Search Results (576)

Transepithelial photorefractive keratectomy (Trans-PRK) offers superior re-epithelialization and visual recovery. This study evaluates the impact of preoperative refractive status on clinical outcomes and identifies prognostic factors across varying myopic severities. This retrospective observational study included 125 eyes [64 patients; age > 20 years; best-corrected visual acuity (BCVA) ≥ 20/25] that underwent Trans-PRK between March and December 2022. Patients were stratified into low myopia (LM: > −5.0 D), moderate-to-high myopia (MHM: −5.0 D to −8.0 D), and extremely high myopia (EHM: ≤ −8.0 D) groups. Analysis focused on preoperative refraction, intraoperative parameters, postoperative uncorrected visual acuity (UCVA), and corneal conditions of superficial punctate keratitis (SPKs) and haze. The mean age was 30.20 ± 6.34 years, with a mean initial manifest sphere (MS) of −6.42 ± 2.27 diopter (D) overall and −3.73 ± 0.15 D, −6.28 ± 0.13 D, and −9.17 ± 0.15 D in the LM, MHM, and EHM groups, respectively. At a mean follow-up of 6.69 ± 3.73 months, the overall mean final manifest spherical equivalent (MSE) was −0.12 ± 0.73 D, and the mean final UCVA was 0.01 [Snellen equivalent (SE), 205/200] ± 0.08 logMAR. Predictability was 94.4%, 88.88%, and 94.3% for the final MS ≤ −1.0 D, final MSE ≤ −1.0 D, and UCVA 0.8, respectively. In the LM and MHM groups, cycloplegic and subjective refractions showed the highest concordance with emmetropia, whereas initial manifest refractions were most accurate for the EHM group. Corneal SPK incidence declined from 32.2% (1 month) to 1.6% (6 months), primarily localized to EHM eyes. Corneal haze peaked at 28.2% at three months before receding to 9.4% by 6 months. Refractive and visual stability were achieved by the third month for the LM and MHM groups, whereas the EHM group (mean MSE: −9.59 ± 0.15 D) required six months to reach both refractive and visual plateaus. Despite transiently higher rates of corneal SPKs and haze in EHM eyes, final visual outcomes remained excellent, achieving a mean UCVA of 18/20. Full article

Purpose: To report intraoperative safety and postoperative complications after small-incision lenticule extraction using the 2 MHz femtosecond platform (SMILE Pro; VisuMax 800) in routine practice. Methods: Retrospective consecutive case series at a single center. All planned SMILE Pro procedures were analyzed (916 eyes from 482 patients). Outcomes included completion rate, intraoperative events, postoperative complications stratified as <3 and >3 months, and retreatment rate. Results: Baseline age was 32.9 ± 6.9 years; average preoperative refraction was −3.60 ± 1.90/−0.87 ± 0.76 D (sphere/cylinder) with best corrected visual acuity of −0.08 ± 0.07 logMAR. Procedures were completed in 911 of 916 eyes (99.45%). Suction loss occurred in six eyes (0.66%); one was completed after redocking, four were converted (two ICL, two femtosecond LASIK) and one did not receive a second procedure. No failed lenticule separations occurred. Retreatment was performed in 14 eyes (1.54%): 11 re-LASIK, 2 ICL, and 1 cataract extraction. Early postoperative events (<3 months) were mainly superficial punctate keratitis (3.51%) and dry eye (1.32%); beyond 3 months, events remained uncommon (dry eye 1.65%, photopsia/halo/glare 0.88%). No severe or sight-threatening complications were observed. Conclusions: SMILE Pro on the VisuMax 800 showed a high completion rate, rare intraoperative disruption, low retreatment, and rare, mostly mild postoperative events. These findings support a favorable early safety profile in routine practice; longer-term follow-up is warranted. Full article

