Compared to traditional phacoemulsification， the femtosecond laser assisted cataract surgery (FLACS) offers many unique advantages， including effective phaco time (EPT) and cumulative dissipated energy(CDE) reduction， better corneal incision morphology， precise capsulorhexis， and better intraocular lens (IOL) stability and position predictability. However， a new technique may develop accompanying with complications. From slightly to severely， complications include suction break， repeated patient interface docking， subconjunctival hemorrhage， corneal incision assisted with keratome or dislocation of corneal incision， pupillary constriction， anterior capsulotomy tags， anterior capsule tear， posterior capsule rupture， vitreous loss， posterior lens dislocation， and capsular block syndrome (CBS). Perfect FLACS presents great advantages， but these advantages of femtosecond laser will disappear and even the postoperative vision acuity will be damaged heavily when severe intraoperative complications occur. Therefore， it is the present important issue to avoid or reduce the intraoperative complications with FLACS. Now this paper will focus on how to avoid or reduce the intraoperative complications with FLACS. All contents related to the operation is covered， from patient selection to the details of surgical techniques.

Objective To compare the clinical effects of femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification cataract surgery (PCS). Methods A prospective nonrandomized parallel cohort study of 212 patients (212 eyes) who underwent cataract surgery were divided into two groups based on the treatment protocol: PCS (112 patients, 112 eyes) and FLACS (100 patients, 100 eyes). The aim of this project was to compare the ultrasound time (UST), cumulative dissipated energy (CDE), and 1 day, 1 week, 1 month and 3 months postoperatively with best corrected visual acuity (BCVA), intraocular pressure (IOP), aqueous flare, central corneal thickness (CCT), endothelial cell density (ECD), and intraoperative and postoperative complications. The data were compared statistically using a t-test and repeated measures ANOVA． Results The CDE and UST of the FLACS group were reduced by 49.5% and 41.6%, respectively (t=13.24, 16.88, P<0.01). There were no statistically significant differences in IOP or BCVA between the two groups after surgery (P>0.05). Postoperative aqueous flare was significantly lower in the FLACS at all time points (t=8.95, 10.47, 8.65, 4.58, all P<0.01) and ECD was significantly higher in the FLACS group (t=-4.28, -3.98, -4.19, -4.78, all P<0.01). CCT was significantly lower in the FLACS group on postoperative day 1 (t=12.44, P<0.01). The main complications in the FLACS group included pupillary constriction (15%) and subconjunctival hemorrhage (36%). Conclusion Femtosecond laser-assisted cataract surgery results in significantly lower CDE and UST. It also reduces the severity of postoperative inflammation and corneal endothelial cell loss.

Objective To compare the accuracy of postoperative diopter after femtosecond laser-assisted cataract surgery and conventional phacoemulsification cataract surgery in cataract patients with high myopia． Methods In this prospective cohort study, 63 cataract patients (63 eyes) with high myopia who underwent cataract surgery were enrolled. Patients were distributed into femtosecond laser-assisted cataract surgery (31 eyes) and conventional phacoemulsification cataract surgery (32 eyes). The predicted postoperative diopter, actual postoperative diopter at 1 month and 3 months were recorded, as well as uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA). Refractive errors, mean absolute error (MAE) were calculated. Data were analyzed using independent t test, paired t test and rank sum test. Results The differences of patients′ demographics parameters(age, intraocular pressure, axial length) were not significant between the two groups. The differences of refractive error, MAE, UCVA and BCVA at 1 month and 3 months postoperation were not significant between the two groups. The MAE of 16 eyes (25%) are greater than 1.0 D. The differences of refractive error and MAE in the two groups were not significant between 1 month and 3 months after surgery. Conclusion Femtosecond laser-assisted cataract surgery did not demonstrate clinically meaningful improvement in accuracy of postoperative diopter and visual acuity over tranditional phacoemulsification in high myopic patients.

