In Vivo Human Lacrimal Gland Imaging Using an Ultrasound Biomicroscopy.

PURPOSE: In the present study, we introduce human lacrimal gland imaging using an ultrasound biomicroscopy (UBM) with a soft cover and show their findings. METHODS: The representative UBM findings of palpebral lobes in seven subjects (four with non-Sjögren dry eye syndrome, one with Sjögren syndrome, and two healthy subjects) were described in this study. To prolapse the palpebral lobe, the examiner pulled the temporal part of the upper eyelid in the superotemporal direction and directed the subject to look in the inferonasal direction. We scanned the palpebral lobes longitudinally and transversely using UBM. We used an Aviso UBM with a 50 MHz linear probe and ClearScan. RESULTS: In UBM of two healthy subjects, the echogenicity of the lacrimal gland was lower than that of the sclera and homogeneous. But the parenchyma of a patient with Sjögren dry eye syndrome was quite inhomogeneous compared to the healthy subjects. In two patients with dry eye syndrome, we were able to observe some lobules in the parenchyma. We could find excretory ducts running parallel at the surface of the longitudinal section in some subjects. In the longitudinal UBM scan of a subject, we observed a tubular structure at a depth of 1,500 µm that was considered a blood vessel. It ran from the superonasal to the inferotemporal direction. In a subject, we observed a large cyst beneath the conjunctiva. CONCLUSIONS: Lacrimal gland imaging using UBM has both advantages of optical coherence tomography and sonography, and could be useful for evaluating dry eye syndrome.

One-year Outcomes of Ultrathin Descemet Stripping Automated Endothelial Keratoplasty Combined with Cataract Surgery in the Korean Population.

PURPOSE: To evaluate the refractive outcomes after ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) combined with phacoemulsification and intraocular lens implantation (triple procedure) in the South Korean population. METHODS: This retrospective observational study included 37 eyes of 36 patients who underwent the UT-DSAEK triple procedure between 2012 and 2021 in a single tertiary hospital. Preoperative and postoperative refractive outcomes and endothelial parameters at 1, 3, 6, and 12 months were observed. RESULTS: At the final postoperative 12-month period, the average best-corrected visual acuity was 0.4 ± 0.5 in logarithm of the minimum angle of resolution. The mean endothelial cell density at 12 months was 1,841.92 ± 731.24 cells/mm2, indicating no significant endothelial cell loss compared to the baseline (p = 0.128). The mean postoperative central corneal thickness at 12 months was 597.41 ± 86.26 µm. The postoperative mean absolute error at 12 months was 0.96 ± 0.89 diopters (D) and mean error was 0.89 ± 0.97 D. CONCLUSIONS: The results of our South Korean cohort study on UT-DSAEK triple surgery showed favorable and safe outcomes. Regardless of graft thickness, it should be noted that a hyperopic shift of 1.00 to 2.00 D needs to be considered in the case of UT-DSAEK triple surgery.

Causes and outcomes of implantable collamer lens explantation in patients with corneal endothelial cell loss.

PURPOSE: To investigate the correlated factors of corneal endothelial cell density (ECD) loss and ECD change in implantable collamer lens (ICL) explantation patients. SETTING: Seoul St. Mary's Hospital, Seoul, South Korea. DESIGN: Retrospective analysis. METHODS: The study cohort consisted of 93 eyes from 50 patients who underwent ICL explantation. Correlation analysis was performed to assess the ocular parameters associated with ECD loss, while percentage of ECD change (ΔECD%) was monitored up to 6 months postoperatively. Receiver operating characteristic (ROC) curve was used to set cutoff values of ocular parameters to prevent ECD loss after explantation. RESULTS: In multiple regression analysis, high vaulting, high vaulting/anterior chamber depth (ACD), low anterior chamber angle (ACA), and high iris pigmentations are the significant factors of ECD loss. At postoperative 6 months, 14 eyes (15.1%) had decrease (10.5% loss), 47 eyes (51.0%) were stationary, and 32 eyes (34.4%) had increase (12.7% gain) of ECD. The ROC curve analysis showed that vaulting had the highest area under the curve (AUC = 0.822), followed by vaulting/ACD (AUC = 0.821), ECD (AUC = 0.753), and ACA (AUC = 0.723) (all P < .01). Preoperative ECD showed a sensitivity of 77.6% and specificity of 86.7% in preventing ECD loss after explantation, with a cutoff value of 1722 cells/mm 2 , as determined by ROC curve analysis. CONCLUSIONS: Our study demonstrated that high vaulting is a significant factor in ECD loss among ICL-inserted patients. To prevent continuous ECD loss in ICL patients, close monitoring of ECD and making appropriate decisions regarding explantation may be necessary.

