Laboratory for Ocular Cell Biology, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland.
Faculty of Medicine, University of Geneva, Geneva, Switzerland.
Transl Vis Sci Technol. 2021 Apr 29;10(5):10. doi: 10.1167/tvst.10.5.10.
To assess whether optimized technical settings for accelerated epithelium-off corneal cross-linking may lead to increases in biomechanical stiffness similar to the benchmark 30-minute epithelium-off Dresden protocol.
Three-hundred porcine eyes were divided equally into six groups for analysis. All samples underwent epithelial debridement and soaking with 0.1% iso-osmolar riboflavin solution for 20 minutes. Corneal cross-linking (CXL) was performed using epithelium-off protocols varying in acceleration and total fluence (intensity in mW/cm² * time in minutes, total fluence in J/cm²): standard (S)-CXL (330, 5.4), accelerated (A)-CXL (910, 5.4), A-CXL (913'20″, 7.2), A-CXL (186'40″, 7.2), and A-CXL (18*9'15″, 10). Control corneas were not irradiated. The elastic modulus of 5-mm wide corneal strips was measured as an indicator of corneal stiffness.
All irradiated groups had significantly higher elastic modulus than controls (P < 0.05), with a stiffening effect of 133% S-CXL (330, 5.4), 122% A-CXL (910, 5.4), 120% A-CXL (913'20″, 7.2), 114% A-CXL (186'40″, 7.2) and 149% A-CXL (189'15″, 10). The high-fluence accelerated epithelium-off protocol (189'15″, 10) showed the highest stiffening effect. Elastic modulus at 5% strain (1%-5% strain) showed significant differences between A-CXL (189'15″, 7.2) and three other accelerated protocols: A-CXL (910, 5.4; P = 0.01), A-CXL (913'20″, 7.2; P = 0.003), and A-CXL (186'40″, 10; P = 0.0001).
An accelerated high-fluence epithelium-off CXL protocol (18 mW/cm² for 9'15″) was identified to provide a significantly greater stiffening effect than any other accelerated protocols and is indistinguishable from the Dresden protocol, with accelerating irradiation times ranging from 30 to 9 minutes; by combining gentle acceleration with higher fluence, such a protocol does not require supplemental oxygen.
This A-CXL (18*9'15″, 10) protocol has the potential to become a new standard in epithelium-off CXL, delivering Dresden protocol-like strengthening over a shorter period.
评估加速去上皮角膜交联的优化技术参数是否会导致生物力学硬度的增加，类似于基准的 30 分钟去上皮德累斯顿方案。
将 300 只猪眼平均分为 6 组进行分析。所有样本均行上皮清创术并用 0.1%等渗核黄素溶液浸泡 20 分钟。采用不同加速和总辐照量（强度 mW/cm²时间分钟，总辐照量 J/cm²）的去上皮方案进行角膜交联（CXL）：标准（S）-CXL（330，5.4）、加速（A）-CXL（910，5.4）、A-CXL（913'20″，7.2）、A-CXL（186'40″，7.2）和 A-CXL（189'15″，10）。对照角膜不照射。测量 5mm 宽角膜条的弹性模量作为角膜硬度的指标。
所有照射组的弹性模量均明显高于对照组（P<0.05），S-CXL（330，5.4）、A-CXL（910，5.4）、A-CXL（913'20″，7.2）、A-CXL（186'40″，7.2）和 A-CXL（189'15″，10）的硬化效果分别为 133%、122%、120%、114%和 149%。高剂量加速去上皮方案（189'15″，10）显示出最高的硬化效果。在 5%应变时的弹性模量（1%-5%应变）在 A-CXL（189'15″，7.2）和其他三种加速方案之间存在显著差异：A-CXL（910，5.4；P=0.01）、A-CXL（913'20″，7.2；P=0.003）和 A-CXL（186'40″，10；P=0.0001）。
确定了一种加速高剂量去上皮 CXL 方案（18mW/cm² 照射 9'15″），与任何其他加速方案相比，该方案可显著增强硬度，与德累斯顿方案相当，加速照射时间从 30 分钟缩短至 9 分钟；通过温和加速与高剂量相结合，该方案不需要补充氧气。
这种 A-CXL（18*9'15″，10）方案有可能成为去上皮 CXL 的新标准，在更短的时间内提供类似于德累斯顿方案的强化效果。
