Published papers

The aim of the present study was to evaluate sleep quality in myopic children and adults. This cross sectional study surveyed 486 participants aged from 10 to 59 years with refractive errors using a questionnaire containing the Pittsburgh Sleep Quality Index (PSQI) and Hospital Anxiety and Depression Scale (HADS). Children (< 20 years) in the high myopia group exhibited the poorest PSQI scores (P < 0.01), while the adults showed no such correlations. Subscales of PSQI and HADS in children disclosed that the high myopia groups had the shortest sleep duration (P < 0.01), worst subjective sleep scores (P < 0.001), and latest bedtime (P < 0.05). Regression analyses in children significantly correlated myopic errors with PSQI (P < 0.05), sleep duration (P < 0.01), and bedtime (P < 0.01). Sleep efficacy (P < 0.05) and daytime dysfunction (P < 0.05) were significantly better in contact-lens users compared to the respective non-user groups across all participants. In conclusion, sleep quality in children was significantly correlated with myopic error, with the high myopia group worst affected.

© 2019 American Medical Association. All rights reserved. Importance: Given the estimates of increasing prevalence of myopia, especially in Asia, it is important to determine the current prevalence of myopia among populations of schoolchildren in Japan. Objective: To investigate the current prevalence rate of myopia and the association between environmental factors and myopia in Japanese schoolchildren. Design, Setting, and Participants: This cross-sectional study assessed 1478 participants, including 726 elementary school students and 752 junior high school students, at 2 schools in Tokyo, Japan, who underwent eye examinations from April 1 to May 31, 2017, that included measurement of the refractive errors by autorefractometry with noncycloplegic refraction and ocular biometric factors. After excluding those who had been treated with atropine or orthokeratology (n = 11), had a history of eye disease (n = 2), had no parental consent (n = 41), and were absent (n = 8), 1416 schoolchildren were analyzed. Main Outcomes and Measures: The primary outcome was the prevalence of myopia and high myopia. Secondary outcomes were environmental factors that were associated with myopia. Results: A total of 1416 schoolchildren (mean [SD] age, 10.8 [2.7] years; 792 [55.9%] male) were studied. The prevalence rates of myopia (spherical equivalent ≤-0.5 diopters [D]) were 76.5% (95% CI, 73.4%-79.7%) among the elementary school students and 94.9% (95% CI, 93.3%-96.5%) among the junior high school students. The prevalence rates of high myopia (spherical equivalent ≤-6.0 D) were 4.0% (95% CI, 2.5%-5.4%) among the elementary school students and 11.3% (95% CI, 8.8%-13.7%) among the junior high school students. The prevalence rates of high myopia classified based on axial length of 26.0 mm or longer were 1.2% (95% CI, 0.4%-2.0%) among elementary school students and 15.2% (95% CI, 12.5%-17.8%) among junior high school students. Multiple regression analysis showed that higher-order aberrations and dry eye disease were associated with refractive error in elementary school students (spherical aberration: β = 6.152; 95% CI, 3.161-9.143; P <.001; dry eye disease: β = -0.626; 95% CI, -1.189 to -0.063; P =.03) and with axial length in junior high school students (spherical-like aberration: β = 26.546; 95% CI, 18.708-34.385; P <.001; dry eye disease: β = 0.354; 95% CI, 0.131-0.578; P <.002). Conclusions and Relevance: Although the use of noncycloplegic autorefraction with a cutoff of -0.50 D could lead to overestimation of results, these findings suggest that the current prevalence rates of myopia among elementary and junior high school students in Asia are high, especially if the results from these 2 schools are generalizable to all schoolchildren in Japan and Asia..

