Search Results (47)

Background/Objectives: Keratoconus (KC) is a bilateral asymmetric corneal ectasia characterized by progressive corneal thinning, irregular astigmatism, and impaired visual acuity. The National Eye Institute (NEI) developed the Visual Function Questionnaire (VFQ-25) to assess the impact of visual impairment on quality of life. This study aimed to evaluate the effect of penetrating keratoplasty (PKP) on quality of life and visual acuity in KC patients one year postoperatively. Methods: A retrospective study was conducted between January 2018 and December 2022 at the Ophthalmology Department of Saint Barbara Hospital, Trauma Center, Sosnowiec, Poland. A total of 71 patients (86 eyes) diagnosed with KC underwent PKP. The VFQ-25 questionnaire and visual acuity measurements were assessed preoperatively and one year postoperatively. Results: The study cohort included 71 patients (20 females, 28.17%; 51 males, 71.83%). Preoperative visual acuity ranged from less than 0.05 on the Snellen chart to 0.5. Postoperatively, visual acuity improved to a range of 0.1–1.0. A visual acuity of 1.0 was achieved in 21 eyes (24.42%; 5 females, 24%; 16 males, 76%), with a statistically significant improvement (p < 0.01). The mean VFQ-25 composite score increased from 57.96 (±17.58) preoperatively to 81.42 (±14.66) postoperatively (p < 0.001). Domains with the lowest preoperative scores were “role difficulties,” “general vision,” and “mental health,” while “color vision” scored highest. Conclusions: PKP significantly enhances both objective visual acuity and subjective quality of life in KC patients, as reflected in VFQ-25 questionnaire outcomes. Full article

Purpose: Pellucid Marginal Degeneration (PMD) is a rare ectatic corneal disorder characterized by inferior peripheral thinning and significant irregular astigmatism. Despite its clinical similarities to keratoconus, PMD presents unique diagnostic and therapeutic challenges. This review aims to provide a comprehensive update on the pathophysiology, clinical features, diagnostic approaches, and management strategies for PMD, emphasizing the latest advancements in treatment options. Methods: A systematic literature search was performed in MEDLINE (via PubMed), Google Scholar, and Scopus up to February 2025 using the terms: “pellucid marginal degeneration,” “PMD,” “ectatic corneal disorders,” “keratoplasty in PMD,” “corneal cross-linking in PMD,” “ICRS in PMD,” “toric IOL PMD” and their Boolean combinations (AND/OR). The search was restricted to English-language studies involving human subjects, including case reports, case series, retrospective studies, clinical trials, and systematic reviews. A total of 76 studies met the inclusion criteria addressing treatment outcomes in PMD. Results: PMD is characterized by a crescent-shaped band of inferior corneal thinning, leading to high irregular astigmatism and reduced visual acuity. Diagnosis relies on advanced imaging techniques such as Scheimpflug-based corneal tomography, which reveals the characteristic “crab-claw” pattern. Conservative management includes rigid gas-permeable (RGP) lenses and scleral lenses, which provide effective visual rehabilitation in mild to moderate cases. Surgical options, such as CXL, ICRS, and toric IOLs, are reserved for advanced cases, with varying degrees of success. Newer techniques such as CAIRS, employing donor tissue instead of synthetic rings, show promising outcomes in corneal remodeling with potentially improved biocompatibility. Penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) remain definitive treatments for severe PMD, though they are associated with significant risks, including graft rejection and postoperative astigmatism. Conclusions: PMD is a complex and progressive corneal disorder that requires a tailored approach to management. Early diagnosis and intervention are critical to optimizing visual outcomes. While conservative measures are effective in mild cases, surgical interventions offer promising results for advanced disease. Further research is needed to refine treatment protocols and improve long-term outcomes for patients with PMD. Full article

