Evaluation of tear film function by Oculus Keratograph 5M and IDRA ocular surface analyser.

PURPOSE: The aim of this study was to evaluate the function of tear film with Oculus Keratograph 5M (Oculus K5M) and IDRA ocular surface analyser (IDRA), analyse their consistency and explore the potential of IDRA in the diagnosis of dry eye disease (DED). METHODS: This cross-sectional study enrolled 36 participants (DED group, 14 eyes; non-DED group, 22 eyes). The parameters of tear film function, including the first noninvasive breakup time (fNIBUT), average NIBUT (aNIBUT), tear meniscus height (TMH), lipid layer thickness (LLT), lipid layer colour (LLC), lipid layer uniformity (LLU), morphology of meibomian glands (MGs) and MG loss, were obtained with Oculus K5M and IDRA. The consistency of parameter measurements between the two devices was evaluated. RESULTS: All the parameters except LLT, which can be measured only by IDRA, were not significantly different between the two instruments in DED eyes. However, IDRA reported lower values of fNIBUT, aNIBUT and TMH as well as higher MG loss scores in non-DED eyes than Oculus K5M did (p < 0.001, < 0.001, = 0.002, and = 0.002, respectively). Further regression analysis revealed that aNIBUT and LLT measured by IDRA were the optimal parameters for diagnosing DED (OR = 0.567 and 0.845, p = 0.057 and 0.043, respectively), and their combination had the strongest diagnostic potential (AUC = 0.841, sensitivity = 85.7%, and specificity = 77.3%). CONCLUSION: As a user-friendly noninvasive device, the tear film function parameters measured by IDRA were highly consistent with those measured by Oculus K5M in DED patients. The combination of aNIBUT and LLT measured by IDRA had the best diagnostic accuracy for DED.

Analysis of the first tear film break-up point in Sjögren's syndrome and non-Sjögren's syndrome dry eye patients.

BACKGROUND: Tear film instability plays an important role in the course of Sjögren's Syndrome dry eye (SSDE) even though it is generally classified as aqueous-deficient dry eye. The measurement of the first tear film break-up point (FTBUP) helps to evaluate the most unstable position of the tear film on ocular surface. We aim to investigate FTBUP in Sjögren's Syndrome dry eye (SSDE) and non-Sjögren's Syndrome dry eye (NSSDE) patients, and explore its correlation with dry eye indices. METHODS: Twenty-two SSDE patients (44 eyes) and 22 NSSDE patients (44 eyes) were enrolled in the study. Oculus Keratograph K5M was used to measure FTBUP, the first and average non-invasive keratographic breakup time (f-NIKBUT and av-NIKBUT), the tear meniscus height, and meibomian gland dropout. Other tests of tear film were also performed including Ocular Surface Dryness Index (OSDI), Schirmer I test, fluorescein break-up time and corneal fluorescein staining. Dry eye indices and the locations of the FTBUP were compared between SSDE and NSSDE patients. Generalized estimating equation (GEE) was used to ajusted the correlations between right and left eyes. The correlations between the FTBUP and ocular symptoms and signs were investigated using Pearson's correlation coefficient test. RESULTS: The FTBUP occurred at the supranasal quadrant in 12/88 eyes, supratemporal quadrant in 8/88 eyes, inferonasal quadrant in 34/88 eyes, and inferotemporal quadrant in 34/88 eyes. The percentage eyes with inferior FTBUP was significantly higher in the SSDE than in the NSSDE subjects (86.3% vs 68.1%, P = .049). Moreover, in SSDE subjects, temporal breakup point was seen more often in those who presented corneal fluorescein staining in any location, while nasal breakup point was more frequent in those who did not present any corneal fluorescein staining (P = .045). CONCLUSION: The location of the FTBUP in SSDE patients had specific characteristics. However, the diagnostic potential of FTBUP in early recognition of SSDE needs further validation.

Trends of Corneal Transplantation in Adults from 2010 to 2019 in East China: A 10-Year Experience.

