Serrano pulls out from Meinke bout after allergic eye reaction
The Puerto Rican, the main event in the San Juan card, was forced to pull out of the bout after failing a medical test.
"I wanted to fight in front of my people. I am so sorry from the bottom of my heart... I can barely see out of my eye," she told the crowd.
"I was ready to fight, all real fighters would have been," she later wrote on Instagram.
"The (doctor) said no and that devastated me... I had an allergic reaction to the chemicals in the braiding (gel)," she added.
"This happened very last minute," said Serrano's promoter Jake Paul, who scored a first-round TKO win over Ryan Bourland earlier in the evening.
"Her cornea is exposed, you can't risk losing your eyesight forever. I know she's a warrior."
The former unified champion, who vacated her WBC belt in December after the organisation refused to sanction three-minute rounds in women's boxing, was scheduled to face Meinke for 12 three-minute rounds.
"I requested a full refund and full pay to my opponent. It wasn't their fault," Serrano said.
"I'm heading to (New York) tomorrow morning to follow up with my private Doctor. I'll be ok in no time."