Background/Objectives: In this study, we aimed to analyze the changes in the expression profiles of selected messenger RNAs (mRNAs) and their encoded proteins in the tears of patients undergoing photorefractive keratectomy (PRK), femtosecond-assisted laser in situ keratomileusis (FS-LASIK), and small-incision lenticule extraction (SMILE) procedures. Methods: A total of 120 patients were divided into three groups based on the laser vision correction (LVC) procedure: PRK, FS-LASIK, or SMILE. Tear samples were collected preoperatively and at 1, 7, 30, and 180 days postoperatively. The expression levels of selected messenger RNAs (mRNAs) and proteins were analyzed by using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Results: PRK and FS-LASIK elicited significantly stronger biological responses than SMILE. Interleukin-15 (IL-15) expression increased notably in the PRK and FS-LASIK groups, with mRNA levels reaching fold changes of 4.65 ± 0.65 and 4.99 ± 0.28, respectively, on day 1, compared with only 2.09 ± 0.23 in the SMILE group. Vascular endothelial growth factor A (VEGFA) levels were also elevated in the PRK (2.98 ± 0.23 fold change) and FS-LASIK groups (3.45 ± 1.09 fold change) on day 1, while the SMILE group showed minimal fluctuations. The protein concentration analysis based on the ELISA confirmed these trends, with IL-15 levels peaking at 54.2 ± 2.5 pg/mL in the PRK group and 52.8 ± 3.1 pg/mL in the FS-LASIK group, compared with 32.4 ± 1.9 pg/mL in the SMILE group on day 1. Similarly, VEGFA protein concentrations were the highest in the PRK (72.4 ± 4.1 pg/mL) and FS-LASIK patients (69.5 ± 3.8 pg/mL) on day 1 but remained low in the SMILE patients (45.6 ± 2.3 pg/mL). By day 180, gene expression and protein levels in all groups had stabilized, returning to near-preoperative values. Conclusions: PRK and FS-LASIK induced more pronounced molecular and protein-level changes during corneal wound healing than the less invasive SMILE procedure, indicating stronger biological responses. These findings suggest that tailored postoperative care based on the specific procedure could optimize healing and patient outcomes. However, further research with larger sample sizes and longer follow-ups is needed to confirm these observations and develop personalized treatment strategies.

Human retinal pigment epithelial (H-RPE) cells contribute to the pathogenesis of proliferative vitreoretinopathy (PVR) by undergoing inflammatory activation and fibrotic transformation. The PI3K/AKT/mTOR signaling pathway plays a central role in this process, integrating extracellular cues that promote survival, proliferation, and matrix remodeling. Tacrolimus, a calcineurin inhibitor with emerging antifibrotic properties, may modulate these responses at both transcriptional and post-transcriptional levels. H-RPE cells were treated with lipopolysaccharide (LPS), tacrolimus, or their combination to simulate inflammatory and immunosuppressive conditions. Transcriptomic profiling was performed using microarrays, followed by RT-qPCR and ELISA validation of selected targets. A parallel analysis of microRNAs (miRNAs) was conducted to assess potential regulatory interactions. Protein–protein interaction (PPI) networks were generated using the STRING database. Microarray analysis identified 38 PI3K/AKT/mTOR-associated mRNAs with significant differential expression (|FC| > 4.0, p < 0.05), including CDK2, PIK3CA, STAT3, MTOR, and COL1A1. LPS treatment led to strong upregulation of inflammatory and fibrotic genes, while tacrolimus reversed or attenuated many of these effects. miRNA profiling revealed inverse regulation of several transcripts by hsa-miR-27a-5p, miR-29a-3p, and miR-1271-5p. Protein measurements confirmed these trends, and STRING analysis highlighted a densely connected network with central nodes including JAK1, EGFR, and MTOR. This study supports the therapeutic potential of tacrolimus in retinal fibrosis by demonstrating its ability to modulate the PI3K/AKT/mTOR–miRNA axis in inflamed H-RPE cells, suppress key fibrotic and proliferative genes, and restore regulatory microRNA expression, offering a promising strategy for controlling H-RPE-driven remodeling PVR.