Background: Fungal ocular infections, including keratitis and endophthalmitis, remain difficult to treat due to limited antifungal efficacy, poor tissue penetration, and biofilm-mediated resistance. This study evaluated the antifungal and host-protective potential of N-(4-methoxycinnamoyl)-anthranilic acid (NMCA) against Candida albicans and the multidrug-resistant Candidozyma auris. Methods: The antifungal activity of NMCA was assessed by analyzing fungal viability over time, ergosterol levels, and its interaction with fluconazole. Its antibiofilm activity was evaluated through biomass and metabolic activity measurements, together with the expression of genes involved in adhesion (ALS3, ALS5, HWP1) and membrane homeostasis (ERG11, OLE1). In addition, infected epithelial models were used to investigate epithelial damage, intracellular fungal burden, oxidative stress, and wound closure. Results: NMCA showed promising antifungal activity (MIC80 75 μg mL⁻¹ against C. albicans and 100 µg mL⁻¹ against C. auris), inducing a time-dependent reduction in fungal viability of about 4-log10 after 24 h. The compound also reduced ergosterol levels and showed synergistic interaction with fluconazole, as indicated by FICI values of 0.203 for C. albicans and 0.375 for C. auris. Moreover, NMCA markedly inhibited biofilm formation by reducing both biomass and metabolic activity up to approximately 80%, while modulating the expression of key adhesion- and membrane-related genes. Beyond its direct antifungal effects, NMCA reduced epithelial damage and intracellular fungal burden, attenuated oxidative stress, and significantly improved wound closure (reaching 76.26% and 90.46% closure in C. albicans- and C. auris-infected cells, respectively) in infected epithelial models. Conclusions: Although limited by the use of in vitro systems, these findings highlight the multifunctional profile of NMCA, which combines antifungal, antibiofilm, and tissue-protective activities. By simultaneously targeting pathogen viability, biofilm formation, and host cell integrity, NMCA appears to be a promising adjunctive candidate for the treatment of ocular fungal infections, where both pathogen eradication and tissue preservation are crucial for clinical outcomes. Full article

Corneal blindness remains a major cause of visual impairment worldwide and may result from trauma, infectious keratitis, degenerative disorders, endothelial dysfunction, and limbal stem cell deficiency (LSCD). Although corneal transplantation remains the standard treatment for advanced disease, its effectiveness is limited by donor tissue shortage, immune-mediated rejection, postoperative complications, and progressive graft failure. These limitations have accelerated interest in regenerative approaches aimed at restoring native corneal structure and function. Induced pluripotent stem cells (iPSCs) have emerged as a promising platform for corneal regeneration because of their pluripotency, self-renewal capacity, and potential for autologous or immune-compatible therapy. Recent advances in differentiation protocols have enabled the generation of corneal epithelial-like cells, stromal keratocyte-like cells, and corneal endothelial-like cells from iPSCs. Preclinical studies have demonstrated encouraging improvements in corneal transparency, epithelial restoration, fibrosis reduction, and endothelial function, while early clinical investigations, particularly in LSCD, have reported favorable short-term safety and functional outcomes. However, major translational barriers remain, including tumorigenicity, immunogenicity, genomic instability, manufacturing complexity, scalability, and long-term safety concerns. Stromal regeneration also remains comparatively underdeveloped relative to epithelial and endothelial applications. This review summarizes current differentiation strategies, biological mechanisms, preclinical and early clinical evidence, and the principal translational challenges associated with iPSC-based corneal regeneration. Overall, iPSC-derived corneal therapies demonstrate considerable regenerative potential, although further standardization, long-term safety evaluation, and multicenter clinical validation remain necessary before widespread clinical adoption. Full article

Contact lens wear is widely used for vision correction by millions of individuals worldwide; however, it remains associated with a spectrum of ocular complications ranging from mild inflammatory conditions to vision-threatening infections. Common contact lens-related complications are predominantly noninfectious, including contact lens discomfort, dry eye syndromes, and papillary conjunctivitis. These conditions are typically mild and manageable with conservative measures. In contrast, corneal inflammatory conditions, such as contact lens-induced acute red eye and peripheral ulcers, represent an intermediate spectrum and may clinically overlap with early infection, creating diagnostic uncertainty. The most serious complication is microbial keratitis, a vision-threatening infection that remains challenging to recognize in its early stages due to its variable and often subtle presentation. Delayed identification may lead to rapid progression and significant visual morbidity. Patients with contact lens-related complaints often present to frontline settings, where early recognition is essential. Distinguishing benign from infectious conditions can be challenging; a risk-based approach with prompt triage and referral, along with proper lens hygiene and patient education, is key. Full article

