Small-incision lenticule extraction (SMILE) has emerged as a new kind of corneal refractive surgery by femtosecond laser. Compared with traditional epithelial and stromal corneal refractive surgery, SMILE shows more obvious effects and application potential for improving the visual quality of patients with ametropia. This paper reviews the recent worldwide research progress on SMILE, aiming to provide some reasonable treatment options for refractive surgery to improve visual quality.

Objective: To evaluate the influence of baseline myopic refraction on controlling the development of myopia using orthokeratology in youngsters. Methods: This was a binocular self-control and case control study. A retrospective analysis of anisomyopic youngsters at Peking University Third Hospital was conducted from January 2009 to December 2017. Patients who wore orthokeratology lenses or spectacles in both eyes were recruited. Forty-nine youngsters (9-17 years old) who wore orthokeratology lenses were enrolled in the experimental group and 32 youngsters who wore spectacles were enrolled in the control group. The more myopic eye of each youngster was assigned to the experimental or control group Max and the less myopic eye of each youngster was assigned to experimental or control group Min.Refraction, corneal topography and axial length were measured at baseline and at the one-year visit.Data were analyzed with t test and Wilcoxon sign-rank test. results: The mean spherical equivalence was -5.00±1.53 D and -3.06±1.60 D for the eyes in the experimental groups Max and Min, respectively(t=-20.593, P<0.001). There were no significant differences in corneal curvature, corneal astigmatism,corneal E value, corneal thickness or pupil diameter between the two subgroups. The mean baseline spherical equivalence was -5.05±1.43 D for the eyes in control group Max, and -2.81(-2.00, -4.38)D for eyes in control group Min (Z=-4.952, P<0.001). Axial length elongation was 0.03±0.14 mm in experimental group Max and 0.12±0.16 mm in experimental group Min at the one-year visit and the difference was statistically significant (t=-4.217, P<0.001). The median axial length elongation of eyes in control groups Max and Min was 0.49(0.07, 0.75)mm and 0.40(0.17, 0.50)mm (Z=-0.510, P=0.610),respectively. The mean interocular difference in axial length at the one-year visit (0.63±0.35 mm) was less than that at baseline (0.72±0.34 mm) (t=-4.217, P<0.001). In the control group, the mean interocular difference in axial length was 0.74±0.38 mm at baseline, and the median interocular difference in axial length was 0.83(0.38, 1.07)mm at the one-year visit but the difference was not statistically significant (Z=-0.510, P=0.610). conclusions: A higher baseline myopic refraction can facilitate the effect of orthokeratology to slow axial growth in myopic youngsters.

Objective: To investigate the refractive status of premature infants with a postmenstrual age of 32 to 40 weeks, and to identify factors (birth weight, gestational age, retinopathy of prematurity) contributing to refractive status. Methods: A prospective study of the refractive status of preterm infants was conducted at the Women's Hospital School of Medicine, Zhejiang University and the Eye Hospital of Wenzhou Medical University from March to December 2016. The infants were recruited from ascreening program for retinopathy of prematurity (ROP) performed on premature infants. Examinations were performed longitudinally at the postmenstrual age of 32 to 40 weeks. Full cycloplegic retinoscopy was performed on the right eyes. Refractive status was recorded in the form of spherical equivalent (SE). Birth weight, gestational age, gender, oxygen and postmenstrual age were recorded for further analyses. Pearson correlation analysis was conducted to study the relationship between SE and multiple factors (birth weight,gestational age, postmenstrual age). An independent samples t test was used to study the relationship between SE and ROP at the postmenstrual age of 40 weeks. results: A total of 542 refractive status readings were recorded from 333 infants (158 females, 175 males) between the postmenstrual age of 32 to 40 weeks. The gestational age of the infants ranged from 26 to 36 weeks (mean: 31.3±2.1 weeks), and birth weight ranged from 740 to 3 390 g (mean: 1 643±418 g). The SE was positively correlated with the postmenstrual age of the infants (r=0.455, P<0.001). Gestational age (r=0.373, P<0.001) and birth weight (r=0.345, P<0.001) were both positively correlated with refractive status between the postnatal age of 4 to 5 weeks. By the postmenstrual age of 40 weeks, the SE was positively correlated with birth weight (r=0.197,P=0.021). However, there was no statistically significant difference between SE and gestational age. And premature infants with ROP were more myopic than those without ROP (t=2.225, P=0.028). conclusions:During the early stages of postmenstrual age of 32 to 40 weeks, there is a positive increase in the SE as postmenstrual age increases. Premature infants with low gestational age and low birth weight are more myopic between the postnatal age of 4 to 5 weeks. By the postmenstrual age of 40 weeks, premature infants with low birth weight or with ROP are more myopic.

