Subacute effects of rose Bengal/Green light cross linking on rabbit thin corneal stability and safety.
BACKGROUND AND PURPOSE
The purpose of this study was to investigate the subacute effects of Rose Bengal (RB) and 532 nm green light-induced photochemical crosslinking (RB-PCL) on rabbit thin corneal stability and safety in vivo.


MATERIALS AND METHODS
Rabbit thin corneal models with 250 μm thickness were created by photorefractive keratectomy surgery. Photochemical crosslinking with green light (wavelength 532 nm) at an illumination intensity of 0.4 W/cm2 for 250 s (100 J/cm2 ) was performed, followed by antibiotic treatment and slit lamp monitoring for four weeks. At the end of week four, corneal biomechanical stiffness, biochemical resistance to collagenase digestion, and corneal cellular morphology were assessed. The penetration depth of RB into the corneal stromal was measured by confocal microscopy.


RESULTS
At the end of week 4, RB-PCL had increased corneal tensile strength by an average 2.5-fold and had extended the corneal collagenase digestion time from 10.17 ± 2.93 to 15.83 ± 2.64 days. RB penetrated approximately 90 µm into the corneal stroma. RB-PCL did not alter the corneal endothelial and stromal morphology at the cellular or subcellular levels, according to electron microscopic examination.


CONCLUSIONS
RB and 532 nm green light irradiation effectively induced crosslinking in rabbit thin cornea, by increasing both the biomechanical stiffness and the biochemical resistance without evidence of morphological damage to the corneal endothelium or stroma. This study demonstrated the efficacy of RB-PCL in strengthening thin cornea at four weeks after the treatment, providing a potential and possibly better option for treating corneal ectasia disorders in cases where corneal thickness is less than 400 µm. Lasers Surg. Med. 50:324-332, 2018. © 2017 Wiley Periodicals, Inc.
['Wang|Ti|T|', 'Zhu|Lu|L|', 'Zhu|Jingyin|J|', 'Peng|Yinbo|Y|', 'Shen|Nianci|N|', 'Yu|Yan|Y|', 'Yao|Min|M|']
D000818:Animals D003315:Cornea D003316:Corneal Diseases D048988:Corneal Surgery, Laser D004195:Disease Models, Animal D000074431:Keratectomy D008297:Male D018613:Microscopy, Confocal D046529:Microscopy, Electron, Transmission D017319:Photosensitizing Agents D011817:Rabbits D011897:Random Allocation D012395:Rose Bengal D012680:Sensitivity and Specificity D013718:Tensile Strength D014945:Wound Healing
Rose Bengal collagenase tensile strength corneal crosslinking photochemical activation