Search Results (271)

Background and Objectives: Corneal allogeneic intrastromal ring segments (CAIRS) are designed to decrease and stabilize the extent of corneal ectasia in keratoconus patients. This systematic review and meta-analysis evaluate the effectiveness of different surgical techniques for CAIRS preparation and the adjunctive use of corneal cross-linking. Materials and Methods: Following the PRISMA statement and checklist, a comprehensive search was conducted in Embase, Medline, and the Cochrane Controlled Trials Register, through the use of a systematic search approach in accordance with the Cochrane Collaboration guidelines. Results: Eighteen studies, involving 567 eyes of 459 patients, met the inclusion criteria. At one month postoperatively, CAIRS implantation significantly improved uncorrected visual acuity (UCVA) (−0.45 logMAR, 95% CI [−0.59 to −0.31], p < 0.001) and best corrected visual acuity (BCVA) (−0.36 logMAR, 95% CI [−0.46 to −0.25], p < 0.001). These improvements remained significant after one year (UCVA: −0.39 logMAR, 95% CI [−0.48 to −0.30], p < 0.001; BCVA: −0.34 logMAR, 95% CI [−0.50 to −0.18], p < 0.001). Similarly, mean simulated keratometry (Kmean) decreased by −4.42 D (95% CI [−5.94 to −2.90], p < 0.001) and maximum keratometry (Kmax) by −3.88 D (95% CI [−6.71 to −1.05], p < 0.001) at one month, with sustained reductions at one year (−3.59 D, 95% CI [−4.35 to −2.84], p < 0.001 and −3.73 D, 95% CI [−4.91 to −2.55], p < 0.001). No significant differences in surgical outcome have been observed between the different surgical techniques. Conclusions: CAIRS implantation appears to be an effective treatment option for keratoconus, regardless of the technique used for segment preparation or the addition of corneal cross-linking. No approach demonstrated clear clinical superiority over others in the first year after surgery. Full article

The ocular surface is a neuro–epithelial–immune unit in which corneal innervation is essential for maintaining tissue integrity and visual function. Sensory nerves regulate reflex tearing and blinking, provide trophic support, and modulate local immune responses. Nerve injury resulting from trauma, surgery, infection, systemic disease, or chronic inflammation disrupts epithelial homeostasis and may lead to neurotrophic keratopathy, neuropathic pain, and pathological remodeling. Beyond classical neurotrophic disease, nerve dysfunction contributes to severe dry eye and immune-mediated cicatricial disorders. Depending on the neuro-inflammatory context, remodeling may evolve toward stromal thinning, as in keratoconus, or progressive fibrosis, as in ocular cicatricial pemphigoid. Blood-derived eye drops, including serum- and platelet-based formulations, represent biologically active therapies that support epithelial repair and nerve regeneration, although greater standardization is needed. Full article

Aim: Our study aimed to evaluate serum oxidative stress-related biomarkers (three pro-oxidants: total oxidant status (TOS), indirect assessment of nitric oxide synthesis (NOx), and malondialdehyde (MDA), and three anti-oxidants: total anti-oxidant capacity (TAC), catalase (CAT), and thiols) in patients with keratoconus (KCN). Methods: We conducted a single-center, cross-sectional study with the prospective enrollment of adult patients attending an outpatient ophthalmology clinic between 1 January 2024, and 1 September 2025. The diagnosis of KCN was established based on the clinical signs and two or more aberrant Pentacam parameters. Results: We evaluated 44 subjects with KCN (median age, 26 years) and 38 without KCN (median age, 28 years), with similar age and sex distributions (p-values > 0.09). All evaluated biomarkers showed statistically significant differences between subjects with KCN and those without KCN (p-values < 0.001), with higher serum TOS, NOx, MDA, CAT, and oxidative stress index levels and lower levels of TACs and thiols in subjects with KCN than in those without KCN. Conclusions: Our findings indicate a systemic imbalance between pro-oxidant and anti-oxidant biomarkers in subjects with keratoconus. Full article

