International journal of ophthalmology最新文献

[This corrects the article DOI: 10.18240/ijo.2024.09.07.].

Aim: To investigate the efficacy and mechanisms of indirect intense pulsed light (IPL) irradiation on meibomian gland dysfunction (MGD).

Methods: A total of 60 MGD patients was included in this prospective randomized controlled trial. Patients were randomly assigned 1:1 into two groups (3-mm group and 10-mm group) in which IPL was applied at distances from the lower eyelid margin of 3 and 10 mm, respectively. Both groups received three times treatment with 3-week interval. Meibomian gland yield secretion score (MGYSS), standard patient evaluation of eye dryness (SPEED) questionnaire, tear break-up time (TBUT), corneal fluorescein staining (CFS), and in vivo confocal microscopy were performed at baseline and after every treatment.

Results: After three IPL treatments, both groups had significant improvement in MGYSS (both P<0.05). The non-inferiority test showed that improvement in 10-mm group was not inferior to that in 3-mm group (P<0.001). In both groups, temporal regions of both upper and lower eyelids showed significant improvement in MGYSS. Scores of SPEED questionnaire in both groups declined significantly (both P<0.001) and changes of SPEED had no difference between two groups (P=0.57). Density of central corneal subepithelial nerves and TBUTs showed no statistically significant changes. The 3-mm group had improvement on corneal fluorescein staining (P=0.048) and meibomian gland morphology (acini wall thickness P=0.003, hyperreflective points P=0.024) while the 10-mm group had not.

Conclusion: The efficacy of IPL indirect irradiation in improving meibomian gland secretion and alleviating dry eye symptoms remains unchanged with increase in treatment distance. IPL may primarily act on the functional improvement of the meibomian glands and corneal nerves.

Aim: To study the causal relationship between obesity-related anthropometric traits and myopia and the mediating role of educational attainment (EA).

Methods: Univariable Mendelian randomization (UVMR) was performed to evaluate the causal association between body mass index (BMI), height, waist-hip ratio (WHR, adjusted for BMI), and mean spherical equivalent (MSE). BMI was divided into fat and fat-free mass and included in multivariable Mendelian randomization (MVMR) to explore the roles of different BMI components in the causal relationship between BMI and MSE. A mediation analysis based on two-step Mendelian randomization (MR) was carried out. Specifically, UVMR was conducted to estimate the causal effect of BMI on EA. The direct effect of EA on MSE was estimated from MVMR. The mediation effect of EA in the BMI-EA-MSE model was calculated by the product of coefficients method. Expression quantitative trait loci (eQTL)-MR, reverse MR, and Linkage Disequilibrium Score Regression (LDSC) were performed to assess the robustness.

Results: Genetically predicted higher BMI had a positive total effect on MSE (βIVW=0.26 D, 95%CI=0.14 to 0.37 D, P<0.001), whereas there was no significant association between height, WHR, and MSE. Fat mass was found to play a significant role in the effect of body mass on MSE (βIVW=0.50 D, 95%CI=0.21 to 0.78 D, P=0.001), but there was no significant association between fat-free mass and MSE. The causal effect of BMI on EA was -0.14 (95%CI=-0.16 to -0.11, P<0.001), and the direct effect of EA on MSE was -0.63 D (95%CI=-0.81 to -0.44 D, P<0.001). The mediating effect of EA in the BMI-EA-MSE model was 0.09 D (95%CI=0.06 to 0.12 D), with a mediation proportion of 33% (95%CI=22.1% to 44.6%). No reverse causal associations were detected except for BMI on EA. The results of eQTL-MR and LDSC were consistent with each MR analysis.

Conclusion: Genetically predicted higher BMI decreases the degree of myopia with a 33% mediation proportion by EA, and fat mass provides a dominant protective role in body mass-myopia. As a supplement to previous observational studies, it provides strong evidence for the relationship between anthropometric traits and refractive errors and offers a theoretical basis for future measures to prevent and control myopia.

Aim: To investigate the role of transmembrane protein 206 (TMEM206) in corneal edema in mice by knockout the TMEM206 gene using CRISPR/Cas9 editing technology.

Methods: TMEM206-knockout mice were generated using the CRISPR-Cas9 system. Variations in ophthalmic pathology were observed using slit lamp microscope and optical coherence tomography (OCT), intraocular pressure (IOP) was measured using a TonoLab Rebound Tonometer, and the ultrastructure of the corneal was observed using a transmission electron microscope.