Efficacy and safety of platelet-rich plasma and autologous-serum eye drops for dry eye in primary Sjögren's syndrome: a randomized trial.

We compared the efficacy and safety of autologous-serum (AS) and platelet-rich plasma (PRP) eye drops for dry eye (DE) treatment in primary Sjögren's syndrome (SS). This prospective, randomized, double-blinded clinical study included patients diagnosed with primary SS DE. Thirty-eight participants were randomly assigned to the AS or PRP groups. Corneal and conjunctival staining scores, Schirmer I test, tear film break-up time (TBUT), and ocular surface disease index (OSDI) scores were evaluated at 4 and 12 weeks. Conjunctival impression cytology (CIC) metaplasia grade and goblet cell density grade at 12 weeks were compared with those at baseline. Corneal and conjunctival staining scores and TBUT significantly improved at 4 and 12 weeks in both groups (all p < 0.005). No significant difference between the AS and PRP groups was observed at 4 and 12 weeks. The Schirmer I values, OSDI scores, CIC metaplasia grade, and goblet cell density grade did not significantly change at 4 and 12 weeks in either group. Both AS and PRP eye drops are effective for primary SS DE without a significant difference. Considering that the preparation time of PRP is shorter than that of AS, PRP can be a good alternative treatment for primary SS DE.

The Effect of Mesenchymal Stem Cells on Dry Eye in Sjogren Syndrome Mouse Model.

Sjögren's syndrome (SS) is a systemic autoimmune disease delineated by chronic lymphocytic infiltrates into the lacrimal or salivary glands, leading to severe dry eye and dry mouth. Mesenchymal stem cells have been shown to be effective in treating numerous autoimmune diseases. This study aimed to illustrate the effects of mesenchymal stem cells on the attenuation of dry eyes (DE) through the inhibition of autophagy markers in a SS mouse model. NOD/ShiLtJ female mice with developed DE were treated with either subconjunctival or lacrimal gland injections of hMSCs (Catholic MASTER Cells). After maintenance for 14 days, clinical DE markers such as tear secretion and corneal staining were observed, as well as goblet cell counts in the conjunctiva, infiltration of inflammatory foci, B and T cells, and autophagy markers in the lacrimal glands. Proinflammatory cytokine expressions of the cornea and conjunctiva, as well as the lacrimal glands, were examined. Clinical markers, such as tear secretion and corneal stain scores, goblet cell counts in the conjunctiva, and foci infiltrations in the lacrimal glands were attenuated in mice treated with subconjunctival or lacrimal gland injections of hMSCs compared to the PBS-treated control group. B cell marker B220 decreased in the lacrimal glands of hMSCs-treated mice, as well as reduced proinflammatory cytokine expressions in the lacrimal glands and cornea. Notably, expression of autophagy markers ATG5 and LC3B-II, as well as HIF-1α and mTOR which play roles in the pathways of autophagy modulation, were shown to be attenuated in the lacrimal glands of hMSCs-treated mice compared to the PBS-treated control mice. Treatment with hMSCs by lacrimal gland or subconjunctival injection demonstrated the alleviation of DE through the repression of autophagy markers, suggesting the therapeutic potentials of hMSCs in a SS mouse model.

Diquafosol ophthalmic solution enhances mucin expression via ERK activation in human conjunctival epithelial cells with hyperosmotic stress.

