Hidemasa Torii

Violet Light Exposure Can Be a Preventive Strategy Against Myopia Progression

Prevalence of myopia is increasing worldwide. Outdoor activity is one of the most important environmental factors for myopia control. Here we show that violet light (VL, 360–400 nm wavelength) suppresses myopia progression. First, we confirmed that VL suppressed the axial length (AL) elongation in the chick myopia model. Expression microarray analyses revealed that myopia suppressive gene EGR1 was upregulated by VL exposure. VL exposure induced significantly higher upregulation of EGR1 in chick chorioretinal tissues than blue light under the same conditions. Next, we conducted clinical research retrospectively to compare the AL elongation among myopic children who wore eyeglasses (VL blocked) and two types of contact lenses (partially VL blocked and VL transmitting). The data showed the VL transmitting contact lenses suppressed myopia progression most. These results suggest that VL is one of the important outdoor environmental factors for myopia control. Since VL is apt to be excluded from our modern society due to the excessive UV protection, VL exposure can be a preventive strategy against myopia progression.

Feasibility of spherical aberration correction with aspheric intraocular lenses in cataract surgery based on individual pupil diameter

PURPOSE: To evaluate the feasibility of correcting spherical aberration with aspheric intraocular lenses (IOLs) in cataract surgery based on individual pupil diameter. SETTING: Keio University Hospital, Tokyo, Japan. METHODS: In this prospective study, eyes having cataract surgery were divided into 4 groups based on IOL type: aspheric SN (AcrySof SN60WF), aspheric ZA (Tecnis ZA9003), aspheric PY (Hoya PY‐60 AD), and spherical (AcrySof Natural SN60AT). Postoperative higher‐order aberrations (HOAs) of the cornea and whole eye and the pupil diameter under photopic and mesopic conditions were measured. The HOA was calculated using the individual pupil diameter. The correlation between corneal and ocular spherical aberrations and pupil diameter was evaluated. RESULTS: Each group comprised 30 eyes. Ocular spherical aberrations were significantly lower than corneal spherical aberrations under mesopic conditions in the aspheric SN group, the aspheric ZA group, and the aspheric PY group (P<.05); there was no significant difference between the aberrations in the spherical group. Linear regression showed significant correlations between postoperative corneal and ocular spherical aberrations (β = 0.39, aspheric SN; β = 0.38, aspheric ZA; β = 0.58, aspheric PY; β = 0.79, spherical). The differences in corneal and ocular spherical aberrations were significantly correlated with pupil diameter in the aspheric IOL groups but not in the spherical IOL group. CONCLUSIONS: The amount of spherical aberration correction by aspheric IOLs varied depending on IOL type and individual pupil diameter. The linear regression equation in this study may make it possible to customize postoperative ocular spherical aberration after cataract surgery.

Effect of experimentally induced astigmatism on functional, conventional, and low-contrast visual acuity

PURPOSE To report the changes in functional visual acuity (FVA) in eyes with experimentally induced astigmatism. METHODS This study included 26 right eyes from 26 healthy participants (mean age: 27.0±4.4 years). After confirming best correction under cycloplegia, the cylinder power ×90° and ×180° (against-the-rule [ATR] and with-the-rule [WTR] astigmatism, respectively) were added with 0.50-diopter (D) steps, from 0.50 to 2.50 D. Conventional visual acuity (VA), FVA as measured by the FVA Measurement System (NIDEK Co Ltd), and 10% low-contrast visual acuity (LCVA) were measured with 3-mm artificial pupil under each condition. RESULTS The mean corrected logMAR VA, FVA, LCVA were -0.18±0.00 (20/13), -0.10±0.08 (20/16), and 0.06±0.06 (20/23), respectively. The VA, FVA, and LCVA had a significant linear negative correlation with the addition of cylinder irrespective of the axes. A significant decrease in FVA was noted on addition of ⩾0.50 D WTR astigmatism and ⩾1.00 D ATR astigmatism. With the addition of 1.00 D of cylindrical lens, 96% of eyes with WTR and ATR astigmatism could maintain 20/20 in VA testing, whereas only 50% and 62% of eyes with WTR and ATR astigmatism, respectively, could maintain 20/20 in FVA testing. CONCLUSIONS Astigmatism may be associated with deterioration of visual function even when conventional VA of 20/20 is attained. Functional VA testing seems to be useful in evaluating the masked astigmatic visual impairment that cannot be detected by conventional VA testing.

A new central–peripheral corneal curvature method for intraocular lens power calculation after excimer laser refractive surgery

Purpose:  To propose the central–peripheral (C‐P) method, which requires no data history to calculate intraocular lens (IOL) powers for eyes that underwent laser in situ keratomileusis (LASIK), and compare the accuracy of the C‐P method with other IOL formulas for eyes after LASIK.

Decreased sleep quality in high myopia children

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.

Effect of neodymium:YAG laser capsulotomy on visual function in patients with posterior capsule opacification and good visual acuity

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. Financial Disclosure None of the authors has a financial or proprietary interest in any material or method mentioned.

