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.

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.

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.

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.

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.

Effect of Hypochlorous Acid on Blepharitis through Ultrasonic Atomization: A Randomized Clinical Trial.

PURPOSE: To evaluate the efficacy and safety of eyelid hygiene using topical 0.01% hypochlorous acid (HOCL) through ultrasonic atomization after 2 weeks in patients with blepharitis. DESIGN: Randomized controlled trial. METHODS: Patients with blepharitis were randomized into two groups: topical 0.01% HOCL through ultrasonic atomization (HOCL group, 42 eyes) or eyelid scrubs (control group, 37 eyes). Patients in both groups received warm compresses twice daily and topical 0.5% levofloxacin three times a day. Primary outcomes were the ocular surface disease index scores (OSDI), lid margin redness, lid margin abnormalities, meibum expressibility, meibum quality, and noninvasive breakup time after 2 weeks. Secondary outcomes were conjunctiva redness, corneal fluorescein staining, and tear meniscus height. A questionnaire of treatment adherence with a free response section was administered to confirm patient compliance and comments. RESULTS: Sixty-seven participants participated in this study. Both groups show an improvement in all primary outcomes, while statistically significant improvements in OSDI, lid margin redness, lid margin abnormality, meibum expressibility and quality are only limited to the HOCL group after 2 weeks of treatment (p < 0.05, p < 0.05, p < 0.001, p < 0.001 and p < 0.001, respectively). Subgroup analysis in HOCL reveals that only the change in lid margin abnormality and meibum expressibility in the mild-moderate meibomian glands loss patients at baseline has a statistically significant difference p < 0.05). Multiple linear regression shows that the improvement in OSDI is negatively associated with meibum expressibility score at the baseline (95% CI [-28.846, -1.815], p = 0.028). The patient compliance is 7.1 ± 2.0 in the HOCL group and 7.1 ± 1.8 in the control group (p > 0.05). No adverse events are reported. CONCLUSION: Topical 0.01% HOCL through ultrasonic atomization is a tolerable and effective eyelid hygiene treatment for blepharitis.

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.

WNT16B enhances the proliferation and self-renewal of limbal epithelial cells via CXCR4/MEK/ERK signaling.

Culture of limbal epithelial cells (LECs) provides the principal source of transplanted limbal stem cells (LESCs) for treatment of limbal-stem-cell deficiency. Optimization of the culture conditions for in-vitro-expanded LECs will help to create a graft with an optimized quality and quantity of LESCs. This study aimed to investigate the effects of WNT16B on LECs and corneal wound healing and the underlying mechanism. Treatment with exogenous WNT16B increased the proliferative capacity and self-renewal of LECs in the cultures. We further revealed that C-X-C chemokine receptor type 4 (CXCR4) was vital for the effects of WNT16B, and activation of CXCR4/MEK/ERK signaling was pivotal in mediating the effects of WNT16B on LECs enriched for LESCs. The stimulatory effect of WNT16B on corneal epithelial repair was confirmed in a mouse corneal-wound-healing model. In summary, WNT16B enhances proliferation and self-renewal of LECs via the CXCR4/MEK/ERK signaling cascade and accelerates corneal-epithelial wound healing.

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.

Cytokeratin 13 Is a New Biomarker for the Diagnosis of Limbal Stem Cell Deficiency.