Purpose: To evaluate the effect of diquafosol tetrasodium on the expression of secretory and membrane-associated mucins in multi-layered cultures of primary human conjunctival epithelial cells (HCEC) using intracellular extracellular signal regulated kinase (ERK) signaling. Methods: HCECs were treated with hyperosmotic stress (400 mOsm/l) for 24 h after air-liquid interface cell culture followed by treatment with diquafosol. HCECs were stimulated for 1 h with or without PD98059, an ERK inhibitor, then treated with diquafosol for 6 h and 24 h. Mucin 1 (MUC1), mucin 16 (MUC16), and MUC5AC mRNA and protein expression levels were analyzed, and cell viability was detected using an MTT assay. Western blot analysis was used to examine p44/42 MAPK (Erk1/2) and phosphorylated p44/42 MAPK (Erk1/2) expression. Results: Hyperosmotic stressed HCECs demonstrated increased MUC5AC secretion and gene expression when treated with diquafosol. MUC1 mRNA levels increased significantly at 24 h (p<0.01), and expression of MUC16 mRNA levels increased at 6 h and were maintained until 24 h (p<0.05).There was no significant difference in cell viability compared to the control group. Immunostaining results for MUC1, MUC16, and MUC5AC in diquafosol tetrasodium-treated HCECs at 24 h showed more positive cells than in the control group. Phosphorylation of p44/42 MAPK (Erk1/2) signaling molecules significantly increased from 5 min to 60 min (p<0.05). The effects of diquafosol on mucin expressions in hyperosmotic stressed HCECs were significantly inhibited by PD98059, an ERK inhibitor, at 6 h and 24 h. Conclusions: ERK signaling may regulate the expression levels of MUC1, MUC16, and MUC5AC induced by diquafosol in hyperosmotic stressed HCECs.

Limbal epithelial stem cell sheets from young donors have better regenerative potential.

To investigate the stemness of limbal epithelial stem cell sheets in relation to the donor's age. Human limbal explants from cadaveric donors were set on human amniotic membrane scaffolds with the xeno-free medium. We evaluated limbal epithelial sheet size, expression of stem/progenitor cell markers, and colony formation efficiency from donors of different age groups (age ≤ 45, age 45-65, and age > 65). Expression of the proliferation marker Ki67, stem/progenitor cell markers p63α and ABCG2, cornea specific marker PANCK, and differentiation marker CK12 were evaluated. To determine the effect of donor age on the storage period of limbal explant sheets, the limbal explant outgrowth sheets were stored in 4 °C for 2 days and analyzed for JC-1, p63α, and PANCK with FACS on each day. From days 6 to 12, the outgrowth area of the limbal epithelial stem cell sheet was significantly larger in the age ≤ 45 groups (296 ± 54.7 mm2, day 9) compared to the other two age groups [age 45-65 group (278 ± 62.6 mm2), age > 65 group (257 ± 44.0 mm2), day 9] (p < 0.01). In terms of stemness, outgrowth cells from aged donors (age > 65) showed lower expression of stem/progenitor cell markers p63α and ABCG2 and decreased CFE compared to the other two groups. There were significantly more p63α+ cells in outgrowth cells in the age ≤ 45 group (18.2 ± 3.6%) compared to the age > 65 group (14.1 ± 4.6%; p < 0.01). Limbal explant outgrowth sheet on the age ≤ 45 group (32.7 ± 7.5%) had higher percentages of cells resisting staining by JC-1 compared with sheets under the age > 65 groups (25.7 ± 7.1%, p < 0.01) (JC-1low). Cells from the age ≤ 45 group showed a higher clonogenic capacity than those from the other two age groups (45 < Age ≤ 65 CFE ratio = 0.7 ± 0.16, p < 0.01; 65 < Age CFE ratio = 0.3 ± 0.06, p < 0.01, vs. Age ≤ 45). In the age > 65 group, positive cells of p63α on D0, 1, and 2 were significantly lower compared to those in the age ≤ 45 group on the storage period (p < 0.01, respectively). Our results imply that donors younger than 65 years of age are a better source of limbal epithelial stem cell sheet generation with high regeneration potential.

Comparative Analysis of the Clinical Outcomes of Mix-and-Match Implantation of an Extended Depth-of-Focus and a Diffractive Bifocal Intraocular Lens.

