Current Eye Research最新文献

Purpose: The study aims to investigate the relationship between pancreatic β-cell function and macular vascular structure and blood flow in patients with type 2 diabetes mellitus (DM) without clinical signs of diabetic retinopathy (DR).

Methods: This prospective cross-sectional study enrolled 121 type 2 DM patients without clinical DR, representing a total of 240 eyes. The area under the C-peptide release curve (AUCC) derived from the oral glucose tolerance test, fasting serum C-peptide level and the updated Homeostasis Model Assessment (HOMA2) model were utilized to reflect pancreatic β-cell function. Insulin resistance (IR) was assessed by HOMA2 model. The macular vascular and blood flow parameters of patients were measured by optical coherence tomography angiography (OCTA). Separate Linear Mixed-Effects Models were employed to analyze the relationship between pancreatic β-cell function indicators and OCTA metrics.

Results: In separate multivariate models, AUCC, fasting serum C-peptide level, and HOMA2 estimates of β-cell function (HOMA2-B) each demonstrated a significant positive association with vessel density (VD) measures in the deep capillary plexus (DCP), including total DCP VD, parafoveal DCP VD, and perifoveal DCP VD.

Conclusions: The impaired pancreatic β-cell function is significantly associated with adverse macular vasculature alterations, suggesting that these vascular changes may occur prior to the clinical manifestation of DR in patients with compromised β-cell function. β-cell function markers might help identify patients at risk of early subclinical retinal microvascular changes.

Purpose: To investigate the causal relationship between age-related macular degeneration (AMD) and inflammatory bowel disease (IBD) by Mendelian randomization (MR) analysis.

Methods: The single nucleotide polymorphism data of IBD and AMD were obtained from the Integrative Epidemiology Unit (IEU) Open genome-wide association study database. MR analysis contained MR-Egger, weighted median, inverse variance weighted, simple mode, and weighted mode. Sensitivity analysis was executed to ensure the reliability of results, containing heterogeneity test, horizontal pleiotropy test, and leave-one-out analysis. Multivariable Mendelian randomization analysis was carried out to investigate potential confounding factors such as C-reactive protein, smoking, vitamin D deficiency. Genes corresponding to the instrumental variables (IVs) and functional enrichment analysis were executed.

Results: MR analysis showed a positive correlation between IBD and AMD (P < 0.05, OR > 1). Sensitivity analyses also did not reveal heterogeneity and horizontal pleiotropy. C-reactive protein, smoking, and vitamin D deficiency had no significant effect on AMD (P > 0.05). Genes corresponding to IVs were mainly associated with monocyte differentiation, cytokine receptor activity, etc., and act on signaling pathways such as Th17 cell differentiation, and there was a complex network of molecular-cell regulation.

Conclusion: Our study explored and demonstrated the causal relationship between IBD and AMD through MR analysis, which provided an important reference and direction for future research and treatment related to AMD.

Purpose: Primary open-angle glaucoma is characterized by trabecular meshwork cell injury and excessive extracellular matrix deposition. Given the established involvement of long non-coding RNAs in primary open-angle glaucoma pathogenesis, this study investigates the role and mechanism of long non-coding RNA H19 in mediating trabecular meshwork cell dysfunction and extracellular matrix production.

Methods: Hydrogen peroxide-treated human trabecular meshwork cells were used to establish in vitro primary open-angle glaucoma models. Cell viability and apoptosis were assessed via cell counting kit-8 and flow cytometry. Gene/protein expression of H19, Smad4, and extracellular matrix components (fibronectin, collagen I, and laminin) was evaluated by real-time quantitative polymerase chain reaction, Western blotting, and immunofluorescence. Subcellular H19 localization was determined by nuclear-cytoplasmic fractionation. The H19-miR-20a-5p-Smad4 regulatory axis was validated through luciferase reporter assays and rescue experiments across three characterized human trabecular meshwork cell strains.

Results: Hydrogen peroxide exposure induced concentration-dependent human trabecular meshwork cell injury and significantly upregulated H19 and Smad4 expression (p < 0.001). H19 knockdown attenuated oxidative damage, restoring viability (p < 0.001), reducing apoptosis (p < 0.001), and suppressing extracellular matrix deposition (p < 0.001). Mechanistically, H19 functioned as a competing endogenous RNA by binding miR-20a-5p, which targeted Smad4. Smad4 overexpression or miR-20a-5p inhibition abrogated H19 deficiency-mediated protection. Notably, H19 knockdown also reduced transforming growth factor-beta/Smad signaling (p < 0.001) while enhancing nuclear factor erythroid 2-related factor 2/heme oxygenase-1 antioxidant responses (p < 0.001).

