Expanding the Phenotypic and Genotypic Landscape of Nonsyndromic High Myopia: A Cross-Sectional Study in 731 Chinese Patients

PrimPol Variant V102A with Altered Primase and Polymerase Activities

PrimPol is a human DNA primase-polymerase which restarts DNA synthesis beyond DNA lesions and non-B DNA structures blocking replication. Disfunction of PrimPol in cells leads to slowing of DNA replication rates in mitochondria and nucleus, accumulation of chromosome aberrations, cell cycle delay, and elevated sensitivity to DNA-damaging agents. A defective PrimPol has been suggested to be associated with the development of ophthalmic diseases, elevated mitochondrial toxicity of antiviral drugs and increased cell resistance to chemotherapy. Here, we describe a rare missense PrimPol variant V102A with altered biochemical properties identified in patients suffering from ovarian and cervical cancer. The Val102 to Ala substitution dramatically reduced both the primase and DNA polymerase activities of PrimPol as well as specifically decreased its ability to incorporate ribonucleotides. Structural analysis indicates that the V102A substitution can destabilize the hydrophobic pocket adjacent to the active site, affecting dNTP binding and catalysis.

The Genetic Determinants of Axial Length: From Microphthalmia to High Myopia in Childhood

The axial length of the eye is critical for normal visual function by enabling light to precisely focus on the retina. The mean axial length of the adult human eye is 23.5 mm, but the molecular mechanisms regulating ocular axial length remain poorly understood. Underdevelopment can lead to microphthalmia (defined as a small eye with an axial length of less than 19 mm at 1 year of age or less than 21 mm in adulthood) within the first trimester of pregnancy. However, continued overgrowth can lead to axial high myopia (an enlarged eye with an axial length of 26.5 mm or more) at any age. Both conditions show high genetic and phenotypic heterogeneity associated with significant visual morbidity worldwide. More than 90 genes can contribute to microphthalmia, and several hundred genes are associated with myopia, yet diagnostic yields are low. Crucially, the genetic pathways underpinning the specification of eye size are only now being discovered, with evidence suggesting that shared molecular pathways regulate under- or overgrowth of the eye. Improving our mechanistic understanding of axial length determination will help better inform us of genotype-phenotype correlations in both microphthalmia and myopia, dissect gene-environment interactions in myopia, and develop postnatal therapies that may influence overall eye growth.

Regulatory network and targeted interventions for CCDC family in tumor pathogenesis

CCDC (coiled-coil domain-containing) is a coiled helix domain that exists in natural proteins. There are about 180 CCDC family genes, encoding proteins that are involved in intercellular transmembrane signal transduction and genetic signal transcription, among other functions. Alterations in expression, mutation, and DNA promoter methylation of CCDC family genes have been shown to be associated with the pathogenesis of many diseases, including primary ciliary dyskinesia, infertility, and tumors. In recent studies, CCDC family genes have been found to be involved in regulation of growth, invasion, metastasis, chemosensitivity, and other biological behaviors of malignant tumor cells in various cancer types, including nasopharyngeal carcinoma, lung cancer, colorectal cancer, and thyroid cancer. In this review, we summarize the involvement of CCDC family genes in tumor pathogenesis and the relevant upstream and downstream molecular mechanisms. In addition, we summarize the potential of CCDC family genes as tumor therapy targets. The findings discussed here help us to further understand the role and the therapeutic applications of CCDC family genes in tumors.

A new polygenic score for refractive error improves detection of children at risk of high myopia but not the prediction of those at risk of myopic macular degeneration

BACKGROUND

High myopia (HM), defined as a spherical equivalent refractive error (SER) ≤ -6.00 diopters (D), is a leading cause of sight impairment, through myopic macular degeneration (MMD). We aimed to derive an improved polygenic score (PGS) for predicting children at risk of HM and to test if a PGS is predictive of MMD after accounting for SER.

METHODS

The PGS was derived from genome-wide association studies in participants of UK Biobank, CREAM Consortium, and Genetic Epidemiology Research on Adult Health and Aging. MMD severity was quantified by a deep learning algorithm. Prediction of HM was quantified as the area under the receiver operating curve (AUROC). Prediction of severe MMD was assessed by logistic regression.

