Recent advances in the biosynthesis of fungal glucan structural diversity

Glucans are the most abundant class of macromolecule polymers in fungi, which are commonly found in Ascomycota and Basidiomycota. Fungal glucans are not only essential for cell integrity and function but also crucial for the immense industrial interest in high value applications. They present a variety of structural characteristics at the nanoscale due to the high regulation of genes and the involvement of stochastic processes in synthesis. However, although recent findings have demonstrated the genes of glucans synthesis are relatively conserved across diverse fungi, the formation and organization of diverse glucan structures is still unclear in fungi. Here, we summarize the structural features of fungal glucans and the recent developments in the mechanisms of glucans biosynthesis. Furthermore, we propose the engineering strategies of targeted glucan synthesis and point out the remaining challenges in the synthetic process. Understanding the synthesis process of diverse glucans is necessary for tailoring high value glucan towards specific applications. This engineering strategy contributes to enable the sustainable and efficient production of glucan diversity.

Accurate prediction of myopic progression and high myopia by machine learning

Background

Myopia is a leading cause of visual impairment in Asia and worldwide. However, accurately predicting the progression of myopia and the high risk of myopia remains a challenge. This study aims to develop a predictive model for the development of myopia.

Methods

We first retrospectively gathered 612 530 medical records from five independent cohorts, encompassing 227 543 patients ranging from infants to young adults. Subsequently, we developed a multivariate linear regression algorithm model to predict the progression of myopia and the risk of high myopia.

Result

The model to predict the progression of myopia achieved an R2 value of 0.964 vs a mean absolute error (MAE) of 0.119D [95% confidence interval (CI): 0.119, 1.146] in the internal validation set. It demonstrated strong generalizability, maintaining consistent performance across external validation sets: R2 = 0.950 vs MAE = 0.119D (95% CI: 0.119, 1.136) in validation study 1, R2 = 0.950 vs MAE = 0.121D (95% CI: 0.121, 1.144) in validation study 2, and R2 = 0.806 vs MAE = -0.066D (95% CI: -0.066, 0.569) in the Shanghai Children Myopia Study. In the Beijing Children Eye Study, the model achieved an R2 of 0.749 vs a MAE of 0.178D (95% CI: 0.178, 1.557). The model to predict the risk of high myopia achieved an area under the curve (AUC) of 0.99 in the internal validation set and consistently high area under the curve values of 0.99, 0.99, 0.96 and 0.99 in the respective external validation sets.

Conclusion

Our study demonstrates accurate prediction of myopia progression and risk of high myopia providing valuable insights for tailoring strategies to personalize and optimize the clinical management of myopia in children.

Electroacupuncture for mild-to-moderate dry eye: study protocol for a multicentre, randomised, single-blind, sham-controlled trial

INTRODUCTION

Dry eye (DE) is a multifactorial ocular surface disease causing considerable medical, social and financial implications. Currently, there is no recognised long-term, effective treatment to alleviate DE. Clinical evidence shows that electroacupuncture (EA) can improve DE symptoms, tear secretion and tear film stability, but it remains controversial whether it is just a placebo effect. We aim to provide solid clinical evidence for the EA treatment of DE.

METHODS AND ANALYSIS

This is a multicentre, randomised, sham-controlled trial. A total of 168 patients with DE will be enrolled and randomly assigned to EA or sham EA groups to receive 4-week consecutive treatments and follow-up for 24 weeks. The primary outcome is the change in the non-invasive tear break-up time (NIBUT) from baseline to week 4. The secondary outcomes include tear meniscus height, the Schirmer I test, corneal and conjunctival sensation, the ocular surface disease index, corneal fluorescein staining, the numerical rating scale and the Chinese DE-related quality of life scale.

ETHICS AND DISSEMINATION

The trial protocol and informed consent were approved by the Ethics Committee of Yueyang Hospital of Integrated Traditional Chinese and Western Medicine Affiliated to Shanghai University of Traditional Chinese Medicine (identifier: 2021-119), Shanghai Eye Disease Prevention and Treatment Center (identifier: 2022SQ003) and Eye and ENT Hospital of Fudan University (identifier: 2022014).

TRIAL REGISTRATION NUMBER

NCT05552820.

[Long-term outcome of EVAHEART I implantable ventricular assist device for the treatment of end stage heart failure: clinical 3-year follow-up results of 15 cases]

Objective: To evaluate the long-term efficacy and safety of the implantable ventricular assist system EVAHEART I in clinical use. Methods: Fifteen consecutive patients with end-stage heart failure who received left ventricular assist device therapy in Fuwai Hospital from January 2018 to December 2021 were enrolled in this study, their clinical data were retrospectively analyzed. Cardiac function, liver and kidney function, New York Heart Association (NYHA) classification, 6-minute walk distance and quality of life were evaluated before implantation and at 1, 6, 12, 24 and 36 months after device implantation. Drive cable infection, hemolysis, cerebrovascular events, mechanical failure, abnormally high-power consumption and abnormal pump flow were recorded during follow up. Results: All 15 patients were male, mean average age was (43.0±7.5) years, including 11 cases of dilated cardiomyopathy, 2 cases of ischemic cardiomyopathy, and 2 cases of valvular heart disease. All patients were hemodynamically stable on more than one intravenous vasoactive drugs, and 3 patients were supported by preoperative intra aortic balloon pump (IABP). Compared with before device implantation, left ventricular end-diastolic dimension (LVEDD) was significantly decreased ((80.93±6.69) mm vs. (63.73±6.31) mm, P<0.05), brain natriuretic peptide (BNP), total bilirubin and creatinine were also significantly decreased ((3 544.85±1 723.77) ng/L vs. (770.80±406.39) ng/L; (21.28±10.51) μmol/L vs. (17.39±7.68) μmol/L; (95.82±34.88) μmol/L vs. (77.32±43.81) μmol/L; P<0.05) at 1 week after device implantation. All patients in this group were in NYHA class Ⅳ before implantation, and 9 patients could recover to NYHA class Ⅲ, 3 to class Ⅱ, and 3 to class Ⅰ at 1 month after operation. All patients recovered to class Ⅰ-Ⅱ at 6 months after operation. The 6-minute walk distance, total quality of life and visual analogue scale were significantly increased and improved at 1 month after implantation compared with those before operation (P<0.05). All patients were implanted with EVAHEART I at speeds between 1 700-1 950 rpm, flow rates between 3.2-4.5 L/min, power consumption of 3-9 W. The 1-year, 2-year, and 3-year survival rates were 100%, 87%, and 80%, respectively. Three patients died of multiple organ failure at 412, 610, and 872 d after surgery, respectively. During long-term device carrying, 3 patients developed drive cable infection on 170, 220, and 475 d after surgery, respectively, and were cured by dressing change. One patient underwent heart transplantation at 155 d after surgery due to bacteremia. Three patients developed transient ischemic attack and 1 patient developed hemorrhagic stroke events, all cured without sequelae. Conclusion: EVAHEART I implantable left heart assist system can effectively treat critically ill patients with end-stage heart failure, can be carried for long-term life and significantly improve the survival rate, with clear clinical efficacy.

[A preliminary study on the tear matrix metalloproteinase 9 point-of-care assay using a domestic kit]

Objective: To compare the point-of-care assays for tear matrix metalloproteinase 9 (MMP-9) using domestic and InflammaDry kits, and to evaluate the feasibility of diagnosing dry eye with the domestic kit. Methods: It was a cross-sectional study. Thirty dry eye patients and 30 age-and sex-matched normal volunteers were continuously enrolled in this cross-sectional study from June 2022 to July 2022. Both domestic and InflammaDry kits were used to detect the tear MMP-9 levels. The positive rates were recorded for qualitative analysis, and the gray ratios of bands (the gray value of detection bands to that of control bands) were collected for quantitative analysis. The correlations of MMP-9 levels with age, ocular surface disease index, fluorescence tear break-up time, tear meniscus height, Schirmer's Ⅰ test score, corneal fluorescein staining score, and meibomian gland dropout were analyzed. The Mann-Whitney U test, paired Chi-square test, Kappa test, and Spearman's correlation coefficient were used for statistical analysis. Results: There were 14 males and 16 females (30 eyes) in the control group, and their age was (39.37±19.55) years. In the dry eye group, 11 males and 19 females (30 eyes), aged (46.87±17.85) years, had moderate to severe dry eye. The positive rates of MMP-9 in tear fluid were significantly different between dry eye patients (InflammaDry: 86.67%; domestic kit: 70.00%) and controls (InflammaDry: 16.67%, P<0.001; domestic kit: 6.67%, P<0.001). Although the sensitivity of the domestic kit was lower than that of the InflammaDry kit (70.0% vs. 86.7%, P=0.001), the specificity was higher (93.3% vs. 83.3%, P=0.001). In dry eye patients, the positive coincidence rate was 80.7% (21/26), the negative coincidence rate was 100% (4/4), and the total coincidence rate was 83.3% (25/30), with no significant difference between the two kits (McNemar test: χ²=3.20, P>0.05), and the results of both kits were consistent (Kappa=0.53, P=0.001). The Spearman's correlation coefficient showed the gray ratios using both kits were positively correlated with the corneal fluorescein staining score (InflammaDry: ρ=0.48, P<0.05; domestic kit: ρ=0.52, P=0.003). Conclusion: The performances of the domestic and InflammaDry kits are consistent in the point-of-care assay for tear MMP-9, and the domestic kit has lower sensitivity but higher specificity.

