Hot towels:The bedrock of Meibomian gland dysfunction treatment – A review

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Corneal Stromal Regeneration: Current Status and Future Therapeutic Potential

The corneal stroma comprises 90% of the corneal thickness and is critical for the corneas transparency and refractive function necessary for vision. When the corneal stroma is altered by disease, injury, or scarring, however, an irreversible loss of transparency can occur. Corneal stromal pathology is the cause of millions of cases of blindness globally, and although corneal transplantation is the standard therapy, a severe global deficit of donor corneal tissue and eye banking infrastructure exists, and is unable to meet the overwhelming need. An alternative approach is to harness the endogenous regenerative ability of the corneal stroma, which exhibits self-renewal of the collagenous extracellular matrix under appropriate conditions. To mimic endogenous stromal regeneration, however, is a challenge. Unlike the corneal epithelium and endothelium, the corneal stroma is an exquisitely organized extracellular matrix containing stromal cells, proteoglycans and corneal nerves that is difficult to recapitulate in vitro. Nevertheless, much progress has recently been made in developing stromal equivalents, and in this review the most recent approaches to stromal regeneration therapy are described and discussed. Novel approaches for stromal regeneration include human or animal corneal and/or non-corneal tissue that is acellular or is decellularized and/or re-cellularized, acellular bioengineered stromal scaffolds, tissue adhesives, 3D bioprinting and stromal stem cell therapy. This review highlights the techniques and advances that have achieved first clinical use or are close to translation for eventual therapeutic application in repairing and regenerating the corneal stroma, while the potential of these novel therapies for achieving effective stromal regeneration is discussed.Funding Agencies|European CommissionEuropean Commission Joint Research Centre [667400]</p

Congenital aniridia - A comprehensive review of clinical features and therapeutic approaches

Congenital aniridia is a rare genetic eye disorder with total or partial absence of the iris from birth. In most cases the genetic origin of aniridia is a mutation in the PAX6 gene, lead-ing to involvement of most eye structures. Hypoplasia of the fovea is usually present and is associated with reduced visual acuity and nystagmus. Aniridia-associated keratopathy, glaucoma, and cataract are serious and progressive complications that can further reduce visual function. Treatment of the ocular complications of aniridia is challenging and has a high risk of side effects. New approaches such as stem cell therapy may, however, offer better prognoses. We describe the various ocular manifestations of aniridia, with a special focus on conditions that commonly require treatment. We also review the growing literature reporting systemic manifestations of the disease. (c) 2021 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ).Funding Agencies|European Union COST Action [CA-18116 ANIRIDIA-NET]</p

High fluence PACK-CXL as adjuvant treatment for advanced Acanthamoeba keratitis

Purpose To describe the outcome of adjuvant high fluence photoactivated chromophore for infectious keratitis cross-linking (PACK-CXL) used to treat an advanced form of refractory Acanthamoeba keratitis (AK) diagnosed several months after initial presentation. Observations An otherwise healthy 24-year old female presented with a severe unilateral keratitis. The diagnosis eluded clinicians for several months and when finally confirmed as AK, anti-amoebic therapy was instated and only appeared to be effective after addition of high fluence PACK-CXL. Conclusion and importance In this case of advanced AK, high fluence PACK-CXL treatment given adjuvant to pharmacologic anti-amoebic therapy resulted in lasting pain relief, re-epithelization and eradication of the Acanthamoeba parasite. Given adjuvant to anti-amoebic pharmacotherapy, high fluence PACK-CXL might be a useful method for treating typically refractory advanced AK

Corneal Regeneration Following Implantation of a Biomimetic Tissue-Engineered Substitute

n/aThis is the authors’ version of the following article:Per Fagerholm, Neil S Lagali, David J Carlsson, Kimberley Merrett and May Griffith, Corneal Regeneration Following Implantation of a Biomimetic Tissue-Engineered Substitute, 2009, CTS-CLINICAL AND TRANSLATIONAL SCIENCE, (2), 2, 162-164.which has been published in final form at: http://dx.doi.org/10.1111/j.1752-8062.2008.00083.xCopyright: Blackwell Publishinghttp://eu.wiley.com/WileyCDA/Brand/id-35.htm

Corneal Regeneration Following Implantation of a Biomimetic Tissue-Engineered Substitute

n/aThis is the authors’ version of the following article:Per Fagerholm, Neil S Lagali, David J Carlsson, Kimberley Merrett and May Griffith, Corneal Regeneration Following Implantation of a Biomimetic Tissue-Engineered Substitute, 2009, CTS-CLINICAL AND TRANSLATIONAL SCIENCE, (2), 2, 162-164.which has been published in final form at: http://dx.doi.org/10.1111/j.1752-8062.2008.00083.xCopyright: Blackwell Publishinghttp://eu.wiley.com/WileyCDA/Brand/id-35.htm

Microdot Accumulation in the Anterior Cornea with Aging - Quantitative Analysis with in Vivo Confocal Microscopy

Purpose: Degenerative microdot deposits in healthy and hypoxic corneas are believed to represent lipofuscin-like material aggregation in the stroma. To accurately assess microdot deposits in a clinical setting, we sought to quantify these deposits for the first time using the non-invasive clinical imaging technique of in vivo confocal microscopy (IVCM). Methods: The corneas of 102 healthy subjects aged 15-88 years were examined by IVCM and microdot density was quantified using a 6-point grading scale by two masked, trained examiners. Microdot density was analyzed with respect to age, sex and stromal depth, and inter-eye and inter-observer differences were evaluated. Results: In healthy subjects, microdot density decreased from the anterior to posterior stroma, with the greatest accumulation observed in the most anterior stroma (subepithelial region). In this region, microdot density correlated strongly with age (P amp;lt; .0001), with increased microdot deposition in older subjects (amp;gt;60 years) relative to younger ones (amp;lt;45 years) (P amp;lt; .001). Microdot density between eyes of the same subject was highly correlated (r = 0.92, P amp;lt; .0001), while no association with sex was noted (P amp;gt;= 0.05). The mean inter-observer difference in microdot assessment was 0.62 +/- 0.09 grades, with a high correlation of grading between observers (r = 0.77, P amp;lt; .0001). Conclusions: IVCM can be used to non-invasively quantify microdot deposits in the subepithelial corneal stroma with good inter-observer reproducibility. Microdot assessment may provide a novel means of quantifying age-related or pathologic degeneration of the corneal stroma in a clinical setting.Funding Agencies|Princess Margaretas Foundation; European CommissionEuropean Commission Joint Research Centre [667400]</p

Analysis of Generalized Mach–Zehnder Interferometers for Variable-Ratio Power Splitting and Optimized Switching

The nonideal integrated optical N x N generalized Mach–Zehnder interferometer (GMZI) employing multimode interference (MMI) couplers is analyzed using transfer matrix techniques. Deviations in the phase relations and the power splitting ratio of the MMI couplers are included in the theory, along with the effects of phase errors in the interferometer arms. The predictions of the theory are compared to the response of a 4 x 4 GMZI which has been fabricated. The device is operated as both a variable-ratio power splitter and a switch by compensating for the phase errors in the interferometer arms, but the performance is ultimately limited by the nonideal imaging in the MMI couplers. The practicality of these applications is investigated by performing a tolerance analysis for the operation of 1 x N power splitters and switches for N up to 10