May 31, 2019 Conference
Georgios Bontzos, OMMA Eye Institute
Larisa Ioannidi, Eye Clinic, University Hospital of Heraklion
Stamatina Kabanarou, Department of Ophthalmology, Korgialenio Benakio Hopsital
Ivana K. Kim, MEEI
Evangelos S. Gragoudas, MEEI
Dr. Joan Miller, Massachusetts Eye and Ear Infirmary
Ioannis Datseris, OMMA Eye Institute
Miltiadis Tsilimbaris, Eye Clinic, University Hospital of Heraklion, Greece.
Dr. Demetrios Vavvas, MEEI
Purpose: The purpose of our study was to investigate the duration of anti-VEGF treatment effect in patients with neovascular age-related macular degeneration (nvAMD), diabetic macular edema (DME) and retinal vein occlusion, and to determine if non- or poor-responders at the standard 4-week interval actually demonstrate a treatment response at an earlier time point.
Methods: This study is a prospective multi-center trial with patients recruited from the Eye Clinic of the University Hospital of Heraklion and from the OMMA Eye Institute in Athens, Greece. Patients received intravitreal anti-VEGF (0.5 mg ranibizumab) injections and subsequently were assessed weekly for a total period of 4-6 weeks by spectral-domain optical coherence tomography (SD-OCT) for reduction in central retinal thickness (CRT) and the presence of intra- and subretinal fluid. Data collected included age, sex, visual acuity, past ocular history, total retinal volume, axial length and lens status.
Results: 52 eyes of 52 patients (mean age 67.8 years, 59.6% female, 54% treatment naive) were assessed. More than half of the eyes (51.5 %) presented with maximal CRT reduction on SD-OCT two-weeks post- injection and almost all had significantly increased CRT at week 4 compared to week 3 or week 2. Eyes that showed no to minimal CRT reduction at week 4 and would have been classified as non-responders in the usual clinical evaluation were found to have CRT reduction at weeks 2 or 3 post-injection. Furthermore, we found a higher proportion of non- and poor responders at week 4 in DME (7 of 12, 58%) compared to nvAMD (6 of 25, 24%) eyes (chi-square 4.194, p=0.0406). The time to maximal CRT reduction was not related to axial length, age, lens status or prior history of injections.
Conclusions: Our study suggests that almost all non-responders or poor responders to anti-VEGF therapy are responders if assessed at an earlier time point such as at week 2 or 3 post-injection. Our study assesses for anti-VEGF treatment response by weekly CRT measurements with SD-OCT and is the first study to describe the treatment response in previously considered non-responders. Further large, prospective studies are needed to optimize dosing intervals and to evaluate whether more frequent anti-VEGF treatment might preserve visual function in this cohort of short-term responders.