When you decide not to perform photorefractive keratectomy (PRK) in a patient, chances are the reasons are either risk of postoperative haze or pain. But can pain after PRK be managed any better? That was the question Ritika Dalal, MD, a refractive surgeon and keratoconus specialist in Mumbai, India, and colleagues tried to answer during a prospective study involving 70 individuals. Specifically, they sought to 1) evaluate the effect of 0.45% preservative-free ketorolac ophthalmic solution (Acuvail) soaked in a bandage contact lens on pain after surgery and 2) to quantify the leakage from the BCL over time.
Ketorolac has been shown to manage pain previously, plus the concentration investigators chose is preservative free and associated with fewer side effects.
Participants undergoing PRK were divided into two arms. After PRK, eyes in both groups were washed with cold BSS and covered with either a regular bandage contact lens (n=35) or a bandage contact lens soaked in the ketorolac solution (n=35). Postoperative antibiotic and lubrication protocols were the same for both groups. All patients were assessed for pain using the Wong-Baker Faces Pain Scale. Among the results:
Armed with the knowledge that ketorolac made a difference one day after surgery, the research team set out to determine exactly how long it worked and the ideal soaking protocol. High-performance liquid chromatography revealed the concentration of ketorolac at different time points. “It showed us that [ketorolac] on the contact lens kept coming out into solution over one hour and it stayed constant for the six hours that we tested,” said Dr. Dalal.
Important Step Ensures Longer Duration
She emphasized the importance of delivering a topical NSAID through the bandage contact lens. “We did a microbiology experiment to check sterility. We noticed was that when the bandage contact lens was not cleaned, there was growth seen in solution, [whereas] the cleaned lens showed no growth. Delivering the topical NSAIDs through the soft bandage contact lens by adsorption is a novel technique which allows for longer duration of analgesia.”
What about those 7% for whom ketorolac did not work? Researchers found that the corneas of these individuals had more dendritic cells, as well as raised cytokines in their tears. “So, there was more inflammation, explained Dr. Dalal. “We also observed that many had low vitamin D [levels] and personality [traits that] resulted in increased pain post-PRK.” The bottom line: “Preoperative inflammation--both clinical and molecular--can be a reason for increased pain in the non-responders.”
Dr. Dalal suggested that once they are identified, these patients be handled differently preoperatively. She advised administering an NSAID preoperatively. “More importantly, spend more time counseling these patients. Warn them [the procedure] is going to be painful. This way they are prepared for it.” Postoperatively, consider giving them ketorolac drops for a longer period of time.
Other strategies to consider for these individuals:
Dr. Dalal and her team are assessing the benefit of the latter in a current study.
Dalal R. Pain Management Following PRK: A Novel Technique. Talk presented at: AAO 2018 annual meeting; October 26-30, 2018; Chicago