© 2018, Japanese Ophthalmological Society. Purpose: Novel spectacle lenses (MyoVision, Carl Zeiss) designed to reduce relative peripheral hyperopia have been developed and reported to be effective for preventing myopia progression in a subgroup of Chinese children. In this study we examined the efficacy of MyoVision lenses in Japanese children. Study design: This was a multicenter prospective randomized double-blind placebo-controlled trial. Method: We enrolled 207 participants (aged 6–12 years) with spherical equivalent refractions (SERs) ranging from −1.5 to −4.5 diopters (D) and with at least 1 myopic parent. The participants were randomized to receive either single vision lenses (SVLs) or MyoVision lenses and were followed up every 6 months for 2 years. The primary outcome was myopia progression evaluated by cycloplegic autorefraction, and the secondary outcome was elongation of axial length. Results: A total of 203 children (98.1%) completed the follow-up. The mean adjusted change in SER was −1.43 ± 0.10 D in the MyoVision group, which was not significantly different from that of the control group wearing SVLs (−1.39 ± 0.07 D) at the 24-month visit (P =.65). The adjusted axial length elongation was 0.73 ± 0.04 mm in the MyoVision group, which was not significantly different from that in the control group wearing SVLs (0.69 ± 0.03 mm) at the 24-month visit (P =.28). Conclusion: The results of this clinical trial could not verify the therapeutic effect of MyoVision for slowing down myopia progression in Japanese children. Additional studies are needed to design lenses that can reduce peripheral hyperopic defocus individually and to examine the effectiveness of these lenses in preventing myopia progression.

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Whether hyperoxia affects the refraction in neonatal and adult mice is unknown. The mice exposed to 85% oxygen at postnatal 8 days (P8d) for 3 days and the mice exposed to normal air were assigned to the neonatal hyperoxia and normoxia groups, respectively. The refraction, the corneal curvature radius (CR) and the axial length (AL) were measured at P30d and P47d. Postnatal 6 weeks (P6w) adult mice were divided into the adult hyperoxia and normoxia groups. These parameters were measured before oxygen exposure, after 1 and 6 weeks, and every 7 weeks. The lens elasticity was measured at P7w and P26w by enucleation. The neonatal hyperoxia group showed a significantly larger myopic change than the neonatal normoxia group (P47d −6.56 ± 5.89 D, +4.11 ± 2.02 D, p < 0.001), whereas the changes in AL were not significantly different (P47d, 3.31 ± 0.04 mm, 3.31 ± 0.05 mm, p = 0.852). The adult hyperoxia group also showed a significantly larger myopic change (P12w, −7.20 ± 4.09 D, +7.52 ± 2.54 D, p < 0.001). The AL did not show significant difference (P12w, 3.44 ± 0.03 mm, 3.43 ± 0.01 mm, p = 0.545); however, the CR in the adult hyperoxia group was significantly smaller than the adult normoxia group (P12w, 1.44 ± 0.03 mm, 1.50 ± 0.03 mm, p = 0.003). In conclusion, hyperoxia was demonstrated to induce myopic shift both in neonatal and adult mice, which was attributed to the change in the CR rather than the AL. Elucidation of the mechanisms of hyperoxia and the application of this result to humans should be carried out in future studies.

Purpose To evaluate the effect of neodymium:YAG (Nd:YAG) laser capsulotomy on the visual function in patients with posterior capsule opacification (PCO) and good visual acuity. Setting Keio University Hospital, Tokyo, Japan. Design Observational case series. Methods Eyes were evaluated that had previous cataract surgery with a clinical diagnosis of PCO requiring Nd:YAG laser capsulotomy regardless of a good corrected distance visual acuity (CDVA) (at least 20/20). The CDVA, 10% low contrast visual acuity (LCVA), wavefront aberrations from the 3rd to 6th order, and retinal straylight were measured before and after Nd:YAG laser capsulotomy. Results The study included 16 eyes of 16 patients (10 men, 6 women; mean age 69.5 years ± 9.3 [SD]). The mean CDVA, LCVA, and straylight after Nd:YAG laser capsulotomy improved significantly (P < .05). The root mean square (RMS) of the 3rd Zernike coefficients (S3) and the RMS of the total higher-order aberrations (HOAs) from the 3rd to 6th order decreased significantly after capsulotomy (P < .05). The straylight correlated significantly with the total HOAs (r = 0.727, P = .002) and S3 (r = 0.748, P = .001) before capsulotomy. Subjective symptoms resolved after capsulotomy in all cases. Conclusions Neodymium:YAG laser capsulotomy enabled a significant improvement in visual function even in patients with PCO with good visual acuity. Straylight measurements might be useful to determine the indications for Nd:YAG laser capsulotomy when patients report visual disturbances without decreased visual acuity.

