Contact lens has been widely used in clinical practice as one of refractive errors correcting medical equipment. During the process of contact lens wearing， the influence of contact lens to eye need to be long-term follow-up. Recently the application of anterior segment optical coherence tomography and confocal microscopy makes it possible to observe the cornea physiological change in vivo and can be the guide in contact clinical practice.

Objective To investigate the effect of using rigid gas-permeable contact lens （RGPCL） for severe myopia. Methods This was a retrospective case study. Twenty-four adults （43 eyes） with severe myopia were fitted with RGPCLs based on their subjective refractions， corneal topography， corneal curvatures and diagnostic fitting. The corrected visual acuity， adverse reactions and complications were observed 7 days， 1 month， 3 months and 6 months after the start of wearing the lenses. Data were analyzed using a chi-square test and non-parameter test. Results Corrected visual acuity with RGPCLs was 4.77±0.16， which was better than that with spectacles （4.62±0.15）. The result was statistically significant （χ2=16.496， P＜0.05）. The pan score， foreign body sensation scores， unstable vision， itching， pain， dryness， and hyperemia changed significantly from 7 days to 1 month after RGPCL wear （χ2=63.948， 63.823， 39.168， 6.459， 57.733， 44.164， 39.420， P<0.05）. Compared with 1 month after RGPCL wear， the pan score， foreign body sensation scores， unstable vision， and hyperemia continued to decrease after 3 months （χ2=35.536， 22.484， 11.537， 16.229， P<0.05）， while no statistical difference was found for itching， pain， or dryness （χ2=0.000， 1.184， 1.398， P＞0.05）. In general， the patients felt comfortable and there were no serious complications. Conclusion RGPCLs are a safe and effective approach to improve visual acuity for severe myopia in adults. RGPCLs are superior to spectacles for providing optical corrections and corrected visual acuity.

Objective  To explore the effect of long-term soft contact lens wear on a unit area of corneal epithelium cell tissue， epithelial thickness， cell morphology and proliferating cell nuclear antigen （PCNA）； to inform about the effects of contact lenses on the cornea in clinical applications. Methods  This was an prospective case control study. Group A consisted of long-term （≥3 years） soft contact lens wearers （66 eyes of 33 patients） and control group B consisted of non-soft contact lens wearers （66 eyes of 33 patients）. The selected patients had undergone an excimer flap-free Epi-LASIK operation， and the corneal flap was removed with an Epi-K corneal epithelial knife. Ultrasound and microscopy were used for measurement of the corneal flap thickness and the basal cell count. Paraffin section and immunohistochemistry were used to study the morphological changes of the corneal flap， basal cells and the proliferating cell nuclear antigen. Data were analyzed using an independent t test. Results  After more than 3 years of soft contact lens wear， the thickness of the corneal epithelium was 55.33±4.56 μm and the number of basal epithelial cells were 3872.6±153.2 cells/mm2. The thickness of the corneal epithelium in the control group was 57.19±3.82 μm and the number of basal epithelial cells were 3989.2±289.6 cells/mm2. There was a statistically significant difference between the experimental and control groups （t=-2.422， -2.757， P＜0.05）. In the experimental group， corneal basal cells were arranged more loosely， the cells had less structured forms， and the basal membrane was thicker and rougher compared to the control group. PCNA positive cells could be found in corneal epithelial basal cells in the experimental group but not in the control group. Conclusion  Long-term wear of soft contact lenses can lead to corneal epithelium injury： the corneal epithelium thickness decrease， corneal epithelial basal cells decrease in number， the structure of the corneal epithelium developes a less organized pathology. There are also changes in cell morphology， cell-cell junctions， destruction of the basal membrane， and the presence of PCNA positive cells.

This article is an analysis and discussion of the differences between the national standard GB 19192-2003 “Hygienic requirement for contact lens care solutions” and relevant international standards. It also reviews the relationship between the industry standard YY 0719 “Ophthalmic optics-contact lens care products” and the relevant international standards for contact lens care products. There are some problems with the national standard so an appeal should be made to the relevant national departments as soon as possible to coordinate the problems in standards， eliminate standards confusion， and promote the healthy development of contact lens care products in the industry.

