China is the country with high incidence of high myopia in the world. High myopia can cause severe vision impairment. So far, there is no effective treatment for high myopia in clinic. Scleral collagen cross-linking surgery has been proven to be effective in preventing animal eye axial elongation in vitro and in vivo. However, the influence of posterior scleral collagen cross-linking on the deformation of the whole eyeball is still unclear. In this study, finite element simulation were used to analyze the changes of eyeball shape and the position of light casting on the retina after posterior sclera cross-linking, and the mathematical algorithm was written to verify their similarity. The results showed that the shape of the whole eyeball was still very similar before and after cross-linking, and the diopter of the eyeball after cross-linking had little change, which had almost no effect on the position of light projection on the retina. Our results indicate that posterior sclera cross-linking wouldn’t lead to distortion to the optometry, that is, the increase of elastic modulus in local scleral tissue after cross-linking wouldn’t cause new problem of optometry and vision.
ObjectiveTo observe and analyze the superficial retinal blood flow density and its related influencing factors in the macular area of adolescents with different types of non-pathological high myopia (HM). MethodsA retrospective clinical study. From March to August 2022, 117 eyes of 117 adolescents who were admitted to Liaocheng Aier Eye Hospital due to myopia were included in the study. According to equivalent spherical degree (SE) and corneal curvature, subjects were divided into mild myopia or emmetropia group (control group), HM group, occult HM (OHM) group, and super HM (SHM) group, with 30 eyes, 28 eyes, 35 eyes, and 24 eyes, respectively. All subjects underwent medical optometry, intraocular pressure, optical coherence tomography (OCT), OCT angiography (OCTA), axial length (AL) and corneal curvature measurements. The diopter was SE. OCTA instrument was used to scan the macular region in the range of 6 mm×6 mm, and the software automatically divided it into three concentric circles centered on the fovea of the macular, namely, the central area with a diameter of 1 mm, the inner ring area with a diameter of 1-3 mm, and the outer ring area with a diameter of 3-6 mm. The superficial retinal vascular density (SRVD), vascular perfusion density (SBPD), the area, perimeter (PERIM), avascular index (AI) of foveal avascular area (FAZ) and retinal thickness were measured in the macular region as a whole and in different regions. One-way analysis of variance was used to compare the data among groups, and the least significant difference t-test was used to compare the data among groups. The correlation of AL, corneal curvature and intraocular pressure with SRVD and SBPD in macula was analyzed by Pearson correlation analysis. ResultsThere were significant differences in SRVD and SBPD in the central, inner and outer regions of macula in control group, HM group, OHM group and SHM group (P＜0.05). There were statistically significant differences in the thickness of the retina above, below and on the temporal side of the central and outer ring regions (P＜0.05). However, no statistically significant difference was in the thickness of the retina on the nasal side (P＞0.05). There was no significant difference in PERIM (P＞0.05). There were significant differences in FAZ area and AI (P＜0.05). Correlation analysis showed that AL was negatively correlated with SRVD and SBPD in macular whole and central, inner and outer ring regions (P＜0.05). Corneal curvature and SE were positively correlated with the SRVD and SBPD of macular whole, central area and outer ring area (P＜0.05). AL was negatively correlated with retinal thickness in the outer ring region (P＜0.05). SE was positively correlated with the thickness of the retina above, below and temporally in the outer ring region (P＜0.05). AL was negatively correlated with FAZ area and AI (P＜0.05). SE was positively correlated with FAZ area and PERIM (P＜0.05). Retinal thickness was positively correlated with SRVD and SBPD (P＜0.05). ConclusionsThe SRVD and SBPD of different types of HM in adolescents decreases to different degrees. The thickness of the retina in the central region is thicker, and the retina in the outer ring region is thinner. With the decrease of SRVD, the retinal thickness gradually is thinner.
ObjectiveTo investigate and analyze the relationship between genotype and phenotype in patients with early-onset high myopia (eoHM) associated with hereditary eye diseases. MethodsA family-based study was conducted among 30 families diagnosed with eoHM at Department of Ophthalmology of People's Hospital of Ningxia Hui Autonomous Region from January 2022 to June 2023. Seven families (23.3%, 7/30), all probands, and their 14 parents were included. These seven families were unrelated. Detailed patient and family histories were collected. All participants underwent comprehensive ophthalmic examinations, including best-corrected visual acuity, color vision testing, fundus color photography, optical coherence tomography, fluorescein fundus angiography, and fundus autofluorescence imaging. Full-field electroretinography was performed in four cases. Peripheral venous blood samples were collected from patients and their parents for whole-genome DNA extraction and whole-exome sequencing. Potential pathogenic variants were identified, and their pathogenicity was analyzed and confirmed by Sanger sequencing. The pathogenicity of newly discovered gene variants was evaluated according to the guidelines of the American College of Medical Genetics and Genomics (ACMG). Literature on previously reported eoHM associated with hereditary eye diseases was reviewed to analyze the relationship between variant genes and clinical phenotypes. ResultsAmong the seven families, three exhibited X-linked inheritance, two showed autosomal recessive inheritance, and two demonstrated autosomal dominant inheritance. All the patients were male. Among the seven patients, one case each was identified with congenital stationary night blindness (CSNB), Bornholm eye disease, X-linked retinitis pigmentosa (XL-RP), cone-rod dystrophy, Knobloch syndrome, familial exudative vitreoretinopathy (FEVR), and Stickler syndrome. Genetic testing revealed nine gene variants highly correlated with the observed phenotypes. The genetic testing results revealed that all patients were found to carry nine gene variants highly associated with the phenotype, including: a hemizygous missense variant NYX c.647A>T (p.N216I) (M1), an OPN1LW LIAVA haplotype variant (M2), a hemizygous frameshift variant RPGR c.3096_3097del (p.E1033RfsTer45) (M3), compound heterozygous variants TTLL5 c.1588_1589del (p.L531EfsTer24) and c.850G>C (p.D284H) (M4, M5), compound heterozygous variants COL18A1 c.2118dup (p.G707RfsTer23) and c.3523_3524del (p.L1175VfsTer72) (M6, M7), a heterozygous missense mutation FZD4 c.1499C>T (p.T500I) (M8), and a heterozygous frameshift variant COL11A2 c.966dup (p.T323HfsTer19) (M9). Among them, M2, M4, M5, M8 and M9 were newly discovered mutation sites, and M1, M3, M6 and M7 were known mutation sites. According to the classification standards and guidelines of genetic variation issued by ACMG, M2, M3, M4, M6, M7, and M9 were judged to be pathogenic variants, while M1, M5, and M8 were of unknown clinical significance. Through literature review, it was found that eoHM was more common among the clinical phenotypes of 4 types of hereditary retinal diseases, including CSNB, Stickler syndrome, FEVR and XL-RP. ConclusioneoHM is intricately associated with inherited eye diseases and may serve as the earliest indicator of such conditions.