[A newborn patient with bilateral ankyloblepharon filiforme adnatum: a case report]

A male neonate who was unable to open both eyes with the adhesion of upper and lower palpebral margins since birth was clinically diagnosed as bilateral ankyloblepharon filiforme adnatum. The fused eyelids were divided surgically under general anesthesia. The neonate can open and close eyes normally with right positions of eyelids and flexible movements of eyeballs to follow light after the surgery.

[Long term results of central hole type posterior chamber intraocular lens in the correction of moderate to high myopia]

Objective: To evaluate the long-term safety,effectiveness,predictability and stability of ICL V4c implantation for moderate to high myopia. Methods: In this retrospective case series study, 95 eyes from 50 patients with moderate to severe myopia who were treated in 2015 underwent central hole type posterior chamber intraocular lens (ICL V4c) implantation at Eye & ENT Hospital of Fudan University. The patients were followed up for a period of five years, during which we assessed various parameters including uncorrected visual acuity (UDVA), corrected visual acuity (CDVA), refractive error, axial length, intraocular pressure, endothelial cell density (ECD), vault, and complications. We used the paired t-test and repeated measures one-way ANOVA in SPSS statistical software to analyze the data. Results: The mean spherical equivalent refraction (SE) decreased significantly from (-12.16±3.04) D preoperatively to (-0.19±0.55) D at one month and (-1.14±0.84) D at five years postoperatively. The safety indices (postoperative CDVA/preoperative CDVA) were 1.24±0.27 and 1.13±0.27, respectively, and the efficacy indices (postoperative UDVA/preoperative CDVA) were 1.14±0.25 and 0.87±0.26 at one month and five years postoperatively. At one month after surgery, 80.00% of the eyes were within ±0.50 D of the expected correction, and 96.84% were within ±1.00 D. There was no significant difference in IOP between preoperative and postoperative measurements. The rate of ECD was 3.87%, and the vault decreased by 106.32 μm at five years postoperatively. Conclusion: ICL V4c implantation is safe and effective with good predictability and stability for long term.

Refractive outcomes and optical quality of PRESBYOND laser-blended vision for presbyopia correction

AIM: To investigate the one-year refractive outcomes and optical quality following PRESBYOND laser-blended vision (LBV). METHODS: This retrospective study included 20 patients who underwent PRESBYOND treatment between Jan 2019 and Aug 2020. The patients were asked to attend a follow-up outpatient visit one year after surgery. Distance and near visual acuity as well as subjective refraction were examined. Optical quality was assessed using wavefront-supported custom ablation. A questionnaire evaluating optical quality and satisfaction was completed at the last visit. RESULTS: The average patient age was 48.1±7.4y (range, 41 to 58y). The mean preoperative spherical equivalent was -7.59±2.39 D. At the one-year follow-up, two eyes (both dominant eyes) lost one line of corrected distance visual acuity (CDVA), while the remaining eyes (38/40) maintained or gained lines of CDVA. The average binocular uncorrected distance visual acuity improved from 0.15±0.03 to 0.90±0.26 (decimal vision; P&#x003C;0.001). The average binocular uncorrected near visual acuity increased from 0.34±0.28 to 0.97±0.07 (P&#x003C;0.001). The spherical aberration was 0.04±0.06 μm in the nondominant eye and 0.09±0.09 μm in the dominant eye (P=0.02). All patients were satisfied with or accepted the outcomes of the surgery. The primary complaints were related to disturbances in night vision and relatively inferior near vision. CONCLUSION: Over the one-year observation period, PRESBYOND is a safe and effective option for presbyopia correction. The optical quality and near vision deserve further investigation.

Corneal histomorphology and electron microscopic observation of R124L mutated corneal dystrophy in a relapsed pedigree

AIM: To investigate the histological characteristics and ultrastructure of recurrent Chinese R124L mutated corneal dystrophy after keratoplasty. METHODS: The subjects were enrolled from a Chinese family of corneal dystrophy with R124L heterozygous gene mutation and with a history of consanguineous marriage. Normal corneal samples were used as controls. RESULTS: In this family, 2 patients (3 eyes) underwent penetrating keratoplasty (PKP) and 2 patients (4 eyes) underwent lamellar keratoplasty (LKP). They had recurrence at 33.5±3.0 (range 30-36)mo after keratoplasty. Among them, 1 patient (1 eye) underwent PKP again and 1 patient (2 eyes) underwent LKP again. In the R124L mutated recurrent corneal dystrophy, the corneal turbidity was mainly distributed from the upper corneal cortex to the anterior stroma; the corneal epithelium surface was rougher and more uneven; and, the corneal erosions were larger. Hematoxylin-eosin staining showed that the thickness of the corneal epithelium was uneven; the arrangement of the epithelial cells was disordered; and, some corneal epithelial cells were swollen. The results of Congo red staining, Masson’s trichrome staining and Periodic acid-Schiff staining were positive, while that of Alcian blue staining was negative. Under a transmission electron microscope, deposition of high electron density substances between epithelial and basal cells, and, apoptosis of basal cells were observed. Many high electron density depositions were observed in the sub-epithelial and anterior corneal matrix. CONCLUSION: In the Chinese family of recurrent corneal dystrophy with R124L gene mutation, the corneal epithelia of the recurrent cases are rougher, and the corneal depositions are extracellular amyloid fibrin.

[Preparation and characterization of a recombinant poly-epitopic vaccine EgG1Y162-2 (4) against cystic echinococcosis based on the linker GSGGSG]

OBJECTIVE

To perform prokaryotic expression and preliminary characterization of the recombinant poly-epitope vaccine EgG1Y162-2 (4) against cystic echinococcosis.

METHODS

The recombinant poly-epitope vaccine EgG1Y162-2 (4) against Echinococcus granulosus based on the linker GSGGSG was subjected to structural three-dimensional (3D) modeling using immunoinformatics to analyze the structural changes and evaluate the antigenicity of the vaccine. The pET30a-EgG1Y162-2 (4) recombinant plasmid was generated using double digestion with EcoR I and Sal I, and then transformed into competent cells. Following protein induction with isopropyl-β-D-thiogalactoside (IPTG), the prokaryotic expression proteins were characterized using Western blotting, and the antigenicity of the recombinant protein was analyzed using sera from cystic echinococcosis patients and health volunteers.

RESULTS

The four EgG1Y162-2 proteins coupled by the 3D structure of the recombinant vaccine EgG1Y162-2 (4) presented independent and effective expression and good antigenicity. The highest protein expression was detected in the supernatant following induction of the recombinant plasmid pET30a-EgG1Y162-2 (4) by 0.2 mmol/L IPTG at 37 °C for 4 h, and a pure protein component was seen following elution with 60 mmol/L imidazole. Western blotting analysis of the recombinant multiepitope protein HIS-EgG1Y162-2 (4) showed a band at approximately 39 kDa, and this band was recognized by sera from cystic echinococcosis patients.

CONCLUSIONS

A recombinant poly-epitope vaccine EgG1Y162-2 (4) against cystic echinococcosis has been successfully constructed, which provides a preliminary basis for researches on recombinant multi-epitope vaccine against cystic echinococcosis.

[Comprehensive treatment options and influencing factors in elderly patients with breast cancer]

Objective: To investigate the treatment options for breast cancer patients aged 65 and over, and analyze the influencing factors. Methods: The clinical data of 521 elderly patients aged 65 years or older,who underwent surgery in Peking Union Medical College Hospital from January 2009 to December 2015, were collected. They were all female and 65-98 years old. The patients were divided into 65-74 years old group (n=353) and ≥ 75 years old group (n=168). The differences of variables including age, functional status, treatment methods, pathological characteristics, comorbidities and survival time between the two groups were compared, and the differences of comprehensive treatment methods and their impact on clinical efficacy were analyzed. Results: The main operation methods of the two groups were modified radical mastectomy [39.1% (138/353) and 33.9% (57/168), respectively], breast conserving surgery [56.9% (201/353) and 61.3% (103/353), respectively]. Among the patients choosing adjuvant therapy, there was no significant difference between the two groups except chemotherapy (all P>0.05). Univariate analysis showed that the choice of chemotherapy was related to age, surgical methods, pathological types, tumor burden, molecular typing, functional status and comorbidities (all P<0.05). The Eastern Cooperative Oncology Group (ECOG) score and the number of comorbidities were independent factors affecting the choice of chemotherapy for breast cancer in the elderly: [ECOG score: adjusted OR=0.45 (95CI: 0.26-0.75), number of comorbidities: adjusted OR = 0.63 (95CI:0.41-0.98); all P<0.05]. The 5-year disease-free survival rate of 521 elderly patients with breast cancer was 86.3%, 5-year overall survival rate was 88.8%, and the breast cancer specific survival rate was 94.3%. Conclusions: The comprehensive treatment of breast cancer patients aged 65 and above is not affected by age, but is associated with tumor burden, pathological type, molecular typing, comorbidities and ECOG score. Among them, ECOG score and the number of comorbidities are the independent factors influencing the choice of adjuvant chemotherapy.

