After 2 weeks of topical application , subjects in 1.5 % TD group showed lower overall visual pain score compared with placebo group ( 4.9 [ 1.9 ] vs. 5.6 [ 2.1 ] , difference : 0.8 ; 95 % CI , 0.1 to 1.3 ; P = 0.04 ) as well as decreased burning pain ( 2.9 [ 2.6 ] vs. 4.3 [ 2.8 ] , difference , 1.4 ; 95 % CI , 0.2 to 2.6 ; P = 0.01 ) .