PURPOSE: The purpose of this study was to evaluate the expression of cytokeratin (K) 13 on the corneal surface and to validate its application in the diagnosis of limbal stem cell deficiency (LSCD). METHODS: This prospective comparative study included 26 corneal impression cytology (IC) specimens from patients diagnosed with LSCD. Twenty-three IC specimens from normal donors served as controls. K12 and K13 expression were detected on the IC specimens by immunohistochemistry study. The number of K12 + or K13 + cells in all areas of the IC was quantified using ImageJ software. RESULTS: The epithelial cells harvested from IC specimens from control corneas were all K12 + . In eyes with LSCD, K13 + and K12 + /K13 + cells accounted for 93.8% and 2.6%, respectively, in the cornea. In eyes with sectoral LSCD, the median number of K13 + cells in the clinically affected area was higher than that in the unaffected area (810.0 vs. 115.0 cells/mm 2 ; P < 0.001). No significant correlation was found between the LSCD severity and the number of K12 + cells (r = -0.284, P = 0.16) or K13 + cells (r = -0.011, P = 0.95). The presence of at least 16 K13 + cells/mm 2 was suggestive of LSCD. CONCLUSIONS: Identification of K13 + cells on IC specimens provides a simple and reliable method to detect conjunctival epithelial cells on the cornea. K13 is a marker for diagnosing LSCD and localizing the involved area in sectoral LSCD.

Biomarkers of in vivo limbal stem cell function.

PURPOSE: To evaluate in vivo parameters as biomarkers of limbal stem cell function and to establish an objective system that detects and stage limbal stem cell deficiency (LSCD). METHODS: A total of 126 patients (172 eyes) with LSCD and 67 normal subjects (99 eyes) were included in this observational cross-sectional comparative study. Slit-lamp biomicroscopy, in vivo laser scanning confocal microscopy (IVCM), and anterior segment optical coherence tomography (AS-OCT) were performed to obtain the following: clinical score, cell morphology score, basal cell density (BCD), central corneal epithelial thickness (CET), limbal epithelial thickness (LET), total corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), and tortuosity coefficient. Their potential correlations with the severity of LSCD were investigated, and cutoff values were determined. RESULTS: An increase clinical score correlated with a decrease in central cornea BCD, limbal BCD, CET, mean LET, maximum LET, CNFL, CNFD, CNBD, and tortuosity coefficient. Regression analyses showed that central cornea BCD, CET and CNFL were the best parameters to differentiate LSCD from normal eyes (Coef = 3.123, 3.379, and 2.223; all p < 0.05). The rank correlation analysis showed a similar outcome between the clinical scores and the central cornea BCD (ρ = 0.79), CET (ρ = 0.82), and CNFL (ρ = 0.71). A comprehensive LSCD grading formula based on a combination of these parameters was established. CONCLUSIONS: A comprehensive staging system combining clinical presentation, central cornea BCD, CET, and CNFL is established to accurately and objectively diagnose LSCD and stage its severity.

Cell Morphology as an In Vivo Parameter for the Diagnosis of Limbal Stem Cell Deficiency.

PURPOSE: The aim of this study was to investigate basal epithelial cell morphology (CM) in the central cornea and limbal areas of eyes with limbal stem cell deficiency (LSCD). METHODS: This was a prospective, cross-sectional comparative study. We developed a CM scoring system based on basal epithelial cell phenotypes graded from 0 (normal) to 3 (severe morphologic alterations); this system was evaluated by 2 independent masked observers. The CM score was compared with the LSCD clinical score, mean best-corrected visual acuity, and in vivo laser scanning confocal microscopy parameters used to stage LSCD (ie, basal epithelial cell density, basal epithelial thickness, and subbasal corneal nerve fiber length density). RESULTS: One hundred sixty-eight eyes with LSCD and 63 normal eyes were included. Compared with the control group, the LSCD group had significantly higher mean (±SD) CM scores in the central cornea (1.8 ± 0.7 vs. 0.5 ± 0.4, respectively; P = 0.01) and limbal areas (1.6 ± 0.2 vs. 1.3 ± 0.0, respectively; P < 0.05). The mean CM score in the central cornea was positively correlated with the clinical score ( P < 0.01, r = 0.66) and negatively correlated with the best-corrected visual acuity ( P < 0.01, r = 0.42). The CM scores were positively correlated with all other in vivo laser scanning confocal microscopy parameters in the central cornea and limbal areas (all P < 0.001). CONCLUSIONS: Basal epithelial CM is altered in the central cornea and limbus of eyes with LSCD and thus can be used to stage the clinical severity of the disease.

