Purpose. To rationale experimentally the use of a viscoprotection of the corneal endothelium on the graft formed with a femtosecond laser for the descemet stripping endothelial keratoplasty. Material and methods. In our study, we used 12 pig's corneoscleral discs. The preservation time before the experiment averaged 12±4 hours. The corneas were divided into 2 groups. In the operating room, the graft was formed using an LDV Z8 femtosecond laser (Ziemer, Switzerland) from the endothelial side. Before applanation of the donor cornea and femtolaser head, a 1% solution of hydroxypropyl methylcellulose (HPMC) was applied to the endothelium - experimental group. The control group was appraised according to the standard technique, with the application of a few drops of a solution for storing the corneas. Then the applanation was monitored and evaluated by laser optical coherence tomography. Then the graft was separated from the bed and transferred to a conservation medium. Under laboratory conditions, to determine the viability of endothelial cells, the graft was stained with a «vital» dye with the commercial name Life and Dead (Abcam, UK) and placed in a confocal laser scanning microscope. Endothelial cells were counted using the ImageJ software. Results. In the experimental and control groups, the number of living endothelial cells (EC) was 91.06±1.49% and 83.86±2.14%, respectively (p<0.001). The number of dead ECs in the control group was 7.2±0.65% more than in the experimental group and amounted to 16.14±2.14% and 8.94±1.49%, respectively (p<0.001). Conclusion. The study demonstrated that the use of viscoprotection of the corneal graft endothelium for posterior lamellar keratoplasty is quite effective, and significantly reduces the loss of EC at the stage of cutting out the graft with a femtosecond laser. Key words: descemet stripping endothelial keratoplasty, femtosecond laser, vital dyes.
MICROINVASIVE FEMTOSECOND LASER POSTERIOR LAMELLAR KERATOPLASTY USING AN ULTRA-THIN GRAFT
