International journal of ophthalmology最新文献

Aim: To characterize the N⁶-methyladenosine (m⁶A) modification patterns in long non-coding RNAs (lncRNAs) in sporadic congenital cataract (CC) and age-related cataract (ARC).

Methods: Anterior capsule of the lens were collected from patients with CC and ARC. Methylated RNA immunoprecipitation with next-generation sequencing and RNA sequencing were performed to identify m⁶A-tagged lncRNAs and lncRNAs expression. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses and Gene Ontology annotation were used to predict potential functions of the m⁶A-lncRNAs.

Results: Large amount of m⁶A peaks within lncRNA were identified for both CC and ARC, while the level was much higher in ARC (49 870 peaks) than that in CC (18 688 peaks), yet those difference between ARC in younger age group (ARC-1) and ARC in elder age group (ARC-2) was quite slight. A total of 1305 hypermethylated and 1178 hypomethylated lncRNAs, as well as 182 differential expressed lncRNAs were exhibited in ARC compared with CC. On the other hand, 5893 hypermethylated and 5213 hypomethylated lncRNAs, as well as 155 significantly altered lncRNA were identified in ARC-2 compared with ARC-1. Altered lncRNAs in ARC were mainly associated with the organization and biogenesis of intracellular organelles, as well as nucleotide excision repair.

Conclusion: Our results for the first time present an overview of the m⁶A methylomes of lncRNA in CC and ARC, providing a solid basis and uncovering a new insight to reveal the potential pathogenic mechanism of CC and ARC.

Myopia is a huge health problem due to its high frequency, vision losses and public health cost. According to the World Health Organization, at least 2.2 billion people have vision impairment. Although myopia can be controlled at its early and middle stages, unfortunately, no cure can be achieved so far. Among the methods to control myopia, atropine, a muscarinic receptor antagonist, is the oldest but still the most effective for retardation of myopia progression. Despite such a fact, standard protocols have not been established for clinicians to use atropine for treatment of myopia. In this article, a concise and up to date summary of myopia epidemiology and pathogenesis and summarized therapeutic effects and side effects, possible mechanisms and application methods of atropine were provided in hope for clinical doctors to effectively control this problematic disease. At present, the protocol is recommend: use higher dose (1%) of atropine intermittently to effectively slowdown myopia progression in schoolchildren for 2y, and to significantly reduce side effects of atropine by decrease of atropine frequency for 1y and inhibit myopic rebound by withdrawal of topical atropine gradually for 1y. Application of a lower dose (0.05%) atropine regime should also be considered due to its effectiveness and application at regular basis.

[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.