[Importance and practice of standardized children's refractive development records]

The prevalence of myopia in China is increasing. The early onset and rapid progression of myopia in younger children have attracted more attention. The establishment of standardized children's refractive development records is the basis of myopic prevention and control. It would be helpful to follow the refractive status and pay more attention to the refractive development of potential myopic children, so as to reduce the prevalence of myopia. (Chin J Ophthalmol, 2021, 57: 724-726).

One-step viscoelastic agent technique for ICL V4c implantation for myopia

AIM

To investigate the safety and efficacy of using a one-step viscoelastic agent technique for posterior chamber phakic implantable collamer lens with a central hole (ICL V4c) implantation for myopia correction.

METHODS

The one-step viscoelastic agent technique for ICL V4c implantation was used in 100 eyes of 52 patients. Refractive outcomes, intraocular pressure (IOP), corneal endothelial cell, and corneal densitometry values were evaluated at 1d, 1wk, 1 and 3mo postoperatively.

RESULTS

All the surgeries were uneventful. No corrected distance visual acuity was lost after 3mo. IOP was 16.12±3.18 mm Hg before surgery, and 14.74±3.08 mm Hg at 1d and 14.50±2.56 mm Hg at 3mo after surgery (P<0.05). Corneal endothelial cell density was 2580±242 cell/mm², the coefficient of variation in cell size was 42.11%±7.92%, and the percentage of hexagonal cells was 40.98%±9.46% before surgery. No significant difference was found when these outcomes were compared between the studied time points (P>0.05). The corneal densitometry values of the central 2 mm and 2 to 6 mm areas showed similar regularities. After surgery, the values significantly increased at 1d, then decreased to the preoperative values at 1wk, and then continued to decrease at 3mo (P<0.05).

CONCLUSION

The one-step viscoelastic agent technique for ICL V4c implantation is found to be safe and effective for myopia correction and causes little disturbance to the cornea.

Auricular acupressure for myopia prevention and control in children and its effect on choroid and retina: a randomized controlled trial protocol

BACKGROUND

Nowadays, because of the increasing incidence, the prevention and control of myopia has become an urgent issue. In China, auricular acupressure has been commonly used in the clinical treatment of myopia in children, but the exact effectiveness remains unproven. The purpose of this trial is to observe the efficacy of auricular acupressure in myopia prevention and control, as well as its effect on the choroidal and retinal thickness.

METHOD/DESIGN

A total of 480 subjects at 8-9 years old will be randomized in a 1:1 ratio to an intervention group versus a control group. The intervention group will receive auricular acupressure for 12 months, while the control group will be taken as a blank control. The primary and secondary outcomes will be measured at baseline, and again at 3, 6, 9, and 12 months after recruitment. The myopia incidence (spherical equivalent ≤ - 0.50 D) and the mean change of spherical equivalent will be taken as the primary variables; the secondary outcome measures include axial length, uncorrected visual acuity, and choroidal and retinal thickness.

DISCUSSION

This trial aims to evaluate the effectiveness of auricular acupressure for myopia prevention and control with objective evidence and to preliminarily explore the plausible mechanism and provide reference for adopting this approach to retard the onset and control the progression of myopia.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2000038456 . Registered on September 23, 2020.

Measuring the Ocular Morphological Parameters of Guinea Pig Eye with Edge Detection and Curve Fitting

AIM

To identify the guinea pig eyeball with edge detection and curve fitting and devise a noncontact technology of measuring ocular morphological parameters of small experimental animal.

METHODS

Thirty-nine eyeballs of guinea pig eyeballs were photographed to obtain the anterior and posterior surface; transverse and sagittal planes after the eyeballs were eviscerated. Next, the eyeball photos were input into digital image analysis software; the corresponding photo pixels-actual length ratio was acquired by a proportional scale. The contour lines of the eyeballs were identified by edge detection technology; conic curve fitting was applied to fit the contour line of the eyeball. The maximum and minimum diameters, the horizontal and vertical diameters, eccentricity, tilt angle, cross-sectional area, equatorial circumference, retrobulbar equatorial maximum length, corneal radius of curvature (CRC) in central region, and the whole cornea were calculated according to the geometric principles. The corneal data of in vitro study were compared with the in vivo results.

RESULTS

The contour line of the selected guinea pig eye was identified correctly by edge detection. There were no significant differences between anterior and posterior surfaces of one eyeball in the maximum diameters, eccentricity, cross-sectional area, equatorial circumference, and tilt angle (P > 0.01). There were significant differences of eccentricity and CRC between central region and the whole cornea (P < 0.01). There were no significant differences between keratometer in vivo and cornea in vitro.

CONCLUSION

It was feasible to measure an experimental animal eye in a noncontact way. Edge detection and curve fitting technology could accurately evaluate the ocular morphological parameters.

Objective optical quality and visual outcomes after the PresbyMAX monocular ablation profile

AIM

To assess objective visual quality after presbyopia correction using the PresbyMAX monocular mode.

METHODS

This prospective, nonrandomized study included 28 eyes from 18 patients (mean age 50.4±5.6y) who underwent presbyopia correction with the PresbyMAX monocular mode. Monocular and binocular visual acuities were evaluated preoperatively, 1d, 1wk, 1, 3mo, and 1y after surgery. Optical quality was analyzed by Hartmann-Shack wavefront aberration supported cornea ablation. Modulation transfer function (MTF) cutoff frequency, Strehl ratio, and objective scattering index (OSI) were analyzed using an optical quality analysis system.

RESULTS

One year after surgery, 100% and 94.4% of patients achieved binocular uncorrected distance and near visual acuity of 20/25, respectively. At the last visit Spherical aberration and total higher aberration were higher than the corresponding preoperative levels (P<0.001); however, no significant difference was found in MTF, OSI, or Strehl ratio. Transient decreases in OSI and MTF mainly occurred in the nondominant eyes. There was no significant difference in optical quality between the dominant and nondominant eyes, except for spherical aberration and horizontal coma (P<0.05).

CONCLUSION

The PresbyMAX monocular mode is safe and effective for presbyopia correction. It has little effect on optical quality, though short-term degraded optical quality occurred mainly in the bi-aspheric ablated eyes.

[The prevalence and related factors of HBV infection among adults in Mianyang]

Objective: To analyze the prevalence and related factors of HBV infection among people aged 18 years old and above in Mianyang city. Methods: A total of 260 950 residents, living in Mianyang city more than 6 months, aging 18 years old and above were employed by multi-stage random sampling method from November 2014 to September 2015. Questionnaire survey was conducted on participants using a self-designed questionnaire, including general demographic characteristics, family history of Hepatitis B, history of Hepatitis B vaccination and history of present illness, etc. 5ml blood was collected from all participants, and the blood samples were detected for HBsAg by enzyme-linked immunosorbent assay (ELISA). The multivariate unconditional logistic regression was performed to identify the related factors of positive HBsAg. Results: Among the 260 950 subjects, 113 184 were males (43.37%), 147 766 were females (56.63%), and the average age was (47.68±17.36) years old. The positive rate of HBsAg was 6.10%(15 822 cases). Subjects who were 25-34 years old (OR=1.23), 35-44 years old (OR=1.26), 45-54 years old (OR=1.23), and 55-64 years old (OR=1.34) were more likely to be HBsAg positive,65 years and older (OR=0.88) were less likely to be, compared with subjects aging 18-24 years old; males were more likely to be HBsAg positive compared with females (OR=1.35); people living in Fucheng district were more likely to be HBsAg positive compared with who living in Jiangyou district(OR=1.91); married people were more likely to be HBsAg positive compared with unmarried ones (OR=1.36); medical staff were less likely to be HBsAg positive compared with non-medical staff (OR=0.61); subjects with a surgery history were more likely to HBsAg positive compared with who without (OR=1.13); subjects with trauma history were more likely to HBsAg positive compared with who without (OR=1.13); people with history of Hepatitis B were more likely to HBsAg positive compared with who without (OR=4.21); people with Hepatitis B vaccination history were less likely to be HBsAg positive compared with who without (OR=0.48); all the P values above were less than 0.05. Conclusion: The positive rate of HBsAg among adults in Mianyang city was very high, and we should pay more attention to people aging between 25 and 64 years old, male, medical staff, with surgery history, trauma history, and a family history of Hepatitis B and Hepatitis B vaccination history.

