Objective To investigate the role of homocysteine(Hcy)in the pathogenesis of irritable bowel syn-drome(IBS)and its effects on intestinal motility,visceral hypersensitivity,and barrier function.Methods Clinical cohorts and animal models were combined for this study.Clinically,fifteen IBS patients meeting Rome Ⅲcriteria and 15 control individuals were enrolled to detect fecal Hcy levels and their correlation with symptoms.As for animal experiments,water avoidance stress(WAS)and 2,4,6-trinitrobenzene sulfonic acid(TNBS)chemical induction were utilized to establish IBS rat and mouse models,combined with a high-methionine diet(HMD)to simulate hyperhomocysteinemia.IBS symptoms were evaluated through fecal water content,carmine red intestinal transit time,and visceral hypersensitivity scores.Immune-fluorescence and Western blot were used to detect intes-tinal epithelial tight junction proteins.Serum and fecal Hcy concentrations were measured to assess Hcy levels.Statistical analyses included t-tests and One-way Anova.Results Fecal Hcy level in IBS patients were signifi-cantly higher than those in the healthy control group which demonstrated a positive correlation with defecation fre-quency(P＜0.01).In animal models,the combination of TNBS administration and a high-methionine diet markedly elevated serum and fecal Hcy levels in mice,while synergistically exacerbated intestinal motility disor-ders and visceral hypersensitivity.In vitro experiments showed that Hcy treatment down-regulates the expression of tight junction proteins in human colon cancer cell line(Caco-2).Conclusions Hcy plays an important role in the pathogenesis of IBS by impairing intestinal barrier function and enhancing visceral hypersensitivity,and it may serve as a potential new target for the treatment of IBS.

Internal limiting membrane (ILM) is a translucent homogeneous membrane composed of Müller cell basement membrane and a small number of glial cells.The alpha collagen, sulfate protein sugar and laminin in ILM play important roles in the development of retinal basement membrane and neurovascular structure and in the formation of retinal barrier.However, when pathological changes occur in its composition, structure and physical and chemical properties, it may cause the occurrence and development of many vitreoretinal diseases.At present, ILM peeling which is widely used in vitreoretinal diseases can effectively relieve the traction of residual vitreous cortex on retina and prevent postoperative epiretinal membrane formation, but there are still some problems such as retinal microstructure and physiological function damage.Therefore, some ILM-modified surgeries have been developed, including fovea-sparing ILM peeling, inverted ILM flap, and ILM transplantation technique.This article summarizes the physical and chemical properties, physiological functions, pathologic changes in ILM-related diseases and ILM-related surgical methods, with the goal of providing an advanced understanding of the ILM and aiding in clinical diagnosis and treatment.

Objective:To analyze the clinical phenotypes and genotypes of a family with posterior segment microphthalmia-retinoschisis and drusen syndrome.Methods:A pedigree investigation study was conducted.A family with four members across two generations treated at Shenzhen Eye Hospital in July 2021 was enrolled.Detailed ophthalmic examinations, including best corrected visual acuity (BCVA), intraocular pressure, slit-lamp microscopy, color fundus photography, optical coherence tomography (OCT), anterior segment OCT, fundus fluorescein angiography (FFA), and visual field tests were performed in the four members.Peripheral venous blood samples were collected from members for whole exome sequencing and data analysis.The pathogenicity of novel variant sites was assessed according to the ACMG guidelines.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Shenzhen Eye Hospital (No.22KYPJ018).Written informed consent was obtained from each subject or the guardian.Results:The proband is a 14-year-old female with high hyperopia since childhood, BCVA of + 9.75 DS-0.75 DC×150°=0.9 and + 11.75 DS-1.25 DC×30°=0.7, corneal transverse diameters of 12.1 and 12.2 mm, anterior chamber depths of 2.56 and 2.92 mm, lens thicknesses of 3.92 and 3.94 mm, and axial lengths of 17.47 and 17.01 mm in the right and left eyes, respectively.Fundus photography revealed diffuse yellow-white drusen-like lesions with unclear borders in the mid-peripheral retina, while OCT showed retinoschisis in the inner nuclear layer and homogeneous mound-like elevations with hyperreflective dense spots under the retinal pigment epithelium.FFA demonstrated diffuse punctate transilllumination of the mid-peripheral retina in both eyes, and visual field tests revealed a general decrease in visual acuity.The proband's 8-year-old brother exhibited similar signs to the proband.The consanguineously married parents were phenotypically normal.Whole exome sequencing identified compound heterozygous mutations in the membrane frizzled-related protein ( MFRP) gene in the proband and her brother, c.1150_1151insC (p.His384Profs*8) in exon 5 and c. 498_499insC (p.Asn167Glnfs*34) in exon 10.The father carried the c. 498_499insC mutation, while the mother carried the c.1150_1151insC mutation.Both were frameshift mutations predicted to alter gene function.These novel mutations had not been reported in the ESP, 1 000 Genomes (Phase 3), or ExAC databases, indicating they are novel variants.The variants co-segregated with the disease and both were classified as pathogenic according to ACMG guidelines.Based on the clinical and genetic findings, the family was diagnosed with posterior segment microphthalmia-retinoschisis and drusen syndrome, inherited in an autosomal recessive manner. Conclusions:The MFRP gene mutations c. 1150_1151insC and c. 498_499insC are the pathogenic variants for the posterior segment microphthalmia-retinoschisis and drusen syndrome in this family, and these compound heterozygous mutations are reported for the first time.