Objective: In a cohort of prematurely born children in the province of Hubei, China, we investigated the dioptric range in 0 - 6 year-old with premature ametropia to provide the basis for clinical diagnosis and therapy. Methods: Follow-up visits were conducted in 1 505 premature infants without retinopathy of prematurity in Renmin Hospital of Wuhan University from May 2016 to May 2017 in this case serial study.Refraction was measured by cycloplegic retinoscopy. According to the correct gestational age groups, the P 50 reference and 75% reference ranges of the spherical diopters and cylindrical lens diopters were obtained respectively. The spherical and cylindrical lens diopters of children at the current ages of 0-0.5, 0.5-1, 1-2,2-3, 3-4, 4-5, and 5-6 years and with birth weights <1.5 kg and ≥1.5 kg were compared by the rank-sum tests. results: The age-related spherical diopter (D) reference values were as follows: 0-0.5 year, +2.02 D; 0.5-1 year, +1.87 D; 1-2 years, +1.60 D. The corresponding absolute reference values of the cylindrical lens were as follows: 2.54 D, 2.29 D, 2.14 D. With increasing age, the spherical diopter diminished (P<0.05),and in 5-6 year-old preterm infants, the process of becoming emmetropic was essentially completed. With increasing age, the cylindrical diopter decreased from age 0 to 3 years (P<0.05). After 3 years, it began to stabilize. For 0-0.5 year old and 1-6 years old age group, premature infants with birth weights <1.5 kg,the spherical diopter was smaller than for those with birth weights ≥1.5 kg (P<0.05), and they had early hyperopia that increased after birth (P<0.05). The hyperopia then gradually diminished, and the eyes were emmetropic by 4-5 years. For premature infants whose gestational age < 32 weeks, the spherical diopter was smaller than for those with gestational age ≥32 weeks. For premature infants whose birth weight <1.5 kg, the cylinder diopter was higher than for those with birth weight ≥1.5 kg (P<0.05), whose gestational age < 32 weeks, the cylindrical diopter was higher than for those with gestational age ≥32 weeks(P<0.05). conclusions: With increasing age, the hyperopia of premature infants gradually decreased. Preterm infants between 5 and 6 years old had essentially completed the emmetropization process. Astigmatism in preterm infants at 0-3 years gradually decreased with age and tended to be stable at age 3 years. Birth weight and gestational age are important influencing factors for the vision of premature infants.

