The Chinese keratoconus (CKC) cohort study.

The Chinese keratoconus (CKC) cohort study is a population-based longitudinal prospective cohort study in the Chinese population involving a clinical database and biobanks. This ongoing study focuses on the prevention of KC progression and is the first to involve the effect of gene‒environment interactions on KC progression. The CKC cohort is hospital-based and dynamic and was established in Zhengzhou, China; KC patients (n = 1114) from a large geographical area were enrolled from January 2019 to June 2023, with a mean age of 22.23 years (6‒57 years). Demographic details, socioeconomic characteristics, lifestyle, disease history, surgical history, family history, and visual and social function data are being collected using questionnaires. General physical examination, eye examination, biological specimen collection, and first-degree relative data were collected and analyzed in the present study. The primary focus of the present study was placed on gene, environment and the effect of gene‒environment interactions on KC progression. The follow-up of the CKC cohort study is expected to include data collection at 3 months, 6 months, and 1 year after the initial examination and then at the annual follow-up examinations. The first follow-up of the CKC cohort study was recorded. A total of 918 patients completed the follow-up by June 1, 2023, with a response rate of 82.40%. Aside from the younger age of patients who were followed up, no significant differences were found between patients who were followed up and patients who were not.

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

Purpose: 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. Methods: 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. Results: 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. Conclusions: 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.

Electrochemical coalescence of oil-in-water droplets in microchannels of TiO2-x/Ti anode via polarization eliminating electrostatic repulsion and ·OH oxidation destroying oil-water interface film.

Electrochemistry is a sustainable technology for oil-water separation. In the common flat electrode scheme, due to a few centimeters away from the anode, oil droplets have to undergo electromigration to and electrical neutralization at the anodic surface before they coalesce into large oil droplets and rise to water surface, resulting in slow demulsification and easy anode fouling. Herein, a novel strategy is proposed on basis of a TiO2-x/Ti anode with microchannels to overcome these problems. When oil droplets with several microns in diameter flow through channels with tens of microns in diameter, the electromigration distance is shortened by three orders of magnitude, electrical neutralization is replaced by polarization coupling ·OH oxidation. The new strategy was supported by experimental results and theoretical analysis. Taking the suspension containing emulsified oil as targets, COD value dropped from initial 500 mg/L to 117 mg/L after flowing through anodic microchannels in only 58 s of running time, and the COD removal was 21 times higher than that for a plate anode. At similar COD removal, the residence time was 48 times shorter than that of reported flat electrodes. Coalescences of oil droplets in microchannels were observed by a confocal laser scanning microscopy. This new strategy opens a door for using microchannel electrodes to accelerate electrochemical coalescence of oil-in-water droplets.

Machine learning analysis with the comprehensive index of corneal tomographic and biomechanical parameters in detecting pediatric subclinical keratoconus.

Background: Keratoconus (KC) occurs at puberty but diagnosis is focused on adults. The early diagnosis of pediatric KC can prevent its progression and improve the quality of life of patients. This study aimed to evaluate the ability of corneal tomographic and biomechanical variables through machine learning analysis to detect subclinical keratoconus (SKC) in a pediatric population. Methods: Fifty-two KC, 52 SKC, and 52 control pediatric eyes matched by age and gender were recruited in a case-control study. The corneal tomographic and biomechanical parameters were measured by professionals. A linear mixed-effects test was used to compare the differences among the three groups and a least significant difference analysis was used to conduct pairwise comparisons. The receiver operating characteristic (ROC) curve and the Delong test were used to evaluate diagnostic ability. Variables were used in a multivariate logistic regression in the machine learning analysis, using a stepwise variable selection to decrease overfitting, and comprehensive indices for detecting pediatric SKC eyes were produced in each step. Results: PE, BAD-D, and TBI had the highest area under the curve (AUC) values in identifying pediatric KC eyes, and the corresponding cutoff values were 12 µm, 2.48, and 0.6, respectively. For discriminating SKC eyes, the highest AUC (95% CI) was found in SP A1 with a value of 0.84 (0.765, 0.915), and BAD-D was the best parameter among the corneal tomographic parameters with an AUC (95% CI) value of 0.817 (0.729, 0.886). Three models were generated in the machine learning analysis, and Model 3 (y = 0.400*PE + 1.982* DA ratio max [2 mm]-0.072 * SP A1-3.245) had the highest AUC (95% CI) value, with 90.4% sensitivity and 76.9% specificity, and the cutoff value providing the best Youden index was 0.19. Conclusion: The criteria of parameters for diagnosing pediatric KC and SKC eyes were inconsistent with the adult population. Combined corneal tomographic and biomechanical parameters could enhance the early diagnosis of young patients and improve the inadequate representation of pediatric KC research.