INTRODUCTION: The aim of the study was to provide an overview of trends in the indications and surgical techniques for corneal transplantation in adults in East China from 2010 to 2019. METHODS: The medical charts of all patients (aged ≥18 years old) undergoing keratoplasty at the Eye, Ear, Nose and Throat Hospital of Fudan University between January 2010 and December 2019 were retrospectively reviewed. The indications for keratoplasty and the surgical techniques were collected. RESULTS: A total of 2,929 cases were included. Acquired nontraumatic corneal diseases (n = 1,927, 65.8%) have been the leading indication for corneal transplantation during the past decade. Although infectious keratitis was still the leading indication among acquired nontraumatic diseases, its absolute number and proportion gradually decreased during this decade (p < 0.001). In contrast, the proportion of endothelial dysfunction/bullous keratopathy increased from 7.8% in 2010 to 12.4% in 2019 (p = 0.029). Penetrating keratoplasty (PKP) has been the predominant surgical technique (n = 1,854, 63.3%), followed by deep anterior lamellar keratoplasty (DALK) (n = 361, 12.3%) and endothelial keratoplasty (EK) (n = 305, 10.4%). Nevertheless, the proportion of PKP decreased from 77.6% in 2010 to 56.9% in 2019 (p = 0.002) and was gradually replaced by DALK (from 7.8% to 16.3%, p < 0.001) and EK (from 3.4% to 10.4%, p = 0.009). CONCLUSIONS: Over the past decade, infectious keratitis and endothelial dysfunction/bullous keratopathy have been the leading indications for keratoplasty in adults. Preferred surgical techniques for keratoplasty have been shifting from PKP to more customized lamellar keratoplasties.

Femtosecond laser-assisted Descemet's stripping endothelial keratoplasty: a prospective study of 6-month visual outcomes, corneal thickness and endothelial cell loss.

PURPOSE: To report 6-month outcomes of visual acuity, the corneal thickness and endothelial cell density (ECD) in patients undergoing femtosecond laser-assisted Descemet's stripping endothelial keratoplasty (FS-DSEK). METHODS: This prospective, consecutive, interventional series examined 25 eyes of 25 patients who underwent FS-DSEK for Fuchs endothelial dystrophy and bullous keratopathy. The pre-cut corneal endothelial graft thickness (CET) was 150 µm. Best-corrected visual acuity (BCVA), central corneal thickness (CCT), donor CET, recipient corneal stromal thickness (CST) and ECD were assessed at 1 week and 1, 2, 3 and 6 months postoperatively. RESULTS: The mean BCVA at 6 months was 0.76 ± 0.35 logMAR units, improving from 1.54 ± 0.52 logMAR. CCT decreased significantly, from 759.8 ± 152.4 µm at 1 week to 631.7 ± 79.7 µm at 6 months (P = 0.001) postoperatively. CET recovered to 153.4 ± 33.7 µm (P = 0.076) at 6 months as pre-cut status. The CST decreased from 561.5 ± 96.3 µm at 1 week to 479.7 ± 57.9 µm at 6 months (P < 0.001). Preoperatively, the donor ECD was 2747.6 ± 255.4 cells/mm2, and the ECD decreased to 1729.1 ± 562.9 cells/mm2 at 6 months, for a peak ECD loss of 36.86%. A greater decrease in CST observed from 1 week to 6 months postoperatively correlated with a lower ECD loss (P = 0.019) and a lower preoperative ECD (P = 0.012). However, a thinner CET correlated with a higher preoperative ECD (P = 0.028). CONCLUSIONS: FS-DSEK is a safe and effective surgical alternative for corneal endothelial decompensation. The donor ECD and its changes could be used as predictive factors for the improvement of CST and CET.

Altered Corneal Nerves in Chinese Thyroid-Associated Ophthalmopathy Patients Observed by In Vivo Confocal Microscopy.

