Vetter J M, Tubic-Grozdanis M, Faust M, Lorenz K, Gericke A, Stoffelns B M
Augenklinik, Universitätsmedizin der Johannes-Gutenberg-Universität Mainz, Langenbeckstrasse 1, Mainz.
Klin Monbl Augenheilkd. 2011 Jun;228(6):509-14. doi: 10.1055/s-0031-1273406. Epub 2011 Jun 7.
During the UVA-cross-linking treatment in keratoconus patients, the UVA rays are partially absorbed in the stroma of the riboflavin-loaded cornea. This effect protects the corneal endothelium from UVA irradiation damage. The intensity of UVA light reaching the endothelium is inversely correlated with corneal thickness. The common composition of riboflavin eye drops may lead to a marked reduction in corneal thickness increasing the risk of endothelial damage.
In a retrospective analysis of 23 UVA-cross-linking procedures on 23 patients we collected data about the pre-, intra- and postoperative corneal thickness (measured with ultrasound). Among these patients and depending on the preoperative state, 8 eyes received Medio Cross (TM) eye drops (group 1), 8 eyes received Medio Cross (TM) eye drops combined with riboflavin 0.1 %/methylhydroxypropylcellulose 1,5 %/NaCl 1.1 % (group 2) and 7 eyes received riboflavin 0.2 %/methylhydroxypropylcellulose 0.5 %/NaCl 0.7 % eye drops (group 3) before and during UVA irradiation. Data are presented as means ± standard deviation. A comparison of the data was performed using (one-way) ANOVA.
The mean corneal thickness at the end of the UVA cross-linking procedure was 67 ± 9 % (means ± standard deviation) of preoperative thickness in group 1, 118 ± 14 % in group 2 and 140 ± 23 % in group 3. The values in groups 2 and 3 were significantly different from those in the reference group 1.
Our results show a strong variability of the postoperative corneal thickness using different standard compositions of riboflavin eye drops. Further studies are needed to find a composition of riboflavin eye drops ensuring a moderate increase in intraoperative corneal thickness to protect the corneal endothelium.
在圆锥角膜患者的紫外线A交联治疗过程中，紫外线A射线在加载核黄素的角膜基质中被部分吸收。这种效应可保护角膜内皮免受紫外线A照射损伤。到达内皮的紫外线A光强度与角膜厚度呈负相关。核黄素滴眼液的常见成分可能导致角膜厚度显著降低，增加内皮损伤风险。
在对23例患者进行的23次紫外线A交联手术的回顾性分析中，我们收集了术前、术中和术后角膜厚度（用超声测量）的数据。在这些患者中，根据术前状态，8只眼使用Medio Cross（TM）滴眼液（第1组），8只眼使用Medio Cross（TM）滴眼液联合0.1%核黄素/1.5%甲基羟丙基纤维素/1.1%氯化钠（第2组），7只眼在紫外线A照射前和照射期间使用0.2%核黄素/0.5%甲基羟丙基纤维素/0.7%氯化钠滴眼液（第3组）。数据以平均值±标准差表示。使用（单因素）方差分析对数据进行比较。
紫外线A交联手术结束时，第1组角膜平均厚度为术前厚度的67±9%（平均值±标准差），第2组为118±14%，第3组为140±23%。第2组和第3组的值与参考组第1组的值有显著差异。
我们的结果表明，使用不同标准成分的核黄素滴眼液，术后角膜厚度存在很大差异。需要进一步研究以找到一种核黄素滴眼液成分，确保术中角膜厚度适度增加以保护角膜内皮。
