In vivo confocal microscopy of sub-basal corneal nerves and corneal densitometry after three kinds of refractive procedures for high myopia.

PURPOSE: To observe corneal nerve fibers and densitometry after small incision lenticule extraction (SMILE), femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) and laser-assisted subepithelial keratomileusis (LASEK) for high myopia. METHODS: This is a prospective, cross-sectional research study. Patients with high myopia (equivalent spherical lens: -6.00 and -11.00D) who underwent laser corneal refractive surgery were divided into three groups: SMILE, FS-LASIK and LASEK. Scheimpflug imaging of corneal nerves in five areas was observed by confocal microscopy before and 6, 12 months after surgery. Corneal densitometry was measured by Pentacam anterior segment analysis system. RESULTS: Overall, 59 patients were enrolled. The nerve density in the central area did not recover to the preoperative level in three groups until 12 months. The density and length of corneal nerves in central and lower area were better in the SMILE group 6 months postoperatively (p = 0.01), while nerve density did not differ significantly among three groups 12 months postoperatively (p = 0.18). Nerve fibers in central and temporal region were wider in LASEK than that in other two groups at 6- and 12-month follow-up. Corneal densitometry in the central 6 mm diameter was significantly higher in the LASEK group compared with other two groups 6 months postoperatively (p = 0.04). Twelve months postoperatively, corneal densitometry in range of all zone was lower in SMILE than in FS-LASIK and LASEK (p = 0.01, 0.03, 0.04). CONCLUSIONS: Compared with FS-LASIK and LASEK, SMILE-treated eyes with high myopia had certain advantages in nerve density, length and nerve connection way and had better corneal transparency after operation.

Artisan versus Artiflex phakic intraocular lens implantation in the treatment of moderate to high myopia: meta-analysis.

BACKGROUND: To compare the postoperative safety, efficacy, predictability, visual quality and biomechanics after implantation of Artisan vs. Artiflex phakic intraocular lenses (PIOLs). METHODS: Pubmed, Embase, Cochrane Library were conducted up from January 2000 to February 2020. Comparative clinical studies reporting in accordance with the eligibility criteria were included in this meta-analysis. The pooled weighted mean differences (WMDs) and odds ratios (ORs) with corresponding 95% confidence intervals were calculated. RESULTS: Comparative trials with myopia patients were selected in this review. The pooled WMD and OR estimates statistical significance in terms of postoperative best corrected visual acuity (BCVA), efficacy, postoperative spherical equivalence (SE), predictability, contrast sensitivity and mean intraocular higher-order aberrations (HOA) (mm) for a 6-mm pupil, manifesting that Artiflex PIOL showed evident beneficial effect for correcting myopia compared to Artisan PIOL. There was no significant difference in the incidence of complications between the two groups. CONCLUSION: Both of two techniques were safe and effective for myopia and compared to Artisan PIOL, Artiflex PIOL had significant improvement in efficacy, predictability, contrast sensitivityand HOA, except safety and complications in the treatment of moderate to high myopia.

The effect of astaxanthin on inflammation in hyperosmolarity of experimental dry eye model in vitro and in vivo.

Hyperosmolarity is pro-inflammatory stress to the ocular surface epithelium associated with dry eye disease (DED). Astaxanthin (AST) is a kind of carotene, which exists in seafood and plays important roles in the amelioration of inflammatory diseases like arteriosclerosis, inflammatory bowel disease, sepsis, rheumatoid arthritis, gastric inflammation, brain inflammatory diseases. The aim of this study was to characterize the protective effect and potential mechanism of AST on DED in vitro and in vivo. Mouse models and human corneal epithelial cell (HCEC) cultures were exposed to hyperosmotic saline solution (HOSS) in in vitro and in vivo experiments, respectively. Experimental subjects were first pretreated with AST, and then the effect of the compound was assessed with clinical evaluation, real-time PCR (RT-PCR), western blot and immunofluorescent staining. We further investigated the possible mechanism of AST in DED by pre-treating with phosphoinositide 3-kinase inhibitor (LY294002). The addition of AST significantly reduced the expression of High-mobility group box 1 (HMGB1), as well as significantly inhibited the increases of TNF-α, IL-1ß in a dose-dependent manner, but promoted the expression of phospho-Akt (p-Akt). BALB/c mice in DE group pretreated with AST showed significantly decreased corneal fluorescein staining scores. Moreover, pretreatment with LY294002 could eliminate the effects of AST preconditioning on the decrease of HMGB1. Our study provides evidence that AST could ameliorate DED which may be related to the inhibition of HMGB1, TNF-α, IL-1ß, while PI3K/Akt signaling pathway may be involved in the expression of HMGB1 and the protective effect of AST preconditioning.

Changes in Subfoveal Choroidal Thickness after Orthokeratology in Myopic Children: A Systematic Review and Meta-Analysis.