Safety and satisfaction of myopic small-incision lenticule extraction combined with monovision

Background

To investigate the safety and optical quality of small-incision lenticule extraction (SMILE) combined with monovision, and patient satisfaction with the procedure.

Methods

The present study assessed a non-random case series involving 60 eyes of 30 patients (mean age 45.53 ± 3.20 years [range 41 to 52 years]) treated bilaterally using the VisuMax 500 system (Carl Zeiss Meditec, Jena, Germany) between January and July 2016. The target refraction was plano for the distance eye, and between − 0.5 and − 1.75 diopters (D) for the near eye. Visual acuity, refraction errors, ocular aberrations, and satisfaction questionnaire scores were calculated 1 year after surgery.

Results

All surgeries were uneventful, with a mean safety index of 1.03 and 1.04 in dominant and nondominant eyes, respectively. Binocular uncorrected distance visual acuity of all patients was ≥20/32, while binocular uncorrected near visual acuity was ≥20/40 1 year postoperatively. Higher-order aberration (0.45 ± 0.14, 0.51 ± 0.15 μm), spherical (0.18 ± 0.15, 0.21 ± 0.14 μm) and coma aberration (0.31 ± 0.16, 0.27 ± 0.17 μm) were identical between dominant and nondominant eyes after surgery. The overall satisfaction rate was 86.7% (26/30), with large contributions from age (OR = 1.76 95% CI: 1.03–2.53; P = 0.036). Binocular uncorrected distance visual acuity was related to preoperative spherical diopter (r = − 0.500; P = 0.005).

Conclusions

Monovision appears to be a safe and effective option for myopia patients with presbyopia who are considering the SMILE procedure. Patients with younger age were more satisfied with the procedure.

Cap morphology after small-incision lenticule extraction and its effects on intraocular scattering

AIM

To investigate cap morphology after small-incision lenticule extraction (SMILE) and its effects on intraocular scattering.

METHODS

Sixty-five eyes of 33 patients undergoing SMILE were enrolled. In addition to regular evaluation, Fourier-domain optical coherence tomography was used to investigate cap thickness at 1d, 1wk, 1 and 3mo postoperatively. The optical quality including modulation transfer function cutoff frequency, Strehl ratio, Optical Quality Analysis System (OQAS) values, and objective scattering index (OSI), were evaluated using OQAS™.

RESULTS

Cap thickness decreased from 1d to 1wk (P<0.001), but remained higher than intended thickness of 120 µm after 3mo (P<0.001). Cap thickness in central area was thinner than that of in the paracentral and peripheral areas (P<0.0001). Total number of microdistortions decreased from 1d to 3mo (P<0.0001). Pearson analysis revealed a weak correlation between OSI and standard deviation of cap thickness at 1d and 1mo, as well as between range of cap thickness and OSI at 1mo. No correlation was found between microdistortion and OSI, but a negative correlation existed between microdistortion and range at 1d and 1moafter surgery.

CONCLUSION

The corneal cap tends to be more accurate and regular with time lapse. Better cap morphology tends to contribute less intraocular scattering in the eyes undergoing SMILE.

Scleral ultrastructure and biomechanical changes in rabbits after negative lens application

AIM

To address the microstructure and biomechanical changes of the sclera of rabbits after negative lens application by spectacle frame apparatus.

METHODS

Five New Zealand rabbits of seven weeks post-natal were treated with -8 D lens monocularly over the course of two weeks. Refractive errors and axial length (AXL) were measured at the 1^st, 7^th and 14^th days of the induction period. Ultrastructure of sclera was determined with electron microscopy. Biomechanical properties were tested by an Instron 5565 universal testing machine.

RESULTS

Lens-induced (LI) eyes elongated more rapidly compared with fellow eyes with AXL values of 15.56±0.14 and 15.21±0.14 mm (P<0.01). Fibril diameter was significantly smaller in the LI eyes compared with control ones in the inner, middle, and outer layers (inner layer, 63.533 vs 76.467 nm; middle layer, 92.647 vs 123.984 nm; outer layer, 86.999 vs 134.257 nm, P<0.01, respectively). In comparison with control eyes, macrophage-like cells that engulfed fibroblasts, dilated endoplasmic reticulum, and vacuoles in fibroblasts were observed in the inner and middle stroma in the LI eyes. Ultimate stress and Young's modulus were lower in the LI eyes compared with those in the control eyes.

CONCLUSION

Negative lens application alters eye growth, and results in axial elongation with changes in scleral ultrastructural and mechanical properties.

[Mediating effect of mental elasticity on occupational stress and depression in female nurses]

Objective: To investigate the interaction between mental elasticityand occupational stress and depressionin female nurses and the mediating effect of mental elasticity, as well as the functioning way of mental elasticity in occupational stress-depression. Methods: From August to October, 2015, cluster sampling was used to select 122 female nurses in a county-level medical institution as study subjects. The Connor-Davidson Resilience Scale (CD-RISC) , Occupational Stress Inventory-Revised Edition (OSI-R) , and Self-Rating Depression Scale (SDS) were used to collect the data on mental elasticity, occupational stress, and depression and analyze their correlation and mediating effect. Results: The 122 female nurses had a mean mental elasticity score of 62.4±15.1, which was significantly lower than the Chinese norm (65.4±13.9) (P<0.05) ; the mean depression score was 41.0±7.7, which was significantly higher than the Chinese norm (33.5±8.6) (P<0.01) , and the incidence rate of depression of 52.5%. Mental elasticity was negatively correlated with occupational stress and depression (r=-0.559 and -0.559, both P<0.01) . Occupational stress and the two subscales mental stress reaction and physical stress reaction were positively correlated with depression (r=0.774, 0.734, and 0.725, all P<0.01) . After adjustment for confounding factors, occupational stress had a positive predictive effect on depression (β=0.744, P<0.01) , and mental elasticity had a negative predictive effect on depression (β=-0.221, P<0.01) . The analysis of mediating effect showed a significant direct effect of occupational stress on depression and a significant mediating effect of mental elasticity (a=-0.527, b=-0.227, c=0.744, c'=0.627; all P<0.01) , and the mediating effect of mental elasticity accounted for 16.08% of the total effect. Conclusion: As a partial mediating variable, mental elasticity has an indirect effect on the relationship between occupational stress and depression and can alleviate the adverse effect of occupational stress and reduce the development of depression.

Implantable collamer lens for residual refractive error after corneal refractive surgery

AIM

To assess the safety, efficacy, predictability and stability of implantable collamer lens (ICL) for residual refractive error after corneal refractive surgery.

METHODS

This study evaluated 19 eyes of 12 patients who underwent ICL implantation after corneal refractive surgeries. They were followed up for 1y to 5y of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refractive error, flat and steep K value, axial length, intraocular pressure, corneal endothelial cell density, adverse events after ICL surgery.

RESULTS

The mean follow-up period was 39.05±19.22 mo (range, 1-5y). Spherical equivalent refractive error changed from -7.45±3.02 D preoperatively to -0.85±1.10 D 1wk to 1mo after ICL implantation, with the safety and efficacy indices being 1.12 and 1.15, respectively. A total of 52.63% of eyes were within ±0.5 D of the predicted spherical equivalents, 73.68% were within ±1.0 D. A trend of mild regression towards myopia with axial elongation after 5y was observed. One eye with mild anterior capsule opacity and retinal detachment 1y after surgery were observed.

CONCLUSION

ICL implantation is safe and effective for the correction of residual refractive error after corneal refractive surgeries, especially in moderate to high residual myopia.

[Hydrogen sulfide in cartilage and its inhibitory effect on matrix metalloproteinase 13 expression in chondrocytes induced by interlukin-1β]

OBJECTIVE

To investigate whether endogenous hydrogen sulfide (H2S) was involved in the pathogenesis of osteoarthritis (OA) and its underlying mechanism, to detect H2S and its synthases expression in knee cartilage in patients diagnosed with different severity of OA, and to explore the transcription and expression of gene MMP-13 in chondrocytes treated with IL-1β or H2S.

METHODS

Synovial fluids of the in-patients with different severity of OA hospitalized in Peking University First Hospital were collected for measurement of H2S content using methylene blue assay. Articular cartilages of the patients who underwent knee arthroplasty were collected for the cell culture of relatively normal chondrocytes. The chondrocytes were cultured to the P3 generation and H2S molecular probes were used for detection of endogenous H2S generation in the chondrocytes. Immunocytochemistry was used to detect the localization of H2S synthases including cystathionine β-synthase (CBS), cystathionine-γ-lyase (CSE), and mercaptopyruvate sulfurtransferase (MPST) in OA chondrocytes. Western blot was used to quantify the protein expressions of CSE, MPST, and CBS in cartilage tissues of the patients who were diagnosed with OA and underwent knee arthroplasty. The relatively normal human chondrocytes were cultured to passage 3 and then divided into 4 groups for different treatments: (1)the normal control group, no reagent was added; (2)the IL-1β group, 5 μg/L of IL-1β was added; (3)the IL-1β+H2S group, 200 μmol/L of NaHS was added 30 min before adding 5 μg/L of IL-1β;(4)the H2S group, 200 μmol/L of NaHS was added. The transcription and expression of gene MMP-13 in chondrocytes of each group were determined with Real-time PCR and Western blot, respectively. And the total NF-κB p65 and phosphorylated NF-κB p65 in chondrocytes were detected with Western blot.