Fourier-Domain Optical Coherence Tomographic Assessment of Changes in the Schlemm's Canal of Nonglaucomatous Subjects After Keratoplasty.

Purpose: This study aimed to evaluate the impact of keratoplasty on the in vivo anatomical structures in the Schlemm's canal (SC) of nonglaucomatous subjects using Fourier-domain optical coherence tomography (FD-OCT). Methods: Sixty-six nonglaucomatous eyes that underwent penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), or triple surgery were enrolled in this prospective, comparative, observational study. The SC imaging was performed using FD-OCT before and after surgery in both the nasal and temporal quadrants. Patient demographics, SC parameters [e.g., cross-sectional area (CSA), meridional diameter of SC (MSC), sagittal diameter of SC (SSC), and circumference (CCF)], and the correlations between the variation of SC parameters and intraocular pressure (IOP) were analyzed. Results: The mean age of all subjects was 40.27 ± 18.97 years. Among all cases, the nasal, temporal, and mean MSC significantly decreased on the first day after surgery and then increased at 1 week (p = 0.04, 0.017, and 0.01, respectively). Temporal CSA (tCSA), temporal MSC (tMSC), and temporal circumference (tCCF) after PK (p = 0.017, 0.020, and 0.018, respectively) and nasal MSC (nMSC) after DALK (p = 0.025) decreased significantly on the first day after surgery. The shift in mean IOP was significantly correlated with the changes in tMSC (r = 0.341, p = 0.003) and CCF (r = 0.207, p = 0.048). Conclusion: SC had significant in vivo morphological changes in the early period after keratoplasty in nonglaucomatous eyes, accompanied with elevation of IOP. Early intervention might be necessary to prevent secondary glaucoma early after keratoplasty.

Indications and Surgical Techniques for Repeat Corneal Transplantation in Eastern China: A Twelve-Year Study.

PURPOSE: To analyze the indications and surgical procedures for repeat keratoplasty in eastern China from 2008 to 2019. METHODS: This retrospective descriptive study included 418 eyes of 411 patients who underwent no less than 2 keratoplasties at the Eye, Ear, Nose and Throat Hospital of Fudan University from 2008 to 2019. Medical charts were reviewed. The primary indications for repeat keratoplasty, the reasons for regrafting, and the surgical techniques used in the treatment were collected and analyzed. RESULTS: Among 418 eyes, 337 eyes (80.6%) had one repeat keratoplasty, and 81 eyes (19.4%) had multiple repeat keratoplasties (≥2 repeat keratoplasties). The median interval between the initial keratoplasty and the first repeat keratoplasty was 25 months, and that between two keratoplasties after the first repeat keratoplasty was 27.5 months. Infectious keratitis was the leading primary indication for single repeat keratoplasty (80 cases, 23.7%) and multiple repeat keratoplasties (19 cases, 23.5%). The second most common primary indication was bullous keratopathy for single repeat keratoplasty (49 eyes, 14.5%) and chemical injury for multiple repeat keratoplasties (14 eyes, 17.3%). The main reason for regrafting was allograft rejection (262 cases, 49.3%), followed by endothelial dysfunction (92 cases, 17.3%), and for vision improvement after tectonic keratoplasty (60 cases, 11.3%). Penetrating keratoplasty (PKP) was the major technique used in repeat keratoplasty (447 cases, 84.2%). However, Descemet stripping endothelial keratoplasty was more frequently used than PKP (72.4% vs. 27.6%, P < 0.001) in the treatment of failed endothelial keratoplasty. CONCLUSION: Infectious keratitis was still the leading cause of repeat keratoplasty in eastern China. Although PKP remains the major technique of repeat keratoplasty, the application of customized lamellar keratoplasty has greatly expanded in the last decade. Cautious selection of indications, surgical techniques, and timing for surgery is crucial for a good prognosis after repeat keratoplasty.