Mitochondrial DNA heteroplasmy analysis in keratoconus patients from China.

Background: Mitochondrial DNA (mtDNA) variants have been implicated in keratoconus (KC). The present study aimed to characterize the mtDNA heteroplasmy profile in KC and explore the association of mitochondrial heteroplasmic levels with KC. Methods: Mitochondrial sequencing of peripheral blood samples and corneal tomography were conducted in 300 KC cases and 300 matched controls. The number of heteroplasmic and homoplasmic variants was calculated across the mitochondrial genome. Spearman's correlation was used to analyze the correlation between the number of heteroplasmic variants and age. The association of mtDNA heteroplasmic level with KC was analyzed by logistic regression analysis. Moreover, the relationship between mitochondrial heteroplasmic levels and clinical parameters was determined by linear regression analysis. Results: The distribution of mtDNA heteroplasmic variants showed the highest number of heteroplasmic variants in the non-coding region, while the COX3 gene exhibited the highest number in protein-coding genes. Comparisons of the number of heteroplasmic and homoplasmic non-synonymous variants in protein-coding genes revealed no significant differences between KC cases and controls (all p > 0.05). In addition, the number of heteroplasmic variants was positively associated with age in all subjects (r = 0.085, p = 0.037). The logistic regression analyses indicated that the heteroplasmic levels of m.16180_16181delAA was associated with KC (p < 0.005). Linear regression analyses demonstrated that the heteroplasmic levels of m.16180_16181delAA and m.302A>C were not correlated with thinnest corneal thickness (TCT), steep keratometry (Ks), and flat keratometry (Kf) (all p > 0.05) in KC cases and controls separately. Conclusion: The current study characterized the mtDNA heteroplasmy profile in KC, and revealed that the heteroplasmic levels of m.16180_16181delAA were associated with KC.

CircularRNA Hsa_circ_0093335 promotes hepatocellular carcinoma progression via sponging miR-338-5p.

Circular RNAs play an important role in the development of various malignancies, including hepatocellular carcinoma (HCC). Nevertheless, the role of Hsa_circ_0093335 (circ0093335) in HCC has not yet been explored. To investigate the biological effects and molecular mechanisms of circ0093335 on HCC. Circ0093335 expression was detected in HCC cells and clinical specimens using qRT-PCR. The association between circ0093335 expression and HCC patients' clinical characteristics was determined using SPSS. The role of circ0093335 in HCC was estimated by overexpression and knockdown experiments in vitro and in vivo. qRT-PCR, nucleoplasma separation assay, FISH assay, RIP, dual luciferase reporter assay and rescue assay were used to validate the regulatory effect of circ0093335 on miR-338-5p. The study findings showed that circ0093335 was upregulated in HCC. High circ0093335 expression was linked with the tumour-node-metastasis stage and microvascular tumour invasion. circ0093335 is greatly involved in HCC cell proliferation, aggressive ability and mouse tumour growth, according to many in vitro and in vivo tests. Mechanistically, circ0093335 downregulated miR-338-5p expression by sponging, consequently promoting HCC progression. Our research indicated that circ0093335 might be a target for HCC therapy since it promotes tumour progression by acting as a miR-338-5p 'sponge'.

A high body mass index strengthens the association between the time of eye rubbing and keratoconus in a Chinese population: a case control study.