Keratoconus is a progressive corneal disorder that causes thinning and irregular astigmatism, often leading to significant visual impairment. In the advanced stages, surgical interventions are necessary to restore corneal shape, improve vision, and enhance contact lens tolerance. Intracorneal ring segments (ICRSs) have emerged as a well-established, minimally invasive option that not only improves vision but also has the potential to delay or prevent the need for corneal transplantation in advanced cases. Recent advancements in the ICRS implantation techniques, patient selection, and femtosecond laser technology have significantly improved the precision and safety of these procedures, reducing complications. The ability to customize the ring parameters—such as thickness, arc length, and positioning—enables a more individualized approach, particularly for patients with irregular astigmatism. Artificial intelligence (AI) is also emerging as a promising tool for optimizing ICRS planning and improving patient outcomes. Although still in the early stages, AI algorithms may refine the treatment strategies by analyzing large datasets, improving the patient selection, and predicting long-term outcomes. Corneal Allogenic Intrastromal Ring Segments (CAIRSs) offer a novel alternative to synthetic ICRSs, with advantages like improved biocompatibility and reduced extrusion risk. However, CAIRSs remain an evolving technique that requires further refinement and long-term evaluation to determine the tissue integration, the durability of the refractive outcomes, and the potential for late-onset complications. In conclusion, ICRSs continue to be a safe and effective option for managing advanced keratoconus. Ongoing refinement of the surgical approaches—combined with advancements such as femtosecond laser technology and the integration of AI—will ensure that both ICRSs and CAIRSs remain key components in the therapeutic arsenal for keratoconus, offering sustained visual improvements and the potential to delay or avoid corneal transplantation. Full article

Keratoconus (KC) is a progressive non-inflammatory disorder characterized by significant changes in the corneal structure, leading to severe vision loss. Risk factors include eye rubbing, a positive family history, and allergic reactions. There is growing evidence suggesting that sex hormones may influence the development and progression of KC, but the exact mechanisms and extent of their impact remain unclear and controversial. This review aims to examine the current literature on the association between KC and sex hormones and to evaluate the potential of these hormones as clinical markers for diagnosing, prognosticating, and managing KC. Full article

Background/Objectives: To evaluate the efficacy, accuracy, safety, and long-term stability of topography-guided photorefractive keratectomy (TGPRK) in eyes where post-LASIK (PLE) ectasia progression was stabilized with under-flap corneal crosslinking (ufCXL). Methods: This retrospective interventional case series included six eyes from five patients with PLE after microkeratome LASIK. All eyes underwent ufCXL to halt ectatic progression. A shallow TGPRK enhancement was performed on the LASIK flap surface after corneal and refractive stability was confirmed (18 months median) post ufCXL Outcome measures included uncorrected and corrected distance visual acuity (UDVA, CDVA), spherical equivalent (SEQ), refractive astigmatism, keratometry, and corneal irregularity indices over a mean follow-up of 47 months. Results: ufCXL stabilized ectatic progression but left residual refractive errors, limiting UDVA. TGPRK performed subsequently significantly improved UDVA, from 0.38 to 0.10 LogMAR (p = 0.017), and increased the LASIK efficacy index from 0.46 to 0.83 (p = 0.0087). Refractive astigmatism was reduced in all eyes achieving a SEQ within ±1.00 D of the target. Long-term stability was maintained, with no ectasia progression, no change in SEQ, no change in corneal irregularity indices, and no increase in maximal keratometry. Conclusions: TGPRK performed in ufCXL stabilized corneas can safely correct residual refractive errors, resulting in significant and sustained improvements in both refractive and visual outcomes in PLE. Full article

Corneal collagen cross-linking (CXL) is a therapeutic intervention that utilizes riboflavin photochemical activation with ultraviolet-A (UV-A) light to induce covalent cross-links within the stromal corneal fibers, effectively increasing corneal biomechanical stability and halting the progressive ectasia. The method was introduced in the late 1990s in Germany at the University of Dresden. The cross-linking method using the Avedro system (Waltham, MA, USA) was approved by the US Food and Drug Administration (FDA) on 18 April 2016, based on three prospective, multicenter, randomized clinical trials for keratoconus and other corneal ectasias. Recent innovations in CXL include a range of new treatment protocols and methods, which have been introduced to further enhance the clinical effectiveness, efficiency, and safety of CXL. These modifications encompass approaches like transepithelial or epithelium-on CXL (TE-CXL or epi-on CXL), accelerated CXL (ACXL), pulsed CXL (PL-CXL), transepithelial iontophoresis-assisted crosslinking (I-CXL), diluted alcohol and iontophoresis-assisted corneal cross-linking (DAI-CXL), slit-lamp CXL, and CXL plus (combined) methods. This review synthesizes findings on currently used modifications of the cross-linking method, the effectiveness, and directions of development of this currently dominant surgical method of treating corneal ectasia. This review concentrates on the long-term follow-up data, based on publications ranging from 1998 up to 2023. Full article

