Cases Of Keratoconus Research Articles

Keratoconus Cases Associated with Medication Use: A Population-Based Pharmacovigilance Study.

Keratoconus (KC) has been linked to atopy, connective tissue disorders, and mechanical trauma from repeated eye rubbing. However, evidence suggesting that certain medications may exacerbate or potentially trigger KC remains largely limited to case reports. This population-based, real-world pharmacovigilance analysis aimed to comprehensively investigate associations between drugs and reports of KC using data from the Food and Drug Administration Adverse Event Reporting System (FAERS). Overall, several pharmacologic agents were associated with disproportionately high reports of KC, including sex hormones such as progesterone and estradiol, olopatadine, isotretinoin, methylphenidate, spironolactone, antipsychotics such as aripiprazole and risperidone, and dupilumab. These results underscore the need for increased clinical vigilance in monitoring for early signs of KC in patients prescribed these medications. Furthermore, healthcare providers should be aware of the potential drug-related associations for KC, especially in high-risk groups.

Evaluation of the Cornea by Anterior Segment Optical Coherence Tomography in Diseases of the Cornea.

The aim of the study was to determine any new findings provided by anterior segment optical coherence tomography (AS-OCT) in different corneal diseases diagnosed by slit lamp examination (SLE). This cross-sectional, observational, hospital-based study was conducted at a tertiary care centre in Western Maharashtra from September 2022 to June 2024, and it included 93 eyes of 93 patients with isolated corneal diseases.A detailed SLE of the anterior segment was done to assess corneal pathology, corneal thickness, corneal structural integrity, presence of corneal opacities, corneal vascularization, presence of other abnormalities like corneal degeneration, corneal foreign bodies, Kayser-Fleischer (KF) ring, ocular surface squamous neoplasia (OSSN). All patients underwent AS-OCT with imaging protocolstailored to each corneal condition, including assessment of focal thinning in Keratoconus patients, graft-host junction integrity in post-keratoplasty cases, Descemet's membrane integrity in post-cataract surgery patients, localization and depth of invasion of corneal foreign bodies, detection of KF rings in Wilson's disease cases, and identifying and assessing extent of corneal dystrophies, corneal degenerations, and OSSN. AS-OCT findings were compared with SLE results to identify any additional information provided by AS-OCT over SLE in the study population.For statistical analysis, data was entered into Microsoft Excel (Microsoft Corporation, Redmond, Washington, United States) and analysed using IBM SPSS Statistics for Windows, Version 26.0 (Released 2019; IBM Corp; Armonk, New York, United States). Inter-rater agreements between SLE and AS-OCT were evaluated by Cohen's Kappa by using IBM SPSS Statistics for Windows, Version 26.0. AS-OCT enabled additional diagnosis of three (15.8%) more cases of keratoconus, which were declared normal on SLE.AS-OCT identified one (5.90%) case of deep-seated stromal corneal foreign body among the cases which were reported to have only superficial corneal foreign body on SLE. Two (50%) casesof suspected OSSNon SLE were ruled out on AS-OCT, whereas two (50%) casesof suspected OSSNon SLE were confirmed on AS-OCT. AS-OCT found a KF ring among two (12.5%) cases that were reported to have no KF ring on SLE. On both SLE and AS-OCT, 26 (81.2%) cases showed the same findings, whereas in 30 (49.2%) cases, AS-OCT rejected the suggested findings of the SLE. In six (18.8%) cases, SLE did not show any findings, but AS-OCT showed findings. Both SLE and AS-OCT showed no findings in 31 (50.8%) cases. This study highlights the significant role of AS-OCT in enhancing the diagnostic accuracy of various corneal diseases. Its ability to detect additional findings in various corneal conditions such as keratoconus, corneal foreign bodies, OSSN, and KF ring in Wilson's disease underscores its value in clinical practice. The utility of AS-OCT in diagnosing subclinical corneal diseases which are beyond the scope of routine SLE has been demonstrated in our study. These capabilities make AS-OCT an effective additional diagnostic toolin evaluating cornea and should be routinely incorporated along with traditional SLE in evaluating various corneal diseases.