OBJECTIVES: To evaluate and compare the clinical outcomes of the extended depth-of-focus intraocular lens (EDOF-IOL) and the diffractive bifocal IOL. METHODS: Fifty-six eyes of 28 patients underwent cataract surgery with implantation of an EDOF-IOL (TECNIS Symfony, ZXR00) in their dominant eye and a diffractive bifocal IOL (+3.25 D add TECNIS ZLB00) in their nondominant eye. Monocular and binocular uncorrected distance, intermediate and near visual acuity, defocus curves, contrast sensitivity, patient satisfaction score (0-5), and spectacle dependence at near vision were evaluated at 3 months after the surgery. RESULTS: Postoperative binocular uncorrected distant visual acuity was 0.009±0.031 logMAR, uncorrected intermediate visual acuity was 0.090±0.158 logMAR, and uncorrected near visual acuity was 0.099±0.068 logMAR. The monocular defocus curve demonstrated better performance at intermediate distance in eyes with an EDOF-IOL and better performance at near distance in eyes with a diffractive bifocal IOL. An EDOF-IOL exhibited better outcomes in contrast sensitivity compared with a diffractive bifocal IOL. Three patients (10.7%) required glasses for near vision. CONCLUSION: Mix-and-match implantation of a diffractive bifocal IOL with an EDOF-IOL provides an excellent range of vision, and high levels of contrast sensitivity and patient satisfaction.

Comparison of a preservative-free nonsteroidal anti-inflammatory drug and preservative-free corticosteroid after uneventful cataract surgery: multicenter, randomized, evaluator-blinded clinical trial.

PURPOSE: To compare the efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) and steroidal eyedrops for inflammation management after cataract surgery using slitlamp indicators. SETTING: 11 eye centers in South Korea. DESIGN: Randomized prospective multicenter study with a blinded evaluator. METHOD: In 125 (250 eyes) patients who underwent cataract surgery, bromfenac sodium hydrate 0.1% (NSAID group) was applied twice a day in 1 eye, whereas the other eye was treated with fluorometholone 0.1% (steroid group), 4 times a day for 4 weeks postoperatively. The primary efficacy outcome was the presence of anterior chamber cells and flare at 1 week postoperatively. Anterior chamber cells and flare at 4 to 8 weeks, corrected distance visual acuity, central corneal thickness, conjunctival hyperemia, dry eye parameters, foveal thickness, and ocular and visual discomfort were evaluated as secondary outcomes. RESULTS: At week 1, residual anterior chamber inflammation was not statistically significantly different between the groups (-1.03 ± 1.27 vs -0.95 ± 1.24, P = .4850). However, the NSAID group recovered from conjunctival hyperemia more rapidly than the steroid group (0.30 ± 0.52 vs 0.44 ± 0.81, P = .0144 at week 1). The increase in central corneal thickness in the NSAID group was less than that in the steroid group 1 week postoperatively (7.87 ± 22.46 vs 29.47 ± 46.60 µm, P < .0001). The change in foveal thickness in the NSAID group was significantly less than that in the steroid group (18.11 ± 68.19 vs 22.25 ± 42.37 µm, P = .0002). Lower levels of postoperative ocular and visual discomfort were reported in the NSAID group than in the steroid group under treatment. CONCLUSIONS: Preservative-free bromfenac was as effective as preservative-free fluorometholone eyedrops in anterior chamber inflammation control and showed better signs and symptoms after cataract surgery.

Comparative Accuracy of Barrett Toric Calculator With and Without Posterior Corneal Astigmatism Measurements and the Kane Toric Formula.

PURPOSE: To compare the accuracy of the Barrett toric calculator with and without posterior corneal astigmatism and the Kane toric calculator. DESIGN: Retrospective cross-sectional study. METHODS: The study included a total of 79 eyes of 79 patients who underwent toric intraocular lens (IOL) insertion during uncomplicated cataract surgery by a single surgeon. Using vector analysis, the mean absolute prediction error, the standard deviation of the prediction error, and the percentage of eyes with a prediction error within ±0.50 diopter (D), ± 0.75 D, and ± 1.00 D were calculated. The IOL Master 700 (Carl Zeiss Meditec AG, Jena, Germany) was used for measuring biometry including posterior corneal astigmatism. The main analysis was designed to provide the clinical outcomes with each formula using the postoperative keratometry values and the measured postoperative IOL axis. Real-world analysis was performed using the preoperative keratometry values and the intended IOL axis. RESULTS: There was no significant difference in mean absolute prediction errors calculated with 2 versions of the Barrett toric formula (predicted posterior corneal astigmatism and measured posterior corneal astigmatism) and the Kane toric formula (P > .05). The Barrett toric calculator with predicted and measured posterior corneal astigmatism yielded the best results, with 60.8% <0.50 D prediction error in the main analysis. In the real-world analysis, the Barrett toric calculator with predicted posterior corneal astigmatism showed the best result, with 53.2% <0.50 D prediction error. CONCLUSION: The Barrett toric formula with and without posterior corneal astigmatism measurements using the IOL Master 700 and the Kane toric formula yielded accurate and comparable outcomes in this single-surgeon analysis. Am J Ophthalmol 2021;221:•••-•••. © 2021 Elsevier Inc. All rights reserved.

