Cornea

Li S, Tang L, Zhou J, Anchouche S, Li D, Yang Y, Liu Z, Wu J, Hu J, Zhou Y, Yin J, Liu Z, Li W. Sleep deprivation induces corneal epithelial progenitor cell over-expansion through disruption of redox homeostasis in the tear film. Stem Cell Reports 2022;17(5):1105-1119.Abstract
Sleep deficiency, a common public health problem, causes ocular discomfort and affects ocular surface health. However, the underlying mechanism remains unclear. Herein, we identified that short-term sleep deprivation (SD) resulted in hyperproliferation of corneal epithelial progenitor cells (CEPCs) in mice. The expression levels of p63 and Keratin 14, the biomarkers of CEPCs, were upregulated in the corneal epithelium after short-term SD. In addition, SD led to elevated levels of reactive oxygen species (ROS), and subsequent decrease in antioxidant capacity, in the tear film. Exogenous hydrogen peroxide (H2O2) could directly stimulate the proliferation of CEPCs in vivo and in vitro. Topical treatment of antioxidant L-glutathione preserved the over-proliferation of CEPCs and attenuated corneal epithelial defects in SD mice. Moreover, the activation of the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway is essential to ROS-stimulated cell proliferation in CEPCs. However, long-term SD ultimately led to early manifestation of limbal stem cell deficiency.
Fan N-W, Wang S, Ortiz G, Chauhan SK, Chen Y, Dana R. Autoreactive memory Th17 cells are principally derived from T-bet+RORγt+ Th17/1 effectors. J Autoimmun 2022;129:102816.Abstract
Effector Th17 cells, including IFN-γ-IL-17+ (eTh17) and IFN-γ+IL-17+ (eTh17/1) subsets, play critical pathogenic functions in the induction of autoimmunity. As acute inflammation subsides, a small proportion of the effectors survive and convert to memory Th17 cells (mTh17), which sustain chronic inflammation in autoimmune diseases. Herein, we investigated the differential contributions of eTh17 versus eTh17/1 to the memory pool using an experimental model of ocular autoimmune disease. Our results show that adoptive transfer of Tbx21-/- CD4+ T cells or conditional deletion of Tbx21 in Th17 cells leads to diminished eTh17/1 in acute phase and functionally compromised mTh17 in chronic phase. Further, adoptive transfer of disease-specific eTh17/1, but not eTh17, leads to generation of mTh17 and sustained ocular inflammation. Collectively, our data demonstrate that T-bet-dependent eTh17/1 cells generated during the acute inflammation are the principal effector precursors of pathogenic mTh17 cells that sustain the chronicity of autoimmune inflammation.
Kwan J, Ahmed H, Ponsetto MK, Succar T, Chodosh J, Saeed HN. Relationship between Atopic Disease and Acute Ocular and Systemic Outcomes in Patients with Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis. Ocul Immunol Inflamm 2022;:1-5.Abstract
OBJECTIVE: To describe the relationship between history of atopic disease on systemic and ocular manifestations of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN). METHODS: Retrospective chart review of patients with SJS/TEN patients. Those with and without prior atopic diagnosis were compared. RESULTS: In total, 200 patients with SJS/TEN were identified. A total of 23 patients also had an atopic diagnosis. Four, 10, and 18 had atopic dermatitis, allergic rhinitis, and asthma respectively. Acute ocular severity was significantly worse in the atopic cohort. No significant differences in overall systemic severity of SJS or mortality were found between the atopic and non-atopic cohorts. Compared to our hospital system's general population, prevalence of an atopic diagnosis was significantly higher in those with SJS/TEN. CONCLUSION: Patients with a history of an atopic diagnosis appear to have more significant acute ocular involvement during their SJS/TEN hospitalization. Atopic conditions appear to occur more frequently in the SJS/TEN population compared to the general population.