Conclusion: Long non-coding RNA H19 facilitates hydrogen peroxide-induced human trabecular meshwork cell injury and extracellular matrix deposition primarily by orchestrating the miR-20a-5p/Smad4 axis, with additional modulation of transforming growth factor-beta/Smad and nuclear factor erythroid 2-related factor 2 pathways.

Purpose: To evaluate the therapeutic effects of bakuchiol on clinical and histopathological outcomes in a rat model of corneal alkali burn.

Methods: Corneal alkali burns were induced in the right eyes of 35 male Wistar rats, which were randomized into five groups: control, carbomer, steroid, 0.14 mg/g bakuchiol, and 0.28 mg/g bakuchiol. Examinations were performed under stereomicroscopy with intraperitoneal ketamine anesthesia on days 0, 3, 7, and 14 to assess corneal epithelial defects and opacity; on day 14, corneal neovascularization was additionally evaluated. After the final examination, the eyes were enucleated, and the corneas were processed for hematoxylin-eosin and immunohistochemical staining. Epithelial necrosis, inflammatory cell density, corneal hemorrhage, stromal edema, and staining intensity for VEGF and TNF-α were semi-quantitatively scored.

Results: Bakuchiol treatment, particularly at 0.28 mg/g, significantly reduced corneal opacity, neovascularization, hemorrhage, and stromal edema compared with the steroid-treated group.

Conclusions: Bakuchiol demonstrated promising anti-inflammatory and anti-angiogenic effects and may represent a potential adjunctive treatment for corneal chemical injuries.

Purpose: When examining the ocular surface, patients are required to look straight ahead and the effects of vertical eye movement on tear film behavior are not considered despite it being natural and common to change gaze without blinking. This exposes parts of the bulbar conjunctiva previously covered by the eyelids and therefore not covered by the tear film during the preceding blink. This study investigates how the tear film behaves when presented with newly exposed areas of ocular surface due to vertical eye movements.

Methods: The tear film dynamics of a sequence of vertical open-eye gaze maneuvers (upgaze-downgaze) were studied in 15 participants with no ocular surface related complaints (OSDI <13) using the TearView infrared camera system. TearView detects the tear film based on natural infrared radiation emitted from the ocular surface. Interferometry was used to examine lipid layer behavior. In a subgroup (n = 3), eyelids were mechanically lifted using a finger to reveal bulbar conjunctiva.

Results: Vertical eye movements exposed bulbar conjunctiva not covered by the tear film during the preceding blink. The fully formed tear film reacted by spreading toward the newly uncovered ocular surface area, thereby recoating it. This also occurred when the eyelids were mechanically lifted to reveal ocular surface previously beneath the eyelids. No apparent flow occurred from the menisci onto the ocular surface.

Conclusions: The fully formed tear film is isolated from the meniscal tear and meibum reservoirs (a completely perched tear film). This tear film spontaneously spreads to cover ocular surface area that is newly exposed during vertical eye movements.

Purpose: Acanthamoeba keratitis (AK) is a sight threatening infection of the cornea caused by opportunistic pathogens belonging to the genus Acanthamoeba. AK is commonly associated with contact lens use, and treatments are currently limited and ineffective. As such, the emergence of antimicrobial resistance in Acanthamoeba poses a significant challenge to the management of AK. This study investigates the development of polyhexamethylene biguanide (PHMB) resistance, a frontline therapeutic, in Acanthamoeba trophozoites and explores potential cross-resistance to hexamidine and voriconazole.

Methods: Acanthamoeba castellanii trophozoites were exposed and maintained in PHMB starting at 2 µg/mL and increasing upon reaching confluence. Cells were subsequently exposed to incrementally higher doses of PHMB in a stepwise manner (2, 4, 5.5, and 7 µg/mL). When sustained growth under PHMB exposure was observed, morphology was assessed by imaging flow cytometry and susceptibility assays were performed by incubating resistant strains with PHMB, hexamidine, and voriconazole for 24 h, and viability determined using alamarBlue.

