Cornea

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 >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, Romano V. Factors Affecting the Success Rate of Preloaded Descemet Membrane Endothelial Keratoplasty With Endothelium-Inward Technique: A Multicenter Clinical Study. Am J Ophthalmol 2022;241:272-281.Abstract
PURPOSE: To evaluate factors affecting the outcomes of preloaded Descemet membrane endothelial keratoplasty (pl-DMEK) with endothelium-inward. DESIGN: Retrospective clinical case series and a comparative tissue preparation study. METHODS: 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 trephination followed by second trephination for loading the graft (8.0-9.5 mm diameter). The tissues were manually preloaded with endothelium-inward and preserved for 4 days or shipped for transplantation. Live and dead assay and immunostaining was performed on ex vivo tissues. For the clinical study, the tissues were delivered using bimanual pull-through technique followed by air tamponade at all the centers. MAIN OUTCOME MEASURES: Tissue characteristics, donor and recipient factors, rebubbling rate, endothelial cell loss (ECL), and corrected distance visual acuity (CDVA) at 3, 6, and 12 months. RESULTS: At day 4, significant cell loss (P = .04) was observed in pl-DMEK with loss of biomarker expression seen in prestripped and pl-DMEK tissues. Rebubbling 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 postoperation (0.23 ± 0.37 logMAR) (P < .01) compared to the baseline (0.79 ± 0.61 logMAR). A significant association (P < .05) between graft diameter, preservation time, recipient gender, gender mismatch, and recipient age to rebubbling rate was observed. CONCLUSION: Graft loading to delivery time of pl-DMEK tissues in endothelium-inward fashion must be limited to 4 days after processing. Rebubbling rate and overall surgical outcomes following preloaded DMEK can be multifactorial and center-specific.
Beining MW, Magnø MS, Moschowits E, Olafsson J, Vehof J, Dartt DA, Utheim TP. In-office thermal systems for the treatment of dry eye disease. Surv Ophthalmol 2022;67(5):1405-1418.Abstract
Dry eye disease affects millions of people worldwide, causing pain, vision disturbance, and reduced productivity. Meibomian gland dysfunction, 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 meibomian gland dysfunction 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 evaluated. 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 1 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.
Qureshi S, Ferguson TJ, Lim M, You JY, Goshe JM, Hood CT. Acute Calcific Band Keratopathy as an Adverse Effect of Recombinant Human Nerve Growth Factor (Cenegermin): A Multicenter Case Series. Cornea 2022;41(1):52-59.Abstract
PURPOSE: Cenegermin, (OXERVATE) a recently Food and Drug Administration-approved topical formulation of recombinant human nerve growth factor, has been used for the treatment of neurotrophic keratopathy (NK). Corneal deposits have been previously reported as a potential adverse effect; however, the clinical characteristics, visual significance, and treatment options have not been fully described. The purpose of this article is to better characterize corneal deposits occurring during treatment with cenegermin for neurotrophic keratopathy. METHODS: This was a retrospective, multicenter consecutive case series. RESULTS: We identified 5 patients from 3 institutions who developed a white opacity in varying layers of the cornea, consistent with calcium deposition, during treatment with cenegermin. In all cases, the opacity occurred rapidly over the course of a few weeks after initiation of treatment. Histopathologic examination of the cornea from one corneal patient demonstrated extensive calcification of the stroma extending to 90% depth. Before treatment, all patients had stage 2 or 3 NK (Mackie classification). The deposits were visually significant in all patients and did not resolve after cessation of cenegermin. There were no differences in age, sex, etiology of the NK, corneal transplant status, or concurrent medications between the patients who developed a deposit and 15 other patients with stage 2 or 3 NK who did not. One patient was successfully treated with superficial keratectomy with ethylenediaminetetraacetic acid chelation, one patient underwent penetrating keratoplasty, and one patient received a Boston keratoprosthesis. CONCLUSIONS: We report the rapid onset of a corneal opacity after initiation of treatment with cenegermin in patients with stage 2 or 3 NK, consistent with acute calcific band keratopathy. This visually significant adverse finding has not previously been described. We could not identify any risk factors for development. We recommend close monitoring of patients receiving cenegermin therapy because the opacity may be irreversible and may require keratoplasty for visual rehabilitation.