FINDINGS

In independent samples of European, African, South Asian and East Asian ancestry, the PGS explained 19% (95% confidence interval 17-21%), 2% (1-3%), 8% (7-10%) and 6% (3-9%) of the variation in SER, respectively. The AUROC for HM in these samples was 0.78 (0.75-0.81), 0.58 (0.53-0.64), 0.71 (0.69-0.74) and 0.67 (0.62-0.72), respectively. The PGS was not associated with the risk of MMD after accounting for SER: OR = 1.07 (0.92-1.24).

INTERPRETATION

Performance of the PGS approached the level required for clinical utility in Europeans but not in other ancestries. A PGS for refractive error was not predictive of MMD risk once SER was accounted for.

FUNDING

Supported by the Welsh Government and Fight for Sight (24WG201).

Nanotechnology Lighting the Way for Gene Therapy in Ophthalmopathy: From Opportunities toward Applications

Hereditary ophthalmopathy is a well-described threat to human visual health affecting millions of people. Gene therapy for ophthalmopathy has received widespread attention with the increasing understanding of pathogenic genes. Effective and safe delivery of accurate nucleic acid drugs (NADs) is the core of gene therapy. Efficient nanodelivery and nanomodification technologies, appropriate targeted genes, and the choice of drug injection methods are the guiding lights of gene therapy. Compared with traditional drugs, NADs can specifically change the expression of specific genes or restore the normal function of mutant genes. Nanodelivery carriers can improve targeting and nanomodification can improve the stability of NADs. Therefore, NADs, which can fundamentally solve pathogeny, hold great promise in the treatment of ophthalmopathy. This paper reviews the limitations of ocular disease treatment, discusses the classification of NADs in ophthalmology, reveals the delivery strategies of NADs to improve bioavailability, targeting, and stability, and summarizes the mechanisms of NADs in ophthalmopathy.

Mutational investigation of 17 causative genes in a cohort of 113 families with nonsyndromic early-onset high myopia in northwestern China

High myopia (HM) is a leading cause of visual impairment in the world. To expand the genotypic and phenotypic spectra of HM in the Chinese population, we investigated genetic variations in a cohort of 113 families with nonsyndromic early-onset high myopia from northwestern China by whole-exome sequencing, with focus on 17 known genes. Sixteen potentially pathogenic variants predicted to affect protein function in eight of seventeen causative genes for HM in fifteen (13.3%) families were revealed, including seven novel variants, c.767 + 1G > A in ARR3, c.3214C > A/p.H1072N, and c.2195C > T/p.A732V in ZNF644, c.1270G > T/p.V424L in CPSF1, c.1918G > C/p.G640R and c.2786T > G/p.V929G in XYLT1, c.601G > C/p.E201Q in P4HA2; six rare variants, c.799G > A/p.E267K in NDUFAF7, c.1144C > T/p.R382W in TNFRSF21, c.1100C > T/p.P367L in ZNF644, c.3980C > T/p.S1327L in CPSF1, c.145G > A/p.E49K and c.325G > T/p.G109W in SLC39A5; and three known variants, c.2014A > G/p.S672G and c.3261A > C/p.E1087D in ZNF644, c.605C > T/p.P202L in TNFRSF21. Ten of them were co-segregated with HM. The mean (± SD) examination age of these 15 probands was 14.7 (± 11.61) years. The median spherical equivalent was - 9.50 D (IQ - 8.75 ~ - 12.00) for the right eye and - 11.25 D (IQ - 9.25 ~ - 14.13) for the left eye. The median axial length was 26.67 mm (IQ 25.83 ~ 27.13) for the right eye and 26.25 mm (IQ 25.97 ~ 27.32) for the left eye. These newly identified genetic variations not only broaden the genetic and clinical spectra, but also offer convincing evidence that the genes ARR3, NDUFAF7, TNFRSF21, and ZNF644 contribute to hereditable HM. This work improves further understanding of molecular mechanism of HM.

