論文

High myopia may develop to pathologic myopia, which brings severe visual impairment; however, the etiology is not fully understood. We, therefore, investigated the relationship between the presence of posterior staphyloma and posterior ocular disorders by assessing the patients with high myopia. A retrospective study was performed for the patients, who have more than 26 mm of the axial length and of whom fundus photography was taken with an ultra-widefield retinal imaging system. The objectives were 138 cases encompassing 229 eyes. In 138 cases, 91 were bilateral and 47 were unilateral. The averages ± SD of axial length of bilateral and unilateral were 28.8 ± 2.2 mm, 27.3 ± 1.2 mm, respectively, showing statistically significant difference. The number of eyes with and without posterior staphyloma were 107 (46.7%) and 122 (53.3%), respectively. Retinal detachment and retinal breaks are more observed in cases without posterior staphyloma (p = 0.017). Myopic choroidal neovascularization (mCNV) (p = 0.002), chorioretinal atrophy (p < 0.001), retinoschisis (p < 0.001), and optic neuropathy (p = 0.038) are more often seen in cases with posterior staphyloma. In conclusion, the prevalence rates of myopic choroidal neovascularization, retinal choroidal atrophy, and optic neuropathy were significantly higher with posterior staphyloma. The rate of periocular disorders such as retinal detachment was significantly higher without posterior staphyloma. These results indicate associations between types of pathological myopia and presence or absence of posterior staphyloma analyzed by ultra-widefield retinal imaging.

Significance The increasing prevalence of myopia is a significant public health concern. Unfortunately, the mechanisms driving myopia remain elusive, limiting effective treatment options. This report identifies a refractive development pathway that requires Opn5 -expressing retinal ganglion cells (RGCs). Stimulation of Opn5 RGCs with short-wavelength violet light prevented experimental myopia in mice. Furthermore, this effect was dependent on the time of day, with evening exposure being sufficient to protect against experimental myopia. Thus, these studies suggest Opn5 RGCs may contribute to the mechanisms of emmetropization and identify the OPN5 pathway as a potential target for the treatment of myopia.

© 2019, The Author(s). This study compared the axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), mean anterior corneal radius of curvature (Rm), and postoperative refractive outcomes obtained from two different swept-source optical coherence biometers, the ARGOS (Movu, Nagoya, Japan), which uses the segmental refractive index for each segment, and the IOLMaster 700 (Carl Zeiss Meditec, Jena, Germany), which uses an equivalent refractive index for the entire eye. One hundred and six eyes of 106 patients with cataracts were included. The refractive outcomes using the Barrett Universal II, Haigis, Hoffer Q, and SRK/T formulas were evaluated. The mean AL, CCT, ACD, and Rm differed significantly (P < 0.001) with the IOLMaster 700 (25.22 mm, 559 µm, 3.23 mm, and 7.69 mm) compared with the ARGOS (25.14 mm, 533 µm, 3.33 mm, and 7.66 mm). The mean LTs did not differ significantly. The percentages of eyes within ±0.50 and ±1.00 diopter of the predicted refraction did not differ significantly (P > 0.05). The accuracy of the intraocular lens power calculations was clinically acceptable with both biometers, although the ocular biometry using these two biometers exhibited certain differences.

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. To identify tissues and molecules involved in refractive myopic shift and axial length elongation in a murine lens-induced myopia model, we performed a comprehensive analysis of microRNA (miRNA) expression. Three weeks after negative 30 diopter lens fixation on three-week-old C57BL/6J mice, total RNA was extracted from individual ocular components including cornea, iris, lens, retina, retinal pigment epithelium (RPE)/choroid, and sclera tissue. The miRNA expression analysis was pooled from three samples and carried out using Agilent Mouse miRNA Microarray (8 × 60 K) miRBase21.0. The expression ratio was calculated, and differentially expressed miRNAs were extracted, using GeneSpring GX 14.5. Myopic induction showed a significant myopic refractive change, axial elongation, and choroidal thinning. Through the comprehensive miRNA analysis, several upregulated miRNAs (56 in cornea tissue, 13 in iris tissue, 6 in lens tissue, 0 in retina tissue, 29 in RPE/choroid tissue, and 30 in sclera tissue) and downregulated miRNAs (7 in cornea tissue, 28 in iris tissue, 17 in lens tissue, 9 in retina tissue, 7 in RPE/choroid tissue, and 40 in sclera tissue) were observed. Overlapping expression changes in miRNAs were also found in different ocular components. Some of this miRNA dysregulation may be functionally involved in refractive myopia shift and axial length elongation.