Prevalence of Macular Abnormalities Identified Only on Optical Coherence Tomography in Korean Patients Scheduled for Cataract Surgery.

PURPOSE: To assess the prevalence of macular abnormalities identified only on macular optical coherence tomography (OCT) which were not suspected by biomicroscopic fundus examination, and examine the clinical outcome of patients with these macular abnormalities during preoperative evaluation for cataract surgery in a large series of Korean patients.<br/>. METHODS: Macular OCT was performed on patients scheduled for routine cataract surgery by the same physician at Seoul St. Mary's Hospital, between June 2018 and November 2019. The patients' medical records were reviewed retrospectively to obtain demographic data and the results of preoperative evaluation before cataract surgery. Patients were divided into two groups based on the preoperative macular OCT. RESULTS: normal and abnormal OCT groups. RESULTS: Nine hundred eighty-seven eyes (698 patients) were included in this study. Macular OCT identified abnormalities in 44 eyes (4.5%) of 35 patients (5.0%). Twenty-one eyes (2.1%) had age-related macular degeneration, 20 eyes (2.0%) had epiretinal membrane, and three eyes (0.3%) had lamellar hole. Patients with macular abnormalities identified on macular OCT had a statistically significant higher mean age than those who had normal OCT findings (p < 0.001). Best-corrected visual acuity was worse in patients with abnormal macular OCT after cataract surgery (p = 0.048). CONCLUSIONS: In the preoperative evaluation for cataract surgery in Korean patients, one in every 20 patients had macular abnormalities identified only on macular OCT in spite of unremarkable macular findings on biomicroscopic funduscopy. Age was significantly higher in patients with abnormal macular OCT findings. Thus, inclusion of macular OCT examination in preoperative screening before routine cataract surgery would be beneficial.

Gene expression profiles of pro-inflammatory mediators in the conjunctiva of patients with epiblepharon.

PURPOSE: To investigate the gene expression of pro-inflammatory mediators in the conjunctiva of pediatric patients with epiblepharon in a case-control study. METHODS: Twenty healthy controls and 15 pediatric patients with epiblepharon were enrolled from April 23, 2020 to June 15, 2020. Epiblepharon severity was divided into class I-III (least to moderate severity) and class IV (most severe). We obtained impression cytologic specimens from the medial palpebral conjunctiva of the participants to measure the gene expression of interleukin (IL)-1ß, IL-6, matrix metalloproteinase 9 (MMP9), and mucin 5AC (MUC5AC) using quantitative reverse transcription polymerase chain reaction. RESULTS: The mean age in the epiblepharon group was 9 years (range 7.5-11 years), and that in the healthy control group was 9.5 years (range 8-11.3 years). IL-1ß, IL-6, and MMP9 expression levels were 2.08 (p < 0.05), 2.11 (p < 0.05), and 2.48 (p < 0.05) fold higher, respectively, in the epiblepharon group than in the healthy control group. However, MUC5AC gene expression was not different between healthy subjects and patients with epiblepharon. IL-1ß, IL-6, and MMP9 expression levels in class IV patients were 1.32 (p < 0.05), 1.77 (p < 0.05), and 1.98 (p < 0.05) fold higher, respectively, than in class I-III patients. CONCLUSION: Epiblepharon may induce chronic inflammatory changes in the conjunctiva in addition to corneal epithelial damage. Therefore, early corrective surgery should be considered to prevent conjunctival inflammation.

Comparison of intraocular lens power formulas according to axial length after myopic corneal laser refractive surgery.