BACKGROUND: Although body mass index (BMI) and eye rubbing are linked to an increased risk of keratoconus (KC), the interactive effect of eye rubbing and BMI on KC is largely unknown. This study aimed to evaluate the independent and interactive effects of BMI and eye rubbing on KC and to further explore the role of environmental factors on the occurrence of KC. METHODS: A total of 621 individuals (291 KC patients and 330 control individuals) were enrolled in this hospital­based study on KC patients in Central China after individuals missing BMI data were excluded. BMI was calculated as weight in kilograms divided by the square of height in meters. Data on eye rubbing was recorded through face-to-face interviews. Generalized linear regression models were used to analyze associations among BMI, eye rubbing and KC. Interaction plots were used to describe the interactive effects of BMI and eye rubbing on KC. RESULTS: The ß and 95% confidence interval (CI) were 0.923 (0.112, 1.733) (p = 0.026) and 3.356 (1.953, 4.759) (p < 0.001), respectively, for the effect of each 10 kg/m2 increase in BMI and each 1 min increase in eye rubbing on KC. The interaction of BMI and eye rubbing were positively correlated with KC (p < 0.001). CONCLUSION: These findings suggested that a high BMI aggravated the negative effect of eye rubbing on KC, implying that individuals with a high BMI may be more susceptible to exposure to eye rubbing, which is related to an increased risk of KC.

Accuracy of tomographic and biomechanical parameters in detecting unilateral post-LASIK keratoectasia and fellow eyes.

Background: Patients with unilateral post-LASIK keratectasia (KE) have clinical ectasia in one eye but not in the fellow eye. As serious complications, these cases are rarely reported but are worth investigating. This study aimed to explore the characteristics of unilateral KE and the accuracy of corneal tomographic and biomechanical parameters to detect KE and distinguish fellow eyes from control eyes. Methods: The study analyzed 23 KE eyes, 23 KE fellow eyes, and 48 normal eyes from age- and sex-matched patients who had undergone LASIK. The Kruskal-Wallis test and further paired comparisons were performed to compare the clinical measurements of the three groups. The receiver operating characteristic curve was used to evaluate the ability to distinguish KE and fellow eyes from the control eyes. Binary logistic regression with the forward stepwise method was performed to produce a combined index, and the DeLong test was used to compare the discriminability difference of the parameters. Results: Males accounted for 69.6% of patients with unilateral KE. The duration between corneal surgery and the onset of ectasia ranged from 4 months to 18 years, with a median time of 10 years. The KE fellow eye had a higher posterior evaluation (PE) value than the control eyes (5 vs. 2, p = 0.035). Diagnostic tests showed that PE, posterior radius of curvature (3 mm), anterior evaluation (FE), and Corvis biomechanical index-laser vision correction (CBI-LVC) were sensitive indicators for distinguishing KE in the control eyes. The ability of PE to detect the KE fellow eye from the control eye was 0.745 (0.628 and 0.841), with 73.91% sensitivity and 68.75% specificity at a cut-off value of 3. The ability of a combined index, constructed using PE and FE, to distinguish fellow eyes of KE from controls was 0.831 (0.723 and 0.909), which was higher than that of PE and FE individually (p < 0.05). Conclusion: The fellow eyes of patients with unilateral KE had significantly higher PE values than control eyes, and a combination of PE and FE enhanced this differentiation in a Chinese population. More attention should be paid to the long-term follow-up of patients after LASIK and to be wary of the occurrence of early KE.

Facilitated OH¯ diffusion via bubble motion and water flow in a novel electrochemical reactor for enhancing homogeneous nucleation of CaCO3.