RESULTS

The content of H2S in the synovial fluid of degenerative knee was (14.3±3.3) μmol/L. Expressions of endogenous H2S and its synthases including CBS, CSE and MPST were present in the cytoplasm of chondrocytes.CSE protein expression in Grade 3 (defined by outerbridge grading) cartilage tissues was significantly increased as compared with that of Grade 1 cartilage tissues (1.67±0.09 vs. 1.26±0.11, P< 0.05). However, no significant difference of CBS or MPST expression among the different groups was observed. The expression of MMP-13 protein in the IL-1βgroup was significantly higher than that in the normal chondrocytes (1.87±0.67 vs. 0.22±0.10, P<0.05), and that in the IL-1β+H2S group was significantly decreased than that in the IL-1β group (0.55±0.11 vs. 1.87±0.67, P< 0.05), and that in the H2S group had no significant difference compared with that in the normal control group. The transcription of MMP-13 protein in the IL-1β group was significantly higher than that in the normal chondrocytes (31.40±0.31 vs. 1.00±0.00, P<0.05), and that in the IL-1β+H2S group was significantly decreased than that in the IL-1β group (24.41±1.28 vs. 31.40±0.31, P<0.05), and that in the H2S group had no significant difference compared with that in the normal control group. The total NF-κB p65 in the IL-1β group was significantly higher than that in the normal chondrocytes (2.13±0.08 vs. 0.73±0.08, P< 0.05), and that in the IL-1β+H2S group was significantly decreased than that in the IL-1β group (1.24±0.13 vs. 2.13±0.08, P<0.05), and that in the H2S group had no significant difference compared with that in the normal control group. The phosphorylated NF-κB p65 in IL-1β group was significantly higher than that in the normal chondrocytes (1.30±0.13 vs. 0.19±0.04, P<0.05), and that in IL-1β+H2S group was significantly decreased than that in the IL-1β group (0.92±0.26 vs. 1.30±0.13, P<0.05), and that in the H2S group had no significant difference compared with that in the normal control group.

CONCLUSION

H2S affected the cartilage degeneration by partly inhibiting the degradation of extracellular matrix.

Effects of exogenous 5-aminolevulinic acid on photosynthesis, stomatal conductance, transpiration rate, and PIP gene expression of tomato seedlings subject to salinity stress

The effects of exogenous 5-aminolevulinic acid (ALA) on photosynthesis, plant growth, and the expression of two aquaporin genes in tomato seedlings under control and salinity conditions were investigated. Exogenous ALA application significantly improved net photosynthetic rate (Pn), total chlorophyll content, and plant biomass accumulation of tomato seedlings under salinity stress. As revealed by real-time PCR analyses, after treatment with ALA alone, expression of both LePIP1 and LePIP2 in the two tomato cultivars was up-regulated at 2 h and subsequently decreased to normal levels. Under salinity stress, transcript levels of LePIP1 in both leaves and roots of salt-sensitive cultivars (cv. Zhongza No.9) increased significantly and were considerably higher than in cultivars exposed to ALA alone. In contrast, the expression levels of LePIP1 and LePIP2 in cvs. Jinpeng No.1 cultivars were slightly lower under salinity stress than under ALA treatment. In addition, transcript levels of both LePIP1 and LePIP2 in the roots of Jinpeng No. 1 cultivars were considerably lower than those in the roots of Zhongza No. 9 cultivars under salinity stress, regardless of ALA supplementation, implying that Jinpeng No. 1 cultivars had a better capacity to maintain membrane intrinsic protein stability. Further, ALA application distinctly counteracted the up- or down-regulation of LePIP1 and LePIP2 in both cultivars under salinity stress, in accordance with the improvements instomatal conductance, transpiration rate, and Pn of tomato leaves. The results presented here indicate that ALA controls aquaporin expression, thus, presumably ALA regulates water homeostasis and enhances salt tolerance of tomato seedlings.

Evaluating the association between pathological myopia and SNPs in RASGRF1. ACTC1 and GJD2 genes at chromosome 15q14 and 15q25 in a Chinese population

BACKGROUND

This study investigated the association of the 27 SNPs located in RASGRF1. GJD2, and ACTC1 genes with pathological myopia in a Chinese Han population.

METHODS

Myopia patients were stratified according to whether they did (n = 274) or did not (n = 131) have myopic macular degeneration (MMD). The SNPbrowser software was used to identify specific SNPs for analysis and minimal allele frequency of >20%, and a pairwise r(2) < 0.85 were genotyped using MALDI-TOF mass spectrometry.

RESULTS

Before controlling for false discovery rate, the frequency of the rs1867315 C/C genotype compared with healthy controls was lower in the myopia group (p = 0.006) and in myopia patients without macular degeneration (p = 0.019). The frequency of the rs670957A/A genotype was also lower in patients without MMD compared with controls (p = 0.045). For rs2070664, the frequency of the A allele was higher in the patients with MMD compared to those without MMD (p = 0.032). After controlling for a false discovery rate of 5%, there was no significant difference in genotype and allele frequencies between these groups.

CONCLUSION

In this study, there was no association of the analyzed SNPs located in RASGRF1. GJD2, and ACTC1 with pathological myopia, suggesting that SNPs included in our study have no or a limited role in causing pathologic myopia in this Chinese Han population.

The effects of monochromatic illumination on early eye development in rhesus monkeys

PURPOSE

Influence of longitudinal chromatic aberration (LCA) on emmetropization during early eye development has not been studied in primates. We investigated the effects of quasi-monochromatic lighting on refractive development and eye growth in rhesus monkeys.

METHODS

Infant rhesus monkeys were raised under one of three lighting conditions for 51 weeks: quasi-monochromatic blue light (peak 455 nm), red light (peak 610 nm), and white light (color temperature 5000 K). All animals underwent biometric measurements using cycloplegic streak retinoscope, keratometry, and A-scan ultrasonography for refraction, corneal power, and axial components, respectively, at designated time points.

RESULTS

At the 51st week, the mean difference in refraction of the white light and blue light groups, compared with that of the red light group, reached 1.71 diopters (D) and 1.43 D, respectively (both P < 0.001). Two monkeys in the red light group developed myopia at the 16th week, whereas the other seven remained hyperopic throughout the experiment. No significant difference in mean refraction was observed between the blue light group and white light group.

CONCLUSIONS

Illumination from long-wavelength light during early life could be a risk factor for the development of myopia in a small proportion of rhesus monkeys that are sensitive to L-cone stimulation.

Refractive change in the adult rabbit eye after corneal relaxation with the femtosecond laser

BACKGROUND

A new procedure to correct myopia that does not disturb the cornea in the optical zone and avoids injuring the corneal epithelium could be a key advance in corneal refractive surgery. The aim of this study is to observe the refractive change in the adult rabbits undergoing femtosecond laser-assisted multilayer intrastromal ablation in the mid-periphery of the cornea without injury of epithelium.

METHOD

The right eyes of 8 New Zealand White adult rabbits were used for the experiments. A 60-kHz femtosecond laser delivery system was used, and three lamellar layers of laser pulses were focused starting at a corneal depth of 180 μm and ending at 90 μm from the surface, with each successive layer placed 45 μm anterior to the previous layer. In the interface of the applanation contact lens cone, a 6-mm diameter aluminum circle was placed at the center to block the laser, limiting ablation to the mid-periphery of the cornea. The laser settings were as follows: spot/line separation, 10 μm; diameter, 8.0 mm; energy for ablating the stroma, 1.3 μJ. An authorefractor was used to assess the manifest refraction.

RESULTS

Mean spherical equivalent (SE) (mean ± SD, SD: standard deviation) was significantly increased at postoperative week 1 (1.67 ± 0.26 D, p < 0.0001), month 1 (1.65 ± 0.23 D, p < 0.0001), and month 3 (1.60 ± 0.22 D, p < 0.0001) compared to baseline (0.68 ± 0.27 D). Mean spherical equivalent showed no significant change between postoperative week 1 and month 3 (p = 0.1168).

CONCLUSION

Femtosecond laser-assisted multilayer corneal intrastromal ablation in the mid-periphery may cause a consequent hyperopic shift with no refractive regression.