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.

Corneal Epithelial Thickness Measured Using Anterior Segment Optical Coherence Tomography as a Diagnostic Parameter for Limbal Stem Cell Deficiency.

OBJECTIVE: Using anterior segment optical coherence tomography (AS-OCT), we investigated the epithelial thickness (ET) of the central cornea and limbal regions in patients with limbal stem cell deficiency (LSCD) as a diagnostic and staging parameter. DESIGN: Prospective, cross-sectional study. METHODS: The central corneal epithelium thickness (CET) and maximum limbal epithelium thickness (mLET) were measured in the superior, inferior, nasal, and temporal limbus on AS-OCT images of the normal and eyes with LSCD. CET was obtained by 1-point (OCT-CET1) and 3-point measurement (OCT-CET3). The values of OCT-CET1 and OCT-CET3 were compared to the CET obtained with in vivo confocal microscopy (IVCM-CET). RESULTS: Sixty-eight eyes of 50 patients with LSCD and 52 eyes of 34 normal subjects were included. The mean (±standard deviation) OCT-CET3 was 55.0 ± 3.0 µm (range, 50.6-62.0 µm) in the control group and 41.6 ± 10.8 µm (range, 0-56.3 µm) in the LSCD group (P < .001). OCT-CET3 had a better correlation with IVCM-CET (r = 0.91) than did OCT-CET1 (r = 0.87, P = .001). The degree of reduction in OCT-CET3 increased in more advanced clinical stages of LSCD (all P < .001). The OCT-CET3 cutoff value that suggests LSCD was 46.6 µm. Compared with the control group, the LSCD group had decreases in mLET in all 4 limbal regions (all P < .001). The sensitivity and specificity of OCT-CET3 is the highest among all mLET in detecting LSCD. CONCLUSIONS: Both CET and mLET were thinner in patients with LSCD than in normal subjects. OCT-CET3 appears to be a reliable parameter to confirm LSCD when there is clinical suspicion.

Outcomes of Limbal Stem Cell Transplant: A Meta-analysis.

Importance: Limbal stem cell transplant (LSCT) can be categorized as direct autologous limbal transplant (AULT), direct allogenic limbal transplant (ALLT), cultivated autologous limbal stem cells transplant (cAULT), and cultivated allogenic limbal stem cells transplant (cALLT). To our knowledge, there is no study directly comparing the outcomes and complications of these procedures. Objective: To evaluate the outcomes of different LSCT procedures. Data Source: We searched PubMed, EMBASE, Web of Science, and Cochrane without language filter for peer-reviewed articles about LSCT. The latest search was performed on June 30, 2019. Study Selection: Clinical studies with the outcome of at least 20 eyes after LSCT were included. Animal studies and studies of other surgical interventions were excluded. Data Extraction and Synthesis: Two reviewers independently abstracted the data from each study. Heterogeneity was evaluated with the I2 statistic, and a meta-analysis was performed using the random-effects model. Main Outcomes and Measures: Outcome measures included the improvement of ocular surface, visual acuity (VA), and adverse events of recipient eyes and donor eyes. Results: Forty studies (2202 eyes) with a mean (SD) follow-up of 31.3 (20.9) months met the inclusion criteria. The mean (SD) age of study participants was 38.4 (13.1) years, and men accounted for 74%. The number of eyes that underwent AULT, ALLT, cAULT, and cALLT were 505, 742, 771, and 184, respectively. Improvement of the ocular surface was achieved in 74.5% of all eyes, 85.7% of eyes after AULT (95% CI, 79.5%-90.3%), 84.7% after cAULT (95% CI, 77.2%-90.0%), 57.8% after ALLT (95% CI, 49.0%-66.1%), and 63.2% after cALLT (95% CI, 49.3%-75.2%). Autologous limbal transplantation resulted in a greater VA improvement rate (76%) than did the other 3 procedures (cAULT: 56.4%; ALLT: 52.3%; cALLT: 43.3%; all P < .001). The most common adverse events in all recipient eyes were recurrent/persistent epithelial erosion (10.5%; 95% CI, 7.2%-23.3%) and elevated intraocular pressure (intraocular pressure, 1.7%; 95% CI, 0.5%-7.8%). Patients who underwent ALLT had the highest rate of recurrent epithelial erosion (27.8%; 95% CI, 17.1%-41.9%) and intraocular pressure elevation (6.3%; 95% CI, 1.8%-19.4%). Conclusions and Relevance: These findings suggest LSCT can improve or stabilize the corneal surface with a low rate of severe ocular complications and that autologous LSCT may have a higher success rate and fewer complications than allogenic LSCT.