Continuum versus micromechanical modeling of corneal biomechanics

Two alternative numerical models of the human cornea are used to simulate the mechanical response under the action of a physiological intraocular pressure (IOP). The first model is continuum or macromechanical, considering the stromal tissue as a bulk material with stochastic distribution of the spatial variability of reinforcing collagen fibers. The second model is discrete or micromechanical, considering the sole collagen-crosslink stiffening micro-structure. The geometry of the two models is reconstructed from corneal topographer images. Simulations consider the behavior of a healthy cornea and of a keratoconus cornea. For the keratoconus the material properties of a portion of the cornea are reduced to 1/8 of the values used for the healthy tissue. It is found that, for suitable choice of the material parameters for the discrete model, in the healthy case the mechanical responses of the two models are fully comparable. In the keratoconus case, both models capture with comparable accuracy the anterior shape of the conus; in addition, the discrete model is able to describe the tissue thinning typical of the pathology. Despite the inclusion of stochastic material properties, starting from a healthy condition, continuum models of the cornea are not able to predict the thinning of a keratoconus cornea, while the inclusion of the underlying collagen microstructure allows for a proper description of pathologic mechanical behaviors.

Evolving Trends in the Diagnosis and Management of Keratoconus Over 3 Decades.

To report the trends in the clinical presentation, diagnosis, and management of keratoconus (KC) in patients presenting to a multitier hospital network over 33 years. This retrospective study included patients with KC presenting from 1987 to 2020. Patients with KC in at least 1 eye were included. The data of 20,576 patients included in this study were retrieved from the electronic medical record database. Data on patient demographics, ocular diagnosis, contact lens usage, and surgical history were collected and exported for analysis. Descriptive statistics and chi square test were used for statistical analysis. A total of 20,576 KC cases were seen from 1987 to 2020. Mean age at diagnosis reduced from 29.3 years (1987-1991) to 22.2 years (2016-2020). Adults (76.64%) were commonly affected with a majority being male (61.25%). Use of contact lenses increased from 4.34% (2002-2006) to 11.23% (2016-2020). Of the total number of surgical interventions, collagen crosslinking (CXL) constituted more than 1/5th (22.28%) between 2007 and 2011, which increased to more than half between 2012 and 2016 (53.61%) and almost 3/4th (72.53%) between 2017 and 2020. Advances in lamellar surgery have led to more patients undergoing deep anterior lamellar keratoplasty (DALK) as compared with penetrating keratoplasty. In the last 8 years, 17.2% patients underwent surgery and the most common was CXL (14.77%) followed by DALK (1.72%) and penetrating keratoplasty (1.04%). We report the trends in the clinical presentation and management of KC over 3 decades. In the last 33 years, advances in diagnostics have helped diagnose KC earlier. Contact lenses and advances in CXL have reduced the number of keratoplasties in KC, DALK being more common.

Diagnosis of forme fruste keratoconus with scheimpflug photography in Ghanaian patients

AimThis study aimed to differentiate moderate to high myopic astigmatism from forme fruste keratoconus using Pentacam parameters and develop a predictive model for early keratoconus detection.MethodsWe retrospectively analysed 196 eyes from 105 patients and compared Pentacam variables between myopic astigmatism (156 eyes) and forme fruste keratoconus (40 eyes) groups. Receiver operating characteristic curve analysis was used to determine the optimal cut-off values, and a logistic regression model was used to refine the diagnostic accuracy.ResultsStatistically significant differences were observed in most Pentacam variables between the groups (p < 0.05). Parameters such as the Index of Surface Variance (ISV), Keratoconus Index (KI), Belin/Ambrosio Deviation Display (BAD_D) and Back Elevation of the Thinnest Corneal Locale (B.Ele.Th) demonstrated promising discriminatory abilities, with BAD_D exhibiting the highest Area under the Curve. The logistic regression model achieved high sensitivity (92.5%), specificity (96.8%), accuracy (95.9%), and positive predictive value (88.1%).ConclusionThe simultaneous evaluation of BAD_D, ISV, B.Ele.Th, and KI aids in identifying forme fruste keratoconus cases. Optimal cut-off points demonstrate acceptable sensitivity and specificity, emphasizing their clinical utility pending further refinement and validation across diverse demographics.

Association of Novel Loci With Keratoconus Susceptibility in a Chinese Genome-Wide Association Study.