This retrospective multicenter cohort study investigated the incidence, treatment, and prognostic impact of dysregulated intraocular pressure (DIOP; >24 mmHg requiring therapy) in patients with acanthamoeba keratitis (AK). Eighty-one eyes from 81 patients with confirmed AK were included; co-infections were excluded. DIOP and best corrected visual acuity (BCVA) were assessed at baseline, follow-up, and after penetrating keratoplasty (PKP). Overall, 28% of eyes were managed conservatively, 46% required one PKP, and 26% required two. DIOP occurred in 4% before AK, 11% after AK onset, and 10% after the first PKP. Eyes with DIOP prior to PKP had significantly worse final BCVA compared to those without DIOP (0.5 ± 0.7 vs. 1.8 ± 1.1 logMAR, p < 0.001) and required PKP more frequently (100% vs. 67%, p = 0.01). Time to correct diagnosis was significantly longer in the AK-associated DIOP group (64 ± 50 vs. 50 ± 68 days, p = 0.03). DIOP was also associated with higher rates of prior cortisone use and complications, including fixed dilated pupil, cataract, anterior synechiae, and anterior chamber irritation. Overall, DIOP represents a major complication in AK and is linked to poorer visual outcomes. Earlier therapy may help reduce DIOP and hence improve prognosis. Full article

Background: Acanthamoeba is a free-living protozoan widely distributed in the environment and causes Acanthamoeba keratitis, skin, and brain disease. Acanthamoeba can exchange genes, potentially increasing antimicrobial resistance and virulence. Therefore, this systematic review aimed to summarize published studies on horizontal gene transfer (HGT) between Acanthamoeba and its intracellular microorganisms and to evaluate the impact of HGTs on the pathogenicity of Acanthamoeba. Methods: This systematic review was conducted following the recommended reporting guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement guideline. The electronic databases PubMed, Embase, and Web of Science were used to search for relevant published research articles. Results: Nineteen studies that fulfilled the inclusion criteria were included in this systematic review. A total of 14 (73.6%) studies reported evidence of HGT involving Acanthamoeba, and five studies of the nineteen (26.3%) analysed the presence of intracellular microorganisms on the pathological effects of the host Acanthamoeba. Horizontally transferred genes were predominantly reported from Pseudomonas species, Legionella pneumophila, and Chlamydia species. Conclusions: HGT can occur among intracellular microorganisms and their host Acanthamoeba. Acanthamoeba harbouring intracellular microbes showed enhanced pathogenic effects on human corneal epithelial cells and in a mouse model. However, heterogeneity among the included studies precluded meta-analysis. Studies using clinical and environmental samples are needed to characterize the horizontal transfer of virulence and antimicrobial resistance genes. Full article

Background/Objectives: Infectious keratitis is a vision-threatening disease. Its prevalence and specific pathogens vary by geographic location. This study characterizes risk profiles, clinical manifestations, and treatment outcomes for various pathogens in the Rostock area. Results: The study included 65 patients (38 viral, 14 bacterial, seven fungal, six parasitic) with a minimum follow-up of three months. The cohort had a mean age of 59 ± 19 years, with 49% female and 51% male participants. All groups showed significant improvement in visual acuity (viral −0.3 logMAR, p = 0.011; parasitic −0.8 logMAR, p = 0.043; fungal −0.9 logMAR, p = 0.018; Wilcoxon). Only the bacterial group did not reach statistical significance (−0.3 logMAR, p = 0.169; Wilcoxon). Final visual acuity did not differ significantly between medical and surgical treatments. Conclusions: No treatment modality (medical vs. surgical) showed superiority regarding visual outcome across pathogen groups. Early diagnosis and prompt therapy initiation are essential to improve visual prognosis and reduce complications. Full article

