MIRUNA GABRIELA BURCEL, CATALINA CORBU, VALERIA COVILTIR, VASILE POTOP, MIHAELA CONSTANTIN, DANA DASCALESCU, CATALINA IONESCU1, RADU CIULUVICA, LILIANA MARY VOINEA CORNEAL CROSSLINKING IN PROGRESSIVE KERATOCONUS: COMPARISON OF DEXTRAN-BASED AND HYDROXYPROPYL METHYLCELLULOSE-BASED RIBOFLAVIN SOLUTIONS DIFFERENCES IN DEMARCATION LINE DEPTH AND 1 YAEAR OUTCOMES Keratoconus is a progressive ectatic disorder characterised by irregular myopic astigmatism and loss of visual acuity due to corneal thinning. Corneal collagen crosslinking is the treatment recognised to stop the progression of keratoconus. Our study evaluates and compares visibility and depth of the stromal demarcation line after corneal collagen crosslinking using anterior segment optical coherence tomography between two groups:crosslinking with dextran-based and hydroxypropyl methylcellulose-based riboflavin solutions. Our work proved a better visibility and a deeper demarcation line when we used HPMC-based riboflavin. Also the study revealed that HPMC-based riboflavin is associated with better biomechanical outcomes than dextran-based riboflavin.