Keratoconus (KC) is a progressive corneal disease that can lead to corneal blindness if not properly managed. The purpose of this study was to identify genetic associations with KC in China and to investigate whether these genetic variants are associated with corneal thickness and corneal curvature in KC cases. A genome-wide association study was conducted on 853 patients with KC and 6248 controls. The KC cases were genotyped with the Illumina Infinium Human Asian Screening Array BeadChip, and the controls were genotyped with the Illumina Infinium Human Global Screening Array BeadChip. Genetic associations with KC, as well as correlations between the positive variants and corneal parameters including central corneal thickness (CCT) and mean keratometry (Km), were compared using PLINK version 1.90. Our present study identified four single-nucleotide polymorphisms (SNPs) within four risk loci (PTGER3: rs2300163, EYA1: rs1077435, ASS1: rs141365191, and CHTF8: rs3743680) associated with KC in Chinese patients that reached genome-wide significance. Among the identified SNPs with P < 1.00 × 10-4, seven SNPs (FOSL2-PLB1: rs12622211, RXRA-COL5A1: rs3118515, rs3132306, rs1536482, rs3118520, KAT6B: rs192187772, RAP2A-IPO5: rs41361245) were observed to be associated with CCT, and one SNP (USP13: rs6767552) was found to be associated with Km. In the first genome-wide association study of KC with a relatively large study population in China, we identified four SNPs in four risk loci associated with the disease. The findings enriched the understanding of genetic susceptibility to KC and provided new insights into the genetic etiology of the disease.

Corneal collagen cross-linking in patients with keratoconus from the Dresden protocol to customized solutions: theoretical basis.

Keratoconus is an ectatic condition characterized by gradual corneal thinning, corneal protrusion, progressive irregular astigmatism, corneal fibrosis, and visual impairment. The therapeutic options regarding improvement of visual function include glasses or soft contact lenses correction for initial stages, gas-permeable rigid contact lenses, scleral lenses, implantation of intrastromal corneal ring or corneal transplants for most advanced stages. In keratoconus cases showing disease progression corneal collagen crosslinking (CXL) has been proven to be an effective, minimally invasive and safe procedure. CXL consists of a photochemical reaction of corneal collagen by riboflavin stimulation with ultraviolet A radiation, resulting in stromal crosslinks formation. The aim of this review is to carry out an examination of CXL methods based on theoretical basis and mathematical models, from the original Dresden protocol to the most recent developments in the technique, reporting the changes proposed in the last 15y and examining the advantages and disadvantages of the various treatment protocols. Finally, the limits of non-standardized methods and the perspectives offered by a customization of the treatment are highlighted.

Prediction of the small aperture intraocular lens on visual acuity in patients with keratoconus.

To investigate the impact of corneal higher-order aberrations (HOAs) on predicted corrected distance visual acuity (CDVA) in patients with keratoconus at varying simulated pupil apertures. Ophthalmology Clinics, Medical University of South Carolina, Charleston, South Carolina. Retrospective chart review study. 56 eyes with keratoconus were examined using Scheimpflug tomography during routine examinations before medical intervention. The severity of keratoconus was graded using the Amsler-Krumeich classification. Zernike analysis was used to obtain corneal aberrations using simulated pupil diameters of 6 mm, 4 mm, and 2 mm. These data were extrapolated to obtain the total root mean square HOAs for a 1.6 mm simulated pupil to evaluate the potential effect of a small aperture intraocular lens (IOL). Correlation analysis was used to study the impact and relative contributions of HOAs on CDVA. Convolution of HOAs from OPD-Scan III provided a clinical method to predict CDVA with different simulated pupil sizes in corneas with irregular astigmatism. There were statistically significant positive correlations between photopic CDVA and the magnitude of total and individual (coma, spherical aberration, and trefoil) HOAs in this cohort of keratoconus participants. A keratoconus case with the small aperture IOL confirms the improvement in vision due to the pinhole effect. The small aperture IOL is expected to markedly reduce aberrations in patients with keratoconus up to Amsler-Krumeich class 4 severity to levels consistent with the levels seen in healthy patients. Convolution of corneal HOAs with the Early Treatment Diabetic Retinopathy Study chart provides a useful simulation of the impact of pinhole optics in aberrated eyes.