Electrochemistry is a potential method for water softening. An essential disadvantage is OH¯ ions from water electrolysis accumulate on cathode surface, inducing the generation of the insulating CaCO3 layer and then interrupting the electrochemical reaction. In order to propel OH¯ diffusion into the bulk solution instead of aggregation at cathode, we designed an electrochemical reactor, whose electrodes were placed horizontally in the middle of the reactor, and the bubbles created by water electrolysis move upward, while the water flows downward. The visual evidence displayed that the unique reactor structure allowed OH¯ to spread to almost all the solution rapidly. Average pH value of bulk solution reached 10.6 in only 3 min. Therefore, homogeneous nucleation of CaCO3 in bulk solution would take primary responsibility for water softening, and the softening efficiency is up to 212.9 g CaCO3/h/m2, higher than reported results. The reactor is easy to scale up, providing a new idea for the softening of circulating cooling water.

Bioinformatics analysis of key candidate genes and pathways in Chinese patients with keratoconus.

Keratoconus (KC) is a multifactorial disease in which genetic factors played important roles in its pathogenesis. The purpose of the current study was to identify the key candidate genes and pathways in Chinese patients with KC through bioinformatics analysis. Totally, we identified 71 candidate genes by analyzing the results of whole exome sequencing on 51 Chinese patients with KC, combining with previous reports on differential expression at transcription and protein levels in KC. Gene enrichment analysis with GeneCodis demonstrated that two significantly enriched terms including 21 genes in biological process (BP) were detected, and six significantly enriched terms containing 14 genes in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were discovered. The STRING was utilized to construct the protein-protein interaction (PPI) network of identified genes. The result showed that a PPI network consisted of 14 nodes with 14 edges was constructed, and two gene modules were obtained. Eight hub genes (LAMB3, LAMA3, LAMA1, ITGA6, ITGA3, COL6A3, COL6A2, and COL6A1) were identified as key candidate genes for KC by cytoHubba in Cytoscape. Functional enrichment analysis with ClueGO and CluePedia indicated that the ECM-receptor interaction was the key pathway accounted for KC. The findings might provide novel insights on the genetic basis of KC.

Portable smartphone-assisted ratiometric fluorescence sensor for visual detection of glucose.

Fluorescence-based visual assays have sparked tremendous attention in on-site detection due to their obvious color gradient changes and high sensitivity. In this study, a novel emission wavelength shift-based visual sensing platform is constructed to detect glucose based on the oxidation of Rhodamine B (RhB). MnO2 nanosheets (MnO2 NS) with strong oxidizing properties were introduced to oxidize RhB, which resulted in a blue shift in the emission wavelength, and a visual color changed of the fluorescence from orange-red to green. The oxidation reaction could be inhibited via reducing and destroying MnO2 NS by H2O2, which was produced by the oxidizing procedure of glucose in the presence of glucose oxidase (GOx). A series of wavelength shifts and fluorescence color variations appeared with the addition of various amounts of glucose. A ratiometric fluorescence glucose sensor with a lowest recorded concentration of 0.25 µM was developed. Meanwhile, test paper-based assays integrated with the smartphone platform were established for the sensing of glucose by means of the significant fluorescence color changes, offering a reliable, sensitive, and portable on-site assay of glucose.

A novel technique to quantify bone-to-implant contact of zygomatic implants: a radiographic analysis based on three-dimensional image registration and segmentation.

OBJECTIVES: The purpose of this study is to establish a novel, reproducible technique to obtain the BIC area (BICA) between zygomatic implants and zygomatic bone based on post-operative cone-beam computed tomography (CBCT) images. Three-dimensional (3D) image registration and segmentation were used to eliminate the effect of metal-induced artifacts of zygomatic implants. METHODS: An ex-vivo study was included to verify the feasibility of the new method. Then, the radiographic bone-to-implant contact (rBIC) of 143 implants was measured in a total of 50 patients. To obtain the BICA of zygomatic implants and the zygomatic bone, several steps were necessary, including image preprocessing of CBCT scans, identification of the position of zygomatic implants, registration, and segmentation of pre- and post-operative CBCT images, and 3D reconstruction of models. The conventional two-dimensional (2D) linear rBIC (rBICc) measurement method with post-operative CBCT images was chosen as a comparison. RESULTS: The mean values of rBIC and rBICc were 15.08 ± 5.92 mm and 14.77 ± 5.14 mm, respectively. A statistically significant correlation was observed between rBIC and rBICc values ([Formula: see text]=0.86, p < 0.0001). CONCLUSIONS: This study proposed a standardized, repeatable, noninvasive technique to quantify the rBIC of post-operative zygomatic implants in 3D terms. This technique is comparable to conventional 2D linear measurements and seems to be more reliable than these conventional measurements; thus, this method could serve as a valuable tool in the performance of clinical research protocols.

