Abstract
Purpose: :
To evaluate the retinal structure of treatment-naïve eyes diagnosed with neovascular AMD at baseline and after one year of Ranibizumab-treatment and find possible correlations between morphological and functional changes.
Methods: :
26 eyes of 25 patients diagnosed with neovascular AMD were included in this retrospective observational study. At each of the monthly visits at our clinic Best Corrected Visual Acuity (BCVA) was obtained using the ETDRS charts. Additionally, at each visit an Optical Coherence Tomography (Heidelberg Spectralis® Spectral Domain (SD)-OCT) volume-scan was obtained. The central 1x1mm of each volume scan was evaluated using proprietary software, which allows the investigator to manually mark different areas in every single B-scan of a volume-scan. Each cross-sectional image within the central 1mm² was graded for following pathologies: Disruption of External Limiting Membrane (ELM) and Inner Segment/ Outer Segment - junction (IS/OS), presence of subretinal fluid (SRF), Pigment Epithelium Detachment (PED), drusen and cysts. The total area of each pathology was calculated (in mm²). The sizes of the different areas at baseline and after one year of Ranibizumab-treatment were compared to BCVA-results at baseline and after one year.
Results: :
On average, each of the eyes received 9,3 injections (range: 4 to 12). After one year the average change in BCVA was +9,96 ETDRS letters (range: -10 to +36). The number of injections did not show significant correlation to the change in BCVA. The average sizes of the areas of the evaluated findigs measured (at baseline and after one year) as follows: ELM disruption: 0,427 mm² and 0,374 mm² ISOS disruption: 0,768 mm² and 0,814 mm² SRF: 0,558 mm² and 0,172 mm² PED: 0,332 mm² and 0,363 mm² Drusen: 0,236 mm² and 0,276 mm² cysts: 0,272 mm² and 0,049 mm² There was good correlation between BCVA at one year and status of the ELM at both baseline and 1 year (R= -,685; p<0,001 and R= -,600; p=0,001). Also, BCVA after one year showed significant correlation to the areas of ISOS disruption and cysts at baseline.
Conclusions: :
The intactness of the ELM seems to be an important marker for the potential of visual recovery in patients with neovascular AMD. In patients who visit the clinic every month, the number of ranibizumab injections administered does not seem to influence the visual outcome at one year.
Keywords: age-related macular degeneration • macula/fovea • retina