Protein Transduction Domain-Mediated Delivery of Recombinant Proteins and In Vitro Transcribed mRNAs for Protein Replacement Therapy of Human Severe Genetic Mitochondrial Disorders: The Case of Sco2 Deficiency

Mitochondrial disorders represent a heterogeneous group of genetic disorders with variations in severity and clinical outcomes, mostly characterized by respiratory chain dysfunction and abnormal mitochondrial function. More specifically, mutations in the human SCO2 gene, encoding the mitochondrial inner membrane Sco2 cytochrome c oxidase (COX) assembly protein, have been implicated in the mitochondrial disorder fatal infantile cardioencephalomyopathy with COX deficiency. Since an effective treatment is still missing, a protein replacement therapy (PRT) was explored using protein transduction domain (PTD) technology. Therefore, the human recombinant full-length mitochondrial protein Sco2, fused to TAT peptide (a common PTD), was produced (fusion Sco2 protein) and successfully transduced into fibroblasts derived from a SCO2/COX-deficient patient. This PRT contributed to effective COX assembly and partial recovery of COX activity. In mice, radiolabeled fusion Sco2 protein was biodistributed in the peripheral tissues of mice and successfully delivered into their mitochondria. Complementary to that, an mRNA-based therapeutic approach has been more recently considered as an innovative treatment option. In particular, a patented, novel PTD-mediated IVT-mRNA delivery platform was developed and applied in recent research efforts. PTD-IVT-mRNA of full-length SCO2 was successfully transduced into the fibroblasts derived from a SCO2/COX-deficient patient, translated in host ribosomes into a nascent chain of human Sco2, imported into mitochondria, and processed to the mature protein. Consequently, the recovery of reduced COX activity was achieved, thus suggesting the potential of this mRNA-based technology for clinical translation as a PRT for metabolic/genetic disorders. In this review, such research efforts will be comprehensibly presented and discussed to elaborate their potential in clinical application and therapeutic usefulness.

Postnatal eye size in mice is controlled by SREBP2-mediated transcriptional repression of Lrp2 and Bmp2

Eye size is a key parameter of visual function, but the precise mechanisms of eye size control remain poorly understood. Here, we discovered that the lipogenic transcription factor sterol regulatory element-binding protein 2 (SREBP2) has an unanticipated function in the retinal pigment epithelium (RPE) to promote eye size in postnatal mice. SREBP2 transcriptionally represses low density lipoprotein receptor-related protein 2 (Lrp2), which has been shown to restrict eye overgrowth. Bone morphogenetic protein 2 (BMP2) is the downstream effector of Srebp2 and Lrp2, and Bmp2 is suppressed by SREBP2 transcriptionally but activated by Lrp2. During postnatal development, SREBP2 protein expression in the RPE decreases whereas that of Lrp2 and Bmp2 increases as the eye growth rate reduces. Bmp2 is the key determinant of eye size such that its level in mouse RPE inversely correlates with eye size. Notably, RPE-specific Bmp2 overexpression by adeno-associated virus effectively prevents the phenotypes caused by Lrp2 knock out. Together, our study shows that rapid postnatal eye size increase is governed by an RPE-derived signaling pathway, which consists of both positive and negative regulators of eye growth.

Whole exome sequence analysis in 51 624 participants identifies novel genes and variants associated with refractive error and myopia

Refractive errors are associated with a range of pathological conditions, such as myopic maculopathy and glaucoma, and are highly heritable. Studies of missense and putative loss of function (pLOF) variants identified via whole exome sequencing (WES) offer the prospect of directly implicating potentially causative disease genes. We performed a genome-wide association study for refractive error in 51 624 unrelated adults, of European ancestry, aged 40-69 years from the UK and genotyped using WES. After testing 29 179 pLOF and 495 263 missense variants, 1 pLOF and 18 missense variants in 14 distinct genomic regions were taken forward for fine-mapping analysis. This yielded 19 putative causal variants of which 18 had a posterior inclusion probability >0.5. Of the 19 putative causal variants, 12 were novel discoveries. Specific variants were associated with a more myopic refractive error, while others were associated with a more hyperopic refractive error. Association with age of onset of spectacle wear (AOSW) was examined in an independent validation sample (38 100 early AOSW cases and 74 243 controls). Of 11 novel variants that could be tested, 8 (73%) showed evidence of association with AOSW status. This work identified COL4A4 and ATM as novel candidate genes associated with refractive error. In addition, novel putative causal variants were identified in the genes RASGEF1, ARMS2, BMP4, SIX6, GSDMA, GNGT2, ZNF652 and CRX. Despite these successes, the study also highlighted the limitations of community-based WES studies compared with high myopia case-control WES studies.

