Résumé
According to the best corrected visual acuity and the morphological changes of the macular fovea,responses to the neovascular age-related macular degeneration (nAMD) who receive anti-vascular endothelial growth factor (VEGF) therapy show large variability,including poor and non-responders.Various factors will be reviewed to account for poor and non-response to anti-VEGF therapy,such as the related susceptibility genes,factors related with the development of choroidal neovascularization and morphologic parameters,pharmacokinetics and tachyphylaxis.The future research should focus on comprehensive assessment of factors affecting the efficacy of anti-VEGF therapy to improve the therapeutic outcome of nAMD.
Résumé
Background Intravitreal injection of ranibizumab (IVR) is one of the most effective therapies for neovascular age-related macular degeneration (nAMD).Understanding the influence of IVR on retinal pigment epithelium (RPE) and choroidal thickness is helpful for us to choose the operative times and timing based on pharmacologic effects and tissue response.However,limited studies are available about quantitative analysis of RPE atrophic area and subfoveal choroidal thickness after IVR for nAMD.Objective This study was to report the changes of RPE atrophic area and subfoveal choroidal thickness after IVR for nAMD.Methods A prospective series cases-observational study was designed.Forty-one eyes of 41 consecutive patients with nAMD were enrolled in Renmin Hospital of Wuhan University from January 2015 to June 2015,and written informed consent was obtained from each patient prior to entering the cohort.The affected eyes received intravitreal injection of 0.05 ml ranibizumab (10 mg/ml) and then followed up monthly for 12 months.The RPE atrophy area around macula and subfoveal choroidal thickness were measured by a newly developed RPE analysis software spectral-domain optical coherence tomography (OCT) and enhanced depth imaging of SD-OCT (EDI-OCT),respectively,and the RPE atrophy area and choroidal thickness changes were compared before IVR and 3,6 and 12 months after IVR.The correlation between RPE atrophy area and choroidal thickness before and after IVR was analyzed.Results All the patients finished the treating procedure and follow up.The visual acuity (logMAR) after IVR was considerably improved in comparison with before IVR (F=7.631,P＜0.001).The mean subfoveal choroidal thickness value was (264.55 ± 100.95) μm before IVR,and that of 3,6,12 months after IVR was (247.42±105.46),(246.81± 99.85) and (253.97±101.15)μm,respectively,showing a significant difference among different time points (F =2.030,P ＜ 0.05),and the mean subfoveal choroidal thickness values 3,6,12 months after IVR were evidently thinned in comparison with before IVR (all at P＜0.05).No significant difference was found in RPE atrophic area among different time points (F=0.116,P =0.951).Weak linear correlations were seen between RPE atrophy area and choroidal thickness (r =-0.185),the RPE atrophy area change values and choroidal thickness change values between IVR ＞ 6 times and ≤ 6 times (r =0.297,-0.327),but these results were not statistically significant (P =0.248,0.282,0.103).At the end of the follow up,weak linear correlations were seen in RPE atrophy area change values and choroidal thickness change values with IVR times (r,=-0.266,0.342),but these results were not statistically significant (P =0.148,0.060).Conclusions IVR for nAMD can lead to subfoveal choroid atrophy instead of RPE atrophy.IVR does not accelerate the atrophy progression of both RPE and choroid.