Abstract
Purpose: :
To analyze the influence of characteristic morphologic retinal changes on retinal function before and during intravitreal ranibizumab therapy in patients with nAMD.
Methods: :
353 patients with nAMD were randomized into 3 groups receiving either 3 intravitreal injections of 0.5mg or 0.3mg ranibizumab in monthly intervals followed by quarterly injections until month 12 or 0.3mg ranibizumab monthly from baseline until month 12. Retinal function was tested using the ETDRS (early treatment of diabetic retinopathy) protocol, retinal morphology was assessed by Stratus OCT (Carl Zeiss Meditec). All imaging data was evaluated in detail by certified readers of the Vienna Reading Center using a standardized reading protocol.
Results: :
At baseline characteristic retinal morphologic changes could be detected in all patients, such as intraretinal cysts, subretinal fluid (SRF) or pigment epithelial detachments (PEDs). During the loading phase (i.e. the time-course during the first 3 injections) the number of patients showing these alterations decreased significantly (p<0.01) and there was a significant correlation between the decrease in retinal thickness and the improvement of visual acuity (p<0.05). During the maintenance phase (month 3 to 12) this correlation did not reach a level of significance above all in the quarterly treatment regimen. Further, there was a strong correlation between the treatment regimen and the recurrence of the characteristic morphologic alterations. Intraretinal cysts and PEDs at baseline turned out to have a significant negative predictive value for the functional improvement throughout the whole treatment period, whereas SRF did not. However, a reoccurrence of cysts during the follow-up did not have an additional negative effect on retinal function.
Conclusions: :
There is a strong treatment regimen dependent correlation between retinal morphology and function in patients with nAMD during Anti-VEGF therapy throughout the first year. Intraretinal cysts and PEDs at baseline seem to cause significant retinal damage decreasing the amount of visual gain that can be expected throughout therapy.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00275821
Keywords: age-related macular degeneration • imaging/image analysis: clinical • visual acuity