Myopia Genetics and Heredity

Myopia is the most common eye condition leading to visual impairment and is greatly influenced by genetics. Over the last two decades, more than 400 associated gene loci have been mapped for myopia and refractive errors via family linkage analyses, candidate gene studies, genome-wide association studies (GWAS), and next-generation sequencing (NGS). Lifestyle factors, such as excessive near work and short outdoor time, are the primary external factors affecting myopia onset and progression. Notably, besides becoming a global health issue, myopia is more prevalent and severe among East Asians than among Caucasians, especially individuals of Chinese, Japanese, and Korean ancestry. Myopia, especially high myopia, can be serious in consequences. The etiology of high myopia is complex. Prediction for progression of myopia to high myopia can help with prevention and early interventions. Prediction models are thus warranted for risk stratification. There have been vigorous investigations on molecular genetics and lifestyle factors to establish polygenic risk estimations for myopia. However, genes causing myopia have to be identified in order to shed light on pathogenesis and pathway mechanisms. This report aims to examine current evidence regarding (1) the genetic architecture of myopia; (2) currently associated myopia loci identified from the OMIM database, genetic association studies, and NGS studies; (3) gene-environment interactions; and (4) the prediction of myopia via polygenic risk scores (PRSs). The report also discusses various perspectives on myopia genetics and heredity.

Identification and Functional Characterization of a Novel Nonsense Variant in ARR3 in a Southern Chinese Family With High Myopia

ARR3 has been associated with X-linked, female-limited, high myopia. However, using exome sequencing (ES), we identified the first high myopia case with hemizygous ARR3-related mutation in a male patient in a Southern Chinese family. This novel truncated mutation (ARR3: c.569C>G, p.S190*) co-segregated with the disease phenotype in affected family members and demonstrated that high myopia caused by ARR3 is not X-linked, female-limited, where a complicated X-linked inheritance pattern may exist. Thus, our case expanded the variant spectrum in ARR3 and provided additional information for genetic counseling, prenatal testing, and diagnosis. Moreover, we characterized the nonsense-mediated decay of the ARR3 mutant mRNA and discussed the possible underlying pathogenic mechanisms.

Implantable collamer lens versus small incision lenticule extraction for high myopia correction: A systematic review and meta-analysis

Purpose

To compare the efficacy, safety, predictability and visual quality between implantable collamer lens (ICL) implantation and small incision lenticule extraction (SMILE) for high myopia correction in adults.

Methods

A systematic review and meta-analysis was conducted. A comprehensive literature search was done based on databases including PubMed, Science Direct, Embase, and the Cochrane Central Register of Controlled Trials. The efficacy index, safety index, changes in Snellen lines of corrected distance visual acuity (CDVA), predictability (difference between post-operative and attempted spherical equivalent error, SER), incidence of halos, and change in higher-order aberrations (HOAs) were compared. Mean difference (MD) and 95% confidence interval (CI) was used to estimate continuous outcomes, risk ratio (RR) and 95%CI was used to estimate categorical outcomes.

Results

Five observational studies involving 555 eyes were included in this review. Studies’ sample sizes (eyes) ranged from 76 to 197. Subjects’ refraction ranged from -6 diopter (D) to -12D. Study duration of most researches were 6 months or 12 months. Compared to SMILE, ICL implantation showed better efficacy index (MD=0.09, 95%CI:0.01 to 0.16) and better safety index (MD=0.08, 95%CI: 0.00 to 0.16). Compared with SMILE, more ICL-treated eyes gained one or more Snellen lines of CDVA (RR=1.54, 95%CI:1.28 to 1.86), more gained two or more lines (RR=2.09, 95%CI:1.40 to 3.13), less lost one or more lines (RR=0.17, 95%CI:0.05 to 0.63). There was no difference in predictability between two treatments, RRs of predictability of within ±0.5D and ±1D were 1.13 (95%CI: 0.94 to 1.36) and 1.00 (95%CI: 0.98 to 1.02). Compared with SMILE, ICL implantation came with a higher risk of halos [RR=1.79, 95%CI: 1.48 to 2.16] and less increase in total HOAs (MD=-0.23, 95%CI: -0.42 to -0.03).

Conclusion

Compared with SMILE, ICL implantation showed a higher risk of halos, but equal performance on SER control, and better performance on efficacy index, safety index, CDVA improvement and HOAs control. Overall, ICL implantation might be a better choice for high myopia correction in adults.

The association of myopia progression with the morphological changes of optic disc and β-peripapillary atrophy in primary school students

PURPOSE

To study the association of myopia progression with the morphological changes of optic disc and β-peripapillary atrophy (β-PPA) in 8-11 years old primary school students.