Background: Keratoconus (KC) is the most common ectatic corneal disorder, causing progressive corneal deformation, visual impairment, and reduced quality of life. Although KC pathogenesis is multifactorial, the contribution of systemic factors, including hormonal regulation, remains incompletely understood. This study aimed to investigate the role of sex hormones and gonadotropins in KC in a predominantly Greek population. Methods: We recruited 105 KC patients and 71 healthy controls (HC). Plasma levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2), prolactin (PRL), testosterone (TES), dehydroepiandrosterone sulfate (DHEA-S), and progesterone (PRG) were measured and analyzed in relation to corneal tomographic and biomechanical parameters, as well as treatment modality. Results: LH showed positive correlations with corneal biomechanical parameters. KC patients who underwent penetrating keratoplasty exhibited higher FSH levels and a reduced LH/FSH ratio compared with those treated with corneal cross-linking. E2 levels were increased in women over 46 years of age, while PRL correlated with Kmax and Q-value. Men with KC demonstrated reduced TES associated with corneal morphology and biomechanics, increased PRG levels, and reduced DHEA-S in keratoplasty-treated patients. Conclusions: These findings suggest that sex hormones and gonadotropins may contribute to KC pathophysiology, supporting a systemic hormonal component in disease progression. Full article

Background and Objectives: Keratoconus is a bilateral but often asymmetric ectatic corneal disease characterized by progressive thinning, increased curvature, and conical shape of the cornea. Previous studies have reported that the use of swimming goggles in patients with keratoconus can lead to increased intraocular pressure (IOP) and a transient reduction in anterior chamber volume (ACV), potentially affecting anterior segment morphology. This study aimed to evaluate the short-term effects of periorbital pressure induced by swimming goggles on corneal parameters in keratoconic eyes. Materials and Methods: A total of 44 eyes of 44 patients (mean age: 26.1 ± 5.1 years) diagnosed with keratoconus Stage 1–4 according to the Amsler–Krumeich classification were included. Measurements were taken using a Pentacam^® Scheimpflug camera before swimming goggle application and immediately after 20 min of wear. The parameters assessed included keratometry values (K1, K2, Km, Kmax), central and thinnest corneal thickness, corneal volume within the 10 mm zone (CV10), ACV, anterior chamber depth (ACD), iridocorneal angle (ICA), and pupil diameter (PD). Results: No statistically significant changes were observed in keratometric values, central and thinnest corneal thickness, ACV, ACD, ICA, PD, or IOP (all p > 0.05). CV10 showed a small reduction following goggle wear (Δ = −0.18 mm³, corresponding to a 0.3% decrease), which was statistically significant in the unadjusted analysis (p = 0.008) but did not remain significant after correction for multiple comparisons (p for false discovery rate [FDR] = 0.10). Conclusions: Short-term swimming goggle use may induce subtle reductions in CV10 in keratoconic eyes, suggesting a potential biomechanical sensitivity to transient periocular pressure. Although the observed change in CV10 did not retain statistical significance after multiple-comparison correction, it may reflect an early physiological response in structurally compromised corneas. CV measurements could serve as exploratory indicators of mechanical responsiveness in keratoconus, warranting further investigation in larger controlled studies. Full article

Background/Objectives: Keratoconus, a condition in which the cornea becomes thinner and steeper, can cause visual problems, particularly when it is progressive. Early diagnosis is important for preserving visual acuity. Raw data, unlike preprocessed data, are unaffected by software modifications. They retain their native structure across versions, providing consistency for analytical purposes. The objective of this study was to design a deep learning-based graphical user interface for predicting the corneal ectasia score using raw optical coherence tomography data. Methods: The graphical user interface was developed using Tkinter, a Python library for building graphical user interfaces. The user is allowed to select raw data from the cornea/anterior segment optical coherence tomography Casia2, which is generated in the 3dv format, from the local system. To view the predicted corneal ectasia score, the user must determine whether the selected 3dv file corresponds to the left or right eye. Extracted optical coherence tomography images are cropped, resized to 224 × 224 pixels and processed by the modified EfficientNet-B0 convolutional neural network to predict the corneal ectasia score. The predicted corneal ectasia score value is displayed along with a diagnosis: ‘No detectable ectasia pattern’ or ‘Suspected ectasia’ or ‘Clinical ectasia’. Performance metric values were rounded to four decimal places, and the mean absolute error value was rounded to two decimal places. Results: The modified EfficientNet-B0 obtained a mean absolute error of 6.65 when evaluated on the test dataset. For the two-class classification, it achieved an accuracy of 87.96%, a sensitivity of 82.41%, a specificity of 96.69%, a positive predictive value of 97.52% and an F1 score of 89.33%. For the three-class classification, it attained a weighted-average F1 score of 84.95% and an overall accuracy of 84.75%. Conclusions: The graphical user interface outputs numerical ectasia scores, which improves other categorical labels. The graphical user interface enables consistent diagnostics, regardless of software updates, by using raw data from the Casia2. The successful use of raw optical coherence tomography data indicates the potential for raw optical coherence tomography data to be used, rather than preprocessed optical coherence tomography data, for diagnosing keratoconus. Full article