BACKGROUND Thyroid-associated ophthalmopathy (TAO) is a common endocrine autoimmune disease. The present study explored corneal nerve changes in TAO patients. MATERIAL AND METHODS Thirty-eight Chinese TAO patients and 20 healthy individuals were included in the study. Central corneal subbasal nerve density and morphology were evaluated with in vivo laser scanning confocal microscopy and quantified using automated CCmetrics software. RESULTS The values of the central corneal subbasal nerve plexus parameters of both active and inactive TAO patients were significantly decreased compared with those of controls, including corneal nerve fiber density (CNFD) (P<0.001 for both), corneal nerve branch density (CNBD) (P<0.001 for both), corneal nerve fiber length (CNFL) (P<0.001 for both), corneal nerve fiber total branch density (CTBD) (P<0.001 for both), corneal nerve fiber area (CNFA) (P<0.001 for both), corneal nerve fiber width (CNFW) (P=0.046, P=0.027, respectively), and corneal nerve fiber fractal dimension (ACNFrD) (P<0.001 for both). In addition, CNFD and ACNFrD values were significantly lower in the active TAO patients compared with those in the inactive TAO patients (P=0.020, P=0.002, respectively). There were significant correlations between CNFD, CNBD, CNFL, CTBD, CNFA, and ACNFrD and the ocular surface parameters and activity assessment items. CONCLUSIONS Abnormal corneal subbasal nerves were observed in both active and inactive Chinese TAO patients, suggesting that nerve degeneration is associated with the disease. However, the exact underlying mechanisms remain to be elucidated.

Social-economic analysis of patients with Sjogren's syndrome dry eye in East China: a cross-sectional study.

BACKGROUND: Sjogren's syndrome is the leading cause for aqueous tear-deficiency dry eye. Little is known regarding the relationship between Sjogren's syndrome dry eye (SSDE) and patients' medical expenditure, clinical severity and psychological status changes. METHODS: Thirty-four SSDE patients and thirty non-Sjogren's syndrome dry eye (non-SSDE) subjects were enrolled. They were required to complete three self-report questionnaires: Ocular Surface Disease Index, Zung Self Rating Anxiety Scales, and a questionnaire designed by the researchers to study the patients' treatment, medical expenditure and income. The correlations between expenditures and these parameters were analyzed. RESULTS: The annual total expenditure on the treatment of SSDE was Chinese Yuan 7637.2 (approximately US$1173.8) on average, and the expense paid by SSDE patients themselves was Chinese Yuan 2627.8 (approximately US$403.9), which were 5.5 and 4.5 times higher than non-SSDE patients (both P < 0.001). The annual total expense on Chinese medicine and western medicine were 35.6 times and 78.4% higher in SSDE group than in non-SSDE group (both P < 0.001). Moreover, indirect costs associated with the treatment were 70.0% higher in SSDE group. In SSDE group, the score of Zung Self Rating Anxiety Scales had significantly positive correlation with total medical expenditure and the expense on Chinese medicine (ρ = 0.399 and ρ = 0.400,both P = 0.019). Nevertheless, total medical expenditure paid by the patients in non-SSDE group positively correlated with the score of Ocular Surface Disease Index (ρ = 0.386, P = 0.035). CONCLUSIONS: Medication expenditures and associated costs is an unignorable economic burden to the patients with SSDE. The medical expense had a significantly correlation with clinical severity of SSDE and the patients' psychological status.

Correlation between the existence of the palisades of Vogt and limbal epithelial thickness in limbal stem cell deficiency.