Background: Corneal allogenic intrastromal ring segments (CAIRSs) offer a novel, biocompatible alternative to synthetic intracorneal ring segments (ICRSs). This review aims to evaluate the clinical outcomes of CAIRS. Methods: Inclusion criteria were studies with a minimum of 20 eyes and six months of follow up. The primary outcome measure was uncorrected distance visual acuity (UDVA). The secondary outcomes were a change in corrected distance visual acuity (CDVA), spherical equivalent (SE), mean keratometry (K-mean), maximum keratometry (K-max), K1, K2, and pachymetry. Results: The primary outcome UDVA improved from 0.83 ± 0.15 to 0.40 ± 0.08 logMAR (p = 0.01), while CDVA improved from 0.52 ± 0.22 to 0.19 ± 0.09 logMAR (p = 0.01). K-max decreased from 57.8 ± 1.09 D to 53.57 ± 2.66 D (p < 0.01), and K-mean reduced from 49.27 ± 0.28 D to 45.30 ± 1.46 D (p < 0.01). An average of 84.92% ± 11.4% of eyes had an improvement in UDVA. No major complications or significant visual acuity deterioration were reported. Conclusions: CAIRSs serve as an alternative to synthetic ICRSs and even corneal transplantation in some cases. They represent a safe, effective, and biocompatible promising advancement in corneal ectasia management to improve visual acuity and corneal topography with minimal complications. Full article

Objective: The aim of this study was to evaluate the effect of a surgical technique for managing post-penetrating keratoplasty (PK) ectasia complicated by late endothelial failure (LEF). Methods: A single-center pilot case series was conducted regarding consecutive patients affected by post-PK ectasia with late graft failure. Using a microkeratome, a single donor cornea was dissected to prepare a two-piece graft, comprising a larger anterior lamella made up of anterior stroma and a smaller posterior lamella made up of posterior stroma, Descemet’s membrane, and endothelium. The two lamellae were then positioned on the appropriately prepared recipient cornea. The technique was applied to 15 patients between 2022 and 2023, and data were retrospectively collected from preoperative evaluations and at 1, 6, and 12 months, post-operatively. At each visit, patients underwent standard clinical evaluation, corneal topography, and endothelial cell density evaluation, and visual acuity was measured using a LogMAR chart. Results: The technique restored normal corneal curvature and achieved a clear graft in all patients, leading to the resolution of preoperative ectasia and improved corneal pachymetry. At the one-year follow-up, the average K was reduced from 51.1 ± 4.5 D to 43.5 ± 1.1 D; the best corrected visual acuity (BCVA) was improved from 1.1 ± 0.4 to 0.3 ± 0.2 LogMAR; the central corneal thickness was reduced from 629 ± 39 μm to 532 ± 45 µm; and the endothelial cell density was 1926 ± 199 cells/mm². None of the patients developed severe complications. Conclusions: The two-piece manual mushroom PK may represent an effective technique for managing complex post-PK ectasia cases combined with endothelial decompensation. Full article

Background: Disruption of HCCS results in microphthalmia with linear skin lesions (MLS) characterized by microphthalmia/anophthalmia, corneal opacity, aplastic skin lesions, variable central nervous system and cardiac anomalies, intellectual disability, and poor growth in heterozygous females. Structural variants consisting of chromosomal rearrangements or deletions are the most common variant type, but a small number of intragenic variants have been reported. Methods: Exome sequencing identified variants affecting HCCS. Results: Three novel intragenic variants and two genomic deletions of HCCS were found in individuals with primarily ocular features of MLS. X-inactivation was highly skewed in affected individuals with all three intragenic variants. Corneal opacity was the most penetrant feature (100%). In addition, a duplication of uncertain significance including both HCCS and AMELX was identified in a male with corneal anomalies, glaucoma, an atrial septal defect, and enamel hypoplasia along with a family history of developmental ocular disorders consistent with X-linked inheritance. Conclusion: Although variable expressivity is a known feature of MLS, our findings provide additional support for including HCCS in testing for individuals with isolated ocular anomalies and provide further evidence for its association with congenital aphakia, aniridia/other iris defects, and corneal staphyloma/ectasia. Full article