Effect of Pupil Size on Uncorrected Visual Acuity in Pseudophakic Eyes With Astigmatism

PURPOSE To study the effect of pupil size on the relationship between refractive astigmatism and uncorrected distance visual acuity (UDVA) and pseudoaccommodation in pseudophakic eyes. METHODS Thirty-six eyes from 36 patients who underwent phacoemulsification and intraocular lens (IOL) implantation were included. All eyes were divided into two groups based on the presence of postoperative-with-the-rule astigmatism or against-the-rule astigmatism. Uncorrected and corrected distance visual acuity (CDVA), refractive astigmatism, subjective accommodation amplitude, and pupil sizes under photopic and mesopic conditions were measured 1 month postoperatively. The effects of pupil size on the relationship between refractive astigmatism and UDVA were investigated. RESULTS Against-the-rule astigmatism had a moderate but significant negative linear correlation with UDVA irrespective of the pupil size (R(2)=0.60, P<.01). A moderate but significant negative linear correlation was found when the pupil diameter exceeded 2.9 mm in eyes with with-the-rule astigmatism (R(2)=0.46, P=.04). Refractive astigmatism was not significantly correlated with pseudoaccommodation regardless of the pupil diameter in either group. CONCLUSIONS The results of the current study suggest that pupil size may have an impact on postoperative UDVA in eyes having against-the-rule astigmatism and in eyes with a large pupil diameter and with-the-rule astigmatism.

Predictability of ocular spherical aberration after cataract surgery determined using preoperative corneal spherical aberration

PURPOSE: To evaluate the predictability of total postoperative spherical aberration after aspheric intraocular lens (IOL) implantation using preoperative corneal spherical aberration. SETTING: Keio University Hospital, Tokyo, Japan. METHODS: Corneal and ocular higher‐order aberrations (HOAs) were analyzed preoperatively and postoperatively in eyes having cataract extraction with aspheric IOL implantation. The predicted postoperative total spherical aberration Z(4,0) was calculated by adding the preoperative corneal spherical aberration and the labeled spherical aberration of the IOL. The prediction error of the postoperative total spherical aberration was calculated by subtracting the predicted postoperative total spherical aberration from the postoperative total spherical aberration. Surgically induced corneal spherical aberration was calculated by subtracting the postoperative from the preoperative corneal spherical aberration. RESULTS: There were no statistically significant differences between preoperative and postoperative corneal spherical aberration, 3rd‐order aberration, or HOAs. The prediction error of the postoperative total spherical aberration was within ±0.05 μm in 9 (24.3%) of the 37 eyes evaluated and within ±0.10 μm in 18 eyes (48.6%). Statistically significantly correlations were found between the surgically induced corneal spherical aberration and prediction error of postoperative total spherical aberration, the preoperative corneal spherical aberration and surgically induced corneal spherical aberration, and the preoperative corneal spherical aberration and prediction error of postoperative total spherical aberration. CONCLUSIONS: Predictability of postoperative ocular spherical aberration after cataract surgery with aspheric IOL implantation was insufficient because of the surgically induced corneal spherical aberration. Considering surgically induced corneal spherical aberration could improve the predictability of postoperative ocular spherical aberration. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Functional visual acuity of early presbyopia

Purpose To evaluate visual function in patients with early presbyopia using the functional visual acuity (FVA) test. Methods This study included 27 eyes of 27 healthy older volunteers (mean age, 44.1 ± 2.6 years) and 14 eyes of 14 healthy young volunteers (mean age, 28.4±4.8 years). The distance-corrected visual acuity (DCVA), distance-corrected near VA (DCNVA), subjective amplitude of accommodation (AA), and distance and near pupillary diameters were measured. The distance FVA and distance-corrected near FVA (DCNFVA) were measured using the FVA Measurement System. The standard Schirmer test and standard tear break-up time measurement also were performed. Results The logarithm of the minimum angle of resolution (logMAR) DCVA was better than 0 in all subjects. The percentages of subjects with logMAR DCNVA below 0 was significantly lower in the presbyopia group than in the young group. The DCNFVA in the presbyopia group was significantly (P < 0.001) poorer than the DCNVA in that group. Significant linear negative correlations were seen between the DCNVA and AA (r = -0.507, P < 0.001) and the DCNFVA and AA (r = -0.681, P < 0.001) in the older subjects. Stepwise regression analysis showed that only the AA was a significant factor predictive of the DCNFVA in the presbyopia group. Tear function parameters were not adopted in the regression model. Conclusions Measurement of the DCNFVA can detect decreased AA in early presbyopia better than measurement of the conventional near VA. The DCNFVA is a good index for early presbyopia.

Violet Light Transmission is Related to Myopia Progression in Adult High Myopia

Myopia is increasing worldwide. Although the exact etiology of myopia is unknown, outdoor activity is one of the most important environmental factors for myopia control. We previously reported that violet light (VL, 360–400 nm wavelength), which is abundant in the outdoor environment, suppressed myopia progression for individuals under 20 years of age. However, whether VL is also effective for adult high myopia, which can be sight-threatening, has remained unknown. To investigate the influence of VL for adult myopia, we retrospectively compared the myopic progression and the axial length elongation over five years in adult high myopic patients over 25 years of age after two types (non-VL transmitting and VL transmitting) of phakic intraocular lens (pIOL) implantation. We found that high myopic patients with the non-VL transmitting pIOLs implanted are almost two times more myopic in the change of refraction and four times longer in the change of axial length, compared to those implanted with the VL transmitting pIOLs. This result indicated that the VL transmitting pIOL suppressed myopia progression and axial length elongation compared with the non-VL transmitting one. In conclusion, our study showed the VL possibly has an anti-myopia effect for human adults with high myopia.