Purpose
The Purpose of this analysis was to evaluate the safety and efficacy of two formulations of riboflavin, Formulation 1 and Formulation 2, for their use in Trans-epithelial corneal collagen cross-linking. In addition, a different light intensity was used with each formulation for 30 minutes.
Methods
Patients with keratoconus who had undergone trans-epithelial CXL in one or both eyes were included in this analysis. Outcome measures included UCVA, BSCVA, and K Max at 6 months and 1 year follow up.
Results
345 eyes were assessed. For formulation 1, 177 eyes were evaluated (69.5% male) the average age was 32.3 with an average corneal loading time of 59.3 minutes, pre-op Kmax of 60.0 D and pre-op thinnest point of 447 microns. 125 eyes went through a 6 month follow up visit. The UCVA improved 1 or more lines for 46% of eyes, worsened in 10% and changed in 44%. The BSCVA improved 1 or more lines in 46% of eyes, worsened in 14% and no change in 41%. K Max average improved from pre-op to 0.56D flattening. 76 eyes with a 12 month follow up visit. The UCVA improved 1 or more lines for 58.2% of eyes, worsened in 7% and no changed in 34%. The BSCVA improved 1 or more lines in 53% of eyes, worsened in 27% and no change in 20%. K Max average improved from pre-op to 0.66D flattening. For formulation 2, 168 eyes were evaluated (70.8 % male) the average age was 32.9 with an average corneal loading time of 27.2 minutes, average pre-op Kmax of 59.6 D and average pre-op thinnest point of 448 microns. 106 eyes underwent to a 6 month follow up visit. The UCVA Improved 1 or more lines for 45% of eyes, worsened in 13% and no change in 42%. BSCVA improved 1 or more lines for 52% of eyes, worsened in 16% and no change in 31%. K Max average improved from pre-op to 0.97D flattening. 56 eyes with a 12 month follow up visit. The UCVA Improved 1 or more lines for 63.0% of eyes, worsened in 14.8% and no change in 22.2%. BSCVA improved 1 or more lines for 50.0% of eyes, worsened in 13.0% and no change in 37.0%. K Max average improved from pre-op to 0.98D flattening.
Conclusions
Epithelial-ON CXL is effective for patients with keratoconus. It Improves corneal shape, UCVA and BSCVA. A newer formulation of Riboflavin combined with a higher energy level of UV light for 30 minutes demonstrated Faster loading time, Improved flattening of Kmax and Similar improvement in UCVA and BSCVA.
Keywords: 574 keratoconus