Purpose: This study aimed to evaluate the diagnostic accuracy of a novel shape index, the Pentacam Random Forest Index (PRFI), in detecting keratoconus (KC), specifically subclinical keratoconus, in Chinese refractive surgery candidates. Methods: This prospective cohort study included 856 participants who were divided into four groups based on their tomographic outcomes: the KC group (n = 137), the very asymmetric ectasia (VAE) group (n = 73), the normal cornea group (n = 363) and the tomographically suspected KC (TSK) group (n = 283). The diagnostic performance of PRFI and other widely used indices, including the shape index BAD-D and the combined index TBI, was assessed using receiver operating characteristic (ROC) curve analysis and compared using DeLong’s test. The area under the curve (AUC), best cutoff values, and Youden index for each parameter are reported. Additionally, the false-positive rates of BAD-D and PRFI were calculated and compared in “normal corneas”. Results: All shape and biomechanical parameters collected in this study were found to be significantly different among the four groups (KC, VAE, TSK, and normal groups; p = 0.000). The AUC of PRFI was the highest in detecting any form of KC (including clinical KC eyes and VAE-NT eyes) in Chinese refractive surgery candidates, outperforming the widely used shape index BAD-D (0.919 vs. 0.890, p < 0.001). There was no significant difference in performance between the PRFI and the combined TBI index (0.919 vs. 0.916, p > 0.05). For detecting subclinical KC eyes (i.e., VAE-NT), the AUC of PRFI was 0.774, which was statistically comparable to TBI (0.774 vs. 0.776, p > 0.05), while outperforming BAD-D (0.774 vs. 0.684, p < 0.001). The best cutoff values of PRFI for detecting any KC and VAE-NT eyes were determined to be 0.37 and 0.27, respectively. Additionally, PRFI demonstrated a lower false-positive rate than BAD-D (13.8% vs. 43.8%, p < 0.001). Notably, the relatively high false-positive rate of BAD-D observed in this study might be attributed to the smaller horizontal corneal diameter in tomographically suspected eyes. Conclusions: The PRFI proved to be a superior shape index compared to BAD-D in detecting any form of keratoconus, including subclinical cases, in Chinese refractive surgery candidates. This finding may be attributed to the relatively small corneas commonly observed in Asians. Full article

Corneal ectasias, including keratoconus (KC), pellucid marginal degeneration (PMD), and post-LASIK ectasia, poses significant visual rehabilitation challenges due to the resultant irregular astigmatism, myopia, and higher-order aberrations (HOAs). These conditions often resist traditional corrective methods, necessitating advanced optical solutions. Scleral lenses (SLs) have emerged as a primary non-surgical option for managing these complex corneal irregularities. SLs form a smooth optical interface by forming a tear-filled chamber between the lens and the cornea, effectively mitigating HOAs and improving both high-contrast and low-contrast visual acuity (VA). This review evaluates the efficacy of SLs in enhancing VA and reducing aberrations in patients with corneal ectasia. It also explores the technological advancements in SLs, such as profilometry and wavefront-guided systems, which enable more precise and customized lens fittings by accurately mapping the eye’s surface and addressing specific visual aberrations. The current body of evidence demonstrates that custom SLs significantly improve visual outcomes across various ectatic conditions, offering superior performance compared to conventional correction methods. However, challenges such as the complexity of fitting and the need for precise alignment remain. Ongoing innovations in SL technology and customization are likely to further enhance their clinical utility, solidifying their role as an indispensable tool in the management of corneal ectasias. Full article

The study aimed to evaluate the precision of different Pentacam indices in diagnosing keratoconus (KC) in pediatric patients with and without Down Syndrome (DS) and determine suitable cutoff values. This prospective multicenter cross-sectional study evaluated 216 eyes of 131 patients aged 6–18 years (mean age 12.5 ± 3.2 years) using Pentacam. Patients were categorized into four groups: KC, forme fruste keratoconus (FK), DS, and control, excluding DS patients with topographic KC. Receiver operating characteristic curves were generated to determine the optimal cutoff points and compare the accuracy in identifying KC and FK in patients with and without DS. In DS patients, corneal morphology resembled KC features. The most effective indices for distinguishing KC in DS patients were the average pachymetric progression index (AUC = 0.961), higher-order aberration of the anterior cornea (AUC = 0.953), anterior elevation (AUC = 0.946), posterior elevation (AUC = 0.947), index of vertical asymmetry (AUC = 0.943), and Belin/Ambrosio enhanced ectasia total derivation value (AUC = 0.941). None of the indices showed good accuracy for distinguishing FK in DS patients. The thresholds of these indices differed significantly from non-DS patients. The results highlighted the need for DS-specific cutoff values to avoid false-positive or false-negative diagnoses in this population. Full article