PURPOSE: To assess the predictive accuracy of 4 no-history intraocular lens (IOL) power formulas in eyes with prior myopic excimer laser surgery, classified in 4 groups according to their axial length (AL), and investigate the relationship between AL and predictive accuracy. SETTING: Seoul St. Mary's Hospital, Republic of Korea. DESIGN: Retrospective case series. METHODS: IOL power was calculated with the Barrett True-K, Haigis-L, Shammas-PL, and Triple-S formulas in 4 groups classified according to AL. Primary outcomes were the median absolute error (MedAE) and percentage of eyes with a prediction error (PE) within ±0.50 diopter (D). RESULTS: This study included 107 eyes of 107 patients. The Barrett True-K had the lowest MedAE when AL was <26.0 mm (0.30 D) and between 26.0 and 28.0 mm (0.54 D); in these subgroups, it had the highest percentages with a PE within ±0.50 D (71.4% and 46.2%). For AL between 28.0 and 30.0 mm, the Triple-S method showed the lowest MedAE (0.43 D) and highest percentage with a PE within ±0.50 D (58.3%). For AL ≥30.0 mm, the Shammas-PL formula produced the lowest MedAE (0.41 D) and highest percentage with a PE within ±0.50 D (58.3%). The Barrett True-K was the only formula with a correlation between AL and PE (r = -0.219/P = .023). CONCLUSIONS: The predictive accuracy of no-history IOL formulas depends on the AL. The Barrett True-K had the highest accuracy when AL was < 28.0 mm and the Triple-S when it ranged from 28.0 mm to 30.0 mm, whereas the Shammas-PL was more accurate when AL was ≥30.0 mm.

Comparison of pulsed and continuous accelerated corneal crosslinking for keratoconus: 1-year results at a single center.

PURPOSE: To compare the clinical outcomes between pulsed and continuous accelerated crosslinking (CXL) for keratoconus. SETTING: Hospital. DESIGN: Retrospective comparison study. METHODS: Korean patients who were treated for keratoconus between September 2015 and January 2018 at Seoul St. Mary's Hospital were included. Eyes were subjected to pulsed accelerated crosslinking (30 mW/cm2 for 8 minutes, 1 second on/1 second off) or continuous accelerated crosslinking (30 mW/cm2 for 4 minutes; delivering 7.2 J/cm2). Outcomes were evaluated after 1 year. RESULTS: At 1 year, the 2 groups did not exhibit changes in their corrected and uncorrected distance visual acuity values. The pulsed group (25 eyes in 25 patients) exhibited significantly improved values for sphere (P = .009) and spherical equivalent (P = .033), although no statistically significant difference was observed in the continuous group (20 eyes in 20 patients). All keratometry (k)values (SimKf, SimKs, SimKmean, and Kmax) improved in both groups (all P < .05), although the pulsed group had significantly greater changes in the SimKmean value (P = .036) and the Kmax value (P = .03). Both groups had significantly decreased central and thinnest corneal thicknesses (all P < .001), although the pulsed group had a substantially lower thinnest corneal thickness (P = .017). Corneal densitometry measured using the Pentacam device increased in both groups (all P < .001), with a higher densitometry value in the pulsed group (P = .013). Furthermore, the depth of the demarcation line was deeper in the pulsed group (P = .015). CONCLUSIONS: Pulsed accelerated crosslinking might provide better postcrosslinking effects than continuous accelerated crosslinking.

Ocular surface inflammation induces de novo expression of substance P in the trigeminal primary afferents with large cell bodies.

We evaluated the changes in substance P (SP)-expressing trigeminal neurons (TNs) innervating the cornea following ocular surface inflammation. Ocular surface inflammation was induced in Sprague-Dawley rats using 0.1% benzalkonium chloride (BAK). The corneal staining score, corneal epithelial apoptosis, conjunctival goblet cells, and density of corneal subbasal nerve plexus (SNP) were assessed, and the mRNA levels of SP, interleukin (IL)-1ß, IL-6, and tumour necrosis factor-α were measured in corneas and ipsilateral trigeminal ganglia (TG). SP-immunoreactivity (IR) was measured in corneal intraepithelial nerves and TNs. The cell size of corneal TNs in the TG was calculated. All parameters were observed immediately (BAK group), at 1 week (1 w group), and 2 months (2 m group) after 2 weeks of BAK application. BAK caused an increase in the corneal staining score and the number of apoptotic cells, loss of conjunctival goblet cells, reduced density of corneal SNP, and upregulated expression of SP and inflammatory cytokines in both the cornea and TG in the BAK group but those changes were not observed in the 2 m group. On the other hand, SP-IR% and mean cell size of corneal TNs increased significantly in the BAK, 1 w, and 2 m groups, compared to the control. Our data suggest that following ocular surface inflammation, large-sized corneal TNs which normally do not express SP, expressed it and this phenotype switching lasted even after the inflammation disappeared. Long-lasting phenotypic switch, as well as changes in the expression level of certain molecules should be addressed in future studies on the mechanism of corneal neuropathic pain.