BACKGROUND: The aims of the study were to investigate limbal epithelial thickness in subjects with limbal stem cell deficiency and to evaluate the correlation between the palisades of Vogt and limbal epithelial thickness. DESIGN: Cross-sectional observational study. PARTICIPANTS: Twenty-four subjects (39 eyes) with limbal stem cell deficiency and 20 normal controls (20 eyes). METHODS: Anterior segment optical coherence tomography and laser scanning confocal microscopy were performed to assess each quadrant of the limbus. MAIN OUTCOME MEASURES: Limbal epithelial thickness and palisades of Vogt morphology in each quadrant were characterized. The correlation between limbal epithelial thickness and palisades of Vogt was analysed. RESULTS: The average limbal epithelial thicknesses in eyes with limbal stem cell deficiency were 19.9%, 23.4%, 13.8% and 13.5% less than normal controls at superior, inferior, nasal and temporal limbus (P = 0.008, 0.006, 0.014 and 0.011, respectively). Limbal epithelial thicknesses within limbal quadrants with palisades of Vogt were similar to those measured in the same quadrants in normal controls, whereas limbal epithelial thicknesses in the superior, inferior, nasal and temporal quadrants without palisades of Vogt were 27.8%, 29.8%, 14.7% and 15.6% less than the limbal epithelial thickness in corresponding regions of normal eyes (superior and inferior: P < 0.001; nasal and temporal: P = 0.005). Limbal epithelial thickness in the nasal and temporal quadrants was significantly less than that in the superior and inferior quadrants, both in normal controls and in limbal stem cell deficiency subjects(P < 0.001 and P = 0.019). Regression analysis showed that limbal epithelial thickness had a significant correlation with the presence of palisades of Vogt in each quadrant (superior, P = 0.002; inferior, P = 0.001; nasal, P = 0.047; temporal, P = 0.030). CONCLUSIONS: A significant correlation was found between limbal epithelial thickness and the presence of palisades of Vogt. Limbal epithelial thinning as observed with anterior segment optical coherence tomography is a sign of limbal stem cell deficiency.

Comparison of human corneal cell density by age and corneal location: an in vivo confocal microscopy study.

BACKGROUND: Peripheral and central regions of the cornea are optically different and have different repair capacity and pathology. For this reason, we characterized the cellular morphology and quantified the cell density of the central and peripheral regions of the cornea with age. METHODS: Eighty healthy subjects were enrolled in the study and divided into four groups according to age: A (0-19 years), B (20-39 years), C (40-59 years), and D (>60 years). In vivo confocal microscopy was used to measure the following parameters for the central and peripheral regions of the cornea: average cellular density and area of the superficial and basal epithelium; average density of the anterior and posterior keratocytes; average endothelial cell density and cellular area; percentage of hexagonal endothelial cells. RESULTS: Statistically significant differences between the central and peripheral cornea were observed for the cellular density of basal epithelial cells in group A. The density of keratocytes in the anterior stroma was significantly greater in the central region compared with the peripheral region in group B and group C. The percentage of hexagonal cells in the endothelial layer was significantly greater in the central region compared with the peripheral region. Age-related changes were found in peripheral basal epithelial cell density, central and peripheral endothelial cell density, and the percentage of hexagonal endothelial cells. CONCLUSION: Both similarities and differences in morphology of the central and peripheral regions of the transparent cornea were observed. These observations would provide a histological basis for further studies to define its regional pathological mechanisms.

Measurement of corneal and limbal epithelial thickness by anterior segment optical coherence tomography and in vivo confocal microscopy.

BACKGROUND: To compare corneal epithelial thickness (CET) and limbal epithelial thickness (LET) measured by anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscope (IVCM) in normal subjects, and evaluate the consistency between them. METHODS: Thirty-eight normal subjects (17 men and 21 women) were enrolled in this study. AS-OCT was performed at central cornea and the superior, inferior, nasal and temporal limbus. Then followed by IVCM examination performed at the same location. Agreement was analyzed by mean difference (AS-OCT minus IVCM), 95 % limits of agreement (LoA) (1.96 standard deviation of the difference), and Bland-Altman analysis. RESULTS: The average CET measured by AS-OCT and IVCM was 55.6 ± 4.0 µm and 51.9 ± 4.9 µm respectively. The value measured by IVCM was significantly lower than that measured by AS-OCT (P = 0.015). The average LET values tested by AS-OCT were 10.3 and 10.9 % less at nasal and temporal quadrant (nasal: P = 0.019, temporal: P = 0.003), and were similar as those measured by IVCM at superior and inferior quadrant. In subjects older than 40 years, CET and LET values measured by AS-OCT were significantly higher than those by IVCM. Such differences were not found in subjects ≤ 40 years old. CONCLUSIONS: CET values measured by IVCM are lower than those by AS-OCT, while LET values measured by two devices have good agreement. These two techniques have their own advantages in measuring epithelial thickness and are mutually complementary.