Results: Corneal opacity was observed in 4/18 homozygous TMEM206^-/- mice whereas a similar change was not observed in heterozygous TMEM206^+/- mice and wild-type littermates. OCT examination showed that the mean central cornea thickness was 125±5.4 µm in 4 homozygous TMEM206^-/- mice developed corneal edema and 115±1.2 µm in wild-type mice (t=3.468, P<0.05) at 43wk. The mean IOP was 12.08±0.07 mm Hg in four right eyes with corneal edema and 12.03±0.03 mm Hg in three normal left eyes (P>0.05). Transmission electron microscopy revealed a disruption in the organization of the collagen fibrils in the central part of the cornea in homozygous TMEM206^-/- mice.

Conclusion: TMEM206 is associated with corneal edema which caused organizational disruption of collagen fibrils in corneas of mice.

Aim: To compare the safety and clinical outcomes of subconjunctival trypsin and dexamethasone (DEX) injections in the treatment of anterior chamber fibrin exudates in eyes with globe rupture following primary wound repair and vitrectomy.

Methods: A retrospective analysis included 42 males and 10 females (mean age 46.0±6.0y, range 34 to 58y) who underwent primary wound sutures and vitrectomy for globe rupture. Patients with pupil-covered fibrinous exudate or/and membrane in the anterior chamber were treated. On the first postoperative day, subconjunctival injections of either 5000 units (0.4 mL) of trypsin solution (n=25) or 0.5 mL (1 mg) DEX (n=27) were administered to accelerate exudate absorption. Efficacy was assessed by observing break time and partial absorption of the fibrin exudate membrane. Safety and comfort were evaluated by monitoring intraocular pressure (IOP), allergy, pain, and foreign body sensation.

Results: Both groups achieved 1/3 absorption of the anterior chamber fibrin exudate membrane, but the trypsin group exhibited shorter break time and partial absorption time compared to the DEX group (P<0.05). Trypsin treatment was also less irritating to patients. No adverse reactions were reported, and IOP remained stable. Visual acuity improved in both groups without statistical difference.

Conclusion: Compared to DEX, trypsin demonstrates a shorter absorption time for the fibrin exudate membrane with a more comfortable process in treating pupil-covered fibrinous exudate or/and membrane after vitrectomy for globe rupture.

Aim: To conduct a bibliometric analysis of studies on microphthalmos and anophthalmos (M/A), explore research hotspots, and provide information on future research interests in this field to benefit clinicians and researchers.

Methods: Totally 751 publications related to M/A from the year 2004 to 2023 were collected from the Web of Science Core Collection database. These publications consist of both original and review articles, that are composed in English. The contributions of different countries, institutions, journals, and authors were analyzed, and network analysis was conducted by using Microsoft Excel 2021, VOSviewer, and R Studio to visualize research hotspots.

Results: Among all publications included, the highest number of publications came from USA (218, 29.03%). China followed with 99 publications (13.18%), and England with 86 publications (11.45%). The publications from the USA had the highest frequency of citations, with 16 699 citations, and the highest H-index of 49. The American Journal of Medical Genetics Part A (43, 5.73%) published the largest number of papers, and the University of London had the most publications (41, 5.46%). The genetic and molecular mechanisms of M/A were still unclear and the clinical intervention for M/A had gained a lot of attention as an emerging area of interest.

Conclusion: Data have been gathered on the yearly count of published materials and citations, as well as the rise in publication trends, the efficiency of regions or countries, authors, journals, and organizations, along with the high-cited publications in M/A. The recent trend of research has shifted from genetic mechanisms to different clinical phenotypes and corresponding clinical interventions, which can give direction to future research.

Aim: To investigate the causal effect of inflammatory bowel disease (IBD) on ocular inflammation using Mendelian randomization (MR) analysis.

Methods: Genetic instruments associated with inflammatory bowel disease (IBD), ulcerative colitis (UC), and Crohn's disease (CD) were derived from the largest genome-wide association studies (GWAS) published to date. The FinnGen research project was utilized to identify genetic risk variants associated with conjunctivitis, keratitis, iridocyclitis, chorioretinitis, episcleritis, and optic neuritis. All participants were of European ancestry. Three methods which included inverse variance weighting (IVW), weighted median (WM), and MR-Egger regression were performed to estimate the causal association in this study. IVW took the inverse variance of each study as the weight to calculate the weighted average of effect sizes, to summarize the effect sizes of multiple independent studies, which could provide the most precise estimated results. IVW was used as the primary outcome, while WM and MR-Egger were used to improve the estimation of IVW.