AIMS: This study aimed to synthesize the variations in subfoveal choroidal thickness (SFCT) observed at different follow-up intervals in myopic children undergoing orthokeratology treatment. MATERIALS AND METHODS: Relevant articles were systematically retrieved from databases such as PubMed, EMBASE, Web of Science, and Cochrane Library. The retrieval period extended from the inception of these databases to November 2023. Means and standard deviations (SD) of baseline and post-treatment SFCT were selected as the results for analysis and calculation. RESULTS: A total of eight articles involving 478 eyes fulfilled the inclusion criteria. At 1 month, 3 months, and 6 months intervals, the SFCT demonstrated significant increases by 16.74 µm (95% CI: 8.66, 24.82; p < 0.0001), 13.41 µm (95% CI: 4.36, 22.45; p = 0.004), and 17.57 µm (95% CI: 8.41, 26.73; p = 0.0002), respectively. Besides, children treated with orthokeratology exhibited a notably thicker change of SFCT in comparison with children with single-vision spectacles (SVL) (WMD = 13.50, 95% CI: 11.69, 15.13; p < 0.0001). CONCLUSION: Myopic children undergoing orthokeratology treatment experience a discernible increase in SFCT at 1 month, 3 months, and 6 months. Furthermore, compared to children utilizing SVL, those undergoing orthokeratology manifest a more pronounced thickening of SFCT.

Long Noncoding RNA MIATNB Regulates Hyperosmotic Stress-induced Corneal Epithelial Cell Injury by Inhibiting Autophagy in Dry Eye Disease.

PURPOSE: Dry eye disease (DED) has a complex etiology and the roles of long noncoding RNAs (lncRNAs) in its pathophysiology are not completely understood. Autophagy is a self-eating process important for cell survival and homeostasis. The present study explored the role of myocardial infarction-associated transcript neighbor (MIATNB) long non-coding RNA in hyperosmolarity-induced autophagy and apoptosis in human corneal epithelial cell (HCEC)-based model of dry eye disease. METHODS: In vitro assays were performed with a human SV40 immortalized corneal epithelial cell line. Different concentrations of NaCl were used to create hyperosmolarity. HCECs were cultured in presence of 70-120 mM NaCl for 24 h to create an in vitro model of dry eye. RT-qPCR was performed to assess the expression of dry eye related LC3B, ATG16L, BECN1, ATG1, ATG7, ATG13, ATG5, ATG10, and ATG101 mRNAs and western blot analysis of LC3B and P62 and RFP -GFP-tagged LC3. Flow cytometry and western blot analysis of caspase 3, BCL2 and BAX were performed to detect apoptosis. Chloroquine (CQ) was used to inhibit autophagy pharmacologically. RESULTS: Autophagy flux was activated in HCECs subjected to hyperosmotic stress. Hyperosmolarity activated apoptosis and inhibited HCEC migration and autophagy. Hyperosmolarity upregulated MIATNB expression, while MIATNB knockdown inhibited autophagosome degradation and promoted HCEC apoptosis. Under hyperosmolar conditions, MIATNB knockdown also inhibited the degradation of autophagolysosomes and stimulated HCEC apoptosis. CONCLUSION: MIATNB plays a vital role in dry eye pathogenesis and serves as a bridge between autophagy and apoptosis. Targeting MIATNB for DED treatment should be further evaluated.

Long Noncoding RNA MIAT Regulates Hyperosmotic Stress-Induced Corneal Epithelial Cell Injury via Inhibiting the Caspase-1-Dependent Pyroptosis and Apoptosis in Dry Eye Disease.

Purpose: The biological role and mechanism of long noncoding RNA (lncRNA) myocardial infarction-associated transcript (MIAT) in dry eye remain to be illustrated. Pyroptosis is a noticeable form of inflammatory activation, which is characteristic of gasdermin D (GSDMD)-driven cell death. The present study was designed to explore the role of MIAT in pyroptosis and apoptosis induced by hyperosmolarity stress (HS) in human corneal epithelial cells (HCECs). Methods: HCECs were cultured in 70-120 mM hyperosmotic medium for 24 h to create a dry eye model in vitro. The level of the pyroptosis marker GSDMD was measured, and the cell inflammatory response was evaluated by detecting IL-1ß and IL-18 levels. Exogenous caspase-1 inhibitor Ac-YVAD-CHO was used. The pyroptosis in HCECs was examined by caspase-1 activity, immunofluorescent staining, and Western blotting. Flow cytometry was performed to test the apoptosis rate of HCECs. Cell migration and proliferation were detected. The expression of the lncRNA MIAT in HCECs was detected by quantitative real-time PCR. MIAT was knocked down by small interfering RNA (siRNA) transfection. The effects of caspase-1 inhibition on pyroptosis, apoptosis, migration, and proliferation were observed. Results: HS promoted pyroptosis in HCECs by elevating caspase-1, GSDMD, and the active cleavage of GSDMD (N-terminal domain, N-GSDMD), and increased the release of IL-1ß, IL-18, LDH and the rate of apoptosis, with reduced cell migration. These changes were prevented by the inhibition of caspase-1. The expression of MIAT was significantly increased in HCECs exposed to a hyperosmotic medium. Silencing MIAT increased the expression of GSDMD, caspase-1, and inflammatory chemokines IL-1ß and IL-18, and promoted apoptosis while inhibiting migration and proliferation in HCECs. Conclusion: The lncRNA MIAT is involved in HS-induced pyroptosis and apoptosis and the inflammatory response of HCECs and provides a new understanding of the pathogenesis of dry eye.