Assessment of Lower Tear Meniscus.

PURPOSE: To evaluate the applicability of the fourth-generation OCULUS keratograph in measuring lower tear meniscus height. METHODS: Seventy cases (140 eyes) with dry eye disease and 37 controls (74 eyes) were enrolled. Tear breakup time (TBUT), Schirmer test I, and corneal fluorescein staining were examined. The images of lower tear meniscus were obtained by OCULUS keratograph. The tear meniscus height was measured and its correlation with traditional tear film diagnostic tests were analyzed. RESULTS: Using the hyper-reflective lines, the height of the tear meniscus was measured using the images of the OCULUS keratograph. For the inter-individual variation, the intraclass correlation coefficients and coefficient of variation values were 0.914 and 16.4%, respectively. For the intra-individual variation, the intraclass correlation coefficients and coefficient of variation values were 0.939 and 15.9%, respectively. The interobserver reproducibility and the intraobserver repeatability were for the control only. The average tear meniscus height value in dry eye disease group was 0.22 (0.19-0.24) mm, being significantly lower compared with 0.29 (0.26-0.34) mm in the control group (p<0.001). Tear meniscus height value had significantly correlation with TBUT and Schirmer test I (r=0.619 and 0.626, both p<0.001). The measurement of lower tear meniscus by OCULUS had lower individual variability and better repeatability. CONCLUSIONS: OCULUS keratograph is a quick, noninvasive, and reliable method to measure lower tear meniscus, whose value has a significant correlation with traditional dry eye disease diagnostic tests.

All-trans retinoid acid promotes allogeneic corneal graft survival in mice by regulating Treg-Th17 balance in the presence of TGF-ß.

BACKGROUND: All-trans retinoid acid (ATRA) has been proven to skew Regulatory T cell-T helper 17 cell (Treg-Th17) balance toward Treg in vitro, favoring graft acceptance. However, its in vivo effect after solid organ transplantation is under investigation. RESULTS: BALB/c mice were given orthotopic corneal grafts from C57BL/6 donors, and recipient mice were administered with ATRA, TGF-ß, and the combination of both agents for 8 weeks after surgery. We found that a mixed treatment of ATRA and TGF-ß significantly promoted graft survival. Moreover, with the presence of TGF-ß, ATRA upregulated CD4(+)CD25(+)Foxp3(+)Treg cells and suppressed Th17 cells in the blood, spleen and draining lymph nodes of recipient mice, as well as enhanced the Foxp3 expression and inhibited the RORγt expression in grafts and peripheral blood mononuclear cells (PBMCs). Simultaneously, increased number of Foxp3+ cells and decreased number of IL-17+ cells in conjunctiva were found in recipients with mixed treatment, along with reduced IL-17 level in serum and aqueous humor and increased IL-10 level in aqueous humor. Tregs isolated from recipient mice treated with ATRA + TGF-ß presented the strongest suppressive activity in vitro. CONCLUSIONS: Combined application of ATRA and TGF-ß may shift the Th17-Treg balance toward Tregs, hence facilitating the induction of immunological tolerance after allogenic corneal transplantation and representing a potential therapeutic approach in the treatment of posttransplant rejection.

Early-Onset Candida glabrata Interface Keratitis after Deep Anterior Lamellar Keratoplasty.