Distinct clinical characteristics of anti-Ro/SSA-negative primary Sjögren's syndrome: data from a nationwide cohort for Sjögren's syndrome in Korea.

OBJECTIVES: To investigate clinical characteristics of patients with primary Sjögren's syndrome (SS) who were negative for anti-Ro/SSA antibody but positive for minor salivary gland biopsy (MSGB) compared to patients who presented positivity for anti-Ro/SSA antibody. METHODS: The data of 355 patients from the Korean Initiative of primary Sjögren's Syndrome (KISS), a nationwide prospective cohort for primary SS in Korea, were analysed. All patients fulfilled the 2016 American College of Rheumatology/European League Against Rheumatism (EULAR) classification criteria. Of these patients, 326 were positive for anti-Ro/SSA antibody and 29 were antibody-negative, although they had positive findings in MSGB. Various clinical features including all kinds of tests for evaluating secretory function, disease-related clinical indices and serological values available in the cohort were compared between the two groups. RESULTS: The anti-Ro/SSA-negative group showed less rheumatoid factor positivity (p<0.001), leucopenia (p=0.003), hyper-gammaglobulinaemia (p<0.001), lower serum ß2-microglobulin level (p=0.034), more anti-centromere antibody positivity (p<0.001), higher score in dryness domain of EULAR SS patient-reported index (p=0.048) and more positivity for peripheral nervous system domain in EULAR SS disease activity index and loss of teeth in SS disease damage index (p=0.021 and 0.041, respectively) than patients who were positive for anti-Ro/ SSA antibody. CONCLUSIONS: Primary SS patients who are negative for anti-Ro/SSA antibody have different clinical characteristics compared to patients who are positive for such antibody in Korea. Therefore, clinicians should consider MSGB in patients with suspicious symptoms who are anti-Ro/SSA-negative.

The Use of Conjunctival Staining to Measure Ocular Surface Inflammation in Patients With Dry Eye.

PURPOSE: To investigate the expression levels of inflammatory cytokines in the conjunctival epithelium and correlations with clinical parameters in dry eye disease (DED). METHODS: This study evaluated 28 patients with Sjögren syndrome (SS) DED, 28 patients with non-SS DED, and 10 controls. The messenger ribonucleic acid (mRNA) expression of inflammatory cytokines such as tumor necrosis factor-α, interleukin (IL)-1ß, IL-6, interferon (IFN)-γ, IL-17, and matrix metalloproteinase 9 (MMP9) from conjunctival epithelium was investigated by real-time polymerase chain reaction. Protein expression was confirmed by immunofluorescence staining. Correlations were evaluated between the mRNA expression of inflammatory cytokines and clinical DED parameters such as ocular surface disease index score, Schirmer I value, tear film breakup time, and corneal and conjunctival staining scores. RESULTS: Patients with non-SS DED expressed significantly more IFN-γ, IL-6, and MMP9 genes in the conjunctival epithelium than the controls (P < 0.05), and all cytokine gene expression was significantly higher in patients with SS DED than in the controls (P < 0.01). Tumor necrosis factor-α, IL-1ß, IL-6, and IL-17 gene expression was higher in patients with SS DED than in the non-SS DED group (P < 0.05). Immunofluorescence staining of conjunctival epithelium demonstrated that positive cells with IL-6 or MMP9 were significantly higher in non-SS DED than in controls (P < 0.01) and much higher in SS DED than in non-SS DED (P < 0.05). Conjunctival staining scores significantly correlated with the expression of IFN-γ, IL-6, IL-17, and MMP9 in both DED groups (P < 0.05 in non-SS DED and P < 0.01 in SS-DED). Interestingly, correlation coefficients of all cytokines were much higher in SS DED compared to non-SS DED. Corneal staining scores showed positive correlations with IFN-γ, IL-17, and MMP9 (P < 0.05), and correlation coefficients were lower than those of conjunctival staining scores. CONCLUSIONS: Conjunctival staining scores may be useful to measure ocular surface inflammation in SS and non-SS DED.