Transfer from blue light or green light to white light partially reverses changes in ocular refraction and anatomy of developing guinea pigs

Relative to the broadband white light (BL), postnatal guinea pigs develop myopia in a monochromic middle-wavelength light (ML, 530 nm) environment and develop hyperopia in a monochromic short-wavelength light (SL, 430 nm) environment. We investigated whether transfer from SL or ML to BL leads to recuperation of ocular refraction and anatomy of developing guinea pigs. Two-week-old guinea pigs were given (a) SL for 20 weeks, (b) SL recuperation (SLR, SL for 10 weeks then BL for 10 weeks), (c) ML for 20 weeks, (d) ML recuperation (MLR, ML for 10 weeks then BL for 10 weeks), or (e) BL for 20 weeks. Two weeks after transfer from ML to BL (MLR group), ocular refraction increased from 1.95 ± 0.35 D to 2.58 ± 0.24 D, and vitreous length decreased from 3.48 ± 0.06 mm to 3.41 ± 0.06 mm. Two weeks after transfer from SL to BL (SLR group), ocular refraction decreased from 5.65 ± 0.61 D to 4.33 ± 0.49 D, and vitreous length increased from 3.18 ± 0.07 mm to 3.26 ± 0.11 mm. The MLR and SLR groups had final ocular refractions that were significantly different from those of the ML and SL groups at 20 weeks (ML vs. MLR: p < 0.0001; SL vs. SLR: p < 0.0001) but were still significantly different from the BL group (BL vs. MLR: p = 0.0120; BL vs. SLR: p = 0.0010). These results suggest that recuperation was not complete after return to BL for 10 weeks.

Effects of chronic exposure to 0.5 Hz and 5 Hz flickering illumination on the eye growth of guinea pigs

AIMS

To investigate the effect of prolonged flickering illumination exposure on the growth of the guinea pig eye.

METHODS

Thirty-six 2-week-old guinea pigs were randomized to one of the three treatment groups (n = 12 for each). Two strobe-reared groups were raised with a duty diurnal cycle of 50 % at a flash rate of 0.5 Hz and 5 Hz respectively. Illumination intensity varied between the minimum-maximum light levels of 0-600 lux during each cycle. The control group was exposed to steady 300 lux illumination. All animals underwent refraction and biometric measurements prior to and after 2, 4, 6, 8, 10 and 12 weeks of treatment. Finally, flash electroretinograms were compared, and retinal microstructures were examined.

RESULTS

There was a significant correlation between refractive errors and axial eye elongation, with myopia increasing between 1.5 and 3.4 D per mm eye elongation. After 12 weeks of treatment, the animals raised in 0.5 Hz flickering light were 5.5 ± 0.4 D more myopic than the group raised in continuous illumination, followed by the group raised at 5 Hz flicker light which was about 2.2 ± 1.3 D more myopic. In animals raised in flickering light of 5 or 0.5 Hz for 12 weeks, the implicit time of the a-wave was delayed by 4 and 8.5 ms, respectively. At this time, the outer segment disc membranes were found deformed and detached.

CONCLUSION

Chronic exposure to 0.5 and 5 Hz temporally modulated illumination induces electrophysiological and histological changes in retinal activities that alter the emmetropization of the guinea pig eye.

Unrecognized and unregistered blindness in people 70 or older in Jing'an district, Shanghai, China

AIM

To evaluate the efficacy of a registration system for the blind people and to monitor the blindness due to uncorrected refractive error and cataract in Jing'an district, Shanghai, China.

METHODS

Five hundred and ten blind people, based on visual acuity screening in a population aged 70 or older were enrolled into the study. Four hundred and forty subjects were interviewed. The following data were collected on each patient: demographic data, number of hospital visits for eye related problems, distance visual acuity, visual fields, ophthalmic diagnoses, education and registration status. If the eligible subject was not registered as blind, the reason for non-registration was recorded.

RESULTS

Ten point nine one percent blindness was due to cataract, 27.5% due to uncorrected refractive error, and only 61.59% met the eligible blindness criteria (uncorrected refractive error and cataract are not considered as eligible blindness). The first four leading causes of eligible blindness were age related macular degeneration (25.09%), myopic macular degeneration (21.40%), glaucoma (18.82%) and corneal disease (8.12%). Only 68.27% eligible blind people were registered. The patients with macular degeneration and glaucoma tended not to register. Blind people with an above primary school education were 2.59 times more likely to be registered than those who were illiterate or had only a primary school education (OR=2.59, 95%CI: 1.49-4.48, P<0.01). Patients who had 4 or more visits to the hospital requesting eye care services in a year were 2.2 times more likely to be registered than those with less than 4 visits to the hospital (OR=2.54, 95%CI: 1.47-4.38, P<0.001). The first two leading reasons of misregistration were unknowing the registration system (48%) and unwilling to register (21%).

CONCLUSION

Under-registration of the eligible blind people exists in the registry system. Education and the number of hospital visits for eye care services were factors associated with registration levels. Uncorrected refractive error and cataract are important causes of blindness.

Effects of the chromatic defocus caused by interchange of two monochromatic lights on refraction and ocular dimension in guinea pigs

To investigate refractive and axial responses to the shift of focal plane resulting from the interchange of two monochromatic lights separately corresponding to the peak wavelengths of the cones absorption spectrum in retina, fifty 2-week-old pigmented guinea pigs were randomly assigned to five groups based on the mode of illumination: short-wavelength light (SL), middle-wavelength light (ML) and broad-band white light (BL) for 20 weeks, SL for 10 weeks followed by ML for 10 weeks (STM), as well as ML for 10 weeks followed by SL for 10 weeks (MTS). Biometric and refractive measurements were then performed every 2 weeks. After 10 weeks, SL and STM groups became more hyperopic and had less vitreous elongation than BL group. However, ML and MTS groups became more myopic and had more vitreous elongation. After interchange of the monochromatic light, the refractive error decreased rapidly by about 1.93D and the vitreous length increased by 0.14 mm in STM group from 10 to 12 weeks. After that, there were no significant intergroup differences between STM and BL groups. The interchange from ML to SL quickly increased the refractive error by about 1.53D and decreased the vitreous length by about 0.13 mm in MTS group after two weeks. At this time, there were also no significant intergroup differences between MTS and BL groups. The guinea pig eye can accurately detect the shift in focal plane caused by interchange of two monochromatic lights and rapidly generate refractive and axial responses. However, an excessive compensation was induced. Some properties of photoreceptors or retina may be changed by the monochromatic light to influence the following refractive development.

Myopia induced by flickering light in guinea pigs: a detailed assessment on susceptibility of different frequencies

AIM

To investigate the effectiveness and feasibility of inducing myopia in guinea pigs by flickering light (FL) stimulation with different frequencies.

METHODS

Seventy 2-week-old guinea pigs were randomly assigned to six groups: five FL groups and a control group (n=12 for each). Animals in the five FL groups were raised under 500lx illumination with a duty diurnal cycle of 50% at a flash rate of 5, 1, 0.5, 0.25 and 0.1Hz respectively. Those in the control group were reared under steady 250lx illumination. Refraction, axial length, and radius of curvature were measured before and at 2, 4, 6, 8, 10 and 12 weeks after treatment. At week 12, the eyeballs were taken out and three ocular dimensions and dry weight of sclera were measured.

RESULTS

A myopic shift and axial eye length increase developed in the five FL groups. Stimulation at 0.5Hz caused greater changes in myopic shift, axial elongation, eyeball dimension, and dry weight of sclera than stimulation at other frequencies. Compared with controls, eyes in 0.5Hz group were approximately -5.5±1.5D more myopic with increase in horizontal, vertical, axial dimensions by 0.89±0.3mm, 0.69±0.2mm, 1.12±0.2mm respectively and with increase in dry weight of sclera by 0.44mg.

CONCLUSION

Chronic exposure to periodic illumination at temporal frequency is attended by development of excessive ocular enlargement and myopic refractive error. Emmetropization could be disrupted differently by frequency alteration.

Arg555Gln mutation of TGFBI gene in geographical-type Reis-Bücklers corneal dystrophy in a Chinese family

OBJECTIVE

Mutations of the transforming growth factor β-induced (TGFBI) gene were studied in a Chinese family with Reis-Bücklers corneal dystrophy (RBCD).

METHODS

Six family members with RBCD and six unaffected family members were investigated. The pedigree showed a typical dominant inheritance pattern. Genomic DNA was extracted from peripheral leucocytes from all study participants. Exons 4, 12 and 14 of the TGFBI gene were analysed using polymerase chain reaction, and standard automated sequencing was performed. Corneal tissue sampled from the proband during phototherapeutic keratectomy was examined using transmission electron microscopy (TEM).

RESULTS

A typical geographical pattern of fine opacities in Bowman's layer of the cornea was seen in all six patients on slit-lamp examination. An Arg555Gln (R555Q) mutation of the TGFBI gene was identified in all six patients but was absent in all unaffected family members. TEM revealed rod-shaped bodies in Bowman's layer of the cornea.

CONCLUSIONS

In this Chinese family an R555Q mutation of the TGFBI gene was associated with RBCD. As the RBCD phenotype is usually associated with an R124L mutation, this novel genotype-phenotype correlation may prompt further investigation of Bowman's layer corneal dystrophy.