Purpose: The purpose of this study was to develop and evaluate deep learning models for automated detection of corneal perforation in microbial keratitis using anterior segment optical coherence tomography (ASOCT) images. Methods: We enrolled 150 patients with microbiologically confirmed keratitis. Contralateral healthy eyes served as controls. Ground-truth labels for perforation were established following consensus grading by two masked ophthalmologist graders. A ResNet-34 backbone was used to encode six radial ASOCT scans of an eye independently and mean-pooled into a single eye-level prediction for classification of the presence or absence of corneal perforation. Four model variants were trained. Models differed in the inclusion of healthy controls and stochastic masking of non-corneal anterior segment anatomy during training. All four model variants were evaluated with 5-fold patient-level cross-validation, and the recommended model was chosen on pooled out-of-fold (OOF) test performance. Results: All four model variants achieved high discrimination, with pooled OOF test receiver operating characteristic area under the curve (ROC AUC) between 0.924 and 0.971. The best-performing model (Model 3), which did not include healthy controls or stochastic masking of the inferior image portion during training, achieved an ROC AUC of 0.971 (95% CI, 0.943–0.993), average precision (AP) of 0.863 (95% CI, 0.713–0.963), sensitivity of 0.875 (95% CI, 0.727–1.000), specificity of 0.913 (95% CI, 0.858–0.959), and F1 of 0.750 (95% CI, 0.609–0.870) at the validation-derived Youden threshold. The addition of healthy contralateral eyes to the training set did not improve pooled OOF test metrics, and stochastic inferior blackout produced opposing effects in the two training cohort settings. In the infected-only cohort, it reduced both ROC AUC and AP, whereas in the +healthy cohort, it increased ROC AUC and substantially increased AP. Conclusions: Deep learning models achieved high diagnostic accuracy for detecting corneal perforation on ASOCT imaging in eyes with microbial keratitis. These findings support the potential role of automated ASOCT analysis as a clinical decision-support tool for identifying this vision-threatening complication. Full article

Regulatory T cells (Tregs, CD4⁺ CD25⁺ Foxp3⁺) play a crucial role as a core cell subset in maintaining immune homeostasis in the ocular immune-privileged microenvironment. This review systematically summarizes the stage-specific regulatory mechanisms of Treg cells in common inflammatory diseases such as keratitis, uveitis, and dry eye syndrome, including intercellular interactions, signal pathway mediation, and cytokine network regulation, as well as key experimental evidence (animal/cell models and clinical sample data) and research progress in targeted therapy. Studies have shown that Treg cells maintain ocular immune balance by secreting anti-inflammatory cytokines (such as IL-10 and TGF-β), regulating signaling pathways (STAT, PI3K/AKT, SIRT1, etc.), and interacting with immune cells (macrophages, dendritic cells). Their functions are regulated by multiple factors such as cytokine networks, epigenetic modifications, and delivery vectors. Targeted interventions based on Treg cells (cell therapy, drug intervention, and signaling pathway regulation) and combined treatment strategies have shown good anti-inflammatory potential. This article, in light of current research limitations (such as insufficient analysis of cell heterogeneity and the disconnect between basic and clinical research), proposes future research directions, providing a theoretical basis for the understanding of the pathogenesis of inflammatory eye diseases and the development of new immunomodulatory therapies, and establishing a complete research framework of “mechanism–evidence–treatment”. Full article

