With the MA gel , tear flow decreased significantly from 5 minutes to 5 hours ; AERRs increased from 24.06 % to 42.67 % ( P < .05 ) ; Maximum efficacy was maintained from 15 minutes to 3 hours ( P < .01 ) ; Tear flow gradually increased from 4 to 5 hours but was still lower than that before atropine use ( P < .05 ) .