaging optical coherence tomography was obtained, and the central foveal, outer retinal hyporeflective layer and inner segment to retinal pigment epithelium aggregate, and the subfoveal choroidal thicknesses were measured. Correlations were calculated among the measured variables and visual acuity. Generalized estimating equation models were used to identify predictors of visual acuity.

RESULTS

The New York cohort was composed of 35 eyes of 25 patients who had a mean age of 57 years (standard deviation, ±18.1 years) and a mean refractive error of -10.9 D (±3.6 D). The Japanese cohort was composed of 110 eyes of 61 patients who had a mean age of 46.8 years (±14.7 years) and a mean refractive error of -9.2 D (±3.1 D) and a mean axial length of 27 mm (±1.4 mm). The mean subfoveal choroidal thickness was 113.3 μm (±53.9 μm) in the New York group and 172.9 μm (±72.8 μm) in the Japanese group. In each group, the subfoveal choroidal thickness showed a significant inverse correlation with age and myopic refractive spherical equivalent. The subfoveal choroidal thickness was inversely correlated with logarithm of the minimum angle of resolution visual acuity (P = 0.041, New York group; P = 0.001, Japan group). The only significant predictor in the pooled data for logarithm of the minimum angle of resolution visual acuity was subfoveal choroidal thickness (P ≤ 0.001). Clinic location was not a significant predictor.

CONCLUSION

Choroidal thickness in high myopia is inversely correlated with increasing age and myopic refractive error and is an important predictor of visual acuity. Given that myopia is increasing worldwide, these findings may have epidemiologic significance.

The complex interactions of retinal, optical and environmental factors in myopia aetiology

Myopia is the commonest ocular abnormality but as a research topic remains at the margins of mainstream ophthalmology. The concept that most myopes fall into the category of 'physiological myopia' undoubtedly contributes to this position. Yet detailed analysis of epidemiological data linking myopia with a range of ocular pathologies from glaucoma to retinal detachment demonstrates statistically significant disease association in the 0 to -6 D range of 'physiological myopia'. The calculated risks from myopia are comparable to those between hypertension, smoking and cardiovascular disease. In the case of myopic maculopathy and retinal detachment the risks are an order of magnitude greater. This finding highlights the potential benefits of interventions that can limit or prevent myopia progression. Our understanding of the regulatory processes that guide an eye to emmetropia and, conversely how the failure of such mechanisms can lead to refractive errors, is certainly incomplete but has grown enormously in the last few decades. Animal studies, observational clinical studies and more recently randomized clinical trials have demonstrated that the retinal image can influence the eye's growth. To date human intervention trials in myopia progression using optical means have had limited success but have been designed on the basis of simple hypotheses regarding the amount of defocus at the fovea. Recent animal studies, backed by observational clinical studies, have revealed that the mechanisms of optically guided eye growth are influenced by the retinal image across a wide area of the retina and not solely the fovea. Such results necessitate a fundamental shift in how refractive errors are defined. In the context of understanding eye growth a single sphero-cylindrical definition of foveal refraction is insufficient. Instead refractive error must be considered across the curved surface of the retina. This carries the consequence that local retinal image defocus can only be determined once the 3D structure of the viewed scene, off axis performance of the eye and eye shape has been accurately defined. This, in turn, introduces an under-appreciated level of complexity and interaction between the environment, ocular optics and eye shape that needs to be considered when planning and interpreting the results of clinical trials on myopia prevention.

Two models of experimental myopia in the mouse

PURPOSE

The purpose of this study was to test the response of the mouse eye to two methods for the induction of experimental myopia.

METHODS

Growth patterns of eyes were determined by axial length measurements from birth to adult in eyes of both sexes of normal mice examined on post-natal day 1 to 6 months and at 1 year. For the induction of experimental myopia, Balb/cJ mice were prepared with either unilateral lid suture or by a -10D spectacle lens placed over one eye at post-natal day 10. Other mice received a plano lens as a control for lens wear. Refraction was carried out at post-natal days of 28, 42 and 56 in lid suture and spectacle lens wear group by streak retinoscopy. Axial length was measured by a combination of video image photography, digital caliper, or Optical Low Coherence Interferometry (OLCI). Corroborative optical modeling of the mouse eye was carried out using ZEMAX ray tracing software.

RESULTS

Axial length (AL) increased linearly between post-natal day 1 to day 56, plateauing at about 140 days. After 18 days of unilateral lid suture initiated 10 days after birth, the AL of experimental eyes was 3.032+/-0.003 mm, while AL in contra-lateral control eyes was 2.981+/-0.005 mm (mean+/-sem, p<0.05, n=40), after 32 days, the AL of experimental eyes was 3.290+/-0.004 mm, and the AL of control eyes was 3.104+/-0.002 mm (p<0.001, n=60). After 46 days of lid closure AL of experimental eyes was 3.592+/-0.003 mm, while AL of control eyes was 3.363+/-0.003 mm (p<0.001, n=80). Spectacle lens wear of 46 days duration increased AL in experimental eyes to 3.721+/-0.002 mm, while AL in control eyes was 3.354+/-0.003 mm (p<0.001, n=100). Refraction and ray tracing analysis substantiated the dimensional changes to be consistent with increased AL.

CONCLUSIONS

Two procedures to induce experimental myopia, initiated at eye opening, produced significant myopic shifts corresponding to increases in axial lengths after 32 and 46 days of lid suture and after 46 days wearing a -10D spectacle lens.

Verteporfin : a review of its use in the management of subfoveal choroidal neovascularisation

Verteporfin (Visudyne) therapy (photodynamic therapy with intravenous liposomal verteporfin) is the first treatment to effectively prevent the loss of visual acuity in patients with subfoveal choroidal neovascularisation (CNV) secondary to age-related macular degeneration (AMD), pathological myopia or presumed ocular histoplasmosis syndrome (POHS). In adult patients with classic subfoveal CNV or occult with no classic subfoveal CNV secondary to AMD, or subfoveal CNV secondary to pathological myopia or POHS, verteporfin therapy slows or prevents loss of visual acuity. In well designed clinical trials, verteporfin therapy was superior to placebo in patients with subfoveal classic-containing CNV and occult with no classic CNV secondary to AMD at 12 and/or 24 months (Treatment of Age-related macular degeneration with Photodynamic therapy [TAP] Investigation and Verteporfin In Photodynamic therapy [VIP-AMD] trial) and in patients with pathological myopia at 12 months (Verteporfin In Photodynamic therapy [VIP-PM] trial). Limited data suggest that verteporfin therapy also prevents loss of visual acuity in patients with subfoveal CNV secondary to POHS. Verteporfin therapy was generally well tolerated in clinical trials; most adverse events were mild to moderate in intensity and transient. The most frequently reported verteporfin therapy-related adverse events (incidence >2%) were visual disturbance, injection-site reactions, photosensitivity reactions and infusion-related back pain. Approximately 5% of patients with occult with no classic subfoveal CNV secondary to AMD reported severe vision decrease within 7 days of treatment in clinical trials; 3 months later, several patients had recovered some of this loss.

CONCLUSION

Photodynamic therapy with verteporfin, the first photosensitiser approved for the treatment of subfoveal CNV, is a well tolerated treatment that stabilises or slows visual acuity loss in adult patients with predominantly classic or occult with no classic subfoveal CNV secondary to AMD, and subfoveal CNV secondary to pathological myopia or POHS. Thus, verteporfin therapy provides a valuable option for the management of these patients for whom treatment options are few, and should be considered as a first-line therapy in these difficult-to-manage conditions.