Background: This study focuses on the diagnosis and treatment of keratoconus in the early stage and aims to identify the environmental and risk factors that contribute to its progression. Methods: This retrospective investigation was carried out at the University Clinical Center of Kosovo (UCCK) and comprised 131 patients newly diagnosed with keratoconus (KC). All procedures adhered to the Declaration of Helsinki, and the University of Pristina ethics committee approved this study before its initiation (Ref.Nr.104/2023). The confidentiality and anonymity of the surveyed patients were respected. The patients’ data consisted of gender, age, and race. Results: There were significant differences in the K1 distribution between groups, as the normal group (41.4 ± 0.5) was significantly lower than the suspect group (45.0 ± 3.2) and the degree of keratoconus (p < 0.001). There were significant differences in K2 between the groups, as the normal group (44.7 ± 5.1) was significantly lower than the suspect group (47.1 ± 2.8) and the other grades of keratoconus (p < 0.001). There were significant differences between groups regarding Kmax, as the normal group (44.5 ± 3.1) was significantly lower than the suspect group (46.9 ± 1.6) and the other grades of keratoconus (where p < 0.001). Statistically meaningful differences were detected between the groups with respect to subtlety, as the normal group (504.0 ± 27.6) was significantly higher than the suspect group (499.0 ± 48.1) and the other degrees of keratoconus (p < 0.001). Conclusions: Disease progression can significantly affect vision; therefore, early screening enables timely treatment (CXL). The evolution of this technique has contributed to preventing and slowing disease progression. Full article

Ocular allergy (OA) is a subtype of seasonal allergy that causes symptoms of itchiness, redness, swelling and irritation of the ocular surface and eyelids, often triggering allergy-induced eye rubbing and sustained inflammation for up to six months of the year during peak allergy season. These symptoms, coupled with reduced sleep quality, impaired daily productivity and decreased mood, highlight a significant yet underrepresented disease burden. Recent advances in tear-based multi-omics have enabled detailed characterisation of OA-associated biochemical changes on the ocular surface, highlighting human tears as a promising biospecimen for diagnostic biomarker and therapeutic target research. This review discusses emerging proteomic, lipidomic, metabolomic and miRNA findings comparing OA sufferers with healthy controls, and, where relevant, with comorbid conditions such as dry eye disease and keratoconus. Differential expression patterns across these analytes implicate key pathways involved in immune response, wound healing, angiogenesis, inflammation, oxidative stress and return to homeostasis on the ocular surface. By integrating these data into a stepwise model of OA biopathway activation, this review outlines candidate biomarkers and highlights methodological advances that may support translation of tear multi-omics into clinical tools for OA management. Full article

Background/Objectives: Meibomian gland dysfunction (MGD) has been shown to be more prevalent in patients with keratoconus (KC) in Turkey, Egypt, and Israel but has not been examined in the Palestinian Authority (PA). Therefore, this study compared the prevalence and clinical features of MGD in patients with keratoconus versus healthy controls seen in an optometry clinic in the PA. Methods: Patients with KC and healthy controls who were non-contact lens wearers were recruited. Habitual visual acuity (VA), tear break-up time (TBUT), meibography, meibomian gland (MG) expressibility (MES) and quality score (MQS), and Schirmer test were evaluated. MGD was defined by an Ocular Surface Disease Index (OSDI) Questionnaire score ≥ 13, TBUT < 10 s, and MG loss > Grade 1. Outcomes were compared using Mann–Whitney U tests, Chi-Square tests and Spearman correlation. Results: The study included 33 eyes of 17 KC (mean age: 29.2 ± 7.7, range:19–50) and 27 right eyes of 27 control participants (mean age: 34.2 ± 11.7, range:18–56). MGD was prevalent in 67% of KC and 30% of control participants. VA was significantly worse (0.8 + 0.2 vs. 1.0 + 0.0, p < 0.001), with significantly greater MG loss in the lower eyelids (p = 0.002), and shorter TBUT (4.1 ± 1.5 s vs. 5.7 ± 1.7 s, p < 0.001) in the KC group. No significant differences were found in symptoms, MES, MQS, MG loss in the upper eyelids, or Schirmer test. Conclusions: KC patients exhibited a significantly higher prevalence and severity of MGD signs compared with controls. These findings highlight the importance of comprehensive ocular surface evaluation and management in this population. Full article

