Effect of inferior-segment Intacs with and without C3-R on keratoconus

PURPOSE: To determine whether corneal collagen cross-linking with riboflavin (C3-R) augments the effect of inferior-segment Intacs (Addition Technology) in the treatment of keratoconus. SETTING: Private practice, Beverly Hills, California, USA. METHODS: A retrospective nonrandomized comparative case series comprised 12 eyes of 9 patients who had inferior-segment Intacs placement without C3-R (Intacs-only group) and 13 eyes of 12 patients who had inferior-segment Intacs placement combined with C3-R (Intacs with C3-R group). The 2 groups were matched preoperatively. All patients had inferior-segment Intacs placed with the incision in the steep axis of manifest refraction. Corneal collagen cross-linking with riboflavin was performed after the Intacs segments were inserted. Outcome measures were topographic keratometry values and the lower-upper (L-U) ratio, which is a topographic measure of the degree of keratoconus. Preoperative data were compared to results 1 day postoperatively and measurements at the last postoperative visit. RESULTS: The Intacs with C3-R group had a significantly greater reduction in cylinder than the Intacs-only group (P<.05). Steep and average keratometry were reduced significantly more in the Intacs with C3-R group (P<.05). There was a greater reduction in L-U ratio in the Intacs with C3-R group (P<.05). CONCLUSION: The addition of C3-R to the Intacs procedure resulted in greater keratoconus improvements than Intacs insertion alone.