Comparative study of substrate free and amniotic membrane scaffolds for cultivation of limbal epithelial sheet.

Transplantation of cultivated limbal epithelial transplantation has been proven to restore the corneal surface in limbal stem cell deficiency (LSCD). Here we comparatively investigated the optimized conditions and the efficiency of limbal epithelial sheet growth in three media conditions as well as with substrate free (transwell), human amniotic membrane (HAM) sutured onto transwell inserts (HAMTW), and HAM slide scaffold (HAMS). Outcomes evaluated were outgrowth sheet size from limbal explants, expression of stem/progenitor cell markers p63α, ABCG2 and CK15, and colony formation efficiency (CFE). Additionally, limbal epithelial sheets on HAMS were transplanted into corneas of LSCD rabbit models. Limbal epithelial sheets with 5% human AB serum showed the greatest increase in ABCG2 efflux activity (JC1low), p63α expression, and CFE compared in both conditions without HAM and with HAM, respectively. The outgrowth sheet size, cell yield, and Ki67 expression were increased in limbal epithelial sheets on HAMS compared to transwell and HAMTW. ABCG2 efflux activity, p63α and CK15 expressions, and CFE were also increased in limbal epithelial sheets on HAMS as well. In corneas of transplanted rabbit LSCD models, p63α expressions were noted in the basal layers and CK12 expressions were observed in superficial layers. Cultivation of limbal epithelial sheet on HAMS with xeno-free medium enhances the growth and stemness of limbal epithelial sheets.

Divergent effects of Wnt/ß-catenin signaling modifiers on the preservation of human limbal epithelial progenitors according to culture condition.

Wnt signaling plays an important role in the regulation of self-renewal in stem cells. Here we investigated the effect of CHIR99021, the primary transducer of the Wnt signaling canonical pathway, and IWP2, a wide action Wnt signal blocker, on the growth and differentiation of the limbal epithelial progenitor cells when these cells are cultured in two different, common culture approaches, outgrowth from limbal biopsy explants and isolated cell seeded in low calcium medium. Consistent with their expected effects, irrespective of the culture system, IWP2 decreased total ß-catenin while CHIR99021 increased it in nuclear localization. However, IWP2 increased stem/progenitor cell marker (p63α and ABCG2) content and clonogenic capacity in the explants but had opposite effects on isolated cells. CHIR99021 reduced the growth rate, stem/progenitor cell marker content and clonogenic capacity in the explants but also had the opposite effect on the isolated cells. These results show that the outcome of Wnt/ß-catenin signaling modification is dependent on the culture systems. Transplantation of limbal epithelial sheets from explant cultures is one of the standard treatments of limbal stem cell deficiency. Our study shows that Wnt-associated activity has a strong negative impact on stem/progenitor cell preservation in limbal explant cultures.

The Use of Conjunctival Pedicle Flaps to Prevent Corneal Perforation in Graft-Versus-Host Disease.

PURPOSE: We report the clinical outcomes of two chronic graft-versus-host disease (cGVHD) corneal thinning cases that were successfully treated with conjunctival pedicle flaps in an effort to prevent impending corneal perforation. METHODS: The patients were treated with topical and systemic corticosteroids, therapeutic contact lenses, lubricants, and punctual plugs. Conjunctival pedicle flaps were used because conventional treatments had failed, and corneal perforation was imminent. RESULTS: Both patients were successfully treated with conjunctival pedicle flaps. Following conjunctival flap removal, one patient had corneal clarity restored following penetrating keratoplasty. CONCLUSIONS: Conjunctival pedicle flaps provided a strong barrier for the corneal surface and stabilized anterior chamber in cGVHD patients with impending corneal perforation following allogeneic hematopoietic stem cell transplant.