Published papers

© 2019 Journal of Visualized Experiments. Murine model of myopia can be a powerful tool for myopia research because of the comparatively easy genetic manipulation. One way to induce myopia in animals is to put clear minus lenses in front of eyes for weeks (lens-induced myopia, LIM). However, extant protocols for inducement and evaluation vary from laboratory to laboratory. Here, we described a highly practical and reproducible method to induce LIM in mice using newly designed eyeglasses. The method fixes the lens stably in front of the mouse eye while allows the lens to be taken off for cleaning or topical drug administration. The phenotype is robust and efficient, and the variance is small. The method described here can be applied to mice right after weaning which extends the possible duration for experiments. We also gave technical advises for achieving reproducible results in refraction and axial length measurements. We hope the step-by-step protocol described here and the detailed article can help researchers perform myopia experiments with myopia more smoothly and make the data comparable across laboratories.

Glycemic control is essential to manage metabolic diseases such as diabetes. Frequent measurements of systemic glucose levels with prompt managements can prevent organ damages. The eye is a glucose highly demanding organ in our body, and the anterior chamber (AC) in the eye has been suggested for a noninvasive blood glucose monitoring site. However, calculating blood glucose levels from measuring glucose levels in AC has been difficult and unclear. In this study, we aimed to examine glucose levels from AC and find a correlation with blood glucose levels. A total of 30 patients with cataracts (men and women, study 1; 7 and 3, study 2; 9 and 11) who visited Keio University Hospital from 2015 to 2018 and agreed to participate in this study were recruited. Glucose levels from AC and the blood were examined by a UV-hexokinase or H2O2-electrode method before/during the cataract surgery. These values were analyzed with regression analyses depending on the groups (blood glucose-ascending and descending groups). In the blood glucose-descending group, glucose levels from AC were strongly correlated with blood glucose levels (a high R2 value, 0.8636). However, the relatively moderate correlation was seen in the blood glucose-ascending group (a low R2 value, 0.5228). Taken together, we showed different correlation ratios on glucose levels between AC and the blood, based on blood glucose dynamics. Stacking data regarding this issue would enable establishing noninvasive blood glucose monitoring from measuring glucose levels in AC more correctly, which will be helpful for proper and prompt managements for glucose-mediated complications.

The increasing prevalence of high myopia has been noted. We investigated the epidemiological characteristics and the related factors of high myopia in a Japanese adult population. Japan Public Health Center-Based Prospective Study for the Next Generation (JPHC-NEXT) Eye Study was performed in Chikusei-city, a rural area in mid-east Japan, between 2013 and 2015. A cross-sectional observational analysis was conducted to investigate prevalence and related factors of high myopia. A total of 6101 participants aged ≥40 years without a history of ocular surgeries was included. High myopia was defined as a spherical equivalent refraction of ≤−6.00 diopters according to the American Academy of Ophthalmology. Potential high myopia-related factors included intraocular pressure (IOP), corneal structure, corneal endothelial cell density, age, height, body mass index, heart rate, blood pressure, biochemical profile, and current history of systemic and ocular disorders. The odds ratios of high myopia were estimated using the logistic regression models adjusted for the associated factors. The prevalence of high myopia was 3.8% in males and 5.9% in females with a significant difference. Age was inversely associated, IOP was positively associated, and none of other factors were associated with high myopia in both sexes. In conclusion, only age and IOP were associated with high myopia in this community-based sample.

目的:Implantable collamer lens(ICL:STAAR Surgical Company)挿入術後にpigment dispersion syndrome(PDS)を発症した症例を経験したので報告する。症例:32歳、男性。ICL希望で当科初診。所見:初診時視力は右眼0.04(1.25 -10.75)、左眼0.032(1.25 -8.50 cyl-4.00 Ax180°)。前眼部・眼底所見に特記すべき所見なし。両眼ICL挿入術(右眼:ICM125V4-15.0D、左眼:ICM130V4-17.0D/+5.0D)を施行、周辺虹彩切除を併施した。術1週間後より両眼霧視を自覚、視力は右眼0.8(1.6 -0.50 cyl-1.00 Ax180°)、左眼0.7(1.25 +0.75 cyl-1.75 Ax20°)、前房内フレア値(photons/millisecond)は右眼12.3、左眼14.6と軽度上昇、ICL前面にびまん性に微細な色素沈着を認めた。眼圧は右眼9mmHg、左眼10mmHg。0.1%ベタメタゾン(サンベタゾン)点眼にて、術後1ヵ月の視力は右眼1.25(1.6 -0.25 cyl-1.00 Ax175°)、左眼1.0(1.6 -0.75 cyl-0.75 Ax30°)、自覚症状も改善した。結論:眼圧上昇なく内科的に治療しえたPDS症例を経験した。術中周辺虹彩切除術がPDS発症に寄与した可能性が考えられた。(著者抄録)