PURPOSE: Fungal interface keratitis by Candida species can occur several weeks to several months after deep anterior lamellar keratoplasty (DALK). Here, we report a case of early-onset fungal interface keratitis by Candida glabrata after DALK. CASE REPORT: A 31-year-old Chinese man complained of decreased vision 4 days after an uneventful DALK for keratoconus. White to cream-colored interface deposits were identified under slit-lamp examination. The confocal scan disclosed clusters of hyperreflective granular deposits of 2 to 4 µm at the interface, without evidence of inflammation or hyphae-like structures. The graft was then removed, along with interface irrigation, and another graft was sutured. Finally, a penetrating keratoplasty was performed because the interface opacities recurred and deteriorated after graft replacement. Histopathological examination disclosed yeast-like structures at the retrocorneal side. The microbiologic results of both corneal scrapings taken from the recipient stromal bed and the removed half cornea button showed C. glabrata. CONCLUSIONS: Candida glabrata interface keratitis can occur early after DALK, which can only be effectively treated with penetrating keratoplasty. Confocal microscopy is a promising tool to diagnose this rare complication. The importance of donor corneoscleral rim cultures should be emphasized during DALK.

Advances in Organoid Technology: A Focus on Corneal Limbal Organoids.

Organoid technology provides a versatile platform for simulating organogenesis, investigating disease pathogenesis, and exploring therapeutic interventions. Among various types of organoids that have been developed, corneal limbal organoids, the three-dimensional miniaturized corneas which are derived from either pluripotent stem cells or limbal epithelial stem cells, are particularly promising for clinical translation. This narrative review summarized the state-of-the-art in corneal limbal organoids research including the cultivation methods, clinical relevance and its limitations and challenges. The potential of corneal limbal organoids in mimicking corneal development, disease modelling, drug screening, and regenerative medicine was discussed. Technical improvements in cultivation techniques, imaging modalities, and gene editing tools are anticipated to overcome current limitations and further promote its clinical potential. Despite challenges and difficulties, the development of corneal limbal organoids opens a new era of regenerative medicine and provides a potential source of stem cell replacement therapies for challenging corneal diseases with the establishment of an in vitro corneal limbal organoid bank.

Evaluating the effectiveness of large language models in patient education for conjunctivitis.

AIMS: To evaluate the quality of responses from large language models (LLMs) to patient-generated conjunctivitis questions. METHODS: A two-phase, cross-sectional study was conducted at the Eye and ENT Hospital of Fudan University. In phase 1, four LLMs (GPT-4, Qwen, Baichuan 2 and PaLM 2) responded to 22 frequently asked conjunctivitis questions. Six expert ophthalmologists assessed these responses using a 5-point Likert scale for correctness, completeness, readability, helpfulness and safety, supplemented by objective readability analysis. Phase 2 involved 30 conjunctivitis patients who interacted with GPT-4 or Qwen, evaluating the LLM-generated responses based on satisfaction, humanisation, professionalism and the same dimensions except for correctness from phase 1. Three ophthalmologists assessed responses using phase 1 criteria, allowing for a comparative analysis between medical and patient evaluations, probing the study's practical significance. RESULTS: In phase 1, GPT-4 excelled across all metrics, particularly in correctness (4.39±0.76), completeness (4.31±0.96) and readability (4.65±0.59) while Qwen showed similarly strong performance in helpfulness (4.37±0.93) and safety (4.25±1.03). Baichuan 2 and PaLM 2 were effective but trailed behind GPT-4 and Qwen. The objective readability analysis revealed GPT-4's responses as the most detailed, with PaLM 2's being the most succinct. Phase 2 demonstrated GPT-4 and Qwen's robust performance, with high satisfaction levels and consistent evaluations from both patients and professionals. CONCLUSIONS: Our study showed LLMs effectively improve patient education in conjunctivitis. These models showed considerable promise in real-world patient interactions. Despite encouraging results, further refinement, particularly in personalisation and handling complex inquiries, is essential prior to the clinical integration of these LLMs.

Establishment of human corneal epithelial organoids for ex vivo modelling dry eye disease.