Trio-based exome sequencing broaden the genetic spectrum in keratoconus.

Keratoconus (KC) is a complex corneal disorder with genetic factors involving in its pathogenesis. The genetic etiology of KC has not been fully elucidated. In this study, we aimed to expand the genetic spectrum in KC by trio-based exome sequencing. Trio-based exome sequencing was conducted in 20 patients with KC and their unaffected parents to broaden the genetic spectrum of the disease. With a series of filtering criteria, de novo, recessive homozygous, and compound heterozygous variants in candidate genes were identified, and the candidate genes were classified for further analysis. Finally, we identified 60 variants in 32 candidate genes through trio-based exome sequencing. Among the candidate genes, 10 genes (ARHGEF10, ARHGEF17, ASPM, FLNA, NDRG1, NEB, PLS3, STARD8, SYNE1, TTN) were classified as cytoskeleton-related genes, 4 genes (COL28A1, SDK1, STAB1, TENM2) were classified as cell adhesion-related genes, and 18 genes (APLP2, BCORL1, CCNB3, FOXN1, FUT8, GALNT10, HEPH, HHIP, HMGB3, HS6ST2, JADE3, KIAA0040, MCF2L, MYOF, QRICH2, RPS6KA6, SMARCA1, TNRC6A) were classified into other genes group. Additionally, the candidate rare deleterious variants in TTN were highly repeated in 25% trios. In conclusion, the study provided new insights into the genetic spectrum of KC which might underlie the genetic etiology for the disease. The findings would improve our understanding of pathogenesis in KC and provide critical clues to future functional validation.

Trends in research on corneal cross linking from 2001 to 2020: a bibliometric analysis.

CLINICAL RELEVANCE: The research status and hotspots in the field of corneal cross linking (CXL) can benefit clinicians, researchers and the general public. BACKGROUND: The purpose of this study was to map the publishing trend on CXL research and explore the research hotspots. METHODS: A bibliometric analysis was performed using the Web of Science Core Collection to investigate the publishing trend on CXL research. VOSviewer was used to build the knowledge map to visualise the number of annual publications, distribution of countries and institutions, international cooperation, author productivity, source journals and research hotspots in the field of CXL. RESULTS: A total of 2061 peer-reviewed articles on CXL research were collected from 2001 to 2020, and the annual research production increased over time. The United States was the country with the largest number of published articles, and the University of Zurich was the most active institution. Hafezi F published the largest number of articles on CXL, while Cornea was the journal with the largest number of studies on CXL. The most frequently cited references mainly focus on CXL in the treatment of keratoconus. The keywords were divided in 5 categories: 1) CXL mechanism, 2) ectasia diseases and refractive surgery, 3) corneal biomechanics, 4) efficacy evaluation, 5) treatment of infectious keratitis. CONCLUSION: The quantity and quality of articles on CXL were evaluated using bibliometric techniques by extracting the data from the Web of Science Core Collection. The research hotspots could provide insights on CXL research, providing valuable information for clinicians to perform research in this field and find potential partners.

Family-based exome sequencing identifies candidate genes related to keratoconus in Chinese families.