Deep anterior lamellar keratoplasty in advanced keratoconus in children: A 4-year study

Purpose: The purpose of the study was to evaluate the outcomes of deep anterior lamellar keratoplasty (DALK) in children and adolescents with advanced keratoconus (KC) at a tertiary eye care center in India. Design: This was a retrospective cross-sectional study. Methods: All cases of KC under the age group of 18 years, operated for DALK at a tertiary eye care center in South India, were evaluated from January 2018 to January 2022; outcome measures were best-corrected visual acuity (BCVA), graft clarity at final follow-up, and complications. Results: Of 27 eyes of 25 cases, 16 were male and 9 were female, with a mean age of presentation at 14.9 years. In stromal dissection technique, big bubble was attempted in 23 eyes and achieved in 20 eyes; manual dissection was done for the rest of the cases. Final BCVA varied from 0.1 to 0.6 logMAR units. Twenty-three eyes had excellent graft clarity at final follow-up. Complications noted in the study were intraoperative microperforation in four cases, postoperatively suture-related complications in three cases, and corneal graft rejection in one case. Conclusion: DALK in pediatric age group for advanced KC is an effective treatment option.

Mortality and Causes of Death Among Individuals With Keratoconus.

The purpose of this study was to determine whether there is an increased risk of mortality among individuals with keratoconus. This was a retrospective, case-control study using the Utah Population Database. Cases were defined as individuals diagnosed with keratoconus from 1996 to 2020 and were matched 5:1 with controls on birth year, sex, whether born in Utah, and follow-up time in Utah. Individuals diagnosed with trisomy 21 or connective tissue disease were excluded. Main outcome measures were the all-cause and cause-specific mortality among keratoconus cases compared with matched controls. Cox regression models were used, additionally adjusting for race and ethnicity. A total of 7847 keratoconus cases and 38,597 controls were studied in the final analyses. The mean age at index diagnosis was 43 ± 17 years, and mean age at last follow-up was 54 ± 17 years for both cases and controls. At last follow-up, 92% of cases were living compared with 91% of controls. After adjusting for covariates, there were no significant differences in all-cause mortality (P = 0.161), mortality from natural causes (0.222), or mortality from unnatural causes (P = 0.494) between cases and controls. When analyzed according to specific causes of death, keratoconus cases had a higher mortality risk from diseases of the nervous system and sense organs compared with their matching controls (hazard ratio 1.59; 95% confidence interval, 1.19-2.11; P = 0.002). There was no evidence of an increased risk of mortality among individuals with keratoconus. There may be an increased risk of death due to diseases of the nervous system and sense organs among individuals with keratoconus.

A rare case of bilateral keratoconus and granular corneal dystrophy managed with contact lens

Keratoconus (KC) is a bilateral, non-inflammatory, progressive thinning disorder of the cornea that results in high irregular astigmatism, distortion, and poor vision. Granular corneal dystrophy (GCD) is an autosomal dominant stromal dystrophy with onset in childhood that involves the entire cornea. KC associated with GCD is a rare combination that could occur due to abnormal synthetic activity of keratocytes and degeneration of defective basal epithelial cells. This case report shows the management of KC associated with GCD – an uncommon condition.

Genetic investigation in a four-generation Chinese family with congenital fibrosis of extraocular muscles and keratoconus

Here, we have reported the genetic and clinical characteristics of four generations of a family patient from China with congenital fibrosis of extraocular muscles 1 (CFEOM1) and keratoconus (KC). The history of diseases, clinical observations, and blood samples of all family members were collected. A total of 100 healthy participants were recruited as normal controls. The whole exome sequencing of the genomic DNA and polymerase chain reaction were performed on samples obtained from the controls and their family members to verify the gene variants. The functional analyses of the variants were performed by using different software. Two single nucleotide polymorphisms were detected in the proband and other patients in his families, including a heterozygous missense variation, g.39726207C > T (c.2860C > T, p.R954W, rs121912585), in the third highly conserved coiled-coil domain of KIF21A, and a heterozygous missense variant, g.30664732A > C (c.136A > C, p.S46R, rs200111443) in TGFBR2. The variant p.R954W in KIF21A was predicted to be pathogenic using software, whereas p.S46R in TGFBR2 was predicted to be of uncertain significance (VUS). Thus, KC might have occurred in the proband and his daughter because of a combination of genetic mutations and involuntary eye rubbing induced by CFEOM1. This is the first case of concomitant KC in a family having CFEOM1. Thus, the study provides new information about patients with KC having CFEOM1. Furthermore, the study suggests that attention should be paid to the early detection and diagnosis of KC in patients with CFEOM1.

