Impact of collagen crosslinking on corneal sensitivity in keratoconus patients

To evaluate changes in corneal sensitivity after corneal collagen crosslinking in patients having progressive keratoconus.

Thirty-six consecutive patients having progressive keratoconus were included in the study. The crosslinking surgery was performed in one eye of each patient (study group) and the opposite eye was used as control (control group). The following steps were done in the procedure: central cornea epithelial debridement, riboflavin solution dropping (1 drop every 5 minutes) for 30 minutes, and subsequently, corneal surface irradiation with Ultraviolet A for 30 minutes, keeping the riboflavin instillation while irradiating. The analysis of corneal tactile sensitivity in each patient was performed using the Cochet-Bonnet aesthesiometer at 5 time points: preoperative and 7, 30, 90, and 180 days after surgery.

The study enrolled 72 eyes of 36 patients. Considering the eyes submitted to crosslinking, there was a significant statistical difference concerning the tactile corneal sensitivity at all 5 evaluated moments. The median sensitivity at each time point studied was: preoperative, 52.5 mm (range, 25-60 mm); 7 days, 20.0 mm (range, 5-60 mm); 30 days, 32.5 mm (range, 5-60 mm); 90 days, 40.0 mm (range, 10-60 mm) and 180 days, 45.0 mm (range, 25-60 mm) (P < 0.001). The control group showed no statistical difference among all 5 time points (P = 0.160).

Corneal crosslinking performed in keratoconus patients induced a considerable decrease in corneal sensitivity. This decrease was more intense at the first week after the procedure, with a progressive recovery up to 6 months.