Objective: To observe the effects of nerve growth factor (NGF) on the treatment of acquired paralytic strabismus. Methods: In this prospective clinical study, 73 patients with acquired paralytic strabismus were reviewed between January 2012 to December 2014 at Tianjin Medical University General Hospital.They were divided into 2 groups depending on whether or not NGF was used. There were 45 patients in the combined NGF group and 28 in the semplice mecobalamin group. Conservative treatment was used in the two groups. Patients in the combined NGF group were injected intramuscularly with 18 μg of NGF and 500 μg of mecobalaminonce a day for 4 weeks. Those in the semplice mecobalamin group were injected by the same method with 500 μg of only mecobalaminonce a day for 4 weeks. Curative effects were estimated at the end of treatment and 3 months after treatment. Differences between the two groups were determined using chi-square tests. results: There was a significant difference in the cure rate and effective rate between the 2 groups at the end of treatment (cure rate: 67% vs. 43%, effective rate: 89% vs. 68%) ( χ 2 =4.005,P=0.045; χ 2 =4.926, P=0.026), and 3 months after treatment (cure rate: 87% vs. 46%, effective rate: 98% vs. 75%) ( χ 2 =13.638, P<0.001; χ 2 =9.177, P=0.002). In addition, the cure rate in the combined NGF group at 3 months after treatment was significantly higher than at the end of treatment (P=0.001). There was no significant difference at 3 months for the semplice mecobalamin group (P=0.711). conclusions: The curative effect of mecobalamin with NGF is superior to semplice mecobalamin alone for the treatment of acquired paralytic strabismus. In addition, the NGF treatment has long-term effects.

Objective: To study the relationship between balance function and visual dysfunction in elderly patients with age-related cataract. Methods: A total of 87 elderly patients with age-related cataract were enrolled in a case-series study at the cataract clinical center of the Eye Hospital, Wenzhou Medical University between April to October 2017. Data from visual function (LogMAR VA), static balance function (Berg Balance Scale, BBS), dynamic balance function (Timed up and go test, TUG), cognitive (MMSE Questionnaire) and depression status (GDS-15 Questionnaire) were collected from subjects. A variance test, regression line and multiple stepwise linear regression were used for statistical analysis. results: The average score of the BBS was 50.0±2.8, the average TUG time was 12.1±3.5 seconds. BBS scores and TUG times were related mainly to binocular visual acuity and age: the multiple linear regression equation of the BBS=62.27 4.37×binocular visual acuity -0.12×age (F=23.87, P<0.001), TUG time=-5.07+3.83×binocular visual acuity +0.19×age (F=15.22, P<0.001). The BBS scores (F=3.45, P=0.067) and TUG times (F=3.88,P=0.052) did not quite reach a significant difference between genders. conclusions: With an increase in visual dysfunction and age, the balance function of elderly patients with cataracts gradually declines,including static balance and dynamic balance function. The effect of age on balance dysfunction is less than that of visual function. Visual impairment mainly affects the dynamic balance function and triggers fall events. Gender differences do not have a significant effect on balance function.

Objective: To compare and quantitatively analyze the different characteristics of multimodal imaging of parapapillary atrophy (PPA) in patients with high myopia. Methods: This was a case series study that included multimodal images of 45 eyes with PPA in 30 high myopia patients. There were 13 males (19 eyes) and 17 females (26 eyes). Age ranged from 27 to 69 years, with a mean age of 53.1±11.6 years. All eyes were examined by color fundus photography (CFP), near infrared spectrum fundus autofluorescence (NIR-FAF), fundus fluorescein angiography (FFA) and spectral domain optical coherence tomography (OCT). Using image J software, two trained ophthalmologists, operating in masked fashion, graded lesions in the CFP and NIR-FAF areas independently and compared the size of the PPA area. OCT was performed to confirm the border of the lesion when NIR-FAF and FFA were difficult to determine. The consistency of the results between the two ophthalmologists was analyzed by Bland-Altman. results:The PPA areas of CFP, NIR-FAF and FFA were 7.1±4.7 mm 2 , 8.3±5.8 mm 2 , 8.1±5.5 mm 2 . The differences in the PPA area between the three multimodal image groups were not statistically significant (F=1.193,P=0.307). The consistency of the results between the two ophthalmologists was high, with a variation range of CFP<NIR-FAF<FFA. conclusions: The mean differences in the size of the PPA measured by CFP,NIR-FAF and FFA are not statistically significant.