Purpose: Preclinical studies report low-intensity ultraviolet C (UVC) light to be safe and effective in treating murine bacterial keratitis, however, limbal impacts of UVC have yet to be investigated directly. This study evaluated the depth and density of UVC-induced DNA damage in the porcine and human limbus following UVC exposures of varying supratherapeutic dose. Methods: The corneoscleral junction (limbus) of full-thickness porcine corneas was exposed to supratherapeutic doses of UVC light (265 nm, 1.93 mW/cm²) for 5, 10, 15, 30, or 60 min (exposure groups) or remained unexposed for the same durations (control groups), with a sample size of 6 per group. In parallel, human corneal tissue was exposed to UVC for 1 or 5 min and processed identically. Following exposure, all tissues were frozen, dissected, and analysed using immunohistochemistry to detect cyclobutane pyrimidine dimers (CPDs) as markers of DNA damage. CPD distribution, depth, and density were subsequently evaluated. Results: CPDs were localised predominantly in the superficial corneal epithelial layers, irrespective of the UVC dose. The mean ± SD thickness of the corneal epithelium in the UVC-exposed groups was 38.9 ± 18.9 µm, and the average depth of CPD formation was 13.3 ± 8.43 µm. The proportions of cells affected by CPDs within the corneal epithelium (mean ± SD) were 47.8 ± 25.6%, 58.5 ± 16.2%, 39.9 ± 26.4%, 41.3 ± 27.3%, and 38.9 ± 28.3% for exposure durations of 5, 10, 15, 30, and 60 min, respectively (p > 0.05). Human cornea showed similarly limited penetration, with no difference in CPD proportions between the 1 and 5 min UVC exposures (p = 0.70). Conclusions: UVC-induced DNA damage in both species was confined to the superficial cellular layers of the cornea, with no detectable damage observed in deeper tissues, including those where limbal stem cells reside, even after supratherapeutic doses of up to one hour of exposure. Full article

Purpose: To compare hypopyon detection using anterior segment optical coherence tomography (ASOCT) versus slit lamp examination (SLE) in microbial keratitis, and to evaluate intra- and inter-grader agreement for ASOCT hypopyon measurement. Methods: Two masked graders independently evaluated ASOCT images for hypopyon presence or absence in eyes with microbial keratitis, with disagreements resolved by consensus. A subset of hypopyon eyes underwent triplicate height measurement using two methods (endothelial length and vertical height). The proportion of eyes with hypopyon, Cohen’s kappa, and intraclass correlation coefficients (ICCs) were calculated comparing diagnostic performance of ASOCT versus SLE. Results: Inter-grader agreement for hypopyon detection on ASOCT was excellent (κ = 0.94; 95% CI 0.84–1.00) and intra-grader agreement was excellent (κ = 0.89–1.00). ASOCT detected hypopyon in 67.1% of eyes versus 57.0% by SLE. Using ASOCT consensus grading as the reference standard, SLE demonstrated a detection proportion of 83.0% (95% CI, 71.4–92.1%). Intra-grader reproducibility was excellent for both endothelial length and vertical height measurements (ICC 0.977–0.996). Inter-grader agreement was good for endothelial length (ICC 0.831) and vertical height (ICC 0.827), though a statistically significant inter-grader bias was identified for vertical height only (Wilcoxon exact p = 0.006). Conclusions: Among eyes with gradable ASOCT images, ASOCT detected a greater proportion of hypopyon than SLE and demonstrated excellent intra-grader and good inter-grader measurement reproducibility. Endothelial length showed slightly superior inter-grader concordance to vertical height measurement. Full article

Exophiala endophthalmitis of exogenous origin is an exceptionally rare but severe ocular infection, characterized by diagnostic delays, limited therapeutic guidance, and frequently poor outcomes. Herein, we report one new case of an 80-year-old woman who presented with severe fungal keratitis progressing to endophthalmitis two years after an uncomplicated cataract surgery. The condition was initially misdiagnosed and treated with topical antibiotics and corticosteroids. By cultivation, microscopy, histopathological, and PCR analysis of the samples, Exophiala dermatitidis was identified as the causative agent. Despite targeted antifungal therapy with voriconazole, the disease rapidly progressed, resulting in corneal perforation and evisceration of the affected eye. The number of confirmed cases of this infection remains very limited. To address this gap, we conducted a structured review of all reported instances of exogenous Exophiala endophthalmitis, in which Exophiala dermatitidis emerged as the predominant causative species. Common predisposing factors included corneal barrier disruption, ocular surgery, diabetes mellitus, and corticosteroid use. Diagnostic confirmation was frequently delayed, and treatment outcomes varied. Amphotericin B-based regimens were associated with poor results, whereas voriconazole, particularly when combined with surgical intervention, demonstrated more favorable outcomes. Exogenous Exophiala endophthalmitis remains underrecognized, with limited evidence to guide management. This entity should be considered in postoperative or trauma-associated intraocular inflammation, and current evidence supports azole-based therapy combined with surgical intervention when indicated. Full article