Results: Trophozoites surviving exposure at 2 µg/mL reached confluence within 11 days. Stepwise increases to 4 µg/mL, 5.5 µg/mL, and 7 µg/mL were achieved within 6-7 days at each stage. PHMB-resistant Acanthamoeba strains exhibited a 9-fold increase in resistance to PHMB relative to naïve cells, alongside significant cross-resistance to voriconazole (159-fold) and hexamidine (8.4-fold). No significant change in trophozoite or cyst morphology was observed relative to the naïve cell line.

Conclusions: These findings represent the first known laboratory-induced PHMB-resistant Acanthamoeba strains, raising concerns regarding the longevity of current therapeutic options and the potential for cross-resistance to alternative treatments. This highlights the need for clinical vigilance and further investigation into the molecular mechanisms of resistance to better inform treatment strategies.

Purpose: Retinopathy of prematurity is a leading cause of childhood blindness, with several predisposing factors, including prematurity and oxygen therapy. This study examines nucleated red blood cell (NRBC) counts at birth in preterm neonates and compares those who developed ROP with those who did not.

Methods: This case-control study included 143 preterm neonates (birth weight <1500 g and/or gestational age <32 weeks) born at Ghaem Hospital, Mashhad, between 2017 and 2020. Umbilical cord blood samples were collected to measure NRBC counts per 100 white blood cells. Neonatal characteristics (birth weight, sex, gestational age, Apgar scores), maternal history (age, pregnancy complications, mode of delivery, parity), and laboratory findings were recorded. Follow-up assessments continued until discharge, with ophthalmologic evaluation for ROP at 32 weeks of gestational age or four weeks post-birth. The control group consisted of preterm neonates without ROP.

Results: Among the 143 neonates studied, 102 (71.3%) developed ROP, while 41 (28.7%) did not. Significant differences were observed between the two groups in NRBC percentage (p = 0.009) and fifth-minute Apgar score (p = 0.002).

Conclusions: Elevated umbilical cord NRBC counts, alongside other clinical markers, may serve as a predictive factor for ROP and its severity.

Purpose: To systematically explore the multi-dimensional mechanisms of the epigenetic regulatory network in uveitis, address the challenges faced by traditional treatments, and provide new ideas and directions for the precise diagnosis and treatment of this disease.

Methods: A systematic review was conducted on the epigenetic regulation in uveitis, focusing on analyzing abnormal DNA methylation, dynamic balance of histone modifications, disease-specific regulatory characteristics of non-coding RNAs, as well as their applications in diagnosis, prognosis assessment, and targeted treatment strategies.

Results: The epigenetic regulatory network in uveitis includes abnormal DNA methylation driving immune imbalance, histone modification dynamics regulating inflammatory signal amplification, and disease-specific non-coding RNAs. Epigenetics shows value in uveitis diagnosis, prognosis, and targeted treatments, with relevant scientific challenges analyzed.

Conclusion: This review clarifies the roles of epigenetics in uveitis, offering new insights for precise diagnosis and treatment, which is conducive to advancing research and clinical practice in the field.

Purpose: To evaluate the safety, efficacy, predictability, and stability of phakic refractive lens (PRL) implantation for the correction of super-high myopia.

Methods: This four-center prospective clinical study included 30 eyes from 16 myopic patients who underwent PRL implantation. The patients were followed up for one year, with evaluations of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refraction, intraocular pressure (IOP), vault, endothelial cell density (ECD), and axial length.

Results: One year postoperatively, eight eyes (27%) achieved a UDVA of 20/20 or better, and 21 eyes (70%) achieved a UDVA of 20/25 or better. The CDVA improved by one line in 22 eyes (73%), with one eye experiencing a loss of CDVA. The mean efficacy and safety index at one year were 1.30 ± 0.49 and 1.61 ± 0.32, respectively. No significant change was observed in the mean refractive spherical equivalent between one week and one year postoperatively. The axial length remained stable pre- and postoperatively. IOP increased significantly at 1 d and 1 week postoperatively (p = 0.002 and p < 0.001, respectively) but returned to preoperative levels by 1 month. ECD showed no significant change pre- and postoperatively except that 5 eyes from 4 patients had a postoperative ECD below 2000 cells/mm² caused by surgical trauma. The mean vault was 393.05 ± 243.54 µm at one week and 385.68 ± 157.41 µm at one year, showing no significant change.

Conclusion: PRL implantation for correction of super-high myopia demonstrated good safety, efficacy, predictability, and stability.