Objective  To evaluate the status of orthokeratology decentration and dynamic changes in higher-order aberrations with different pupil diameters and to discuss its effect on visual quality. Methods  This was a prospective clinical study. Thirty myopic subjects （30 right eyes） were fitted with overnight orthokeratology lenses. The mean age was 23.6±2.3 years and the initial mean spherical equivalent （SE） refractive error was -2.61±0.83 D. All subjects underwent corneal topography measurements and wavefront aberration measurements before orthokeratology and 1 week， 1 month and 3 months after orthokeratology. The decentration （distance and angle） of the center of the flattened corneal area after orthokeratology was calculated relative to the pupil center. The higher-order aberrations under 3 mm and 6 mm pupil diameters were evaluated. Data were analyzed using pearson correlation， repeated measured ANOVA. Results  The decentrations at 1 week， 1 month， and 3 months after orthokeratoloty were 0.53±0.26 mm， 0.54±0.32 mm and 0.60±0.35 mm， respectively. The decentration was mainly located in the superior temporal quadrant. There were no statistically significant differences in the decentration measurements at different timepoints after orthokeratology. The location and magnitude of decentration had no correlation with initial SE or astigmatism. Total higher-order aberrations， third order， fourth order， combined coma， and spherical-like aberrations under 3 mm and 6 mm pupil diameters significantly increased after orthokeratology treatment （P<0.05）. However， there were no statistically significant differences in wavefront aberrations at different timepoints after orthokeratology.  The aberrations under a 6 mm pupil diameter had increased significantly compared to a 3 mm pupil diameter （P＜0.05） after orthokeratology treatment. The magnitude of decentration in the horizontal or vertical direction was positively correlated with the coma in the corresponding direction. However， no correlations were found between the total magnitude of decentration and other higher-order aberrations. Conclusion  The decentration from orthokertology present throughout the entire process， but it is very subtle and became stable after 1 week. Decentration increase higher-order aberrations.

Objective  To calculate the Q-values of the meridian sections of the anterior corneal surface based on the tangential radius and curve-fitting calculations； to analyze the distribution of the Q-values and the characteristics of the anterior corneal surface in young myopes. Methods  This was a cross-sectional study. Ninety right eyes of 90 myopia subjects with an age range of 16-30 years and mean spherical equivalent of -5.45±2.75 D underwent corneal topography examinations using the OrbscanⅡ system.  The tangential curvatures along the meridian section at 0.1 mm intervals from the apex to the periphery of the anterior surface were calculated and the Q-values of the semi-meridian section were calculated by linear regression of the tangential radius. Matlab R2009b （Matrix Laboratory） was used for curve fitting calculations. Results  The average calculated Q-values on the nasal and temporal horizontal intervals were -0.32±0.11 and -0.30±0.12， with a significant difference between them （t=2.009， P<0.05）. The coefficients of determination for curve fitting calculations in all the semi-meridians were over 0.9 based on Matlab R2009b （Matrix Laboratory） for 72 eyes. There were no significant differences before and after curve fitting calculations （nasal： t=1.299， P>0.05； temporal： t=0.848， P>0.05）. The average calculated Q-values along the superior and inferior intervals were -0.26±0.12 and -0.21±0.23， respectively. Conclusion  This study analyzes the calculated Q-values of the semi-meridian section in myopes based on the linear regression of the tangential radius using tangential topography and curve-fitting calculations. The anterior corneal surface proved to be a prolate elliptical shape in subjects with myopia. The vertical meridians were more round.

Objective  To investigate the recovery of distance stereopsis， zero disparity， crossed disparity and uncrossed disparity in ametropic amblyopic and anisometropic amblyopic children. Methods  In this prospective consecutive case study， the best distance corrected visual acuity of 58 amblyopic children was tested during treatment. Zero disparity， crossed disparity and uncrossed disparity were measured by Yan′s random dot stereogram； distance stereopsis was detected by synoptophore. Data were analyzed with linear regression. Results  Patients who had better visual acuity before treatment or those whose visual acuity increased quickly during treatment had better recovery of stereoscopic vision [regression equation for zero disparity and visual acuity before treatment was Y=-0.92X+3.13 （F=9.203， P<0.01）； regression equation for zero disparity and visual acuity at the completion of treatment was Y=-0.81X+3.23（F=9.886， P<0.01）]. With the improvement in visual acuity， distance stereopsis recovered earlier than near stereopsis， and zero disparity， crossed disparity and uncrossed disparity recovered in order. Conclusion  Distance stereopsis， near zero disparity， crossed disparity and uncrossed disparity recovered in order with the improvement of visual acuity in amblyopic children.