The aim of this study was to investigate the prediction accuracy of intraocular lens (IOL) power formulas with artificial intelligence (AI) for high myopia. Cases of highly myopic patients (axial length [AL], >26.0 mm) undergoing uncomplicated cataract surgery with at least 1-month follow-up were included. Prediction errors, absolute errors, and percentages of eyes with prediction errors within ±0.25, ±0.50, and ±1.00 diopters (D) were compared using five formulas: Hill-RBF3.0, Kane, Barrett Universal II (BUII), Haigis, and SRK/T. Seventy eyes (mean patient age at surgery, 64.0 ± 9.0 years; mean AL, 27.8 ± 1.3 mm) were included. The prediction errors with the Hill-RBF3.0 and Kane formulas were statistically different from the BUII, Haigis, and SRK/T formulas, whereas there was not a statistically significant difference between those with the Hill-RBF3.0 and Kane. The absolute errors with the Hill-RBF3.0 and Kane formulas were smaller than that with the BUII formula, whereas there was not a statistically significant difference between the other formulas. The percentage within ±0.25 D with the Hill-RBF3.0 formula was larger than that with the BUII formula. The prediction accuracy using AI (Hill-RBF3.0 and Kane) showed excellent prediction accuracy. No significant difference was observed in the prediction accuracy between the Hill-RBF3.0 and Kane formulas.

目的:OKULIX(OK)、A-P法(A-P)、Shammas-PL式(S)、Haigis-L式(H-L)、Iida-Shimizu method(I-S)の5式を用いて、laser in situ keratomileusis(LASIK)後の白内障手術における眼内レンズ(IOL)度数計算の精度を比較する。方法:LASIK術後に白内障手術を行い、術後1ヵ月以上経過観察できた28例36眼で、前述のIOL計算式による術後屈折誤差を後方視的に比較した。結果:術後屈折誤差(算術値)の中央値(D)はOK、A-P、S、H-L、I-Sの順に0.00、0.48、-0.69、-0.83、-0.33でSおよびH-Lは他よりも近視寄りだった(P<0.01)。術後屈折誤差が±1.0D以内の割合(%)は、同順に83.3、80.6、76.0、60.0、86.1であり、±1.0D以内の割合はH-LがOK、I-Sよりも低かった(P<0.05)。結論:計算式によって屈折誤差の分布は異なる。LASIK術後のIOL度数決定の際には各計算式による誤差の特徴も考慮すべきである。(著者抄録)

目的:LASIKを受けたのちに生じた白内障に対し,多焦点眼内レンズを挿入した2例の報告。症例:2症例とも男性で,年齢は47歳と55歳である。それぞれ6年前と2年前に近視に対するLASIKを受けた。両症例とも右眼に白内障があり,矯正視力はそれぞれ1.2と0.7であった。白内障手術を行い,回折型多焦点眼内レンズを挿入した。遠見と近見裸眼視力は,1例では1.2と1.0,他の1例ではいずれも1.0で,自覚的には満足が得られた。術後コントラスト感度は2症例とも正常値の下限にあった。結論:LASIKの既往がある眼での白内障手術と多焦点眼内レンズの挿入では,術後の屈折値の誤差と視機能低下の可能性があり,術前のインフォームド・コンセントが必要である。(著者抄録)

Myopia is increasing worldwide and its preventable measure should urgently be pursued. N-3 polyunsaturated fatty acids (PUFAs) have been reported to have various effects such as vasodilative and anti-inflammatory, which myopia may be involved in. This study is to investigate the inhibitory effect of PUFAs on myopia progression. A lens-induced myopia (LIM) model was prepared using C57B L6/J 3-week-old mice, which were equipped with a −30 diopter lens to the right eye. Chows containing two different ratios of n-3/n-6 PUFA were administered to the mice, and myopic shifts were confirmed in choroidal thickness, refraction, and axial length in the n-3 PUFA-enriched chow group after 5 weeks. To exclude the possibility that the other ingredients in the chow may have taken the suppressive effect, fat-1 transgenic mice, which can produce n-3 PUFAs endogenously, demonstrated significant suppression of myopia. To identify what elements in n-3 PUFAs took effects on myopia suppression, enucleated eyes were used for targeted lipidomic analysis, and eicosapentaenoic acid (EPA) were characteristically distributed. Administration of EPA to the LIM model confirmed the inhibitory effect on choroidal thinning and myopia progression. Subsequently, to identify the elements and the metabolites of fatty acids effective on myopia suppression, targeted lipidomic analysis was performed and it demonstrated that metabolites of EPA were involved in myopia suppression, whereas prostaglandin E2 and 14,15-dihydrotestosterone were associated with progression of myopia. In conclusion, EPA and its metabolites are related to myopia suppression and inhibition of choroidal thinning.