Objective To evaluate surgically induced astigmatism (SIA) resulting from femtosecond laser-assisted phacoemulsification cataract surgery with a 2.2 mm clear corneal incision. Methods A prospective, comparative analysis was performed in a case series. A total of 105 eyes of 84 patients (from No. 1 cataract department of Shanxi Eye Hospital) who underwent femtosecond laser-assisted phacoemulsification cataract surgery between March 2014 and April 2016 were enrolled in this study. The main outcomes were a comparison of SIA, far visual acuity, and spherical refractive power preoperatively and 1, 3, and 6 months postoperatively. Distance visual acuity was recorded as logMAR. Based on follow-up times (1, 3, and 6 months postoperatively), lens nucleus hardness (grades Ⅱ, Ⅲ, Ⅳ), corneal astigmatism types (with-the-rule, against-the-rule, oblique) and laterality (left, right), SIA was analyzed using Alphins vector analysis. Data were analyzed using repeated measured ANOVA. Results The mean preoperative logMAR visual acuity was 0.65±0.24, which was significantly different from postoperative logMAR visual acuity at 1 month (0.07±0.02), 3 months (0.06±0.01), and 6 months (0.06±0.01). No significant logMAR visual acuity differences were found at the three postoperative follow-up times. SIAs at 1, 3, and 6 months after surgery were 0.28±0.11 D, 0.25±0.13 D, 0.24±0.10 D, respectively. No statistically significant differences in SIA were found when postoperative follow-up times (1, 3, and 6 months) and factor groups for lens nucleus hardness (grades II, Ⅲ, Ⅳ), corneal astigmatism types (with-the-rule, against-the-rule, oblique) and laterality (left, right) were compared. Conclusion Femtosecond laser-assisted phacoemulsification cataract surgery using a 2.2 mm clear corneal incision can provide stable SIA and better postoperative visual acuity.

Objective To develop and test a Chinese version vision-relatde quality of life questionnaire-25. Methods In this investigtion study, the National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was translated and adapted into the Chinese version vision-related quality of life questionnaire (CVRQoL-25). The questionnaire items were completed by 113 patients with age-related cataract, hypermyopia, glaucoma, diabetic retinopathy and by a reference group (n=38). The rates of missing data, Cronbach′ alpha coefficient, content validity, construct validity and discriminant validity of CVRQoL-25 were computed. The results were compared with patient demographics multivariate analysis of variance, factor analysis and Pearson correlation were used for statistical analysis. Results Based on the information from the participants, one item-“Driving” was changed to conclude driving cars and riding bicycles. At scale “Driving”, the rate of missing data was very high both in patient and control groups, while all the other scales were responded to each member in the research. Cronbach′ alpha coefficient for the ten scales and the total CVRQoL-25 scale were above 0.6. There was significant difference between the two groups. The content validity of all scales were above 0.4 and each scale was included in one of the major factors. The scores of CVRQoL-25 were highly correlated with visual acuity of the better eye, both eye, and with education. Conclusion With minor modifications from the English version, CVRQoL-25 can be used as one measure instrument to evaluate the vision-related quality of life of patients with eye disease. The scores of CVRQoL-25 had no significant relations with sex, and had negtive relations with age. Subjects who with higher education degree had higher scores of CVRQoL-25.

