The FDA approval of RHA Redensity Eye represents the second hyaluronic acid (HA) filler cleared specifically for the infraorbital hollows, after Juvéderm Volbella XC, and the first to use a coprimary patient-reported outcome, the modified Facial Appraisal and Checklist of Effects Questionnaire, alongside a clinician-graded scale, the Teoxane Infra-Orbital Hollows Scale, in this anatomic region.
The pivotal trial (TEO-RHA-1902) was a staged, prospective, randomized, evaluator-blinded, multicenter, no-treatment-controlled study enrolling approximately 248 subjects, 183 of whom received RHA Redensity Eye across stage 1 and stage 2 and the remainder of whom were untreated or assigned to no-treatment controls. Patients were followed through 52 weeks.
The sample size for this trial was explicitly powered for safety detection thresholds of greater than or equal to 2.5% incidence in the Fitzpatrick IV to VI subgroup and greater than or equal to 0.5% incidence in the overall treated population — not for events rarer than that. Applying the “rule of three” to a treated population of approximately 183 subjects, a trial with zero observed events can only exclude, with 95% confidence, a true event rate above roughly 1.5% to 1.6%.