[The progress of fixation eye movement research]

When eyeball fixes targets, it will produce one frequent and regular movement which is difficult to detect. Such movements is called fixation eye motion. This motion can be further divided into drift, tremor and microsaccades. In recent years, research in this field is strikingly increasing. Due to the significant role on the control of fixation positron, maintaining continuous sense of perception, keeping bistable condition, clear vision, spatial orientation and attention, research in this field is maybe a worthwhile myopia research direction.

Influence of internal optical astigmatism on the correction of myopic astigmatism by LASIK

PURPOSE

To investigate the influence of the origin of astigmatism on the correction of myopic astigmatism by LASIK.

METHODS

A retrospective study was conducted of the records of 192 patients (192 eyes) undergoing LASIK for correction of myopia and myopic astigmatism from January to September 2010. Ocular residual astigmatism (ORA) and lenticular astigmatism (LA) were determined by vector analysis using objective refraction and Pentacam (Oculus Optikgeräte GmbH) imaging of both corneal surfaces. Patients were divided into two groups according to ORA (high ORA group: ORA/preoperative refractive astigmatism >1; normal ORA group: ORA/preoperative refractive astigmatism ≤ 1) and LA (high LA group: LA/preoperative refractive astigmatism >1; normal LA group: LA/preoperative refractive astigmatism ≤ 1). Procedural efficacy was compared between those eyes with and without a significant amount of internal optical astigmatism using index of success.

RESULTS

Mean preoperative vectors for the astigmatism of the anterior cornea, posterior cornea, and lens were -1.33 × 3.0°, -0.33 × 95.3°, and -0.27 × 103.3°, respectively. Mean indices of success in the high and low ORA groups were 1.75 and 0.59, respectively (t=7.81, P<.001). Mean indices of success in the high and low LA groups were 2.07 and 0.70, respectively (t=12.36, P<.001). The higher indices of success in the high ORA and high LA groups suggest a lower efficacy of LASIK in treating astigmatism primarily located intraocularly.

CONCLUSIONS

Myopic LASIK is less effective in correcting astigmatism when astigmatism is mainly located at the internal optics. Topography and refractive value should be incorporated in the treatment of patients when a significant amount of internal optical astigmatism is detected preoperatively.

Effects of age on ocular anterior segment dimensions measured by optical coherence tomography

BACKGROUND

Older subjects tend to have smaller ocular anterior segment. The present study aimed to measure anterior segment dimensions with optical coherence tomography (OCT) and quantitatively assess the effect of age and other factors.

METHODS

Anterior segment OCT images were obtained in normal subjects residing in the greater Los Angeles area. Four line scans were acquired at the 90°, 45°, 0° and 135° meridians of each eye. Computer calipers acquired anterior segment dimensions of corneal diameter, anterior chamber width, corneal vault and anterior chamber depth on OCT images. Measurements from 4 meridians were averaged. Axial length and corneal power were measured by partial coherence interferometry. Univariate and multivariate analyses were performed to assess correlations.

RESULTS

Sixty-six eyes of 33 normal subjects (aged 22 - 65 years, 19 Asians, 14 Caucasians) were enrolled. For every 1 year of age, corneal diameter was 0.033 mm narrower (P < 0.01), anterior chamber width was 0.031 mm narrower (P < 0.01), corneal vault was 0.016 mm lower (P < 0.01), and anterior chamber depth was 0.025 mm lower (P < 0.01). Asian eyes had smaller corneal diameter (P = 0.035) and anterior chamber width (P = 0.015) compared with those of Caucasian eyes. Body height showed positive correlation with corneal diameter (0.039 mm per centimeter of height, P < 0.01) and corneal vault (0.024 mm per centimetre of height, P < 0.01). Gender did not have an independent effect on anterior segment dimensions.

CONCLUSIONS

Anterior segment dimensions were smaller in older subjects. Age-related changes may affect the tolerability of long-term implants such as phakic intraocular lens.

The role of eIF5A in epidermal growth factor-induced proliferation of corneal epithelial cell association with PI3-k/Akt activation

PURPOSE

After excimer laser surgery, epidermal growth factor (EGF) plays an important role in injured corneal epithelial cell on myofibroblastic cell formation in corneal stroma. The purpose of the study is to investigate the precise mechanism of EGF on corneal wound healing, particularly on epithelial proliferation and migration.

METHODS

In this study we applied small interference RNA (siRNA) to knock down the expression of eukaryotic translation initiation factor 5A (eIF5A) in corneal epithelial cells. The relative mRNA and protein expression of matrix metallopeptidase 9 (MMP9) and proliferating cell nuclear antigen (PCNA) was determined via real-time PCR and western blot analysis. The proliferative potential of EGF was evaluated via a proliferation assay using the measurement of (3)H-thymidine incorporation ((3)H-TdR). HCEpiC apoptosis was subjected to flow cytometric analysis.

RESULTS

The results showed eIF5A expression was enhanced and there was a statistically significant increase in EGF treatment compared to the control group. Real-time PCR, western blot analysis, and the proliferation assay demonstrated significantly lower MMP9 and PCNA expression and proliferation cell counts in eIF5A siRNA-treated groups versus significantly higher levels in EGF plus eIF5A siRNA-treated groups. The data analysis showed that eIF5A, MMP9, and PCNA expression decreased as a result of the inhibitor LY294002. Apoptotic cells were increased in the EGF plus eIF5A siRNA, EGF plus LY294002, and EGF plus eIF5A siRNA plus LY294002 groups as compared with the EGF siRNA group.

CONCLUSIONS

These results indicate that EGF-induced upregulation of eIF5A stimulates corneal epithelial cell proliferation in vitro. EGF stimulation of corneal epithelial proliferation was through the phosphatidylinositol 3-kinase (PI3-k)/protein kinase B (Akt) signaling pathway.

Physical characteristics of ocular structures in Chinese children with emmetropia

PURPOSE

To evaluate whether accommodation has effects on eye elongation.

METHODS

Two hundred seventy-three eyes with a refractive error between +1.0 and -0.5 diopters were divided into three groups: pre-school children, grade-school children, and middle-school children. Ocular structures were measured using autorefraction and A-scan ultrasonography.

RESULTS

There was a negative correlation between age and corneal power (r = -0.227, P = .0001), lens thickness (r = -0.263, P = .00001), and Gullstrand lens power (r = -0.452, P << .0001). There was a positive correlation between age and axial length (r = -0.432, P << .0001) and vitreous chamber depth (r = 0.505, P << .0001). Mean corneal power (P < .001) and lens power (P < .001) were significantly greater in pre-school children than in grade-school children, whereas axial length (P < .001) and vitreous chamber depth (P < .001) were greater in grade-school children. Mean lens thickness (P = .01) and lens power (P = .07) were higher in grade-school children than in middle-school children, whereas axial length (P = .024) and vitreous chamber depth (P < .001) were higher in middle-school children.

CONCLUSION

Ocular structures may play different roles in maintaining emmetropia. Accommodation during near work and its potential attendant hyperopic defocus could potentially drive eye elongation.

Effects of femtosecond laser-assisted multilayer intrastromal ablation in the midperipheral cornea

We describe the femtosecond laser-assisted midperipheral multilayer intrastromal ablation technique, which combines the benefit of radial keratotomy, ie, not disturbing the optical zone, with currently available technology to correct myopia. The technique was performed in 2 patients, both of whom experienced a decrease in mean corneal power. In 1 patient, the manifest refraction improved, with a 1-line increase in uncorrected visual acuity 1 day postoperatively. The multilayer intrastromal ablation technique, which flattens the cornea and decreases corneal power, can be used to correct moderate myopia without injuring the corneal epithelium.

[The relationship between eyeball structure and visual acuity in high myopia]

OBJECTIVE

To explore the relationship between eyeball structure and visual acuity in high myopia.

METHODS

Totally, 152 people (283 eyeballs) with different levels of myopia were tested for visual acuity, axial length, and fundus. All cases were classified according to diopter, axial length, and fundus. The relationships between diopter, axial length, fundus and visual acuity were studied. The mathematical models were established for visual acuity and eyeball structure markers.

RESULTS

The visual acuity showed a moderate correlation with fundus class, comus, axial length and diopter ([r] > 0.4, P < 0.000 1). The visual acuity in people with the axial length longer than 30.00 mm, diopter above -20.00 D and fundus in 4th class were mostly below 0.5. The mathematical models were established by visual acuity and eyeball structure markers.

CONCLUSION

The visual acuity should decline with axial length extension, diopter deepening and pathological deterioration of fundus. To detect the structure changes by combining different kinds of objective methods can help to assess and to judge the vision in high myopia.

[Clinical study of diffuse lamellar keratitis after laser in situ keratomileusis]

OBJECTIVE

To investigate a new clinical grading scale of diffuse lamellar keratitis (DLK) following laser in situ keratomileusis (LASIK) and to observe the clinic outcomes of eyes treated with corresponding classified therapy.