Fjaervoll K, Fjaervoll H, Magno M, Nøland ST, Dartt DA, Vehof J, Utheim TP. Review on the possible pathophysiological mechanisms underlying visual display terminal-associated dry eye disease. Acta Ophthalmol 2022;Abstract
BACKGROUND: Visual display terminal (VDT) use is a key risk factor for dry eye disease (DED). Visual display terminal (VDT) use reduces the blink rate and increases the number of incomplete blinks. However, the exact mechanisms causing DED development from VDT use have yet to be clearly described. PURPOSE: The purpose of the study was to conduct a review on pathophysiological mechanisms promoting VDT-associated DED. METHODS: A PubMed search of the literature investigating the relationship between dry eye and VDT was performed, and relevance to pathophysiology of DED was evaluated. FINDINGS: Fifty-five articles met the inclusion criteria. Several pathophysiological mechanisms were examined, and multiple hypotheses were extracted from the articles. Visual display terminal (VDT) use causes DED mainly through impaired blinking patterns. Changes in parasympathetic signalling and increased exposure to blue light, which could disrupt ocular homeostasis, were proposed in some studies but lack sufficient scientific support. Together, these changes may lead to a reduced function of the tear film, lacrimal gland, goblet cells and meibomian glands, all contributing to DED development. CONCLUSION: Visual display terminal (VDT) use appears to induce DED through both direct and indirect routes. Decreased blink rates and increased incomplete blinks increase the exposed ocular evaporative area and inhibit lipid distribution from meibomian glands. Although not adequately investigated, changes in parasympathetic signalling may impair lacrimal gland and goblet cell function, promoting tear film instability. More studies are needed to better target and improve the treatment and prevention of VDT-associated DED.
Okumura Y, Inomata T, Midorikawa-Inomata A, Sung J, Fujio K, Akasaki Y, Nakamura M, Iwagami M, Fujimoto K, Eguchi A, Miura M, Nagino K, Hirosawa K, Huang T, Kuwahara M, Dana R, Murakami A. DryEyeRhythm: A reliable and valid smartphone application for the diagnosis assistance of dry eye. Ocul Surf 2022;Abstract
PURPOSE: Undiagnosed or inadequately treated dry eye disease (DED) decreases the quality of life. We aimed to investigate the reliability, validity, and feasibility of the DryEyeRhythm smartphone application (app) for the diagnosis assistance of DED. METHODS: This prospective, cross-sectional, observational, single-center study recruited 82 participants (42 with DED) aged ≥20 years (July 2020-May 2021). Patients with a history of eyelid disorder, ptosis, mental disease, Parkinson's disease, or any other disease affecting blinking were excluded. Participants underwent DED examinations, including the Japanese version of the Ocular Surface Disease Index (J-OSDI) and maximum blink interval (MBI). We analyzed their app-based J-OSDI and MBI results. Internal consistency reliability and concurrent validity were evaluated using Cronbach's alpha coefficients and Pearson's test, respectively. The discriminant validity of the app-based DED diagnosis was assessed by comparing the results of the clinical-based J-OSDI and MBI. The app feasibility and screening performance were evaluated using the precision rate and receiver operating characteristic curve analysis. RESULTS: The app-based J-OSDI showed good internal consistency (Cronbach's α = 0.874). The app-based J-OSDI and MBI were positively correlated with their clinical-based counterparts (r = 0.891 and r = 0.329, respectively). Discriminant validity of the app-based J-OSDI and MBI yielded significantly higher total scores for the DED cohort (8.6 ± 9.3 vs. 28.4 ± 14.9, P < 0.001; 19.0 ± 11.1 vs. 13.2 ± 9.3, P < 0.001). The app's positive and negative predictive values were 91.3% and 69.1%, respectively. The area under the curve (95% confidence interval) was 0.910 (0.846-0.973) with concurrent use of the app-based J-OSDI and MBI. CONCLUSIONS: DryEyeRhythm app is a novel, non-invasive, reliable, and valid instrument for assessing DED.
Wang X, Jacobs DS. Contact Lenses for Ocular Surface Disease. Eye Contact Lens 2022;48(3):115-118.Abstract
ABSTRACT: Ocular surface disease can be difficult to manage, causing patients discomfort and vision loss. Therapeutic contact lenses are an important treatment option that is often neglected because it is conventional wisdom that eyes that are dry or irritated are not good candidates for contact lens. In this focused review, we consider the substantial literature on the use of bandage soft contact lenses (BSCL), scleral lenses, and customized prosthetic devices in the management of ocular graft-vs-host disease. Reports on BSCLs for recurrent corneal erosion are reviewed, as is literature on scleral lenses and prosthetic replacement of the ocular surface ecosystem treatment for Stevens-Johnson syndrome. Clinical pearls for fitting BSCLs are presented, and the issue of antibiotic prophylaxis is considered.