Objective: To understand the dynamics and significance of perceptual eye position (PEP) in patients with intermittent exotropia by comparing it with subjective squint deviation (SSD). Methods: In this case series study, patients with intermittent exotropia treated at Beijing Tongren Hospital from February to August 2017 were tested for SSD using a synoptophore and, at the same time, were tested for PEP using a computer-based visual perceptual test. A total of 120 patients who were identified by the above two tests were accepted as research subjects. Linear correlation analysis was performed to assess the horizontal eye positions of SSD and PEP. The detection rate of SSD in vertical eye deviation was assessed, and the distribution of vertical PEP was analyzed in nonvertical SSD. Linear correlation and regression analysis were performed to assess horizontal and vertical PEP. results: In the horizontal direction, the mean SSD was -8.1±5.3°, and the mean PEP was 332±233 pixels. The more SSD migrated outward, the greater was the horizontal PEP, with a linear correlation between them (r=0.383, P<0.001). In the vertical direction,the detection rate of SSD was 2.5%. Among the remaining117 patients with nonvertical SSD, 113 patients were identified with PEP. The mean amount was 22±29 pixels, with 67.5%(81/120) of patients in the range of 1~26 pixels (≤0.5°) and 82.5%(99/120) in the range of 1~53 pixels (≤1°). The mean vertical PEP of the 120 patients was 24±32 pixels. There was a linear correlation between the vertical and horizontal PEP (r=0.373, P<0.001). The linear regression equation was vertical PEP=6.403+0.052×horizontal PEP (F=19.093, P<0.001). conclusions: In patients with intermittent exotropia, both SSD and PEP can reflect the deviations of the horizontal position of the eyes in the binocular deviated gaze state, but the detection rate of PEP in the vertical direction is much higher than that of SSD. The vertical PEP increases as the horizontal PEP becomes larger. PEP is a more sensitive and more comprehensive test of eye position deviation.

Objective: To explore the inf luence of ocular surface stability secondary to botulinum toxin A injection in patients with essential blepharospasm by comparing the changes in ocular surface indexes. Methods: In this prospective study, 30 patients with essential blepharospasm were recruited and underwent botulinum toxin A injections at the Affiliated Hospital of Yan'an University (January to June 2017). Ocular examinations,including frequency and severity of blepharospasm (using JRS chat), ocular surface symptoms (using OSDI questionnaire), tear break-up time and corneal fluorescence staining with slit-lamp examination, and tear secretion by a Schirmer Ⅰ test, were performed before and 2 weeks after botulinum toxin A injections.Results were analyzed with a paired t-test and spearman correlation test. results: Of the 30 patients (60 eyes) with essential blepharospasm who were enrolled in this study, 60%(18/30) showed dry eye symptoms, and the OSDI scores were positively correlated with JRS scores (r=0.278, P=0.032). Botulinum neurotoxin A treatment relieved blepharospasm in all the patients and JRS scores decreased from 5.5±1.0 to 0.6±1.0 (t=25.730, P<0.001). At the same time, dry eye symptoms also improved in 12 patients (12/18),and OSDI scores decreased from 34.0±7.8 to 21.7±9.1 (t=7.946, P<0.001). BUT increased from 6.3±2.1 s to 8.0±2.0 s (t=4.389, P<0.001), and corneal fluorescence staining scores decreased from 1.0±1.0 to 0.6±0.7 (t=2.963, P=0.004). All the differences were statistically significant. conclusions: Botulinum toxin A injection is effective for dry eye symptoms secondary to essential blepharospasm.