METHODS

It was a prospective case-control study. Eyes that developed DLK after LASIK were diagnosed by a new criterion of clinical grading scale based on both severity and scope of inflammatory cells infiltrations in the corneal interface. Dose and frequency of topical or systemic corticosteroid were determined by the classified profiles according to each grade. Clinical symptoms, corneal inflammatory cells infiltrations, visual acuity, refractive error and intraocular pressure (IOP) were evaluated on 1, 3, 5, 7, 10 days and 1 month after diagnosis as well as at the time of diagnosis.

RESULTS

Among the 35 eyes of 29 patients that developed DLK, mild inflammatory cells infiltrations were mostly seen. Thirty eyes had degree I DLK and 3 had degree II DLK. One eye had degree III DLK and one had degree IV DLK. Inflammatory cells infiltrations in 20 eyes invaded peripheral zone (zone 1) and those in 11 eyes invaded mid-peripheral zone (zone 2). Inflammatory cells infiltrates in 4 eyes invaded central zone (zone 3). Nineteen eyes had degree I zone 1 DLK. Thirty three eyes were diagnosed between the 1st day and the 3rd day after surgery. Uncorrected visual acuity (UCVA) was worse than preoperative best spectacle corrected visual acuity (BSCVA). Inflammatory cells infiltrations retreated within 6.06 2.04 days after classified corticosteroid therapy. One month after the treatment, UCVA had improved to the level of preoperative BSCVA. BSCVA in 30 eyes were equal to or better than those before surgery. Spherical equivalent of the refractive error was (-0.21 +/- 1.16) D. There was no statistic difference in the retreat time of inflammatory cells infiltrations, recovery of visual acuity and refractive error among the different grades of DLK or among the DLK treated with different therapy profiles. No eye suffered from high intraocular pressure during the treatments.

CONCLUSIONS

Clinical grading scale and corresponding classified therapy were proved to be effective in the treatment for DLK.

[The effects on corneal wound healing of LASIK with ultra-thin corneal flaps and LASEK in rabbits]

OBJECTIVE

To evaluate the corneal wound-healing response of LASIK with ultra-thin corneal flaps and LASEK in rabbits.

METHODS

It was an experimental study. Thirty-two adult New Zealand rabbits were divided into 2 groups with 16 each. Two surgical procedures, LASIK with ultra-thin corneal flaps and LASEK were performed on the right eye of each group, with the left eye as control. A myopic ablation of 10 diopters was performed in each group. Corneal wound-healing and histopathological changes of the ablation zone were studied through slit lamp, light microscope and transmission electronic microscope. The expression levels of collagen I , collagen III, fibronectin (FN) and transforming growth factor beta-1 (TGF-beta1) were investigated by immunohistochemistry and RT-PCR assays.

RESULTS

In the group of LASIK with ultra-thin corneal flaps, the corneas were clear without haze followed by slight wound healing and fast recovery. While in the group of LASEK, corneal wound healing was obviously delayed. There was haze in grade 1 (62.5%) and grade 2 (37.5%) in 1 month, with grade 0.5 (43.75%) and grade 1 (56.25%) in 3 months. 1 month and 3 months after surgery, proteins and mRNA of collagen III, FN and TGF-beta1 were expressed in the anterior corneal stromal layer in each group. But the expression was much higher in the group of LASEK (t = 18.47, 11.98, P < 0.05). The protein and mRNA expression of collagen I had no difference between the two groups (t = 0.72, 0.36, 0.47, 2.38, P > 0. 05). The mRNA expression of collagen I, collagen III, FN and TGF-beta1 had no statistical difference between the groups of control and LASIK with ultra-thin flap in 3 months (t = 2.42, 1.54, -0.83, P > 0.05).

CONCLUSION

According to the animal experiments, it was suggested that the corneal wound-healing response of LASIK with ultra-thin corneal flaps was much better than that of LASEK.

[A compare study on cornea biomechanical properties in normal and keratoconic eyes]

OBJECTIVE

To compare the corneal hysteresis (CH) and corneal resistance factor (CRF) measured with the Ocular Response Analyzer (ORA) in normal and keratoconic eyes.

METHODS

It was a case-control study. Random selected 96 normal eyes and 46 keratoconic eyes in the same period were included in this study. Normal eyes were divided into 2 groups: high corneal astigmatism (> or = 3.00 D) and low-to-moderate corneal astigmatism (< 3.00 D). Keratoconic eyes were also divided into 3 groups based on Amsler-Krumeich classification: mild (stage I), moderate (stage II) and severe (stage III/IV). CH and CRF were compared between groups and the areas under ROC curves of the CH and CRF were calculated.

RESULTS

The mean CH and CRF were (7.1 +/- 1.6) mm Hg and (6.3 +/- 1.5) mm Hg in keratoconic eyes compared with (10.1 +/- 1.3) mm Hg and (10.5 +/- 1.6) mm Hg in normal eyes. The difference were statistically significant(t = -11.813, -14.943; P < 0.001). In normal eyes, there was no difference of CH or CRF between the high corneal astigmatism and low-to-moderate corneal astigmatism (t = 0.373, 0.095; P > 0.05). In keratoconic eyes, there was a significant negative correlation between CH and the keratoconus grade (r = -0.627, P < 0.001) and the same relationship was found between CRF and the keratoconus grade (r = -0.587, P < 0.001). In multiple linear regression analysis,CH was correlated with central corneal thickness (CCT) and corneal curvature (r = 0.320, -0.375; P < 0.05) and CRF was correlated with corneal curvature in keratoconic eyes (r = -0.441, P < 0.01) , while they were only correlated with CCT in normal eyes (r = 0.367, 0.459; P < 0.001). The areas under ROC curves of the CH and CRF were 0.9282 and 0.9731 (Z = 20.462, 38.305; P < 0.0001), the difference between them was significant (Z = 7.134, P = 0.008).

CONCLUSIONS

The CH and CRF were significantly lower in keratoconic eyes than in normal eyes, especially on CRF. The long-term follow-up of CH and CRF may provide information for evaluation of progression of keratoconus. They may be included as indicators for detecting keratoconus.

Morphologic and histopathologic changes in the rabbit cornea produced by femtosecond laser-assisted multilayer intrastromal ablation

PURPOSE

To observe morphologic and histopathologic changes in the midperiphery of the rabbit cornea produced by femtosecond laser-assisted multilayer intrastromal ablation, determine whether this method may be used to correct myopia, and study how the cornea heals when the epithelium is not injured.

METHODS

The right eyes of 10 New Zealand White rabbits were used for the experiments. A 60-kHz femtosecond laser delivery system was used, and three lamellar layers of laser pulses were focused starting at a corneal depth of 180 microm and ending at 90 microm from the surface, with each successive layer placed 45 microm anterior to the previous layer. In the interface of the applanation contact lens cone, a 6-mm diameter aluminum circle was placed at the center to block the laser, and ablation was limited to the midperiphery of the cornea. The laser settings were spot/line separation, 10 microm; diameter, 8.5 mm; energy for ablating the stroma, 1.3 microJ. Topography examination was used to document changes in corneal power. Light microscopy, transmission electron microscopy (TEM), and confocal microscopy in vivo were applied to observe changes in the cornea.

RESULTS

There was significant change in mean corneal power between baseline and postoperative month 3 (n = 8; P = 0.0001), with a decrease from 46.82 D to 44.42 D. There was no haze formation or refractive regression throughout the follow-up. There were no corneal structural abnormalities under light microscopy. Activated keratocytes and necrotic debris were visible under confocal microscopy. Fibroblasts were observed, and no myofibroblasts appeared under TEM.

CONCLUSIONS

Multilayer intrastromal ablation by the femtosecond laser with intact epithelium in the midperiphery of the corneal stroma can flatten the cornea without causing haze formation or refractive regression. This procedure allows the cornea to heal differently than when traditional corneal refractive surgery is performed and the epithelium is damaged.

Incidence of myopia in high school students with and without red-green color vision deficiency

PURPOSE

To investigate the influence of color vision on myopia development by testing refraction error and axial length of the eye for high school students with and without color vision deficiency (CVD).

METHODS

A school-based cross-sectional, cluster sample study was conducted to test the color vision and refractive error of 16,539 high school students. Students were screened for CVD using a pseudoisochromatic plate. CVD was confirmed in students failing the test using a Farnsworth-Munsell 100-Hue Test which also served to classify the subtype (protan or deutan). Three classmates of each CVD subject, matched in five myopia risk factors, were chosen to form the normal color vision (CN) control group. Ophthalmic examinations were performed to determine refractive status and axial length.

RESULTS

Of the students, 309 were found to have red-green CVD and 927 were selected as the CN control group. The prevalence of myopia in the CVD group (45.6%) was significantly lower than that of the CN group (65.8%; P<0.001). The CVD group was also less myopic in refraction (P<0.001) than CN, and protan subjects had shorter axial lengths than those in the control group (P=0.007).

CONCLUSIONS

Color vision deficiencies appear to influence the development of myopia. The observed lower incidence of myopia in people with CVD may be linked to the reduced functionality of the L/M chromatic mechanism.