Alhayek Adel, Lu Pei-Rong
Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu Province, China.
Int J Ophthalmol. 2015 Apr 18;8(2):407-18. doi: 10.3980/j.issn.2222-3959.2015.02.35. eCollection 2015.
Keratoconus is a condition characterized by biomechanical instability of the cornea, presenting in a progressive, asymmetric and bilateral way. Corneal collagen crosslinking (CXL) with riboflavin and Ultraviolet-A (UVA) is a new technique of corneal tissue strengthening that combines the use of riboflavin as a photo sensitizer and UVA irradiation. Studies showed that CXL was effective in halting the progression of keratoconus over a period of up to four years. The published studies also revealed a reduction of max K readings by more than 2 D, while the postoperative spherical equivalent (SEQ) was reduced by an average of more than 1 D and refractive cylinder decreased by about 1 D. The major indication for the use of CXL is to inhibit the progression of corneal ecstasies, such as keratoconus and pellucid marginal degeneration. CXL may also be effective in the treatment and prophylaxis of iatrogenic keratectasia, resulting from excessively aggressive photo ablation. This treatment has been used to treat infectious corneal ulcers with apparent favorable results. Most recent studies demonstrate the beneficial impact of CXL for iatrogenic ecstasies, pellucid marginal degeneration, infectious keratitis, bullous keratopathy and ulcerative keratitis. Several long-term and short-term complications of CXL have been studied and documented. The possibility of a secondary infection after the procedure exists because the patient is subject to epithelial debridement and the application of a soft contact lens. Formation of temporary corneal haze, permanent scars, endothelial damage, treatment failure, sterile infiltrates, bullous keratopathy and herpes reactivation are the other reported complications of this procedure.
圆锥角膜是一种以角膜生物力学不稳定为特征的疾病，呈进行性、不对称和双侧性。核黄素与紫外线A（UVA）交联的角膜交联术（CXL）是一种新的角膜组织强化技术，它将核黄素作为光敏剂与UVA照射结合使用。研究表明，CXL在长达四年的时间内有效阻止圆锥角膜的进展。已发表的研究还显示，最大角膜曲率读数降低超过2D，而术后等效球镜（SEQ）平均降低超过1D，屈光柱镜降低约1D。使用CXL的主要适应症是抑制角膜扩张症的进展，如圆锥角膜和透明边缘变性。CXL在治疗和预防因过度激进的光消融导致的医源性角膜扩张方面也可能有效。这种治疗方法已用于治疗感染性角膜溃疡，效果明显良好。最近的研究表明CXL对医源性角膜扩张、透明边缘变性、感染性角膜炎、大疱性角膜病变和溃疡性角膜炎有有益影响。CXL的几种长期和短期并发症已得到研究和记录。术后存在继发感染的可能性，因为患者需要进行上皮清创并佩戴软性隐形眼镜。暂时性角膜混浊、永久性瘢痕、内皮损伤、治疗失败、无菌浸润、大疱性角膜病变和疱疹复发是该手术其他已报道的并发症。
