Department of Ophthalmology, University of California, San Francisco, California 94143-0730, USA.
Invest Ophthalmol Vis Sci. 2013 Aug 28;54(8):5908-12. doi: 10.1167/iovs.13-12133.
To determine whether ultrasound treatment can promote the permeation of topical riboflavin into the corneal stroma.
Fresh cadaveric rabbit eyes with intact epithelium were left for 45 minutes in riboflavin 0.1% solution and divided in the following groups: A--untreated, epithelium-on; B--ultrasound-treated (1 W/cm(2) at 880 kHz for 6 minutes) with epithelium-on; and C--epithelium-off (no ultrasound). Eyes were removed from the riboflavin solution, corneas were excised, and group B was divided into B1 (with epithelium maintained) and B2 (epithelium removed for the fluorescence analysis). Confocal microscopy was performed to quantify the fluorescence intensity in the cornea according to the distance from the surface (with epithelium in groups A and B1; without epithelium in groups B2 and C).
The average fluorescence intensity of riboflavin at a depth of 100, 150, 200, and 250 μm was 69.97, 58.83, 49.23, and 41.72 arbitrary units (A.U.) in group A, respectively; 255.26, 206.01, 159.81, 124.20 A.U. in group B1; 218.90, 177.90, 141.43, 110.45 A.U. in group B2; and 677.64, 420.10, 250.72 and 145.07 A.U. in group C. The difference in fluorescence was statistically significant between groups A and B1 (P = 0.001) and groups B2 and C (P < 0.0001).
Ultrasound treatment increased the entry of topical riboflavin into the corneal stroma despite the presence of a previously intact epithelial barrier. This approach may offer a means of achieving clinically useful concentrations of riboflavin within the cornea with minimum epithelial damage, thereby improving the risk profile of corneal cross-linking procedures.
确定超声处理是否能促进局部核黄素渗透到角膜基质中。
将完整上皮的新鲜离体兔眼在核黄素 0.1%溶液中放置 45 分钟，分为以下三组：A-未处理，上皮保留；B-超声处理（1 W/cm²，880 kHz，6 分钟），上皮保留；C-上皮去除（无超声）。将眼球从核黄素溶液中取出，切除角膜，并将 B 组分为 B1（上皮保留）和 B2（去除上皮进行荧光分析）。根据距离表面的距离（A 组和 B1 组有上皮；B2 组和 C 组无上皮），利用共聚焦显微镜定量角膜的荧光强度。
在 A 组中，深度为 100、150、200 和 250μm 处核黄素的平均荧光强度分别为 69.97、58.83、49.23 和 41.72 任意单位（A.U.）；B1 组分别为 255.26、206.01、159.81 和 124.20 A.U.；B2 组分别为 218.90、177.90、141.43 和 110.45 A.U.；C 组分别为 677.64、420.10、250.72 和 145.07 A.U.。A 组和 B1 组（P=0.001）以及 B2 组和 C 组（P<0.0001）之间的荧光差异有统计学意义。
尽管存在先前完整的上皮屏障，超声处理仍能增加局部核黄素进入角膜基质的量。这种方法可能提供一种在最小上皮损伤的情况下使角膜内达到临床有用的核黄素浓度的方法，从而改善角膜交联手术的风险状况。