Dry eye disease (DED) is a growing public health concern affecting millions of people worldwide and causing ocular discomfort and visual disturbance. Developing its therapeutic drugs based on animal models suffer from interspecies differences and poor prediction of human trials. Here, we established long-term 3D human corneal epithelial organoids, which recapitulated the cell lineages and gene expression signature of the human corneal epithelium. Organoids can be regulated to differentiate ex vivo, but the addition of FGF10 inhibits this process. In the hyperosmolar-induced DED organoid model, the release of inflammatory factors increased, resulting in damage to the stemness of stem cells and a decrease in functional mucin 1 protein. Furthermore, we found that the organoids could mimic clinical drug treatment responses, suggesting that corneal epithelial organoids are promising candidates for establishing a drug testing platform ex vivo. In summary, we established a functional, long-term 3D human epithelial organoid that may serve as an ex vivo model for studying the functional regulation and disease modelling.

Benchmarking four large language models' performance of addressing Chinese patients' inquiries about dry eye disease: A two-phase study.

Purpose: To evaluate the performance of four large language models (LLMs)-GPT-4, PaLM 2, Qwen, and Baichuan 2-in generating responses to inquiries from Chinese patients about dry eye disease (DED). Design: Two-phase study, including a cross-sectional test in the first phase and a real-world clinical assessment in the second phase. Subjects: Eight board-certified ophthalmologists and 46 patients with DED. Methods: The chatbots' responses to Chinese patients' inquiries about DED were assessed by the evaluation. In the first phase, six senior ophthalmologists subjectively rated the chatbots' responses using a 5-point Likert scale across five domains: correctness, completeness, readability, helpfulness, and safety. Objective readability analysis was performed using a Chinese readability analysis platform. In the second phase, 46 representative patients with DED asked the two language models (GPT-4 and Baichuan 2) that performed best in the in the first phase questions and then rated the answers for satisfaction and readability. Two senior ophthalmologists then assessed the responses across the five domains. Main outcome measures: Subjective scores for the five domains and objective readability scores in the first phase. The patient satisfaction, readability scores, and subjective scores for the five-domains in the second phase. Results: In the first phase, GPT-4 exhibited superior performance across the five domains (correctness: 4.47; completeness: 4.39; readability: 4.47; helpfulness: 4.49; safety: 4.47, p < 0.05). However, the readability analysis revealed that GPT-4's responses were highly complex, with an average score of 12.86 (p < 0.05) compared to scores of 10.87, 11.53, and 11.26 for Qwen, Baichuan 2, and PaLM 2, respectively. In the second phase, as shown by the scores for the five domains, both GPT-4 and Baichuan 2 were adept in answering questions posed by patients with DED. However, the completeness of Baichuan 2's responses was relatively poor (4.04 vs. 4.48 for GPT-4, p < 0.05). Nevertheless, Baichuan 2's recommendations more comprehensible than those of GPT-4 (patient readability: 3.91 vs. 4.61, p < 0.05; ophthalmologist readability: 2.67 vs. 4.33). Conclusions: The findings underscore the potential of LLMs, particularly that of GPT-4 and Baichuan 2, in delivering accurate and comprehensive responses to questions from Chinese patients about DED.

The progress in techniques for culturing human limbal epithelial stem cells.

In vitro culture of human limbal epithelial stem cells (hLESCs) is crucial to cell therapy in the treatment of limbal stem cell deficiency, a potentially vision-threatening disease that is characterized by persistent corneal epithelial defects and corneal epithelium conjunctivalization. Traditionally, hLESCs are cultivated based on either limbal tissue explants or single-cell suspensions in culture media containing xenogenous components, such as fetal bovine serum and murine 3T3 feeder cells. Plastic culture dishes and human amniotic membranes are classical growth substrates used in conventional hLESC culture systems. The past few decades have witnessed considerable progress and innovations in hLESC culture techniques to ensure a higher level of biosafety and lower immunogenicity for further cell treatment, including complete removal of xenogenous components from culture media, the application of human-derived feeder cells, and the development of novel scaffolds. Three-dimensional artificial niches and three-dimensional culture techniques have also been established to simulate the real microenvironment of limbal crypts for better cell outgrowth and proliferation. All these progresses ensure that in vitro cultured hLESCs are more adaptable to translational stem cell therapy for limbal stem cell deficiency.

