[Interest of optical coherence tomography performed immediately before intravitreal injection of anti-VEGF in exudative AMD]

Abstract

Introduction: Two or three systematic intravitreal injections (IVT) may be prescribed in a PRN approach to treat an exudative recurrence of neovascular age-related macular degeneration (AMD), according to the phenotype. Optical coherence tomography (OCT) may be performed immediately before the 2nd or the 3rd scheduled IVT, making it possible to cancel the procedure in the absence of exudation. The aim of the study was to evaluate the usefulness of this OCT examination and to assess the percentage of IVT cancelled, in order to evaluate a potential medico-economic benefit.

Methods: Monocentric retrospective study, in which were included 292 consecutive eyes with exudative recurrence of AMD, for which 2 or 3 IVT were scheduled between January 1st and April 30th, 2014. All patients received a first systematic IVT in the seven days following the diagnosis. Then, on the days of the 2nd and 3rd scheduled IVT, each patient had a visual acuity measurement and a Spectral domain-OCT (Spectralis, HRA Heidelberg Engineering). This measurement allowed for the IVT to be either performed as scheduled or cancelled. Both ranibizumab and aflibercept were used. A Chi(2) test was used to compare the qualitative variables and an adjusted Wilcoxon test for the quantitative values.

Results: Two hundred and ninety-two consecutive eyes were included; 172 in the "2 scheduled IVT" group (group A) and 120 in the "3 scheduled IVT" group (group B). At the first follow-up, 37.6% of scheduled IVT were cancelled after the OCT (44.1% in group A and 28.3% in group B). At the second follow-up, 33.3% of IVT were cancelled in group B. Overall, 150/412 (36.4%) IVT were avoided in this series. Presence of serous retinal detachment, retinal edema and increased central macular thickness were statistically correlated with confirmation of the scheduled IVT at the two follow-ups (P<0.001, P<0.001 and P=0.002, respectively). A savings of 429.80 € per patient was calculated during this short period of follow-up.

Conclusion: An average non-injection rate of 36.4% of scheduled IVT was found in this protocol of management of recurrences with OCT performed the day of IVT. This protocol allowed to avoid unnecessary IVT one-third of the time and appeared highly cost-effective.

Keywords: Age-related macular degeneration; Anti-VEGF; Bénéfice médico-économique; Dégénérescence maculaire liée à l’âge; Economic benefit; Exudative recurrence management; Injection intra-vitréenne; Intravitreal injection; Optical coherence tomography; Tomographie à cohérence optique.