Hydroxychloroquine is widely used in a variety of autoimmune diseases. However, long-term use of hydroxychloroquine can cause severe retinopathy, which has a complex pathogenic mechanism and diverse clinical manifestations, mainly manifested as photoreceptor and retinal pigment epithelial damage and irreversible vision loss. Identifying damage before retinitis pigment epithelium lesions preserve central vision, so early detection is crucial to slow disease progression and reduce vision loss. The development of multimodal imaging technology and the issuance of the latest treatment guidelines provide a powerful tool for the early screening and treatment of hydroxychloroquine retinopathy. Proficient in the latest guidelines for the treatment of hydroxychloroquine can better guide clinicians to do a good job in disease screening and management, recommend risks, safe dosages and appropriate screening procedures to patients and strengthen the prevention of hydroxychloroquine retinopathy, which will help save the vision of more patients and reduce the waste of medical resources.

High myopia is a disease with a high incidence rate and an increasing trend, which could lead to irreversible visual impairment worldwide. Myopia traction maculopathy (MTM), belonging to one of the pathological changes of high myopia, could cause vision damage and even blindness in patients. Recently, a new classification of MTM based on optical coherence tomography can effectively evaluate the condition of patients and is helpful for the diagnosis and treatment of MTM. Moreover, the improvement of internal limiting membrane peeling method and the innovation of macular buckle material provide new ideas for the treatment of MTM based on traditional surgery. New treatment such as vitreal traction release laser surgery, enzymatic vitreolysis and posterior scleral crosslinking have gained increasing attention. By combining these new treatments with artificial intelligence, 3D printing technology and advanced vitrectomy equipment, it is hoped that a safer and more effective treatment for MTM will be found in the future.

Objective:To investigate the ultrastructural and biomechanical properties of the internal limiting membrane (ILM) in high myopic macular hole (HM-MH) eyes.Methods:ILM specimens were peeled from 14 eyes with HM-MH from August to December in 2017, and 16 eyes with idiopathic macular hole (IMH) in the same period were served as a control.Specimens were detected by immunefluorescence, transmission electron microscopy (TEM) and atomic force microscopy (AFM). This study followed the Declaration of Helsinki, and was approved by the Ethics Committee of Zhongshan Ophthalmic Center.Results:The immunofluorescence staining results showed that collagen Ⅳ was mainly distributed on the vitreal side and laminin on the retinal side of ILM in both groups.TEM findings revealed that the thickness of ILMs in the HM-MH group was (1.01±0.17)μm, which was significantly decreased compared with (1.92±0.21)μm in the IMH group ( t=12.880, P<0.001). The stiffness of the ILMs in the HM-MH group was (2.86±0.33)MPa, which was significantly higher than (0.88±0.23)MPa in the IMH group ( t=-12.650, P<0.001). The stiffness of the ILMs in the HM-MH group was positively correlated with the axial length ( r=0.832, P<0.001). Conclusions:Compared with IMH, the thickness of ILMs from HM-MH patients is thinner and the stiffness is higher, which contribute to a deep understanding of the pathogenesis of HM-MH.

Objective To evaluate the efficacy and safety of 27-gauge sutureless vitrectomy with air tamponade for rhegmatogenous retinal detachment (RRD).Methods The clinical data of 35 consecutive eyes with primary RRD from 35 patients who received 27-gauge vitrectomy with intraocular air tamponade in Zhongshan Eye Center from April 2016 to January 2017 were retrospectively analyzed.The mean follow-up duration was 8.6 months.Best corrected visual acuity (BCVA) (LogMAR) and intraocular pressure (IOP) were examined before surgery,1 week and 3 months after surgery.The operative duration,sclerotomy sites,retinal reattachment rate,intraoperative and postoperative complications were recorded.Results The mean duration of vitreous removal was (15.3 ± 3.6) minutes,and the mean duration of operation was (34.5 ± 4.8) minutes.No suturing process was performed at sclerotomy sites in all eyes.The retinal reattachment rate following a single procedure was 100％.The mean BCVA was significantly different among before surgery,1 week and 3 months after surgery (F =64.12,P＜0.01),and the BCVA at 1 week and 3 months after surgery was evidently improved in comparison with before surgery (0.82±0.31 vs.1.01 ±0.40;0.68±0.30 vs.1.01 ±0.40) (both at P＜0.05).The mean IOP was (14.69±3.66),(17.37±2.32) and (16.69±2.45) mmHg (1 mmHg =0.133 kPa) before surgery,1 week and 3 months after surgery,showing a significant difference among them (F=14.82,P＜0.01),and the IOP 1 week and 3 months after surgery was evidently higher than that before surgery (both at P＜0.05).The complications included intraoperative iatrogenic retinal breaks in 2 eyes,postoperative hypotony in 1 eye and hypertension in 5 eyes.These complications were curable.Conclusions 27-Gauge vitrectomy and air tamponade for RRD is an effective and safe approach.