Objective To evaluate the effects of incision width on visual outcomes by comparing visual acuity, refractive error, higher-order aberrations and corneal topography parameters after femtosecond small-incision lenticule extraction (SMILE). Methods This was a prospective case-control study. Thirty-four patients (68 eyes) who underwent SMILE to correct myopia and myopic astigmatism were included. We divided them into two groups by a side cut of 2 mm or 4 mm. Twenty-two patients (44 eyes) were in the 2 mm side-cut group while 12 patients (24 eyes) were in the 4 mm side-cut group. All patients underwent routine examinations before the surgery in case of surgical contraindications. Preoperatively and 1 week and 1, 3 and 6 months postoperatively, we measured UCVA, BCVA, refractive error, total higher-order aberrations (HOAs), spherical aberrations (Z40), vertical coma (Z3-1), horizontal coma (Z31), anterior corneal surface astigmatism, corneal irregularity measurement (CIM) and shape factor (SF). A repeated measures analysis of variance was used to compare the differences in these data between the two groups and between pre- and post-operation. Results No differences were found in UCVA, BCVA or refractive error between the two groups at any time point. For Z3-1, the outcomes in the 4 mm side-cut group were higher than in the 2 mm side-cut group at 1 week postoperatively (t=－2.031, P＜0.05). For anterior corneal surface astigmatism, the outcomes in the 4 mm side-cut group were higher than in the 2 mm side-cut group at 1 week and 1 month postoperatively (t=－2.126, －2.108, P＜0.05). For CIM, the outcomes in the 4 mm side-cut group were higher than in the 2 mm side-cut group at 1 week and 1 month postoperatively (t=－2.360, －2.395, P＜0.05). Conclusion When considering Z3-1, anterior corneal surface astigmatism and CIM, SMILE with a 2 mm side cut has advantages over SMILE with a 4 mm side cut.

Objective Investigating whether the effect of long-term wearing orthokeratology on cornea is completely reversible or not and its myopia control effect. Methods This was a prospective cohort study. Fifty-five adolescent (110 eyes) wearing orthokeratology and 55 adolescent (110 eyes) wearing full correction single vision(SV) spectacles were collected. After 2 years′ wearing, orthokeratology group stop wearing at least 30 days before re-examination. Spherical equivalent (SE) and axial length(AL) of SV spectacles group were tested before trial and 2 years later. SE, AL, astigmatism, SimK, corneal horizontal and vertical refractive power (corneal k value), uncorrected visual acuity(UCVA), etc. were recorded in orthokeratology group before trial and 2 years later. Data were analyzed using paired and independent t test, repeated measurement ANOVA, and Pearson correlation regression analysis. Results Forty-six cases (92 eyes) and 43 cases (86 eyes) finished the trial in SV and orthokeratology group, respectively. Two years later, SE and axial length increased -1.68±0.84 D, 0.59±0.48 mm in SV spectacles group and -0.80±1.04 D, 0.37±0.34 mm in orthokeratology group, respectively, there were significant difference between the two groups (t=25.81, 20.13, P<0.01). For orthokeratology group, there are some increase in astigmatism and SimK, 0.30±0.24 D and 0.28±0.22 D respectively (t=5.83, 5.45, P<0.05), in corneal horizontal refractive power reducted (0.31±0.18 D, t=7.43, P<0.05). There was a significant difference in UCVA at different time points before and after wearing orthokeratology, and the UCVA was significantly improved after wearing orthokeratology (F=250.80, P<0.01). Conclusion Wearing orthokeratology could significantly improve the UCVA of myopia patients, and control the progression of adolescent myopia. But Long-term wearing may result in slight increase in astigmatism, slight reduction in corneal horizontal K, this indicates that the effect of orthokeratology may not be completely reversible.