Corneal biomechanics is a hot topic in ophthalmology. The biomechanical properties (BMPs) of the cornea have important implications in the management and diagnosis of corneal diseases such as ectasia and keratoconus. In addition, the characterization of BMPs is crucial to model the predictability of a corneal surgery intervention, the outcomes of refractive surgery or the follow-up of corneal diseases. The biomechanical behavior of the cornea is governed by viscoelastic properties that allow, among other structural implications, the damping of excess intraocular pressure and the reduction of damage to the optic nerve. Currently, the most versatile and complete methods to measure corneal viscoelasticity are based on air-puff corneal applanation. However, these methods lack the ability to directly measure corneal viscosity. The aim of this work is to propose a new methodology based on the analysis of corneal air-puff measurements through the standard linear solid model (SLSM) to provide analytical expressions to separately calculate the elastic and time-dependent (corneal retardation time and viscosity) properties. The results show the mean values of elasticity (E), viscosity (Ƞ) and corneal retardation time (τ) in a sample of 200 young and healthy subjects. The influence of elasticity and viscosity on viscoelasticity, high-order corneal aberrations and optical transparency is investigated. Finally, the SLSM fed back from experimental E and Ƞ values is employed to compare the creep relaxation response between a normal, an ocular hypertension patient and an Ortho-K user. Corneal biomechanics is strongly affected by intraocular pressure (IOP); however, corneal hysteresis (CH) analysis is not enough to be employed as a risk factor of glaucoma progression. Low values of CH can be accompanied by high or low corneal elasticity and viscosity depending on the IOP threshold from which the time-dependent biomechanical properties trends are reversed. Full article

Background: A higher prevalence of ophthalmological alterations in systemic inflammatory diseases has been demonstrated. Objectives: Our objectives were to determine anterior segment findings and corneal properties in alopecia areata (AA). Methods: This is a case-control study. Severe AA patients (Severity of Alopecia Tool > 50%) and non-AA subjects underwent a general ophthalmological examination, a Pentacam and Corvis scheimpflug technology examination (Oculus Optikgeräte GmbH, Wetzlar, Germany). Visual acuity, refractive error, corneal aesthesiometry, and biomechanical and topographic variables were registered. Results: In total, 25 AA patients (50 eyes; 50.6 ± 8.1 years) and 29 controls (58 eyes; 49.4 ± 8.6 years) were included. AA patients had decreased corneal sensitivity, more corneal staining, and a more advanced cataract (p ≤ 0.004). The anterior topographic flat meridian, mean anterior keratometry, and maximum keratometric point were increased in AA (p ≤ 0.040), while pachymetry values were thinner (p ≤ 0.001). Keratoconus index and Belin/Ambrosio-enhanced ectasia total deviation display were increased (p ≤ 0.007). Two eyes with a topographic diagnosis of keratoconus and four eyes with subclinical keratoconus were detected in AA. Applanation lengths were smaller in AA (p ≤ 0.029). The Corvis Biomechanical Index was increased in AA (p = 0.022). Conclusions: AA patients have reduced corneal sensitivity and increased corneal staining. Topographic and biomechanical parameters are altered, and there could be a higher risk of keratoconus, thus possibly requiring routine ophthalmological examination. Full article

Background: Scheimpflug tomography has for many years been an integral part of our pre-operative assessment in cataract extraction. We retrospectively reviewed the incidence of topographic keratoconus and keratoconus suspicion in our routine cataract surgery population over 5 years. Setting: The Laservision Clinical and Research Institute, Athens, Greece. Methods: In 1250 consecutive cataract surgery cases in otherwise naïve eyes, accounting for years 2017 to 2021, we retrospectively evaluated preoperative Pentacam HR imaging. The cases already classified as keratoconus were included in group A. The residual cases were assessed by five different experienced evaluators (two ophthalmic surgeons and three optometrists) for topographic and tomographic keratoconus suspicion based on irregular pachymetry distribution, astigmatism truncation, and/or astigmatic imaging irregularity and included in group B. Regular corneas, by this assessment, were included in group C; irregular corneas, as determined by the evaluators but unrelated to keratoconus, were included in group D. Results: Based on the above, 138 cases (11.08%) were classified by Pentacam tomography as keratoconus and by default were included in group A. Of the residual cases, 314 or 25.12% were classified as suspect keratoconus and included in group B; 725 cases (58%) were classified as normal and non-keratoconus and included in group C; and 73 cases or 5.84% were placed in group D as non-keratoconus but abnormal. There was no disagreement between the five evaluators over any of the cases in groups C and D, and little variance among them for cases included in group B (less than 5% by ANOVA). Conclusions: The incidence of keratoconus and corneas suspicious for keratoconus in Greece appears to be much higher than respective reports from other regions: one in ten Greeks appear to have topographic keratoconus, most not diagnosed even by the age of cataract surgery, and almost an additional one in four may have suspicious corneal imaging for keratoconus. These data strongly imply that routine screening for disease should be promoted among Greeks, especially during puberty, to halt possible progression; moreover, careful screening should be performed when laser vision correction is being considered. Full article