Elbasiony E, Cho W, Mittal SK, Chauhan SK. Suppression of lipopolysaccharide-induced corneal opacity by hepatocyte growth factor. Sci Rep 2022;12(1):494.Abstract
Keratitis induced by bacterial toxins, including lipopolysaccharide (LPS), is a major cause of corneal opacity and vision loss. Our previous study demonstrates hepatocyte growth factor (HGF) promotes epithelial wound healing following mechanical corneal injury. Here, we investigated whether HGF has the capacity to suppress infectious inflammatory corneal opacity using a new model of LPS-induced keratitis. Keratitis, induced by two intrastromal injections of LPS on day 1 and 4 in C57BL/6 mice, resulted in significant corneal opacity for up to day 10. Following keratitis induction, corneas were topically treated with 0.1% HGF or PBS thrice daily for 5 days. HGF-treated mice showed a significantly smaller area of corneal opacity compared to PBS-treated mice, thus improving corneal transparency. Moreover, HGF treatment resulted in suppression of α-SMA expression, compared to PBS treatment. HGF-treated corneas showed normalized corneal structure and reduced expression of pro-inflammatory cytokine, demonstrating that HGF restores corneal architecture and immune quiescence in corneas with LPS-induced keratitis. These findings offer novel insight into the potential application of HGF-based therapies for the prevention and treatment of infection-induced corneal opacity.
Sun T, Shu H-Y, Wu J-L, Su T, Liu Y-J, Zhang L-J, Li Q-Y, Pan Y-C, Ge Q-M, Shao Y. Investigation of changes in the activity and function of dry eye-associated brain regions using the amplitude of low-frequency fluctuations method. Biosci Rep 2022;42(1)Abstract
OBJECTIVE: The local characteristics of spontaneous brain activity in patients with dry eye (DE) and its relationship with clinical characteristics were evaluated using the amplitude of low-frequency fluctuations (ALFF) method. METHODS: A total of 27 patients with DE (10 males and 17 females) and 28 healthy controls (HCs) (10 males and 18 females) were recruited, matched according to sex, age, weight and height, classified into the DE and HC groups, and examined using functional magnetic resonance imaging (fMRI) scans. Spontaneous brain activity changes were recorded using ALFF technology. Data were recorded and plotted on the receiver operating characteristic (ROC) curve, reflecting changes in activity in different brain areas. Finally, Pearson correlation analysis was used to calculate the potential relationship between spontaneous brain activity abnormalities in multiple brain regions and clinical features in patients with DE. GraphPad Prism 8 (GraphPad Software, Inc.) was used to analyze the linear correlation between the Hospital Anxiety and Depression Scale and ALFF value. RESULTS: Compared with HCs, the ALFF values of patients with DE were decreased in the right middle frontal gyrus (MFG)/right inferior orbitofrontal cortex (OFC), left triangle inferior frontal gyrus, left MFG, and right superior frontal gyrus. In contrast, the ALFF value of patients with DE was increased in the left calcarine. CONCLUSION: There are significant fluctuations in the ALFF value of specific brain regions in patients with DE versus HCs. This corroborates previous evidence showing that the symptoms of ocular surface damage in patients with DE are related to dysfunction in specific brain areas.