Objective To analyze the changes of the parameters of anterior segment of eyes after femtosecond laser LASIK. Methods In this prospective clinic study, 50 eyes of 25 patients who underwent femtosecond laser laser in situ keratomileusis (LASIK) were included. The corneal endothelium density, anterior chamber depth, anterior chamber angle width, posterior corneal surface height (4 mm diameter), distance between pupil center and corneal vertex, pupil diameter under light and dark environment were compared before and 6 months or more after surgery. Distance between pupil center and corneal vertex using absolute value. Data were analyzed using paired t test. Results After surgery, corneal endothelium density (2 829.7±227.2 cells/mm2 vs. 2 716.4±255.2 cells/mm2), anterior chamber depth(3.18±0.19 mm vs. 3.08±0.21 mm), anterior chamber angle width (39.39°±3.90°, 37.92°±3.76°) decreased (t=3.077, 11.079, 5.241, P＜0.01). The differences of posterior corneal surface height (4 mm diameter), pupil diameter under light and dark environment before and after surgery were insignificant. The distance between pupil center and corneal vertex on X axis increased (0.11±0.10 mm vs. 0.14±0.12 mm, t=-3.318, P＜0.01). The distance between pupil center and corneal vertex on Y axis increase(0.11±0.08 mm vs. 0.15±0.11 mm, t=-4.157, P＜0.01). Conclusion The parameters of anterior segment of eyes after femtosecond laser LASIK changed obviously, especially for the distance between pupil center and corneal vertex. Maybe this change is important in guiding the following surgery.

Objective By investigating the prevalence of refractive errors in older adults in rural populations in Tongxin county, Ningxia Hui Autonomous Region, it was feasible to get more actual data on the prevalence of blindness and low vision before and after refractive correction. Methods A population-based cross-sectional study was carried out. A questionnaire was designed for people aged 50 or older in Tongxin county, Ningxia, to obtain a general medical history, dietary habits, previous ocular history and treatment. Measurements were taken, including visual acuity, intraocular pressure, refraction, slit-lamp microscopy and non-mydriatic digital fundus photography in order to analyze the distribution of people with refractive errors associated with gender, age, education level and different ethnic groups, as well as etiological factors causing prevalence and noncorrectable vision with different refractive conditions. Visual impairment standards that included best-corrected visual acuity (BCVA) and presenting visual acuity (PVA) were used to analyze the prevalence of blindness and low vision before and after refractive correction. A Chi-square test was used for comparing the rate among groups. Results There were 5 493 people aged 50 or older in the rural population in Tongxin county, among which 5 046 people completed the examination, sponse rate were 91.86%, and 2 116 of them were diagnosed with ametropia, a prevalence rate of 41.93%. Based on PVA and BCVA, the prevalence of blindness was 5.35% and 2.02％, respectively, and the difference was statistically significant (χ2=78.78, P<0.01). Similarly, based on PVA and BCVA standards, the prevalence of low vision was 15.28％ and 5.77％, respectively, which was statistically significant (χ2=244.54, P<0.01). The prevalence of ametropia in different educational levels: under primary school, primary school, middle school, senior high school and above was 45.94%, 36.42%, 25.38%, and 33.79%, the differences were significant (χ²=97.89, P<0.01). The prevalence of Hui and Han nationalities was 43.33% and 35.92%, respectively. The prevalence rate of the Hui population was higher than the Han population (χ2=17.40, P<0.01). Conclusion Prevalence of refractive error is 41.93% in Tongxin County, Ningxia. Prevalence of refractive error is different in different age, eductional levels, ethnic group. Blindness and low vision impairment could be eliminated in most elderly people with refractive correction.