Objective  To compare the release rate of inflammatory cytokines in tears and the clinical outcomes for off-flap epi-LASIK eyes and the contralateral on-flap Epi-LASIK eyes； to explore the possible mechanisms for the clinical differences. Methods  This prospective and randomized study enrolled 18 myopic patients who underwent off-flap Epi-LASIK in one eye （off-flap group） and on-flap Epi-LASIK in the contralateral eye （on-flap group）. Tears were collected from each eye preoperatively and 2 hours， 1 day and 5 days postoperatively. Concentrations of interleukin-1β （IL-1β）， IL-6， IL-8 and tumor necrosis factor α （TNFα） were measured by a multiplex immunobead assay. The release rate （tear fluid flow-corrected concentration） was calculated by multiplying the concentration by tear fluid flow. Uncorrected visual acuity （UCVA）， refraction， best-corrected visual acuity， haze score， and percentage of corneal epithelial healing were also evaluated. Data were analyzed using a paired t test， Wilcoxon rank sum test， and a chi-square test. Results  Compared with the on-flap group， the off-flap group had better UCVA outcomes （t=-4.832， P<0.01） and higher percentages of epithelial healing （Z=5.861， P<0.01） at 5 days after surgery， and lower levels of haze at 1 month after surgery （U=6.045， P<0.05）. Preoperatively， there were no significant differences in the release rate of all tear cytokines between the two groups. At 2 hours postoperatively， the mean release rates of IL-8 and TNFα in the off-flap group were significantly lower than those in the on-flap group （Z=-1.965， -2.145， P<0.05）. On postoperative days 1 and 5， no significant differences were observed in the release rate of all cytokines between the 2 groups. Conclusion  Off-flap Epi-LASIK offers faster corneal epithelial healing and visual recovery， and temporarily less haze than from on-flap Epi-LASIK. The lower tear levels of IL-8 and TNFα in the off-flap group 2 hours after surgery may suggest a possible mechanism for the clinical differences.

Objective To investigate the effect on cornea topographical characteristcs of thyroid-associated ophthalmology （TAO） disease. Methods In this prospective case control study， 46 eyes of 24 patients diagnosed with the inactive TAO were recruited as study group， 30（30 eyes） age and sex matched healthy volunteers were as control group. TAO was diagnosed based on the basis of criteria of Eruopean Group Grave′s Orbitopathy and the activity was decided by the Clinical Activity Score （CAS）. Cornea topographical characteristics of each group was obtained by using Pentacam system via one experienced doctor， including the index surface virance （ISV）， index of vertical asymmetry （IVA）， index of highest asymmetry （IHA）， index of highest decentration （IHD） and minimal sagittal curvature （Rim）， central cornea thickness （CCT）， refractive power and astigmatism of front and back cornea. Data were analyzed using independent to test and rank sum test. Results ISV in TAO was 21.00（10-71）， higher than control group [14.0（10-34）] （Z=1.31， P＜0.01）； IVA was 0.180（0.07-0.70）， higher than control group [0.100（0.50-0.37）]（Z=1.08， P＜0.01）； IHA was 5.950（0.0-28.7）， higher than control group [1.65（0.2-13.9）]（Z=84.34， P＜0.01）； IHD was 0.020±0.015， higher than control group （0.010±0.004）（t=5.67， P＜0.01）； Rim was 7.43±0.30 mm， lower than control group （7.62±0.26 mm）（t=-2.505， P＜0.01）； CCT was 523.74±26.00 μm， lower than control group （546.25±28.84 μm）（t=3.230， P＜0.01）； K1 of front cornea was 43.58±1.18 D， higher than control group （42.86±1.43 D）， （t=2.123， P＜0.05）； K1 of back cornea was -6.20 D（-7.2--5.7 D）， higher than control group [-6.10 D（-6.6--5.7 D）]（Z=101.4， P＜0.01）. There was no siginificant difference in K2， astigmatism between study and control group. Conclusion The TAO may lead to the decrease of cornea symmetry and have an effect on refractive power of cornea.