Sharifi S, Sharifi H, Akbari A, Lei F, Dohlman CH, Gonzalez-Andrades M, Guild C, Paschalis EI, Chodosh J. Critical media attributes in E-beam sterilization of corneal tissue. Acta Biomater 2022;138:218-227.Abstract
When ionizing irradiation interacts with a media, it can form reactive species that can react with the constituents of the system, leading to eradication of bioburden and sterilization of the tissue. Understanding the media's properties such as polarity is important to control and direct those reactive species to perform desired reactions. Using ethanol as a polarity modifier of water, we herein generated a series of media with varying relative polarities for electron beam (E-beam) irradiation of cornea at 25 kGy and studied how the irradiation media's polarity impacts properties of the cornea. After irradiation of corneal tissues, mechanical (tensile strength and modulus, elongation at break, and compression modulus), chemical, optical, structural, degradation, and biological properties of the corneal tissues were evaluated. Our study showed that irradiation in lower relative polarity media improved structural properties of the tissues yet reduced optical transmission; higher relative polarity reduced structural and optical properties of the cornea; and intermediate relative polarity (ethanol concentrations = 20-30% (v/v)) improved the structural properties, without compromising optical characteristics. Regardless of media polarity, irradiation did not negatively impact the biocompatibility of the corneal tissue. Our data shows that the absorbed ethanol can be flushed from the irradiated cornea to levels that are nontoxic to corneal and retinal cells. These findings suggest that the relative polarity of the irradiation media can be tuned to generate sterilized tissues, including corneal grafts, with engineered properties that are required for specific biomedical applications. STATEMENT OF SIGNIFICANCE: Extending the shelf-life of corneal tissue can improve general accessibility of cornea grafts for transplantation. Irradiation of donor corneas with E-beam is an emerging technology to sterilize the corneal tissues and enable their long-term storage at room temperature. Despite recent applications in clinical medicine, little is known about the effect of irradiation and preservation media's characteristics, such as polarity on the properties of irradiated corneas. Here, we have showed that the polarity of the media can be a valuable tool to change and control the properties of the irradiated tissue for transplantation.
Roldan AM, De Arrigunaga S, Ciolino JB. Effect of Autologous Serum Eye Drops on Corneal Haze after Corneal Cross-linking. Optom Vis Sci 2022;99(2):95-100.Abstract
SIGNIFICANCE: Corneal haze remains a frequent post-operative finding in patients undergoing corneal cross-linking. It has been shown that autologous serum tears promote epithelial healing and reduce post-operative pain; however, the role in the prevention of corneal haze has not been reported. PURPOSE: This study aimed to compare the effect of autologous serum tears versus preservative-free artificial tears on the prevention and resolution of post-cross-linking corneal haze. METHODS: A retrospective cohort study was conducted in a sample population from one surgeon at a tertiary eye center from 2016 to 2019. Seventy-six eyes of consecutive patients who underwent cross-linking were included. Records were reviewed for corneal Scheimpflug densitometry values and maximum keratometry, epithelial healing time, and the use of either autologous serum tears or preservative-free artificial tears. Corneal densitometry values, expressed in standardized grayscale units (GSU), were recorded for the anterior 150-μm corneal stroma and in the 0.0 to 2.0 mm and 2.0 to 6.0 mm zones. RESULTS: Forty-four eyes received autologous serum tears, whereas 32 eyes received preservative-free artificial tears. The baseline GSU of the anterior stromal 0 to 2 mm annulus and the 2 to 6 mm annulus did not significantly differ between groups (P = .50 and P = .40, respectively). There was a statistically significant increase in mean GSU for both anterior 0 to 2 mm and 2 to 6 mm zones between baseline and 1 month (P < .001) and 3 months (P < .001). When comparing the two groups, no statistically significant difference was found post-operatively between the mean GSU at 1 month for the anterior 0 to 2 mm (P = .38) nor the 2 to 6 mm zone (P = .12), or for the third month (P = .60 and P = .44, respectively). CONCLUSIONS: Using Scheimpflug densitometry, we did not find a significant difference in the post-cross-linking corneal haze at 1 and 3 post-operative months between patients who use autologous serum tears and those who use preservative-free artificial tears.

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