Objective To study the axial elongation resulting from form deprivation caused by unilateral congenital cataract. Methods This was a retrospective case-series study that included 90 patients with unilateral congenital cataract who underwent cataract surgery from March 2009 to July 2015 in the Qingdao Eye Hospital. Of those patients, aged 2 months to 14 years (mean 4.04±3.06 years), 46 were males and 44 were females. Patients were divided into 5 groups by age, ranging from -6 months (11 cases), -1 year (6 cases), -3 years (20 cases), -5 years (20 cases) and ～14 years (33 cases). The axial lengths (AL) of the cataract eyes and fellow eyes were compared using a paired t test. Based on the differences in AL, patients were divided into 2 groups: one group had shorter ALs (40 cases) in the cataract eye and the other group had longer ALs (50 cases). Linear regression was used to analyze the correlation between the form deprivation and the differences in AL length. Patients were divided into a full-opacity group (24 cases) and partial-opacity group (66 cases) based on the degree of lens opacity. Multiple regression was used to analyze the effects of form-deprivation duration, gender and degree of lens opacity on AL. Results AL was shorter in the cataract eyes in patients aged -6 months (t=-4.80, P＜0.01), and longer in patients aged -14 years (t=2.54, P＜0.05). The differences in AL in the other 3 groups were not significant (t=-0.36, 0.30, 1.43, P＞0.05). A correlation test showed that the difference in AL significantly increased with the duration of form deprivation (r=0.294, P＜0.01), and the proportion of the patients in the group with longer ALs was greater in older children than in younger children. Multiple regression showed that the difference in AL increased with the duration of form deprivation (r=0.142, P＜0.05), and the difference in AL was significantly higher in the full opacity group (r=0.819, P＜0.01). Gender did not significantly influence AL. Conclusion AL was initially shorter in the cataract eye. The AL of the cataract eye increased with an increase in the duration of form deprivation and eventually became longer. Full-opacity cataract affected AL more severely.

Objective Observe filtering bleb after compound trabeculectomy combined HEMA glaucoma shunting device implantation operation in primary chronic angle-closure glaucoma (PCACG) patients using ultrasound biomicroscopy(UBM). Methods This was a prospective cohort study. Sixty eyes of 60 subjects with PCACG were randomly devided into the research group (30 cases) and the control group(30 cases). The control group received compound trabeculectomy, and the research group received compound trabeculectomy combined with HEMA glaucoma shunting device implantation. The best corrected visual acuity (BCVA) and the intraocular pressure (IOP) were measured 1 day preoperation, and 3 months and 6 months postoperation. Filtering bleb morphology were observed at 3 months and 6 months postoperation using UBM. Data were analyzed using independent t test, repeated measured ANOVA, Fisher exact test. Results The BVCA (logMAR) of the control group were 0.63±0.48, 0.54±0.35 and 0.55±0.34, while were 0.66±0.56, 0.49±0.25 and 0.50±0.27 in the treatment group. The differences were not significant between groups and time points (P>0.05). The IOP of the control group was 19.2±12.2 mmHg, 16.3±4.5 mmHg and 16.8±4.6 mmHg (1 mmHg=0.133 kPa), respectively, while were 18.7±10.2 mmHg, 12.4±4.1 mmHg and 12.9±3.7 mmHg in the the treatment group. There was no significant difference between the two groups at 1 day preoperation (P>0.05) but with significant diffrences at 3 months and 6 months postoperation (t=-3.480, -3.628, P<0.01). There were without significant differences among the three time points in the the control group (P>0.05), but with significant differences in the research group (F=10.435, P<0.05). At 3 months postoperatively, There was 97% type L (low-reflective) bleb in the control group while 100% in the research group, the difference was not significant (P>0.05). At 6 months after surgery, There was 77% type L bleb in the control group while 97% in the research group, the differences were significant between the two groups (χ2=5.192, P<0.05). Conclusion Compound trabeculectomy combined with HEMA glaucoma shunting device implantation is effective to reduce IOP, and easy to form functional filtering bleb, surgical success rate higher.

Epigenetics, as a branch of genetics, has been gaining more attention recently. Epigenetic mechanisms influence gene expression and function without modification of the base sequence of DNA. The mechanisms include DNA methylation, post-translational histone modifications, and deployment of non-coding RNA, with a particular focus on DNA methylation. Much research on the pathogenesis of genetic eye disease has emerged and more and more pathogenic genes are being screened out. Researchers have also found that DNA methylation plays a complex and important role. In this review, we summarize the role of DNA methylation in common inherited eye diseases.

This paper reviews the developing status, evolution process and trends in the international standards system for contact lenses and contact lens care products. By an invitation from the standards system, this paper summarizes the rules and technical characteristics of the system and provides references and good examples of developments in the field of contact lenses and lens care products in order to establish a standardized system in China.