Objective To evaluate the precision of laser in situ keratomileusis （LASIK） using two different devices， the Esiris excimer and Visx S4-IR laser systems， and small incision lenticule extraction （SMILE） surgery with the VisuMax femtosecond laser system. Methods This was a prospective case control study. Central corneal thickness was measured by using ultrasonic pachymetry before and 1 month after surgery in 274 consecutive eyes of 138 patients with no previous history of surgery. Corneal refractive surgery was then performed on all patients. Among all eyes， 100（51 patients） underwent LASIK with the Esiris excimer laser system； 100（50 patients） underwent LASIK with the Visx S4-IR excimer laser system； and 74（37 patients） underwent SMILE with the VisuMax femtosecond laser system. The changes in central corneal thickness before and after surgery were compared with their theoretically expected values calculated before surgery. The differences between them were defined as the central corneal cutting error， the index of the surgical precision， and were compared for different types of surgery and different magnitudes of refractive errors. An independent sample t test， two-way analysis of variance and Pearson correlation were used for data analysis. Results The extent of myopia， the extent of astigmatism and the central corneal thickness before surgery had no significant effects on the central corneal cutting error. In contrast， the cutting error showed significant differences between groups， suggesting a strong effect based on the equipment and procedure used in the refractive surgery. In the Esiris-LASIK group， there were significant differences （low myopia， t=4.672， P<0.01； moderate myopia， t=10.629， P<0.01； high myopia， t=11.021， P<0.01） between the changes in central corneal thickness and their expected values. Similarly， there were significant differences （low myopia， t=3.910， P<0.01； moderate myopia， t=4.922， P<0.01； high myopia， t=4.807， P<0.01） between the changes in central corneal thickness and their expected values in the Visx-LASIK group. In contrast， the central corneal cutting error was statistically equivalent to zero for both moderate （t=1.158， P＞0.05） and high （t= 0.836， P＞0.05） myopia in the VisuMax-SMILE group. Conclusion There are significant differences in central corneal cutting error when corneal refractive surgeries are performed with different devices.

Objective To explore the trends in orbital fat volume in different age groups using magnetic resonance imaging （MRI）. Methods Investigative study. One hundred forty-four normal adults （18～72 year olds， 288 eyes） were divided into six groups according to age and sex： 18～35 years old， 36～50 years old， ≥51 years old with 24 cases in every group. The orbital fat volumes in all the above groups were examined by MRI scans and the measured data were standardized. ANOVA was used to analyze the changes in orbital fat volume in the different gender and age groups. Independent t test and Spearman correlation was also used. Results The orbital fat volume showed no significant differences among the three different male age groups （F=0.787， P>0.05） and female groups （F=1.183， P>0.05）. In addition， there was no significant difference in the orbital fat volume between the male and female groups （t=1.029， P>0.05）. There was no correlation between orbital fat volume and age （r=-0.087， P>0.05）. Conclusion There were no significant changes in orbital fat volume with increasing age and there were no differences in orbital fat volume between normal adult male and female groups.

Objective To review the management of malignant eyelid tumors with primary reconstruction and the long-term outcomes. Methods Retrospective case study. The data from 46 eyes with malignant eyelid tumors were analyzed in patients who had undergone surgical excision from 2005 to 2008 in Shanghai Eye and ENT Hospital. The cancer type， location， extension， type of the procedure， appearance after surgery， comfort level and survival rate were evaluated. Results Among 46 cases， basal cell carcinoma （21 cases）， sebaceous gland carcinoma （19 cases）， squamous cell carcinoma （4 cases）， lymphoma （1 cases） and Merkel cell carcinoma （1 case） were included. Various techniques were used， such as the Hughes procedure， Cutler-Beard reconstruction， myocutaneous advancement flap， semicircular rotational flap， lateral cantholysis， periosteal strip， free autogenous tarsal graft， full-thickness skin graft， glabellar flap， et al. Median follow-up was 59.7±12.9 months （15-84 months）. According to the Kaplan-Meier survival estimate， the overall five-year and seven-year survival rates were 94% and 91%， respectively. The five year tumor-free survival rate was 91%. During the follow-up period， local recurrence occurred in two patients who refused further treatment and they were still alive at the last follow-up. Cervical lymph node enlargement was detected in two cases， followed by lymph node debridement. Both of them were in good condition until now. Four patients died， two of metastasis， one of old age， and one of primary esophageal carcinoma. Conclusion Eyelid reconstruction techniques can effectively repair defects after resection of malignant eyelid tumors and lead to satisfactory clinical results. Active surveillance is still mandatory.

Pathological myopia is one of the most common and severe hereditary ocular disease leading to blindness. A number of candidate genes of pathological myopia have been found. This article reviews the recent advances in studying the single nucleotide polymorphism of genes related to pathological myopia．

The Bangerter filter was first introduced as an adjunctive therapy in children with amblyopia. Recent studies have demonstrated its unique effect compared to eye patches. Its applications in the clinic and in research are reviewed.