METHODS

This study was a prospective, school-based investigation. This study included 610 children (1008 eyes) who were continuously observed and had data available from 2016 to 2017 in the Sanhe Cohort Study of the Risk Factors for Myopia (SCSRFM). The children underwent a comprehensive eye examination including measurement of visual acuity, autorefractometry, and posterior segment of the eye. β-PPA regions and optic disc ovality index were identified and measured on the fundus photographs.

RESULTS

The prevalence of myopia was 72.62% (732/1008) in 2016. In myopic children, the prevalence of the vertical β-PPA, the horizontal β-PPA, and the oval optic disc were 75.68% (554/732), 75.96% (556/732) and, 11.61% (85/732) respectively. From 2016 to 2017, with the progression of vertical β-PPA, horizontal β-PPA, area of β-PPA, and optic disc ovality index, the myopic diopter and the axial length (AL) were increased. The progression of horizontal β-PPA was significantly correlated with the progression of myopic diopter and AL (all p < 0.05). The analysis on the distribution of progression rate of parameters in different groups found that the progression rate of horizontal β-PPA, area of β-PPA, and optic disc ovality index increased with the increase of the progression of diopter and AL. The progression of horizontal β-PPA, area of β-PPA, optic disc ovality index, and diopter in girls were greater than that in boys, and the progression of optic disc ovality index and diopter had a statistical significance (all p < 0.05).

CONCLUSIONS

The 1-year follow-up study of the third-grade primary school students showed that with the progression of myopia and the growth of AL, β-PPA and optic disc ovality index also changed. There was a positive correlation between the change of β-PPA and optic disc ovality index and the progression of myopia diopter and AL.

SLC39A5 dysfunction impairs extracellular matrix synthesis in high myopia pathogenesis

High myopia is one of the leading causes of visual impairment worldwide with high heritability. We have previously identified the genetic contribution of SLC39A5 to nonsyndromic high myopia and demonstrated that disease‐related mutations of SLC39A5 dysregulate the TGF‐β pathway. In this study, the mechanisms underlying SLC39A5 involvement in the pathogenesis of high myopia are determined. We observed the morphogenesis and migration abnormalities of the SLC39A5 knockout (KO) human embryonic kidney cells (HEK293) and found a significant injury of ECM constituents. RNA‐seq and qRT‐PCR revealed the transcription decrease in COL1A1, COL2A1, COL4A1, FN1 and LAMA1 in the KO cells. Further, we demonstrated that TGF‐β signalling, the regulator of ECM, was inhibited in SLC39A5 depletion situation, wherein the activation of receptor Smads (R‐Smads) via phosphorylation was greatly blocked. SLC39A5 re‐expression reversed the phenotype of TGF‐β signalling and ECM synthesis in the KO cells. The fact that TGF‐β signalling was zinc‐regulated and that SLC39A5 was identified as a zinc transporter urged us to check the involvement of intracellular zinc in TGF‐β signalling impairment. Finally, we determined that insufficient zinc chelation destabilized Smad proteins, which naturally inhibited TGF‐β signalling. Overall, the SLC39A5 depletion–induced zinc deficiency destabilized Smad proteins, which inhibited the TGF‐β signalling and downstream ECM synthesis, thus contributing to the pathogenesis of high myopia. This discovery provides a deep insight into myopic development.

Whole-Exome Sequencing in a Cohort of High Myopia Patients in Northwest China

High myopia (HM) is one of the leading causes of visual impairment worldwide. In order to expand the myopia gene spectrum in the Chinese population, we investigated genetic mutations in a cohort of 27 families with HM from Northwest China by using whole-exome sequencing (WES). Genetic variations were filtered using bioinformatics tools and cosegregation analysis. A total of 201 candidate mutations were detected, and 139 were cosegregated with the disease in the families. Multistep analysis revealed four missense variants in four unrelated families, including c.904C>T (p.R302C) in CSMD1, c.860G>A (p.R287H) in PARP8, c.G848A (p.G283D) in ADAMTSL1, and c.686A>G (p.H229R) in FNDC3B. These mutations were rare or absent in the Exome Aggregation Consortium (ExAC), 1000 Genomes Project, and Genome Aggregation Database (gnomAD), indicating that they are new candidate disease-causing genes. Our findings not only expand the myopia gene spectrum but also provide reference information for further genetic study of heritable HM.