Background: Keratoconus (KC) is a complex corneal disorder with a strong genetic component. The present study aimed to identify candidate genes related to KC in Chinese families. Methods: Family-based exome sequencing was performed in ten patients suffering from KC who belong to five families with two affected members in each. The candidate rare variants were identified with multi-step bioinformatics analysis. The STRING website was used to perform the protein interaction of the identified genes. Results: Our analyses identified 32 candidate rare variants in 13 genes by family-based exome sequencing. The molecular analyses of identified genes showed that EPCAM directly interacted with CTNNB1 of the Hippo signaling pathway and focal adhesion pathway, and directly interacted with CTNNB1, CDH1 of the WNT signaling pathway. SHROOM3 directly interacted with ROCK2, ROCK1 of the focal adhesion pathway. SYNE1 directly interacted with MUSK of the extracellular matrix organization pathway. TEK directly interacted with VEGFA, SHC1, PIK3R1, GRB2 of the focal adhesion pathway. TTN directly interacted with CAPN3 of the extracellular matrix organization pathway. Conclusion: The EPCAM, SHROOM3, SYNE1, TEK, and TTN genes were potential high-risk candidate pathogenic genes of familial KC. The findings might significantly improve our understanding of the genetic etiology of the disease, providing novel insights on KC pathogenesis.

Bacterial Keratitis Following Small Incision Lenticule Extraction.

Purpose: To describe the development of bacterial keratitis after small incision lenticule extraction in 5 patients and to explore its appropriate therapies. Methods: We retrospectively summarized the clinical treatments of five patients with postoperative bacterial infection after small incision lenticule extraction, who were referred to our hospital from 2019 to 2021. Results: Five male patients had undergone bilateral SMILE in the local hospital due to myopia aged from 18 to 26 years. The onset of keratitis during 1-3 days postoperatively and four of them were severe infection (2 bilateral, 2 unilateral). In five cases, 1 patient (1 eye) who was infected mild keratitis after SMILE was treated with only topical antibiotics; the others who respond poorly to topical antibiotics require surgical treatment, which 1 patient (1 eye) infected necrotic mass of the corneal cap was scraped and irrigated with antibiotic, and 3 patients (5 eyes) were treated by converting the cap to flap, curetting the necrotic tissue and irrigating with the antibiotic solution. In all patients, the duration from onset to resolution was 1-5 weeks. The final uncorrected visual acuity was above 20/32. Conclusion: Owing to the upward popularity of refractive surgery, the incidence of keratitis after SMILE should not be ignored. Early diagnosis and timely treatment of post-SMILE keratitis are essential. For severe keratitis that fails to respond to topical antibiotics, the corneal cap should be opened as a flap.

Distribution of pediatric keratoconus by different age and gender groups.

Purpose: To evaluate the distribution of pediatric keratoconus patients and the disease severity based on different age and gender groups in China. Materials and methods: A total of 446 keratoconus eyes in 266 pediatric patients from January 2019 to January 2022 were included in the cross-sectional study. The clinical findings and severity of keratoconus were recorded and Kruskal-Wallis test, chi-squared test, and Cochran-Mantel-Haenszel (CMH) test were used to compare the parameters between different gender and age groups. Results: The male/female ratio was 353/93 (3.8:1), and the median age was 16 years (range: 6-17 years). Male patients were statistically younger than female patients (P = 0.041). The male/female ratio decreased with age (P for trend = 0.011). The distribution of the topographic keratoconus classification (TKC) stage was significantly different between gender and age groups (all P < 0.05). Male patients had a higher ratio of advanced keratoconus eyes (TKC ≥ 3) than female patients (P < 0.001), and CMH analysis indicated that being a male was a risk factor for advanced keratoconus after controlling for age (odds ratio: 2.581, P < 0.001). Conclusion: Male keratoconus patients were younger, with a higher ratio of advanced keratoconus than female patients in the Chinese pediatric patients evaluated. Multicenter studies with larger sample sizes are necessary in the future.

Heritability of Corneal Parameters in Nuclear Families With Keratoconus.

