With the rapid development of the light-emitting diode(LED) industry, research on the impact of LED lighting on health becomes the key for future industrial development. This article introduces progress both domestically and abroad on the current research and standardization dynamic of LED lighting on health. The systematic framework and research progress on the impact of LED lighting on health is emphasized using the visual physiological index.

Objective To compare changes of visual quality index that before and after 90 minutes′s visual task under three kinds of different color temperature lighting environment, to explore the relationship between visual fatigue and human wave-front aberration. Methods This research study included 94 adults and divided into 3 groups [4 000 K (37 cases), 5 000 K (27 cases) and 6 500 K (30 cases)] to underwent visual task, wave-front aberration before and after the visual task were tested and recorded. Visual fatigue score were tested after visual task. Data were analyzed using ANOVA. Results The changes of modulation transfer function (MTF) was minimum under 5 000 K color temperature lighting environment, corresponding visual fatigue score was lowest, the differences were significant with the other two groups (P<0.05). No significant difference of 3rd-7th higher order aberrations were found between the three group. The changes of vertical coma aberration under 6 500 K color temperature lighting environment were negative, and differences were significant compared with 5 000 K and 4 000 K groups (P<0.05). Conclusion Under 5 000 K color temperature lighting environment, human eyes feel most comfortable. MTF and vertical coma aberration could reflect human visual quality status effectively.

Objective To compare the difference among changes of the visual quality index that before and after 90 minutes of visual task under four kinds of fluctuation depth lighting environment, to find relationship between visual fatigue and human wave-front aberration. Methods In this research study, 85 adults divided into four groups [5%(20 cases), 15%(22 cases), 30%(23 cases) and 50%(20 cases) fluctuation depth lighting environment] to underwent visual task, the changes of modulation transfer function(MTF), higher order aberrations before and after the visual task were calculated and recorded. Data were analyzed using ANOVA. Results Under 50% fluctuation depth lighting environment, the change of MTF before and after visual task was maximum, visual fatigue degree was highest, and the difference was significant compare with 5% group (P<0.05). The differences of changes of 5th aberration before and afer visual task among the 4 groups were significant （F=2.222，P<0.05）. After visual task under 50% fluctuation depth, vertical coma aberration increased, the difference of change before and after visual task were significant compare with 5% group (P<0.05). Visual fatigue score of 50% group were highest. Conclusion Under 50% fluctuation depth lighting environment, visual fatigue score is highest; MTF changes obviously, so we guess MTF may could reflex human visual fatigue status.

Objective To study the impact on human visual function after viewing 2D/3D television; to explore the corresponding relationship between visual fatigue and human wavefront aberrations. Methods Thirty healthy adults were recruited for this research study. They watched the same film on 2D and 3D television but they wore two types of polarized 3D glasses for the 3D task-type A and type B (the optical index of type A was better than type B). Wavefront aberrations of the subjects was recorded before and after the visual task, included the modulation transfer function (MTF), root mean square (RMS) of higher order aberrations amplitude, etc. A single factor analysis of variance was used to compare values between the groups. Results The MTF variation was maximized when watching 3D television with type B glasses (3D-B), so the MTF tended to diminish after watching the film. The differences between 2D, 3D-A and 3D-B condition were significant (P<0.05). In the three test conditions, there were significant differences in RMS3 and RMS4 comparisons between 3D-A and 3D-B condition (F=0.293, 0.044, P<0.05). Vertical coma variations under the 2D/3D conditions were negative, and there were significant differences between 2D, 3D-A and 3D-B condition (F=0.025, P<0.05). Conclusion The stimulation of 2D/3D film can lead to changes in visual quality, which improves the index change in wavefront aberrations. This can be used in the future for evaluating visual comfort when viewing 3D television.