AutoML-based neural network for the detection of keratoconus

For many years, the diagnosis of Keratoconus (KCN) has heavily relied upon the expertise and subjective judgment of clinicians. However, this study represents a pioneering effort to revolutionize KCN identification through the integration of Convolutional Neural Network (CNN) classification. In this innovative approach, the model is specifically designed to process corneal images as its primary input data, categorizing them into one of three distinct classes: KCN, suspect, or normal. Remarkably, this CNN model, meticulously implemented on the Edge Impulse platform, has achieved an astounding accuracy rate of 98.2% in correctly identifying KCN cases. Nevertheless, there remains substantial potential for improvement in the accurate classification of the suspect and normal categories. In conclusion, this study exemplifies the vast potential of CNNs to transform the diagnosis of keratoconus. With ongoing refinements, including enhanced data preprocessing, attention mechanisms, and quantitative integration, this approach could herald a transformative era in KCN identification and management.

Comparative posterior corneal profile of keratoconus hydrops versus Haab's striae in congenital glaucoma.

Keratoconus eyes develop corneal decompensation more often compared to eyes with primary congenital glaucoma (PCG) following Descemet's membrane (DM) tear. This study was conducted to compare the posterior corneal morphology in areas with DM breaks with regards to DM and pre-Descemet's layer (PDL) between the two. In this cross-sectional comparative study, anterior segment optical coherence tomography (AS-OCT) scans of the posterior cornea of advanced keratoconus eyes with hydrops ( n = 12), PCG eyes with Haab's striae ( n = 15), and healthy control eyes ( n = 14) were compared for DM-PDL morphology. These were further corroborated by the histopathology of corneal buttons from keratoconus ( n = 14) and PCG ( n = 13) cases obtained following penetrating keratoplasty and compared with controls (enucleated retinoblastoma globes, n = 6) on light microscopy and collagen IV immunostaining. AS-OCT showed a thicker median DM/PDL complex in PCG (80 µm) versus keratoconus eyes (36 µm, P = 0.01; Kruskal-Wallis test). The median height and length of detached DM-PDL were significantly more in keratoconus versus PCG (145 μm, 1766.1 ± 1320.6 μm vs. 26.5 μm, 453.3 ± 303.2 μm, respectively, P = 0.012; Kruskal-Wallis test). Type-1 DM/PDL detachment (seen as a characteristic taut chord) in keratoconus (90%) was the most common morphological pattern versus intracameral twin protuberance (92%) following DM breaks in PCG. Histopathology confirmed thicker DM in PCG (median: 63.4 μm) versus keratoconus eyes (median: 33.2 µm) or controls (27.1 μm) ( P = 0.001; Kruskal-Wallis test). Greater height/length of DM/PDL detachment compounded by poor healing response (lower DM/PDL thickness) probably causes more frequent corneal decompensation in keratoconus eyes when compared to PCG eyes following DM tears.

Keratoconus characteristics and associations: A cross-sectional keratoconus study in western India (CKSWI).

To study the clinical and tomographic characteristics and associations of keratoconus (KC) patients visiting a tertiary eye care hospital. This was a cross-sectional, observational study that included 242 newly diagnosed clinical KC patients. Detailed ocular and systemic history, visual complaints, habit of eye rubbing, best spectacle-corrected visual acuity (BSCVA), retinoscopy reflex, detailed slit-lamp examination and tomographic findings, and presence of any ocular and systemic associations were documented for the included patients. Severity of KC was further graded into stages 0, 1, 2, 3, and 4 according to the ABCD grading system. The most common visual complaint was blurred vision (82.64%), followed by itching (48.76%), tearing (43.80%), and photophobia (41.32%). A total of 44.62% of patients had the habit of eye rubbing and 4.54% had a family history of KC. Most common clinical signs were scissor reflex (94.21%), Rizutti's sign (77.27%), corneal protrusion (69.83%), and Fleischer ring (67.35%). A total of 14.05% of patients had stage 0, 42.15% had stage 1, 19.83% had stage 2, 18.60% had stage 3, and 5.37% had stage 4 KC. Of these patients, 70.25% had a BSCVA visual acuity of ≥6/12 or better; 26.45% had a BSCVA of ≥6/60 to <6/12; and 3.30% had a BSCVA of <6/60. Ocular allergies, atopy, and asthma were found in 32.32%, 4.96%, and 2.48% cases, respectively. This study gives an overview of the clinical findings of KC cases in western India. Our results suggest that use of retinoscopy should be promoted in early KC detection in primary eyecare screening programs.