Background/Objectives: Keratoconus (KC) is a bilateral eye disease characterized by corneal thinning and cone-like deformation, leading to visual impairment. This study evaluated the radial peripapillary capillaries (RPCs) in keratoconus patients with and without penetrating keratoplasty (PKP) using OCT and angio-OCT, comparing the results to a control group. Methods: This retrospective study included 149 eyes, 97 from patients who underwent PKP between January 2018 and February 2023 and 52 from patients who did not undergo PKP. The control group comprised 72 patients (144 eyes) who were healthy volunteers. Measurements included the best corrected visual acuity (BCVA), the intraocular pressure (IOP), slit-lamp biomicroscopy, a fundus examination, and corneal topography, as well as OCT and angio-OCT assessments of the RPCs, retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), and central retinal thickness (CRT). Statistical analyses were performed using Student’s t-test and Pearson’s correlation coefficient. Results: The RNFL was significantly thinner in KC eyes after PKP compared to control eyes (p < 0.001), and the CRT was significantly thicker in KC eyes after PKP compared to control eyes (p = 0.003). However, the GCC was similar across the groups (p = 0.0885). Additionally, RPCs inside the disc were significantly reduced in KC eyes after PKP compared to control eyes (p < 0.0001). A significant positive correlation was found between RPC whole vessel density and RNFL thickness as measured via angio-OCT (r = 0.308, p < 0.0001). Conclusions: This study found that the RPC density inside the disc is significantly reduced in keratoconus patients after penetrating keratoplasty, highlighting RPCs inside the disc as a potential diagnostic tool for further assessment of keratoconus.

The retinal pigment epithelium (RPE) plays a crucial role in maintaining retinal homeostasis, and dysregulation of the transforming growth factor-beta (TGF-β) signaling pathways contributes to retinal fibrosis and inflammatory diseases, including proliferative vitreoretinopathy (PVR). Tacrolimus (FK506), an immunosuppressant, has shown potential antifibrotic properties, but its effects on TGF-β-related genes and microRNAs (miRNAs) in RPE cells remain unclear. Human RPE (H-RPE) cells were treated with lipopolysaccharide (LPS) to induce inflammation and subsequently exposed to tacrolimus. Gene and miRNA expression profiling related to TGF-β signaling pathways were conducted using microarrays, followed by Quantitative Reverse-Transcription Polymerase Chain Reaction (RT-qPCR) validation. Protein levels were assessed via enzyme-linked immunosorbent assay (ELISA), and interactions were analyzed using STRING database network analysis. Tacrolimus modulated key components of the TGF-β pathway, upregulating TGF-β2, TGF-β3, SMAD2, and SMAD4 while downregulating TGF-βR1 and SMAD7. JAK/STAT and MAPK pathways were also affected, indicating broad regulatory effects. miRNA profiling identified hsa-miR-200a-3p, hsa-miR-589-3p, hsa-miR-21, and hsa-miR-27a-5p as key regulators. STRING analysis confirmed strong functional interactions within the TGF-β network. In conclusion, tacrolimus modulates both canonical (upregulation of SMAD2/4 and downregulation of SMAD7) and non-canonical (JAK/STAT and MAPK) TGF-β signaling pathways in LPS-stimulated RPE cells. These changes collectively suggest a dual anti-inflammatory and anti-fibrotic effect. The increased TGF-β2 and decreased SMAD7 levels, alongside altered miRNA expression (e.g., downregulation of miR-200a-3p), indicate that tacrolimus may inhibit key profibrotic mechanisms underlying PVR. These findings support the potential therapeutic repurposing of tacrolimus in PVR and warrant further in vivo validation.

Background: The retinal pigment epithelium (RPE) is central to retinal health and immune regulation. In diseases, such as proliferative vitreoretinopathy (PVR), dysregulated RPE function, driven by aberrant signaling pathways like mitogen‐activated protein kinase (MAPK), contributes to fibrotic membrane formation and retinal detachment. Tacrolimus, an immunosuppressive agent, has shown potential to modulate signaling beyond immune cells, but its effect on MAPK signaling in RPE cells remains unclear. This study aimed to investigate the impact of tacrolimus on MAPK pathway gene expression and microRNA (miRNA)‐mediated regulation in human RPE (H‐RPE) cells under inflammatory conditions induced by lipopolysaccharide (LPS). Methods: H‐RPE cells were treated with LPS and tacrolimus, and cell viability was evaluated by 3‐ (4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay. Transcriptomic profiling of 300 MAPK‐related genes and corresponding miRNAs was performed using Affymetrix microarrays. Key targets were validated via quantitative reverse‐transcription polymerase chain reaction (RT‐qPCR) and enzyme‐linked immunosorbent assay (ELISA). Gene interaction networks were analyzed with STRING. Results: LPS significantly suppressed MAPK pathway gene and protein expression, including transforming growth factor beta 1 (TGF‐β‐1), mitogen‐activated protein kinase kinase 7 (MAP2K7), mitogen‐activated protein kinase 3 (MAPK3), and dual specificity phosphatase 4 (DUSP4). Tacrolimus reversed these effects in a time‐dependent manner, restoring expression levels and modulating regulatory miRNAs (e.g., miR‐3196, miR‐27a/b‐3p, miR‐190a‐3p, miR‐149‐3p). STRING analysis revealed a highly connected protein network, with MAPK3, MAPK8, and TRAF6 acting as central nodes. Conclusion: Tacrolimus modulates MAPK signaling in H‐RPE cells by reversing LPS‐induced suppression and regulating specific miRNAs. These findings suggest a potential therapeutic role for tacrolimus in mitigating inflammatory and fibrotic responses associated with PVR.