Objective To investigate the influence of RXRα on refractive development and ocular growth, we used peribulbar injections of selective RXRα agonist and antagonist in normal and form-deprived myopic (FDM) guinea pigs. Methods In this experimental study, 245 3-week-old guinea pigs weighing approximately 100 g were randomly assigned to normal and FD groups. Each group included these subgroups: untreated group, vehicle group and drug-treated group. The vehicle group and drug-treated group received peribulbar injections of DMSO, RXRα agonist Fluorobexarotene and RXRα antagonist HX531 every day for 4 weeks. Refraction and ocular biometric parameters were measured in both eyes of the individual animals before treatment and 2 and 4 weeks after treatment. RXRα expression was detected by immunofluorescence (IF) after all measurements were taken. The results were analyzed with a paired-sample t test and one-way analysis of variance. Results RXRα expression increased after peribulbar injections of RXRα agonist Fluorobexarotene. In addition, the expression of RXRα decreased after RXRα antagonist HX531 treatment. Peribulbar injection of either RXRα agonist Fluorobexarotene or RXRα antagonist HX531 did not result in statistically significant differences in refraction, vitreous chamber or axial length in the normal vision and FDM guinea pigs. Conclusion Peribulbar injection of RXRα agonist Fluorobexarotene and RXRα antagonist HX531 had no significant effect in refractive development and ocular growth in normal and FDM guinea pigs, suggesting that RXRα alone has no direct effect in the regulation of normal refractive development and form deprivation myopia in guinea pigs.

Objective To investigate the benefit of shielding 460-480 nm wavelength light, its effect on the visual function of healthy adults, and the prospects of light damage protection using optical thin-film technology. Methods This was a self-controlled study. Twenty-four healthy adults were recruited for this study. Under photopic (1 000 lx) and mesopic (40 lx) conditions, the total error score (TES) and partial error score (PES) in the ten color bands of the Farmsworth-Musell 100-Hue test were calculated to detect variations in color perception among a non-intervention group, a group wearing a 460-480 nm blue light-shielded filter and a group wearing ordinary yellow sunglasses (filtering 380-550 nm light). The contrast sensitivities of five spatial frequencies under photopic、mesopic and mesopic glare conditions were also compared. The results were analyzed with a signed-rank test. Results Under photopic and mesopic conditions, the TES and PES for several color bands were significantly higher when either the narrow-band filter group or the sunglass group compared to the non-intervention group (P<0.017). Under photopic and mesopic conditions, the TES and PES for several bands were significantly higher for the sunglass group compared to the narrow-band filter group (P<0.017). Under photopic and mesopic conditions, the contrast sensitivity differences for the groups were not statistically significant. Under the mesopic glare condition, the contrast sensitivities of spatial frequency 6.0 c/d were higher in the narrow-band filter group than in the non-intervention group (P<0.017). Conclusion With optical thin-film technology to shield harmful light, the color perception of healthy adults is affected but contrast sensitivity improves. The technology has a significant advantage compared with ordinary yellow sunglasses. Optical thin-film technology provides better prospects for light damage protection.

Objective To examine choroidal thickness and its relationship with axial length and spherical equivalence using spectral domain optical coherence tomography (SD-OCT) in patients with high myopic foveoschisis (MF). Methods Twenty-five patients with MF were prospectively recruited in the Beijing Jingmei Group General Hospital from November 2014 to February 2016. Fifty eyes of 50 age- and sex-matched people were used as controls. SD-OCT was used to measure choroidal thickness subfoveally and at 1.5 mm superiorly, inferiorly, nasally and temporally. A paired t test was used to assess the difference in spherical equivalence, axial length and choroidal thickness between the MF group and the controls. Logistic regression analysis was performed to evaluate the correlation between age, spherical equivalence, axial length, choroidal thickness and MF. Results The differences in spherical equivalence and axial length between the MF group and controls were not statistically significant (P＞0.05). Choroidal thicknesses subfoveally and at 1.5 mm superiorly, inferiorly, nasally and temporally were greater in the controls than in the MF eyes (t=24.131, 20.345, 16.140, 13.923, 19.037, P<0.01) and contralateral eyes (t=22.033, 18.066, 14.818, 13.049, 17.247, P<0.01). The differences were statistically significant. Subfoveal choroidal thickness was less in the MF group compared to the controls (130.3±27.8 µm vs. 147.8±25.6 µm). The difference was statistically significant (t=2.317， P<0.05). Logistic regression demonstrated that decreased choroidal thickness at the subfoveal location was associated with MF (OR, 1.78; 95%CI, 1.39-2.26, P<0.05). Conclusion Subfoveal choroidal thickness was greatly decreased in the MF group, suggesting an association with the mechanism of this disease.

