Cool Crosslinking: " Riboflavin at 4^o C for the Management of Pain After Crosslinking for Keratoconus Patients.”

Abstract

Purpose : To evaluate the effect of the application of riboflavin at 4^oC in the perception of postoperative pain in subjects with keratoconus after corneal collagen crosslinking (CXL).

Methods : Prospective, comparative, randomized, interventional study of 196 eyes of 98 subjects older than 18 years with a diagnosis keratoconus on which progression was documented and 0pithelium-off accelerated crosslinking was indicated. The central 8 mm corneal epithelium was removed. Impregnation was performed with 0.1% Riboflavin, Saline, HPMC (Vibex Rapid, AVEDRO) for 10 minutes and the cornea irradiated with 30mw for 4 minutes (AVEDRO). Group 1 0.1% Riboflavin, Saline, HPMC was stored at room temperature, Group 2 0.1% Riboflavin, Saline, HPMC was stored at 4^oC and mantained with ice covering during the procedure. A bandage contact lens was placed after the procedure. Postoperative treatment included moxifloxacin) (Vigamox, Alcon) 1 gtt every 8 hours, fluormetholone (Flarex, Alcon) every 8 hours hyaluronic acid drops 0.15% (Thea) as needed and ketorolac 10mgs (Supradol,Liomont) as needed. A previously validated visual analog scale pain scale and questionnaire was applied, 2 hours after surgery and in the postoperative days from 1 to 5. A single blind investigator conducted all the questionnaires. The demarcation line was measured between postoperative month 1 to 3 . Statistical analysis was performed with STATA v.13.

Results : We included 98 subjects (196 eyes) . Mean pain value at 2 hours postoperatively in the group 1 was 8.08 and 3.8 (p = 0.0005) in group 2. Other symptoms included in the test (tearing, photophobia, foreign body sensation and irritation) also showed statistically significant improvement in group 2 at 2 hours postoperatively (p = 0.0005, p = 0.01, p = 0.0003, p = 0.0004, respectively). Pain was statiscally signficantly greater in postoperative day 1, 2, and 4 in group 1(p = 0.028, p = 0.05, p = 0.05, respectively). Depth of demarcation line measured at average 1.5 months postop was 279.32 μm and 279.66 μm in group 1 and 2 respectively (p =0.93).

Conclusions : Riboflavin at 4^oC significantly reduced pain perception after crosslinking for keratoconus

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.