The fact that outdoor light environment is an important suppressive factor against myopia led us to invent violet light-transmitting eyeglasses (VL glasses) which can transmit violet light (VL), 360–400 nm in wavelength, for the suppression of myopia, and can meanwhile block harmful ultra-violet waves from sunlight. The current study is a double-blinded randomized clinical trial to investigate the myopia-suppressive effect of VL glasses compared to conventional eyeglasses (placebo glasses) that do not transmit VL. The subjects were children aged from 6 to 12 years old, the population in which myopia progression is generally accelerated, and the myopia suppressive effect was followed up for two years in a city in Japan. Periodical ophthalmic examinations, interviews, and measurements of reflection and axial length under mydriasis were performed at the initial visit (the baseline) and at 1, 6, 12, 18, and 24 months. The mean change in axial length in the VL glasses group was significantly smaller than in the placebo glasses group when time for near-work was less than 180 min and when the subjects were limited to those who had never used eyeglasses before this trial (p < 0.01); however, this change was not significant without subgrouping. The suppressive rate for axial elongation in the VL glasses group was 21.4% for two years.

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.

Epipolis LASIKを施行した近視・近視性乱視14例28眼(男6例・女8例・平均32.6歳)の成績を報告した。術前の平均等価球面度数は-5.53D、乱視度数-0.86D、角膜厚540μm、裸眼視力0.06、矯正視力1.48であった。平均目標矯正量は-5.39Dで、切除深度70.3μm、術後乱視度数-0.30D、術後角膜厚468μmであった。全例のうち目標屈折値の±0.5D以内に71.4%が、±1.0D以内に96.4%が入っていた。術後3ヵ月の裸眼視力は1.0以上が80.8%、0.7以上が88.5%、0.5以上が96.2%で、平均1.19と良好な成績であった。矯正視力は全例1.0以上、平均1.58であった。術後に矯正視力が低下した例はなく、safety indexは1.07、efficacy indexは0.80で、コントラスト感度も有意な変化はなかった。術中合併症はフリーラップ1眼、不完全フラップ1眼で、術後合併症はgrade 0.5のhazeが1眼であった。また、近視の戻りは1例2眼にあり、エキシマレーザー角膜屈折矯正手術を追加した。

Purpose: To compare the accuracy of several methods of intraocular lens (IOL) power calculations used for cataract surgery in eyes treated with phototherapeutic keratectomy (PTK) that results in changes in the anterior corneal surface and axial length; these results make power calculations less predictable. Methods: We evaluated the medical records of 23 eyes of 13 patients (mean age, 68.8 years; range 62–80 years) who underwent cataract surgery after PTK at Keio University Hospital, Tokyo, Japan. The prediction error, defined as the difference between the estimated postoperative spherical equivalent and the postoperative manifest refraction at the spectacle plane, was calculated using five formulas: SRK/T, Haigis-L, Shammas-PL, Camellin–Calossi, and OKULIX ray tracing software. We compared the median values of the arithmetic and absolute prediction errors among the five formulas. Results: The median arithmetic errors after cataract surgery for the five formulas were 0.70 D (diopter) (range −0.41 to 2.78), −0.96 D (range −2.14 to 0.81), −0.81 D (range −1.89 to 1.15), −0.04 D (range −1.35 to 1.47), and 0.68 D (range −0.61 to 2.50), respectively. Conclusion: The Camellin–Calossi formula is a good option for calculating IOL powers in eyes that underwent PTK.

Purpose: To compare the clinical outcomes of 3 marking methods for toric intraocular lens (IOL) implantation in cataract patients. Methods: This study included 48 eyes of 48 cataract patients who underwent cataract surgery with toric IOL implantation. The rotational errors of 3 marking methods—the iris pattern marking method (iris pattern group), the pendulum marking method (pendulum group), and the 3-point marking method (3-point group)—were assessed. Results: The respective rotational errors were 4.0° ± 3.1° (mean ± SD), 5.3° ± 4.1°, and 7.3° ± 6.0°. The iris pattern group had significantly (P = 0.048) smaller rotational errors than did the 3-point group; no significant difference was found between the iris pattern and pendulum groups. However, the differences in postoperative uncorrected distance visual acuity and astigmatism did not reach significance among the 3 groups. Conclusion: The refractive and visual results of toric IOL implantation using the 3-point marking method were comparable to the other methods evaluated in this study, although the accuracy of the axis alignment of the toric IOLs was significantly lower than that obtained with the iris pattern method.