Keratoconus is a progressive, non-inflammatory corneal ectasia characterized by stromal thinning and conical protrusion. Corneal collagen cross-linking (CXL) remains the only proven treatment to halt its progression. This review compares the mechanisms, efficacy, and safety of standard (Dresden), accelerated, and transepithelial (including iontophoretic) protocols, with particular emphasis on pediatric keratoconus. Studies from PubMed, Scopus, and Web of Science were comprehensively reviewed. Standard CXL remains the gold standard due to its strong biomechanical effect and long-term stability. Accelerated protocols reduce treatment time while maintaining comparable outcomes in selected patients, though the stiffening effect may be shallower. Transepithelial and iontophoretic approaches improve comfort and reduce complications but show reduced efficacy. Future perspectives include oxygen supplementation, customized fluence modulation, and pharmacologic enhancers to improve riboflavin diffusion and oxygen availability. Full article

Background and Objectives: Keratoconus (KC) is a progressive ectatic corneal disease that can cause irregular astigmatism and visual impairment. To describe the demographic and clinical profile of KC patients attending major eye care centers in Riyadh City, Saudi Arabia, and to explore associations with laterality, disease severity, and management patterns. Materials and Methods: This multi-center hospital-based cross-sectional study enrolled consecutive patients with a confirmed diagnosis of KC (new or follow-up) presenting between April 2022 and April 2023. All participants underwent standardized ophthalmic assessment and Scheimpflug tomography (Pentacam). Disease severity was categorized as early, moderate, or advanced using Pentacam-derived keratoconus staging, and ocular parameters (refraction, keratometry, pachymetry, and higher-order aberrations) were compared across severity categories. Results: A total of 157 patients (264 eyes) were included (mean age 31.8 years; 56.7% female), with bilateral KC in 68.2%. Eye rubbing (67.8%) and allergic symptoms (61.7%) were common. Keratometric indices and higher-order aberrations differed significantly by severity grade (p < 0.001). Management patterns differed by sex and laterality, with corneal cross-linking and glasses reported more frequently in males, and soft contact lens use concentrated among bilateral cases. Conclusions: In this hospital-based Riyadh sample, KC was often associated with eye rubbing and allergic symptoms and showed clear stage-dependent worsening of tomographic indices and optical quality. These findings support early detection and targeted counseling on modifiable behaviors, while population-based studies with non-diseased comparators are needed to quantify incidence and prevalence in Riyadh. Full article

Background: Keratoconus (KC) is a progressive corneal ectasia and a leading cause of corneal transplantation in young adults. Once regarded as a biomechanical disorder, KC is now recognized as a complex disease driven by genetic predisposition, epigenetic modulation, and environmental triggers. Advances in genomics and transcriptomics have begun to elucidate the molecular mechanisms underlying corneal thinning and ectasia. Objectives: This review synthesizes two decades of evidence on the genetic and epigenetic architecture of keratoconus, highlights key molecular pathways implicated by these findings, and discusses translational implications for early diagnosis, risk prediction, and novel therapeutic strategies. Methods: A narrative review was conducted of peer-reviewed human, animal, and in vitro studies published from 2000 to 2025, with emphasis on genome-wide association studies (GWAS), sequencing data, methylation profiling, and non-coding RNA analyses. Findings were integrated with functional studies linking genetic variation to molecular and biomechanical phenotypes. Results: Genetic studies consistently implicate loci such as ZNF469, COL5A1, LOX, HGF, FOXO1, and WNT10A, alongside rare variants in Mendelian syndromes (e.g., brittle cornea syndrome, Ehlers–Danlos spectrum). Epigenetic research demonstrates altered DNA methylation, dysregulated microRNAs (e.g., MIR184, miR-143, miR-182), and aberrant lncRNA networks influencing extracellular matrix remodeling, collagen cross-linking, oxidative stress, and inflammatory signaling. Gene–environment interactions, particularly with eye rubbing and atopy, further shape disease expression. Translational progress includes polygenic risk scores, tear-based biomarkers, and early preclinical studies using RNA-based approaches (including siRNA and antisense oligonucleotides targeting matrix-degrading and profibrotic pathways) and proof-of-concept gene-editing strategies demonstrated in corneal cell and ex vivo models. Conclusions: Keratoconus arises from the convergence of inherited genomic risk, epigenetic dysregulation, and environmental stressors. Integrating multi-omic insights into clinical practice holds promise for earlier detection, precision risk stratification, and development of targeted therapies that move beyond biomechanical stabilization to disease modification. Full article

