The Effect of Riboflavin-UV-A Treatment on Corneal Limbal Epithelial Cells-A Study on Human Cadaver Eyes

作者：Vimalin Jeyalatha; Gupta Nidhi; Jambulingam Malathi; Padmanabhan Prema^*; Madhavan Hajib N

来源：Cornea, 2012, 31(9): 1052-1059.

DOI：10.1097/ICO.0b013e3182498902

• collagen cross-linking
• limbal stem cell
• riboflavin-UV-A
• limbal protection

Purpose: To determine the effect of riboflavin-UV-A treatment on the corneal limbal epithelial cells during a corneal collagen cross-linking (CXL) procedure.
Methods: Thirty freshly enucleated human cadaveric eyeballs were subjected to a CXL procedure, mimicking the clinical protocol. During the UV-A exposure, one half of the limbus (sector A) was left unprotected, whereas the other half (sector B) was covered by a metal shield. Limbal biopsies from both sectors before and after the procedure were analyzed. Each strip of tissue was divided into 3 segments, for cell count of viable cells, for cultivation on human amniotic membrane (HAM), and for stem cell and differentiated corneal epithelial cell marker studies using reverse transcriptase-polymerase chain reaction.
Results: Compared with the cell count before CXL, there was a statistically significant drop in the mean number of viable cells after CXL in sector A but not in sector B. Biopsies from both sectors before CXL and from sector B after CXL showed good growth on HAM. Biopsies from sector A after CXL showed no growth on HAM. The putative stem cell marker ABCG2 was absent in all samples and p63 was absent in 3 of 10 samples taken from sector A after CXL. All markers were present in all samples from sector B after CXL.
Conclusions: Riboflavin-UV-A treatment can result in damage to limbal epithelial cells, particularly the stem cells. Covering the limbal region with a metal shield effectively prevents this damage.

• 出版日期2012-9