Diagnostic criteria for limbal stem cell deficiency before surgical intervention-A systematic literature review and analysis.

An accurate diagnosis of limbal stem cell deficiency (LSCD) is the premise of an appropriate treatment; however, there is no consensus about the diagnostic criteria for LSCD. We performed a systematic literature search of the peer-reviewed articles on PubMed, Medline, and Ovid to investigate how LSCD was diagnosed before surgical intervention. The methods used to diagnose LSCD included clinical presentation, impression cytology, and in vivo confocal microscopy. Among 131 eligible studies (4054 eyes), 26 studies (459 eyes, 11.3%) did not mention the diagnostic criteria. In the remaining 105 studies, the diagnosis of LSCD was made on the basis of clinical examination alone in 2398 eyes (62.9%), and additional diagnostic tests were used in 1047 (25.8%) eyes. Impression cytology was used in 981 eyes (24.2%), in vivo confocal microscopy was used in 29 eyes (0.7%), and both impression cytology and in vivo confocal microscopy were used in 37 eyes (0.9%). Our findings suggest that only a small portion of patients underwent a diagnostic test to confirm the diagnosis of LSCD. Treating physicians should be aware of the limitations of clinical examination in diagnosing LSCD and perform a diagnostic test whenever possible before surgical intervention.

Indications and Techniques of Pediatric Keratoplasty in Eastern China From 2008 to 2017.

PURPOSE: To explore the transition of indications and surgical techniques of pediatric keratoplasty in Eastern China in the past 10 years. METHODS: Medical charts of 1026 pediatric patients (1059 eyes) who underwent keratoplasties at the Eye, Ear, Nose and Throat Hospital of Fudan University from 2008 to 2017 were retrospectively reviewed. The indications for keratoplasty and the surgical techniques were collected and analyzed. RESULTS: A total of 634 infants (≤3 years) (661 eyes), 207 toddlers and older children (4-12 years) (211 eyes), and 185 adolescents (13-18 years) (187 eyes) were included. The median age at the time of surgery was 2 years. The surgical indications were composed of congenital abnormalities (74.6%), acquired nontraumatic diseases (16.5%), acquired traumatic diseases (3.6%), and regraft (5.3%). Only congenital abnormality had a significant growing trend during this decade (P = 0.023). Keratoconus (67.2%) exceeded infectious keratitis (14.9%) and was the most common acquired nontraumatic cause in our study. The annual number of pediatric keratoplasties increased significantly from 40 cases in 2008 to 190 cases in 2017 (P < 0.001). Although penetrating keratoplasty was performed in 414 eyes (39.1%), its application in the treatment of keratoconus decreased significantly during this decade (P = 0.04). By contrast, deep anterior lamellar keratoplasty showed an increasing trend because of its popularization in the treatment of keratoconus (P = 0.003). CONCLUSIONS: Congenital abnormalities have replaced infectious keratitis and have been the leading indications of pediatric keratoplasty in the past 10 years. Although the using of penetrating keratoplasty was still the predominant procedure to treat pediatric corneal pathologies, the adoption of deep anterior lamellar keratoplasty showed a significant increasing trend during the past decade.