Yeung V, Zhang TC, Yuan L, Parekh M, Cortinas JA, Delavogia E, Hutcheon AEK, Guo X, Ciolino JB. Extracellular Vesicles Secreted by Corneal Myofibroblasts Promote Corneal Epithelial Cell Migration. Int J Mol Sci 2022;23(6)Abstract
Corneal epithelial wound healing is a multifaceted process that encompasses cell proliferation, migration, and communication from the corneal stroma. Upon corneal injury, bidirectional crosstalk between the epithelium and stroma via extracellular vesicles (EVs) has been reported. However, the mechanisms by which the EVs from human corneal keratocytes (HCKs), fibroblasts (HCFs), and/or myofibroblasts (HCMs) exert their effects on the corneal epithelium remain unclear. In this study, HCK-, HCF-, and HCM-EVs were isolated and characterized, and human corneal epithelial (HCE) cell migration was assessed in a scratch assay following PKH26-labeled HCK-, HCF-, or HCM-EV treatment. HCE cells proliferative and apoptotic activity following EV treatment was assessed. HCF-/HCM-EVs were enriched for CD63, CD81, ITGAV, and THBS1 compared to HCK-EV. All EVs were negative for GM130 and showed minimal differences in biophysical properties. At the proteomic level, we showed HCM-EV with a log &gt;two-fold change in CXCL6, CXCL12, MMP1, and MMP2 expression compared to HCK-/HCF-EVs; these proteins are associated with cellular movement pathways. Upon HCM-EV treatment, HCE cell migration, velocity, and proliferation were significantly increased compared to HCK-/HCF-EVs. This study concludes that the HCM-EV protein cargo influences HCE cell migration and proliferation, and understanding these elements may provide a novel therapeutic avenue for corneal wound healing.
Ponsetto MK, Elhusseiny AM, Kwan J, Saeed HN. Corneal stromal deposits in connective tissue disease, a case series. Am J Ophthalmol Case Rep 2022;25:101264.Abstract
Purpose: We report two cases of refractile, peripheral, corneal stromal deposition in two patients with arterial tortuosity syndrome (ATS) and Ehlers-Danlos syndrome (EDS), two closely related connective tissue diseases (CTDs). Observations: Patient 1: A 21-year-old man with history of ATS and keratoectasia presented with bilateral peripheral corneal neovascularization with numerous whitish brown, refractile, deep stromal opacities that were circumferential along the inferotemporal cornea. After 3 years of follow-up, the corneal deposits did not progress, but the ectasia did, with significant bilateral corneal steepening and thinning for which the patient was recommended to undergo repeat corneal collagen cross linking. Patient 2: A 26-year-old man with presumed diagnosis of EDS presented with numerous whitish brown, refractile, deep stromal opacities that were circumferential along the temporal cornea in the right eye, and superiorly in the left eye. The left eye had a pseudopterygium involving 50% of the cornea. After 2 years of follow-up, the corneal opacities did not progress; however, the patient underwent primary excision of the pseudopterygium and subsequently had conjunctivalization of the entire cornea. The lesions in both cases resembled those seen in Terrien's marginal degeneration. Conclusions and importance: Peripheral corneal stromal deposits have never been reported before in EDS or ATS or other connective tissue diseases. This case series may prompt further inquiry and characterization of these findings in patients with CTDs.
Chen Y, Wang S, Alemi H, Dohlman T, Dana R. Immune regulation of the ocular surface. Exp Eye Res 2022;218:109007.Abstract
Despite constant exposure to various environmental stimuli, the ocular surface remains intact and uninflamed while maintaining the transparency of the cornea and its visual function. This 'immune privilege' of the ocular surface is not simply a result of the physical barrier function of the mucosal lining but, more importantly, is actively maintained through a variety of immunoregulatory mechanisms that prevent the disruption of immune homeostasis. In this review, we focus on essential molecular and cellular players that promote immune quiescence in steady-state conditions and suppress inflammation in disease-states. Specifically, we examine the interactions between the ocular surface and its local draining lymphoid compartment, by encompassing the corneal epithelium, corneal nerves and cornea-resident myeloid cells, conjunctival goblet cells, and regulatory T cells (Treg) in the context of ocular surface autoimmune inflammation (dry eye disease) and alloimmunity (corneal transplantation). A better understanding of the immunoregulatory mechanisms will facilitate the development of novel, targeted immunomodulatory strategies for a broad range of ocular surface inflammatory disorders.
