Cornea is a thin and transparent structure in the most anterior part of the eyeball and plays an important role in controlling vision. From the most anterior part of the cornea, the tear film, and to the most posterior part, the corneal endothelium, a defect in any layer may impair visual function. Accordingly, treatment strategy should focus on the layer of the corneal disease and treat the defect layer by layer.In this issue, we selected several important and interesting articles about diseases in different layers of the cornea and the respective treatments.
Treatment of Dry Eye
Topical autologous serum has long been used to treat severe dry eye syndrome.[1234] However, the pros and cons of using autologous serum in the treatment of primary and secondary Sjogren syndrome (SS) have seldom been systemically discussed. Hwang et al. reported that primary and secondary SS could react differently to treatments because of the elevated serum pro-inflammatory cytokine levels in secondary SS.[5] In this issue, Ma et al. analyzed the serum components and the therapeutic effects of topical autologous serum in treating dry eye caused by primary and secondary SS. The study emphasized the importance of using erythrocyte sedimentation rate as an indicator of disease activity and predictor of therapeutic effects.
Treatment of Limbal Insufficiency
Although cell therapy using cultivated limbal or oral mucosal epithelial cell sheets has been regarded as the standard therapeutic option for limbal insufficiency,[678] the various cultivating protocols are known to lead to different treatment results. Among these protocols, whether the cell products should receive air lifting has not been well explored. In this issue, Chen et al. airlifted cultivated rabbit corneal epithelial cells for different durations and concluded that airlifting could trigger cell stratification and differentiation without changing the pattern and localization of several important cytokeratin and stem cell markers. Their results suggest that a suitable duration of airlifting may be considered in the cell therapy for limbal insufficiency.
Lamellar Keratoplasty
Nowadays, lamellar keratoplasty has replaced penetrating keratoplasty in most cases of corneal transplantation.[910] Deep anterior lamellar keratoplasty (DALK) has the benefit of removing the lesions in the stromal layer without disrupting the recipient's own corneal endothelium. This procedure can thus prevent corneal endothelial rejection after transplantation and increase the success rates of surgeries. Ma et al. reported on the surgical outcomes of layer-by-layer DALK in this issue and provided an interesting option for patients with previous inflammation or fibrosis.This issue also included the study by Akbar et al. which compared the surgical outcomes for transepithelial corneal crosslinking and epithelial off crosslinking in adult population with progressive keratoconus and the report by Hou et al. on corneal endothelial cell loss in penetrating keratoplasty, endothelial keratoplasty, and DALK.Through these articles, we aim to provide the readers with a thorough understanding of the new treatment strategies for corneal disorders.