The association between corneal hysteresis and surgical outcomes from trabecular meshwork microinvasive glaucoma surgery.

PURPOSE: To assess whether an association exists between pretreatment corneal hysteresis (CH) and the magnitude of intraocular pressure (IOP) and medication burden reduction following microinvasive glaucoma surgery (MIGS).
METHODS: Retrospective chart review of 84 eyes from 57 patients with CH measurements who underwent trabecular meshwork MIGS in a glaucoma practice in New York City with follow-up visits at 3-6 and 9-12 months. MIGS included canaloplasty, goniotomy, microbypass stents, or a combination thereof.
RESULTS: The lowest and middle CH tertiles experienced significantly reduced mean IOP at 3-6-month follow-ups (p = .007, < .001), whereas the highest tertile did not (p = .06). At 9-12-month follow-ups, a significant mean IOP reduction only persisted in the middle tertile (p = .001). For medication burden reduction, only the highest CH tertile experienced significant mean reductions at both 3-6- and 9-12-month follow-ups (p = .015, .028). Notably, 7 patients in the lowest CH tertile failed MIGS and required an additional surgical or laser procedure within 24 months of MIGS, whereas only 3 patients failed in the other tertiles (likelihood ratio < .05). Multivariate analysis excluding MIGS failures demonstrated an inverse association between CH and the magnitude of post-operative IOP reduction at both 3-6- and 9-12-month follow-ups when controlling for baseline IOP and medication changes (p = .002, .026).
CONCLUSION: There was an inverse association between pretreatment CH and the magnitude of IOP reduction following surgery. There is also evidence of an increased need for repeat surgery or other intervention in patients with lower CH who undergo MIGS.