Objective To investigate the improvement in visual quality in high myopia patients after sub-Bowman′s keratomileusis (SBK) using femtosecond laser or a mechanically guided system using Q values. Methods In this prospective study, 110 cases (220 eyes) of high myopia patients were treated and screened in our department from June 2013 to January 2015. They were divided into an OUP group and a Femto group randomly. Fifty-five high myopia patients (110 eyes) in the Femto group were treated with SBK using femtosecond laser to create corneal flaps guided by the Q value, and the same number of high myopia patients in the OUP group were treated with SBK using femtosecond laser alone to create corneal flaps. Visual acuity, corneal flap thickness, residual refractive error, total higher-order aberrations, spherical aberration, horizontal coma, vertical coma, and contrast sensitivity were evaluated during the follow-up. t-tests and repeated measures analysis of variance were used for data analysis in the first day, the first week, the first month, the third month, and the sixth month after SBK. Results There were no statistically significant differences between the two groups for visual acuity, residual refractive error, vertical coma, or contrast sensitivity(P>0.05), but results for patients in the Femto group were better than results in the OUP group for corneal flap thickness and default (t=24.45, P＜0.01). In addition, the added values of total higher-order aberrations,spherical aberration and horizontal coma in patients in the Femto group were better than those in the OUP group(t=12.87, 7.12, 7.26, P＜0.01). Conclusion Aberrations from femtosecond laser flap SBK surgery for high myopia are milder and the procedure can provide relatively better visual quality.

Objective To measure central corneal thickness (CCT) in full-term newborns, and to study the association with gestational age, birth weight, delivery mode, and gender. Methods This was a cross-sectional study. A subset of 221 full-term neonates (442 eyes) was included. The age of the neonates ranged from 1 to 3 days. There were 111 male neonates and 110 female neonates. CCT was measured quantitatively by a hand-held corneal pachymeter. Associations with neonatal factors were also studied. These included gender, gestational age, birth weight, and delivery mode. Data were analyzed using a t test, one-way ANOVA, Pearson correlation and multivariable linear regression analysis. Results No significant difference in CCT was found between right eyes (580±51 µm) and left eyes (583±53 µm). The mean value of the left and right eye CCT was defined as the neonatal CCT. Mean longitudinal CCT was 582±50 µm, 95%CI was 575-588 µm. The neonatal CCT of male and femal were 591±50 µm and 572±48 µm, respectively. This difference was statistically significant (t=2.927, P<0.01). No significant difference was found between neonates delivered by a caesarean or vaginal method. Gestational age at birth was negatively correlated with CCT (r=-0.225, P<0.01). The mean CCTs at different gestational ages from 37 weeks to 41 weeks were 607±42 µm, 600±56 µm, 577±48 µm, 576±48 µm, and 562±43 µm. No correlation between birth weight and CCT (r=0.069, P>0.05) was found. Multiple linear regression analysis showed the regression equation: CCT (µm)=980.52-10.42×gestational age(week)+18.60×gender. Conclusion The full-term newborn CCT was 575-588 µm (95%CI). There was no significant difference in CCT between the right and left eyes. CCT values were higher in male neonates than females, and were negatively correlated with gestational age. However, there was no significant correlation between birth weight and CCT.

Matrix metalloproteinases （MMPs） are a group of zinc-dependent proteolytic enzymes able to cleave all major protein components in the extracellular matrix during the processes of wound healing and tumor formation. Tissue inhibitors of MMPs （TIMPs）， which exist in the human body， can regulate the activity of MMPs. According to different sources， MMP inhibitors are divided into TIMPs， natural MMP inhibitors and synthetic inhibitors. The classification and functional features of MMPs and MMP inhibitors are summarized and the relationship between MMPs， MMP inhibitors and posterior capsular opacification （PCO） are reviewed.

Cataract represents a major cause of vision loss in uveitis. The visual outcome of surgical treatment is impaired by both the complications of uveitis and the inflammation itself. Thus, surgeons are required to pay more attention to choose an appropriate time for operation, to select suitable procedures and intraocular lens, and to control complications after surgery in order to obtain satisfactory visual outcome by surgical treatment.

Vascular endothelial growth factor can increase vascular permeability and promote neovascularization, playing an important role in the pathogenesis of diabetic retinopathy. At present, its monotherapy or combination therapy have been widely used in the clinical treatment of diabetic retinopathy, especially diabetic macular edema, neovascular glaucoma and vitreous hemorrhage. In this paper, the points mentioned above will beare systematically reviewed.