Purpose: This study aimed to investigate the heritability of corneal parameters obtained by Pentacam in nuclear families with keratoconus (KC). Methods: A total of 82 patients with KC and their biological parents (n = 164) were recruited in the current study. All subjects underwent corneal tomography with Pentacam. Family units were analyzed to calculate the heritability of corneal parameters by linear mixed effects model using the R statistical software. Results: The pachymetry at apex, pupil, and thinnest point were all significantly heritable at 43.26%, 42.63%, and 43.09%, respectively. The heritability of flat meridian keratometry, steep meridian keratometry, and mean keratometry in the anterior surface were 10.36%, 9.05%, and 10.21%, respectively, and that of flat meridian keratometry, steep meridian keratometry, and mean keratometry in the posterior surface were 8.44%, 9.67%, and 9.06%, respectively. The posterior radius of curvature had higher heritability in comparison with anterior radius of curvature (19.16% vs. 14.37%). Moreover, among combined topometric indices, the heritability of index of vertical asymmetry was the highest (19.49%), and that of central keratoconus index was the lowest (6.64%). Conclusions: The present study demonstrated a substantial heritability of corneal parameters in nuclear families with KC. The pachymetric indices are heritable and may be suitable as KC endophenotypes, suggesting a necessity to discover the genes associated with corneal thickness in KC. Translational Relevance: The pachymetric indices are heritable and may be suitable as KC endophenotypes, indicating that the pachymetric indices might be a corneal characteristic to predict the occurrence of KC.

A Hospital-Based Study on the Prevalence of Keratoconus in First-Degree Relatives of Patients with Keratoconus in Central China.

Purpose: The present study investigated the prevalence of keratoconus (KC) among first-degree relatives of KC patients in Central China. Methods: From July 2018 to March 2022, 661 first-degree relatives of 384 KC patients were included in the present study. Corneal tomography, uncorrected distance visual acuity, manifest refraction with corrected distance visual acuity, intraocular pressure, slit-lamp microscopy, and fundus examination were performed. The diagnosis of KC was based on the Belin/Ambrosio enhanced ectasia total deviation value (BAD-D value) on the Pentacam® system (Oculus GmbH). BAD-D value <1.6 was diagnosed as healthy, 1.6≤ BAD-D value <2.6 was diagnosed as suspected KC, and BAD-D value ≥2.6 was diagnosed as KC. Results: The present study included 337 (50.98%) female and 324 (49.02%) male subjects. The prevalence of KC and suspected KC in first-degree relatives was 8.77% (n = 58) and 29.05% (n = 192), respectively. The prevalence of KC was 9.70% among parents and 7.23% among siblings. Conclusions: The higher prevalence of KC among first-degree relatives of patients with KC suggests that first-degree relatives of KC are at high risk of developing KC.

A Bibliometric Analysis of 100 Most-Cited Articles on Corneal Cross-Linking.

Background: Highly cited papers are expected to have high-quality data that significantly contribute to the body of knowledge. The study aimed to evaluate the characters of the 100 most-cited articles on corneal cross-linking (CXL) through a bibliometric analysis. Materials and Methods: The Web of Science database was searched to identify papers published from 1950 to 2020. A bibliometric analysis of the top 100-cited articles was conducted in the current study. The citation differences between basic research, clinical research, and reviews were compared by Kruskal-Wallis test. The association between citations and publication year was evaluated by Spearman correlation analysis. The VOSviewer software was used to create networks of co-authorship and keywords map. Results: The median values of the number of citations, citations/year since publication, and citations since 2013 were 101, 9.5, and 11.92, respectively. A total of 61% of articles were clinical research. The citations since 2013 of clinical research were lower than basic research and the reviews (all p < 0.001). The publication year was positively correlated with the number of publications (r = 0.665, p = 0.013), and the total number of citations decreased for basic research (r = -0.447, p = 0.017), and clinical research (r = -0.433, p < 0.001). The J REFRACT SURG publishes the highest number of articles. The corresponding authors were predominantly from the Italy (N = 17), Germany (N = 16), and United States (N = 15). Spoerl Eberhard has the highest number of citations and total link strength with 15 articles. Extensive collaboration existed among the main core nodes containing "cross-linking (N = 45)," "riboflavin (N = 44)," and "ultraviolet A (UVA) (N = 42)." Conclusion: The present study focused on the comprehensive analysis of the top 100-cited articles on the CXL research, providing insight into research developments over the past decades.