P4HA2 promotes cell proliferation and migration in glioblastoma

Glioblastoma (GBM) is a primary malignant tumor characterized by high infiltration and angiogenesis in the brain parenchyma. Glioma stem cells (GSCs), a heterogeneous GBM cell type with the potential for self-renewal and differentiation to tumor cells, are responsible for the high malignancy of GBM. The purpose of the present study was to investigate the roles of significantly differentially expressed genes between GSCs and GBM cells in GBM progression. The gene profiles GSE74304 and GSE124145, containing 10 GSC samples and 12 GBM samples in total, were obtained from the Gene Expression Omnibus (GEO) database. The overlapping differentially expressed genes were identified with GEO2R tools and Venn software online. Subsequently, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis was performed on the 41 upregulated and 142 downregulated differentially expressed genes in GSCs compared with in GBM cells via the DAVID website. Protein-protein interaction and module analyses in Cytoscape with the STRING database revealed 21 hub genes that were downregulated in GSCs compared with in GBM cells. Survival analysis conducted via the GEPIA2 website revealed that low expression levels of the hub genes prolyl 4-hydroxylase subunit α2 (P4HA2), TGF-β induced, integrin subunit α3 and thrombospondin 1 were associated with significantly prolonged survival time in patients with GBM. Further experiments were performed focusing on P4HA2. Reverse transcription-quantitative PCR was used to detect P4HA2 gene expression. In agreement with the bioinformatics analysis, P4HA2 expression was higher in U87 cells than in GSCs. Cell Counting Kit-8, EdU incorporation, cell cycle analysis, wound healing and Transwell assays demonstrated that the cell proliferation and migration increased after P4HA2 overexpression and decreased after P4HA2-knockdown. In conclusion, the present study demonstrated that low P4HA2 expression in GSCs promoted GBM cell proliferation and migration, suggesting that P4HA2 may act as a switch in the transition from GSCs to GBM cells.

Variants in FLRT3 and SLC35E2B identified using exome sequencing in seven high myopia families from Central Europe

PURPOSE

High myopia (HM) is an eye disorder with both environmental and genetic factors involved. Many genetic factors responsible for HM were recognized worldwide, but little is known about genetic variants underlying HM in Central Europe. Thus, the aim of this study was to identify rare sequence variants involved in HM in families from Central Europe to better understand the genetic basis of HM.

MATERIALS AND METHODS

We assessed 17 individuals from 7 unrelated Central European families with hereditary HM using exome sequencing (ES). Segregation of selected variants in other available family members was performed using Sanger sequencing.

RESULTS

Detected 73 rare variants were selected for verification. We observed 2 missense variants, c.938C>T in SLC35E2B - encoding solute carrier family 35 member E2B, and c.1642G>C in FLRT3 - encoding fibronectin leucine rich transmembrane protein, segregating with HM in one family.

CONCLUSIONS

FLRT3 ​and/or ​SLC35E2B ​could represent disease candidate genes and identified sequence variants might be responsible for HM in the studied family.

Eyes on coronavirus

Recently, coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 has spread around the world and is receiving worldwide attention. Approximately 20% of infected patients are suffering from severe disease of multiple systems and in danger of death, while the ocular complications of SARS-CoV-2-infected patients have not been reported generally. Herein, we focus on two major receptors of SARS-CoV-2, ACE2 and CD147 (BSG), in human ocular cells, and interpret the potential roles of coronaviruses in human ocular tissues and diseases.

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.

Nonhuman Primate Model of Oculocutaneous Albinism with TYR and OCA2 Mutations

Human visual acuity is anatomically determined by the retinal fovea. The ontogenetic development of the fovea can be seriously hindered by oculocutaneous albinism (OCA), which is characterized by a disorder of melanin synthesis. Although people of all ethnic backgrounds can be affected, no efficient treatments for OCA have been developed thus far, due partly to the lack of effective animal models. Rhesus macaques are genetically homologous to humans and, most importantly, exhibit structures of the macula and fovea that are similar to those of humans; thus, rhesus macaques present special advantages in the modeling and study of human macular and foveal diseases. In this study, we identified rhesus macaque models with clinical characteristics consistent with those of OCA patients according to observations of ocular behavior, fundus examination, and optical coherence tomography. Genomic sequencing revealed a biallelic p.L312I mutation in TYR and a homozygous p.S788L mutation in OCA2, both of which were further confirmed to affect melanin biosynthesis via in vitro assays. These rhesus macaque models of OCA will be useful animal resources for studying foveal development and for preclinical trials of new therapies for OCA.