Results: A nominal causal effect of genetically predicted IBD on risk of non-infectious conjunctivitis, keratitis, iridocyclitis, and optic neuritis, but not on chorioretinitis or episcleritis. After Bonferroni correction, the results showed that genetically predicted UC was significantly associated with an increased risk of iridocyclitis (IVW: OR, 1.17; 95%CI, 1.10-1.24, P=2.54×10^-7). CD was significantly associated with conjunctivitis (IVW: OR, 1.05; 95%CI, 1.03-1.08, P=3.20×10^-5), keratitis (IVW: OR, 1.06; 95%CI, 1.02-1.09; P=1.13×10^-3), and iridocyclitis (IVW: OR, 1.09; 95%CI, 1.04-1.14; P=1.43×10^-4).

Conclusion: IBD causally poses a risk of inflammation of conjunctiva, cornea, Iris-ciliary body complex, and optic neuritis. CD is more closely associated with the eye inflammation than UC. These impliy that the relationship of IBD and different parts of the eye structure are different, and provide novel evidence linking based on the association of the gut-eye axis.

Aim: To understand the current situation of parental perspectives, knowledge, and practices concerning myopia prevention and control for both pre- and school-aged children.

Methods: This study was a cross-sectional survey that involved children aged 0 to 15y and their parents. Participants were required to respond to an online questionnaire by scanning a quick response (QR) code. The questionnaire consisted of 25 tick-box questions and was open to response from December 22, 2022, to January 5, 2023. The dioptric traits of the children, the visual status and educational background of the parents, the parental perspectives towards myopia and its risks, and the parents' knowledge and practices related to myopia prevention and control were recorded and measured. The Chi-square test and binomial logistic regression were used for statistics.

Results: Totally 350 parents responded to the questionnaire. The prevalence and severity of myopia among the surveyed children exhibited a positive correlation with advancing age (P<0.001 and P=0.004, respectively). Nearly half of parents with myopic children considered myopia did not pose any health threat and could be effectively corrected (P<0.001). Parents who held master's or doctoral degree demonstrated a better understanding of children's vision standards for each age group (P=0.001), and 31.63% of them could undergo initial vision screening for their children during the age of 0 to 3y while parents with bachelor's degree (34.04%) and below (32.43%) mainly initiated the vision examination for their children at the age of 4 to 6y (P=0.05). Parents with master's or doctoral degree also exhibited more rational practices concerning outdoor time (P=0.048) and sleep time (P=0.044). No other significant discrepancy among the different educational groups in additional conceptions of myopia, such as hyperopia reserve, axis length, and corneal curvature alterations. Most parents preferred to employ conventional interventions, such as enhancing indoor lighting condition (80.00%) and ensuring appropriate reading posture and distance (71.71%).

Conclusion: The current status of parental knowledge and practices about myopia prevention and control remains outdated and deficient. The administrative department should implement efficacious and adaptable measures to enhance parental awareness and foster their commitment towards myopia prevention and control.

Aim: To compare relative peripheral refractive errors (RPREs) in Chinese children with and without myopic anisometropia (MAI) and to explore the relationship between RPRE and myopia.

Methods: This observational cross-sectional study included 160 children divided into two groups according to the interocular spherical equivalent refraction (SER) difference ≥1.0 D in the MAI group (n=80) and <1.0 D in the non-MAI group (n=80). The MAI group was further divided into two subgroups: ∆SER<2.0 D group and ∆SER≥2.0 D group. Basic ocular biometric parameters of axial length (AL), average keratometry (Ave K), cylinder (CYL), surface regularity index (SRI), and surface asymmetry index (SAI) were recorded. In addition, multispectral refraction topography was performed to measure RPRE, and the parameters were recorded as total refraction difference value (TRDV), refraction difference value (RDV) 0-10, RDV10-20, RDV20-30, RDV30-40, RDV40-53, RDV-superior (RDV-S), RDV-inferior (RDV-I), RDV-temporal (RDV-T) and RDV-nasal (RDV-N).

Results: In the non-MAI group, the interocular differences of all parameters of RPRE were not significant. In the MAI group, the interocular differences of TRDV, RDV10-53, RDV-S, RDV-I, RDV-T, and RDV-N were significant. In subgroup analysis, the interocular differences of TRDV, RDV30-53, RDV-I, and RDV-T were significant in ∆SER<2.0 D group and ∆SER≥2.0 D group, but the interocular differences of RDV10-30, RDV-S and RDV-N were only significant in the ∆SER≥2.0 D group. In correlation analysis, ∆TRDV, ∆RDV 10-53, ∆RDV-S, and ∆RDV-N were negatively correlated with ∆SER but positively correlated with ∆AL.

Conclusion: The more myopic eyes have larger hyperopic RPRE in Chinese children with MAI in certain retinal range, and partial ∆RPRE is closely associated with ∆SER and ∆AL.