Background/Objectives: Acanthamoeba keratitis (AK) is a rare but sight-threatening corneal infection. This study reviews the clinical profile, diagnostic pathways, treatment strategies, and outcomes of AK cases managed over a 34-year period. Methods: We conducted a retrospective analysis of 52 microbiologically AK cases from 1983 to 2017. Results: The mean age at presentation was 27.7 ± 9.4 years, with a female predominance (63.5%). The majority (82.7%) were contact lens users, almost exclusively soft lens wearers, with documented risk behaviors such as poor hygiene and sleeping with lenses. 44.2% were initially misdiagnosed as nonspecific microbial keratitis. Common clinical findings included epithelial defects (30.8%), ring infiltrates (44.2%), superficial infiltrates (53.8%), hypopyon (30.8%), and corneal thinning (13.5%). Diagnosis was confirmed by culture/stain in 61.5% of cases, while others required confocal microscopy or corneal biopsy. Co-infections with bacteria were noted in ~20%. Prior to referral, 82.7% of patients had received empirical topical therapy. At KKESH, all received dual anti-Acanthamoeba therapy, and 69.2% underwent surgical intervention, including tectonic PKP (46.2%) and optical PKP (19.2%). Visual acuity improved from a mean logMAR of 1.51 at presentation to 0.87 at last follow-up. Anti-Acanthamoeba therapy was discontinued in 95.9% of patients by the end of follow-up, with steroid use tapering from 61.5% at 3 months to 16.3% at final visit. Conclusions: Acanthamoeba keratitis in Saudi Arabia predominantly affects young female contact lens users and often presents with diagnostic delays and misclassification as herpetic or bacterial keratitis. Despite aggressive medical and surgical therapy, visual outcomes remain suboptimal in many cases. Full article

Qin Bing eye drops, a traditional Chinese medicine-based in-hospital preparation, were historically indicated for the treatment of conjunctivitis, keratitis, and photokeratitis. This study aimed to develop Qin Pi extract (QP-E) using a proprietary extraction method, and to evaluate the therapeutic efficacy of QP-E alone, QP-E combined with Bing Pian (BP), and an ophthalmic formulation (QP-D) comprising both constituents in a preclinical model of dry eye disease (DED). DED was induced in mice via subcutaneous scopolamine administration alone, whereas a more robust dry eye phenotype was established in rats through combined treatment with scopolamine and environmental stressors. Ocular surface evaluation included measurement of tear secretion volume and corneal fluorescein staining scores. The results demonstrated that both QP-E monotherapy and the QP-E–BP combination significantly ameliorated key pathological features of DED, including tear film instability and corneal epithelial damage. QP-D—formulated with rationally optimized concentrations of QP-E and BP—significantly enhanced basal tear secretion and attenuated corneal epithelial injury in both murine and rat dry eye models. Mechanistic investigations revealed that QP-E treatment markedly inhibited VEGF-C secretion from classically activated (M1) macrophages, suppressed phosphorylation-dependent activation of the VEGF-C/VEGFR-3 signaling axis, and consequently impaired lymphatic endothelial cell migration and in vitro tube formation. These correlative findings indicate that QP-E may partially alleviate DED by suppressing lymphangiogenesis; however, direct causal evidence—such as genetic ablation of VEGF-C or pharmacological inhibition of VEGFR-3—was not established in the present study. Collectively, our data yield a testable mechanistic hypothesis and propose a novel therapeutic strategy targeting lymphatic remodeling for DED intervention. Full article