© 2019, The Author(s). Increased global incidence of myopia necessitates establishment of therapeutic approaches against its progression. To explore agents which may control myopia, we screened 207 types of natural compounds and chemical reagents based on an activity of a myopia suppressive factor, early growth response protein 1 (Egr-1) in vitro. Among the candidates, crocetin showed the highest and dose-dependent activation of Egr-1. For in vivo analysis, experimental myopia was induced in 3-week-old C57BL/6 J mice with −30 diopter (D) lenses for 3 weeks. Animals were fed with normal or mixed chow containing 0.003% (n = 19) and 0.03% (n = 7) of crocetin during myopia induction. Refraction and axial length were measured at 3-week-old and the 6-week-old with an infrared photorefractor and a SD-OCT system. Compared to controls (n = 14), crocetin administration showed a significant smaller change of refractive errors (−13.62 ± 8.14 vs +0.82 ± 5.81 D for 0.003%, p < 0.01, −2.00 ± 4.52 D for 0.03%, p < 0.01) and axial elongation (0.27 ± 0.03 vs 0.22 ± 0.04 mm for 0.003%, p < 0.01, 0.23 ± 0.05 mm for 0.03%, p < 0.05). These results suggest that a dietary factor crocetin may have a preventive effect against myopia progression.

Copyright © 2018 Contact Lens Association of Ophthalmologists, Inc. Unauthorized reproduction of this article is prohibited. During the past 30 years, the prevalence rate of myopia has been increased dramatically. Myopia has become one of the leading causes of vision loss in some countries, whereas the mechanism of the main pathological change in myopia is still largely unknown. Although several studies showed genetic background influences the phenotype of myopia to some extent, the sudden increase of morbidity cannot be explained by genetics only. The change in lifestyle results in tremendous change in the light environment, which can be considered to play an important role in the onset and progression of myopia. The difference between indoor and outdoor light environments such as intensity and wavelength of modern electronic lighting equipment may be a cue for myopia control as environmental factors. In this review, we discuss the relationship between myopia and light environment focusing on the basic and clinical studies.

© 2020 The Authors Purpose: To evaluate the features of the axial length-to-corneal radius (AL/CR) ratio in Japanese patients with cataracts and to determine the accuracy of intraocular lens (IOL) power calculation formulas according to the AL/CR features and the axial length (AL). Design: Retrospective observational case series. Methods: Setting was a clinical practice. Patient population was a total of 1,135 eyes (1,135 patients) with cataracts. Observation procedures included measurement of the AL and corenal radius (CR) by optical biometry and evaluation of the refractive outcomes by using the SRK/T, Holladay 1, Hoffer Q, Haigis, and Barrett Universal II formulas. Main outcome measurements were the features of the AL/CR ratio and the accuracy of IOL power calculations based on the AL/CR ratio and the AL. Results: The mean AL/CR ratio was 3.15 ± 0.19. Significant weak negative correlations were observed between the spherical equivalent (SE) and AL (r = −0.7489; P < .001) and between the SE and AL/CR ratio (r = −0.8069; P < .001); no correlation was found between the SE and CR (r = 0.0208, P = .483). For medium ALs and high AL/CR ratios, the SRK/T formula performed less accurately. For long ALs and high AL/CR ratios, the Holladay 1 and Hoffer Q formulas performed less accurately. The Barrett Universal II formula performed well across a range of ALs and AL/CR ratios. Conclusions: The AL/CR ratio explained the total variation in the SE better than the AL alone. Surgeons should pay attention to the selection of IOL power calculation formulas in eyes with high AL/CR ratios.