Cross-regulation between SOX9 and the canonical Wnt signalling pathway in stem cells.

SOX9, a member of the SRY-related HMG-box transcription factors, has been reported to critically regulate fetal development and stem cell homeostasis. Wnt signalling is a highly conserved signalling pathway that controls stem cell fate decision and stemness maintenance throughout embryonic development and adult life. Many studies have shown that the interactions between SOX9 and the canonical Wnt signalling pathway are involved in many of the physiological and pathological processes of stem cells, including organ development, the proliferation, differentiation and stemness maintenance of stem cells, and tumorigenesis. In this review, we summarize the already-known molecular mechanism of cross-interactions between SOX9 and the canonical Wnt signalling pathway, outline its regulatory effects on the maintenance of homeostasis in different types of stem cells, and explore its potential in translational stem cell therapy.

Impact of Dry Eye Disease on the Uncorrected Distance Visual Acuity after Small Incision Lenticule Extraction.

The aim of this study was to explore the impact of dry eye disease (DED) on the uncorrected distance visual acuity (UDVA) and refractive status after small incision lenticule extraction (SMILE). This prospective cohort study enrolled 29 patients (DED group, 11 eyes; non-DED group, 18 eyes) who underwent SMILE in our center from July to September 2022. The examinations on DED, refractive status and UDVA were performed before surgery, and on day 7 and 20 after surgery. The results showed that on day 20 after SMILE, subjects in the non-DED group reported greater changes of ocular surface disease index value increase and tear-film breakup time reduction compared to baseline than those in the DED group (p < 0.001 and p = 0.048, respectively). Compared to preoperative status, DED patients had greater improvements of UDVA and better optometric outcomes on day 20 after surgery than non-DED subjects (p = 0.008 and 0.026, respectively). Multiple linear regression analysis showed age, contact lens daily wearing time, and tear meniscus height before surgery were of the highest value to predict UDVA on day 20 after SMILE in contact lens wearers (p = 0.006, 0.010 and 0.043, respectively). In conclusion, preoperative tear function could affect UDVA after SMILE. The impact of DED on UDVA and refraction should be taken into consideration before surgery.

WNT16b promotes the proliferation and self-renewal of human limbal epithelial stem/progenitor cells via activating the calcium/calcineurin A/NFATC2 pathway.

Our previous finding revealed that WNT16b promoted the proliferation of human limbal epithelial stem cells (hLESCs) through a ß-catenin independent pathway. Here, we aimed to explore its underlying molecular mechanism and evaluate its potential in the treatment of limbal stem cell deficiency (LSCD). Based on the findings of mRNA-sequencing, the expression of key molecules in WNT/calcineurin A/NFATC2 signalling pathway was investigated in WNT16b-co-incubated hLESCs and control hLESCs. An epithelial wound healing model was established on Wnt16b-KO mice to confirm the regulatory effect of WNT16b in vivo. The therapeutic potential of WNT16b-co-incubated hLESCs was also evaluated in mice with LSCD. Our findings showed that WNT16b bound with Frizzled7, promoted the release of Ca2+ and activated calcineurin A and NFATC2. With the translocation of NFATC2 into cell nucleus and the activation of HDAC3, WDR5 and GCN5L2, the expression of H3K4me3, H3K14ac and H3K27ac in the promoter regions of FoxM1 and c-MYC increased, which led to hLESC proliferation. The effect of the WNT16b/calcium/calcineurin A/NFATC2 pathway on LESC homeostasis maintenance and corneal epithelial repair was confirmed in Wnt16b-KO mice. Moreover, WNT16b-coincubated hLESCs could reconstruct a stable ocular surface and inhibit corneal neovascularization in mice with LSCD. In conclusion, WNT16b enhances the proliferation and maintains the stemness of hLESCs by activating the non-canonical calcium/calcineurin A/NFATC2 pathway in vitro and in vivo, and accelerates corneal epithelial wound healing.