Aqueous flare is a common measure of subclinical inflammation after Descemet membrane endothelial keratoplasty (DMEK) for Fuchs endothelial dystrophy, but it should resolve quickly—when it doesn’t, clinicians should beware.

A new study of 173 DMEK eyes of 169 patients and 19 age-matched healthy control eyes assessed aqueous flare (by laser flare photometry) at one day, one week and one month post-DMEK in one group and an average of 28 months in a second group. 

They found flare levels decreased from one day to one week in group one and remained stable up to a month after DMEK, although average flare was higher than that in healthy controls at one month. “Aqueous flare after DMEK quickly decreased within the first postoperative month, indicating fast recovery of the blood–aqueous barrier,” the researchers said in the study.

Long-term flare, as measured in group two, was higher in eyes associated with allograft rejection compared with those without rejection. “Long-term flare levels were higher in eyes associated with rejection, suggesting persistent subclinical inflammation,” the study concludes. “A flare level above 10ph/ms may be used as a threshold for identifying eyes associated with or at risk of allograft rejection after DMEK.”