Objective: To measure the clinical efficacy and safety of 25-G vitrectomy combined with transscleral intraocular lens (IOL) implantation. Methods: In this prospective study, patients (n=39, 39 eyes) without capsule support and experiencing lens dislocation, IOL dislocation, and aphakia were enrolled and treated with 25-G vitrectomy combined with transscleral IOL implantation. Differences in visual acuity, intraocular pressure (IOP), number of corneal endothelial cells, location of IOL, postoperative anatomic success, and the recurrence rate of IOL dislocation and complications were recorded. Data paired t-tests and repeated measured ANOVA. results: The average visual acuity (LogMARs) at 1 week, 1 month, 3 months, and 6 months after surgery were significantly differences improved compared with the pre-surgical values (P<0.05). The average IOPs at 1 week, 1 month, 3 months, and 6 months after operation were significantly ifferences lower compared with the pre-surgical values (P<0.05). One week after surgery, all of the implanted IOLs were in the correct position. One month after surgery, the IOLs in 36 eyes (92%) were in the correct position. The haptics of one IOL (3%) were exposed to the conjunctiva. Dislocation of two IOLs (5%) required alignment surgery at 3 and 6 months after insertion, positions of 36 IOLs were stable.conclusions: The 25-G vitrectomy combined with transscleral IOL implantation in the treatment of eyes without capsule support was effective and safe.

Objective: To investigate the correlation between an increased rate of juvenile myopia and seasonal variation in the Tangshan area. Methods: In this prospective study, 212 myopic juveniles (424 eyes) (age 8-16 years) were recruited from the Tangshan City Ophthalmology Hospital from March 20 to March 26, 2017. The refractive errors of the juveniles were recorded after cycloplegia, and monofocal glasses were prescribed. The same procedure was repeated September 23 to September 29, 2017 and March 21 to March 27, 2018. The changes in refractive error between summer and winter were compared using a paired t-test. Results: Myopia increased faster in the winter (0.46±0.12)D than in the summer (0.31±0.09)D,and the differences were significant (t=5.43, P=0.009). The same tendencies happened in juvenile males(t=4.36, P=0.013) and females (t=4.87, P=0.012), 8-10 years of age (t=2.31, P=0.042), 11-13 years of age (t=5.25, P=0.010), and 14-16 years of age (t=4.72, P=0.011). Conclusions: Myopia increase faster in the winter than in the summer in Tangshan area. We should pay more attention to the prevention and control of myopia in the winter half of the year in Tangshan.

Objective: To investigate the in vivo confocal microscopy (IVCM) findings of corneal in Posner-Schlossman syndrome (PSS) patients. Methods: In this retrospective study, the record of 56 PSS patients (56 eyes) who visited Peking University Third Hospital Ophthalmology Department from May 2014 to May 2017 were reviewed. Data of visual acuity, intraocular pressure (IOP), keratic precipitate (KP) and IVCM results were recorded. IVCM examination included corneal stromal cell activation, corneal endothelium cell change,the morphology of KPs and the morphology of Langerhans cells (LCs). Statistical analysis was performed by a chi-square test. Results: Visual acuity of the 56 PSS patients was 0.3±0.2 (LogMAR), and IOP was 29.7±13.4 mmHg with 2.6±1.0 anti-glaucoma medications. IVCM identified 50 patients (89%) who had keratocyte activation of the affected eyes. LCs could be seen in 32 patients (57%) of the affected eyes and 6 types of KP could be observed in 44 patients (79%) of the affected eyes. There was a statistically significant difference with contralateral eyes (χ2=69.14, 41.29, 60.89, P<0.001). The corneal endothelial cells of all patients were hexagon. Conclusions: Keratocyte activation, LCs in the endothelium layer and different types of KP could be seen in PSS patients.

Ocular surface disease, particularly dry eye disease (DED), is one of the most common conditions influencing quality of life, and morbidity is increasing with changes in the environment, way of life and age composition, especially in females and old people. Since age-related cataract is the most common reason for patients to undergo phacoemulsification, the overlapping demographics aggravate the incidence and severity of DED even further after cataract surgery. Furthermore, cataract surgery has been shown to lead to worsening DED, which may lead to a dissatisfaction with vision quality and an increase in complications.This review discusses the related factors of DED in the perioperative period of cataract surgery and the latest advances in treatment.