Asymmetric All-Femtosecond Laser–Cut Corneal Allogenic Intrastromal Ring Segments

Purpose: To describe a novel technique for cutting asymmetric allogenic segments using the femtosecond laser for the management of cases of keratoconus with non-coinciding astigmatism and coma axes. Methods: Four eyes of 2 patients with irregular keratoconus and asymmetric allogenic segments were included. Visual, refractive, tomographic, and aberrometric outcomes, and optical coherence tomography (OCT) sections were measured preoperatively and 6 months postoperatively. Evaluations included slit-lamp examination, manifest refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuity, and simulated and maximum anterior keratometry (Kmax) using anterior segment OCT. Results: Spherical and cylindrical refractive errors decreased from −2.38 ± 2.96 and −2.94 ± 2.16 to −1.81 ± 2.77 ( P = .04) and −1.75 ± 2.07 ( P = .01) diopters (D), respectively, 6 months postoperatively. There was an average gain of three lines of CDVA. Kmax decreased from 50.02 ± 1.99 to 47.89 ± 3.05 D (P= .03) and coma from 1.05 ± 0.21 to 0.21 ± 0.19 D ( P = .01). Conclusions: Asymmetric femtosecond laser–cut allogenic segments allow a higher level of customization based on size, shape, and arc length, in contrast to the limited range of available synthetic asymmetrical segments. [ J Refract Surg . 2023;39(12):856–862.]

Association between Polymorphism rs61876744 in PNPLA2 Gene and Keratoconus in a Saudi Cohort.

The genetic etiology of Keratoconus (KC) in Middle Eastern Arabs of Saudi origin is still unclear. A recent genome-wide study identified two significant loci in the region of PNPLA2 (rs61876744) and CSNK1E (rs138380) for KC that may be associated with KC in the Saudi population. In addition, polymorphisms in the apolipoprotein E (APOE) gene, namely, rs429358 and rs7412, responsible for APOE allelic variants ε2, ε3, and ε4, may influence KC via oxidative stress mechanism(s). Thus, we investigated the possible association of polymorphisms rs61876744, rs138380, rs429358, rs7412, and APOE genotypes in KC patients of the Saudi population. This study included 98 KC cases and 167 controls. Polymorphisms rs6187644 and rs138380 were genotyped using TaqMan assays, and rs429358 and rs7412 were genotyped via Sanger sequencing. Although the allele frequency of rs61876744(T) in PNPLA2 was a protective effect against KC (odds ratio (OR) = 0.64, 95% confidence interval (CI) = 0.44-0.93), the p-value (p = 0.020) was not significant for multiple testing correction (p = 0.05/4 = 0.015). However, rs6187644 genotype showed a modestly significant protective effect in the dominant model (OR = 0.53, 95% CI = 0.32-0.88, p = 0.013). Polymorphisms rs138380, rs429358, and rs7412 showed no significant allelic or genotype association with KC. However, the ε2-carriers (ε2/ε2 and ε2/ε3 genotypes) exhibited a greater than 5-fold increased risk of KC, albeit non-significantly (p = 0.055). Regression analysis showed no significant effect of age, gender, and the four polymorphisms on KC. Our results suggest that polymorphism rs6187644 in PNPLA2 might be associated with KC in the Middle Eastern Arabs of Saudi origin but warrant a large-scale association analysis at this locus.