Tran JA, Jurkunas UV, Yin J, Davies EC, Sola-Del Valle DA, Chen TC, Lin MM. Netarsudil-associated reticular corneal epithelial edema. Am J Ophthalmol Case Rep 2022;25:101287.Abstract
Purpose: To describe 8 cases of reversible reticular corneal epithelial edema of the cornea that developed after use of the topical Rho-kinase inhibitor netarsudil. Methods: This is a retrospective chart review case series of 8 patients treated with netarsudil at an academic medical center. Observations: Patients had predisposing corneal conditions including penetrating keratoplasty, corneal decompensation after trabeculectomy-associated endophthalmitis, congenital glaucoma with Haab striae, aphakic bullous keratopathy, history of Ahmed valve and silicone oil, and Fuchs endothelial corneal dystrophy undergoing Descemet stripping only. One patient did not have clear predisposing corneal disease other than low endothelial cell density and a history of trabeculectomy. All patients developed reticular corneal epithelial edema, which appeared as collections of moderate sized superficial epithelial bullae arranged in a reticular pattern resembling a honeycomb. Most developed these changes within weeks of initiating netarsudil, but unique to this series are 2 cases in which netarsudil was tolerated by the cornea for months before developing reticular corneal epithelial edema after diode laser cyclophotocoagulation. In cases which underwent anterior segment optical coherence tomography, the imaging demonstrated that the corneal stroma was not edematous, and the reticular corneal epithelial edema involved both host and donor corneal epithelium in cases of penetrating keratoplasty. This fully resolved in all cases upon cessation of netarsudil, and this series is the first to document resolution via a pattern in which the individual bullae become smaller and more widely spaced apart. Conclusion: Netarsudil can cause a reversible reticular corneal epithelial edema.
Parekh M, Pedrotti E, Viola P, Leon P, Neri E, Bosio L, Bonacci E, Ruzza A, Kaye SB, Ponzin D, Ferrari S, Roman V. Factors affecting the success rate of pre-loaded DMEK with endothelium-inwards technique: a multi-centre clinical study. Am J Ophthalmol 2022;Abstract
PURPOSE: To evaluate factors affecting the outcomes of pre-loaded DMEK (pl-DMEK) with endothelium-inwards. DESIGN: Retrospective clinical case series and a comparative tissue preparation study PARTICIPANTS: Fifty-five donor tissues for ex vivo study and 147 eyes of 147 patients indicated with Fuchs endothelial dystrophy or pseudophakic bullous keratopathy with or without cataract. INTERVENTION: Standardized DMEK peeling was performed with 9.5 mm diameter followed by second trephination for loading the graft (8.0-9.5 mm diameter). The tissues were manually pre-loaded with endothelium inwards and preserved for 4 days or shipped for transplantation. Live/dead assay and immunostaining was performed on ex vivo tissues. For the clinical study, the tissues were delivered using bi-manual pull-through technique followed by air tamponade at all the centres. MAIN OUTCOME MEASURES: Tissue characteristics, donor and recipient factors, re-bubbling rate, endothelial cell loss (ECL) and CDVA at 3, 6 and 12 months. RESULT: At day 4, significant cell loss (p=0.04) was observed in pl-DMEK with loss of biomarker expression seen in pre-stripped and pl-DMEK tissues. Re-bubbling was observed in 40.24% cases. Average ECL at 3, 6 and 12 months was 45.87%, 40.98% and 47.54% respectively. CDVA improved significantly at 3 months post-op (0.23 ± 0.37 logMAR) (p<0.01) compared to the baseline (0.79 ± 0.61 logMAR). A significant association (p<0.05) between graft diameter, preservation time, recipient gender, gender mismatch and recipient age to re-bubbling rate was observed. CONCLUSION: Graft loading to delivery time of pl-DMEK tissues in endothelium-inwards fashion must be limited to 4 days after processing. Re-bubbling rate and overall surgical outcomes following pre-loaded DMEK can be multi-factorial and centre specific.
Beining MW, Magno M, Moschowits E, Olafsson J, Vehof J, Dartt DA, Utheim TP. In-office thermal systems for the treatment of dry eye disease. Surv Ophthalmol 2022;Abstract
Dry eye disease affects millions of people worldwide, causing pain, vision disturbance, and reduced productivity. Meibomian gland dysfunction (MGD), a major cause of dry eye, is characterized by chronic glandular inflammation, thickening of the meibum, obstruction of terminal ducts, and glandular atrophy. Treatment of MGD can utilize heat and pressure applied to the meibomian glands, increasing meibum expression. With self-treatments, however, not all patients achieve lasting improvement, and compliance is often low. In-office thermal systems offer a second line of treatment and could be a much-needed addition for patients who do not respond to conventional treatment. We critically evaluated the efficacy and safety of LipiFlow, iLux and TearCare based on existing literature. While the studies found a single in-office thermal treatment to be safe and effective in improving short-term signs and symptoms in patients with dry eye, long-term efficacy needs to be further studied. Thus, well-controlled, long-term efficacy studies are warranted to draw clear conclusions. The treatment seemed to provide rapid relief of symptoms that may last up to one year, but at a considerably higher cost than the at-home treatments. The choice of treatment depends on cost, compliance with at-home treatment, and personal preference.

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