Abstract
Purpose: :
Anti-VEGF-therapies show characteristic effects on the retinal morphology and function typically found in the first months following treatment initiation. Functional effects can be observed by changes in best corrected visual acuity (BCVA), morphological by changes in central retinal thickness (CRT) assessed with optical coherence tomography (OCT). As both values are frequently used as re-treatment criteria in clinical trials, their correlation and interdependency was analyzed.
Methods: :
339 patients with choroidal neovascularizations (CNV) secondary to age-related macular degeneration (AMD) received monthly intravitreal injections with 0.3mg or 0.5mg ranibizumab (Lucentis®). OCT (OCT 3) examinations and best corrected visual acuity (BCVA) assessments using the ETDRS protocol were performed on day 0, 8 and monthly up to month 12. Results were correlated and evaluated regarding lesion classification and therapy-induced morphological and functional changes.
Results: :
At baseline, there was a clear and significant correlation between CRT in OCT and BCVA.The initial loading dose of both dose regimen of intravitreal ranibizumab induced a decrease in central retinal thickness assessed with OCT within 1 week. Accordingly there was a significant decrease in CRT. Nevertheless, there was no direct correlation between this decrease in CRT (ΔCRT) and the level of functional improvement (ΔETDRS). Neither was there a significant correlation between the BCVA score and the CRT value at each single visit following treatment initiation.
Conclusions: :
Even if there is a significant decrease in CRT in OCT and a significant increase in BCVA, the CRT value itself does not allow for an estimation of BCVA improvement following an intra-vitreal therapy with ranibizumab. CRT is a necessary value for subsuming therapy-induced morphological changes, nevertheless, detailed morphological OCT grading seems to be prior in explaining functional benefits than retinal biometry.
Clinical Trial: :
Eudract 2005-003517-33
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: outcomes/complications • vascular endothelial growth factor