Purpose: The purpose of this study is to evaluate changes in corneal thickness and anterior and posterior corneal curvature after one year of scleral lens wear in keratoconus eyes and to determine their impact on visual performance. Methods: Sixty-five keratoconus subjects were divided into two groups: with intrastromal corneal ring segments (KC-ICRS) and without ICRS (KC). All participants wore 16.5 mm scleral lenses for 8 h daily over 1 year. Measurements included corneal thickness, anterior and posterior curvature, and high-contrast visual acuity assessed before and after lens wear. Results: Corneal thicknesses increased significantly in the superior region of the KC-ICRS group. In curvature analysis, the KC group showed inferior steepening and superior flattening, while the KC-ICRS group exhibited central and superior-nasal anterior flattening. Posterior curvature changes included central flattening and peripheral steepening. Visual acuity remained stable across all visits and groups. Conclusions: Long-term scleral lens wear induced measurable morphological changes, including increased superior corneal thickness and region-specific curvature alterations, which varied by ICRS presence. These changes did not compromise visual acuity, supporting scleral lenses as a safe and effective option for sustained vision correction in keratoconus. The findings highlight the importance of personalized fitting and monitoring strategies in clinical practice. Full article

Background and Objectives: Keratoconus is a progressive corneal ectatic disorder and a leading cause of corneal transplantation in developed countries. Early detection is critical for initiating timely interventions such as corneal cross-linking, which can halt disease progression and preserve long-term visual function. This review aims to synthesize current diagnostic approaches for early keratoconus detection and assess their clinical impact on visual outcomes. Materials and Methods: A comprehensive literature search was conducted across PubMed/MEDLINE, Web of Science, Google Scholar, Scopus and the Cochrane Library through September 2025. Search terms included “early keratoconus,” “subclinical keratoconus,” “forme fruste keratoconus,” “keratoconus detection,” “corneal topography,” “corneal tomography,” “anterior segment optical coherence tomography (AS-OCT),” “corneal biomechanics,” “artificial intelligence,” “genetic risk, “environmental factors”, and “machine learning.” Two independent reviewers analyzed the data. Studies were included if they investigated diagnostic modalities for early-stage keratoconus and discussed their relevance to visual outcomes. Results: One hundred and seven studies were included in the final review. Four diagnostic modalities demonstrated consistent clinical value: 1. corneal topography for assessing anterior surface irregularities; 2. corneal tomography, currently regarded as the gold standard due to its ability to detect early posterior elevation and pachymetric changes; 3. AS-OCT for epithelial and stromal profiling; and 4. biomechanical assessments, which evaluate corneal tissue stability prior to structural alterations. Artificial intelligence, when integrated with imaging data, enhances diagnostic sensitivity and standardizes interpretation across clinical settings. Conclusions: Early keratoconus detection is crucial for preserving vision; and integrating multimodal, AI-supported diagnostics into routine care—especially for high-risk groups—enhances accuracy, improves outcomes, and reduces progression rates of disease. Full article

Corneal diseases are a leading cause of blindness worldwide, although their early detection remains challenging due to subtle clinical presentations. Recent advances in artificial intelligence (AI) have shown promising diagnostic performance for anterior segment disorders. This narrative review summarizes current applications of AI in the detection of corneal conditions—including keratoconus (KC), dry eye disease (DED), infectious keratitis (IK), pterygium, Fuchs endothelial corneal dystrophy (FECD), and corneal transplantation. Many AI models report high accuracy on test datasets, comparable to, and in some studies exceeding, that of junior ophthalmologists. In addition to detection, AI systems can automate image labeling and support education and patient home monitoring. These findings highlight the potential of AI to improve early management and standardized classification of corneal diseases, supporting clinical practice and patient self-care. Full article