Prevalence and Economic Burden of Keratoconus in the United States

To assess the prevalence and economic burden of keratoconus in the United States. Retrospective cohort study. Patients enrolled in Medicaid and Children's Health Insurance Program (CHIP) who were diagnosed with keratoconus between 2016 and 2019 were included. The data reported to the Centers for Disease Control and Prevention (CDC) Vision and Eye Health Surveillance System (VEHSS) were analyzed. The crude prevalence rates (national and statewise) were obtained from the database and extrapolated to estimate the keratoconus case count in the United States. The keratoconus prevalence was compared between male and female individuals using the Mann-Whitney test, whereas Brown-Forsythe 1-way analysis of variance was used to compare prevalence between age and racial groups. The Dunnett T3 multiple comparison test was used for intergroup comparison. Finally, the economic burden of keratoconus was assessed by inflation-adjusted direct costs to patients and total cases in the country. In the cohort of 69,502,000 patients enrolled for Medicaid and CHIP, the national prevalence of keratoconus was computed to be 0.04% in 2019 and had increased from 0.03% in 2016. The highest prevalence of keratoconus was observed in patients 18 to 39 years of age, followed by patients 40 to 64 years of age; comparable prevalence rates were observed in these age groups in the Black population. The prevalence was moderately higher in female compared to male individuals; however, significantly higher keratoconus prevalence was observed in Black female individuals compared to male individuals. A significantly high prevalence of keratoconus was observed in the Black population, followed by Hispanic population. In 2019, the average inflation-adjusted lifetime cost of keratoconus treatment was USD 28,766.69, with a cumulative economic burden of USD 3.8 billion. In the United States, keratoconus is most prevalent in individuals 18 to 39 years of age. The keratoconus prevalence is higher in the Black population, specifically female individuals, and the diagnosis is often delayed in these patients.

Compensatory Corneal Epithelial Changes After Femtolaser - Assisted Intracorneal Rings Implantation in Early and Moderate Cases of Keratoconus.

To study the compensatory corneal epithelial changes after femtolaser-assisted intracorneal ring segment (ICRS) implantation in early and moderate cases of keratoconus (KC) using anterior segment optical coherence tomography (AS-OCT). A prospective observational non-randomized study of 40 eyes with mild to moderate KC received femtolaser-assisted ICRS implantation. Ferrara ICRS with different arc lengths and thicknesses were used according to the patients' tomographic pattern. Patients had a clear central cornea, keratometry reading < 60 diopters, and corneal thickness > 400 microns. AS-OCT was performed preoperatively and at 1, 3, and 6 months after surgery. Corneal epithelial thickness (CET) was measured over 17 points (2 mm central and 16 points on 2-5 mm and 5-7 mm annular zones) over the pupil center. All data were collected and analyzed. Comparing the preoperative and postoperative data, there was a statistically significant increase in the CET postoperatively throughout the 6-month follow-up period in all zones (p<0.001). The epithelial thickness (ET) was noticed shortly around and central to the ring ridges by the first month (5-7 mm zone). By the third month, the flattened central cornea (2 mm zone) and the 2-5 mm zone showed a significant increase in ET up to the 6th month. ICRS implantation in KC results in a thicker and more regular epithelium in the central corneal zone as a secondary response to the corneal stromal changes induced by the implants.

Development of a Web-Based Algorithm for Understanding the Intraocular Lens-Based Surgery in Stable and Progressing Keratoconus for Non-Specialist Ophthalmologists

Purpose To propose an algorithm to facilitate lens-based surgery in keratoconus. Methods A literature review was performed to prepare a software algorithm based on cone location, stability, best spectacle-corrected distance visual acuity (BSCVA) level and whether there is a clear or cataractous lens. The software usability was assessed through a 10-question questionnaire and two hypothetical keratoconus case histories (moderately simple and moderately complex) given to 15 trainees. The usability questionnaires were graded on a Likert scale (1 = strongly disagree to 5 = strongly agree) and two case histories (1 = very difficult to 7 = very easy). Results The algorithm can be found at https://www.sussexeyelaserclinic.co.uk/keratoconus/. Thirteen trainees completed the questionnaire. 91.9% would frequently use it; for 100%, it was easy to use independently without technical support; for 63.7%, it was strongly integrated; for 100%, it was consistent; 100% thought that most people would learn to use it quickly, 91.9% found the system not cumbersome to use, felt very confident to use it and need not learn a lot to use it. The first case was found easy by 63.7% and the second by 45%. Conclusion We present an algorithm as a guide for lens-based surgery in stable and progressing keratoconus, which is classified based on cone location. This algorithm will help trainee and “non-specialist” ophthalmic surgeons understand the pre-operative planning for the surgery and referral to the “specialist” corneal surgeon, considering factors such as progression, BSCVA, keratometry, topography and apex location of the cone in keratoconus patients.