Abstract
Purpose: :
To evaluate the effects of intravitreal ranibizumab on retinal function and morphology and to identify a realistic correlation between anatomy and function by using high-resolution optical coherence tomography (HR-OCT).
Methods: :
Twenty three patients affected by neovascular AMD received three monthly injections of ranibizumab and were monitored by assessing best-corrected visual acuity (BCVA) and central retinal sensitivity (CRS) as well as distinct parameters of morphologic changes at the level of the retina and the retinal pigment epithelium (RPE) using HR-OCT segmentation. BCVA, CRS, mean retinal thickness (MRT), central retinal thickness (CRT), mean retinal volume (MRV), area of the RPE pathology (lesion area) were evaluated.
Results: :
BCVA increased significantly from a mean 60.1±8.7 letters at baseline to 67.0±10.9 at month 3 (p=0.0003). At the 0° position of the tested microperimetric field the CRS increased from 2.8±3.1 dB at baseline to 4.0±5.7 at week 1 remaining stable until month 3. Absolute scotoma size decreased continuously from baseline until month 3 from a mean of 5.3±5.8 to 3.6±4.0 test point locations.By HR-OCT, MRT decreased from 308.6±25.9µm at baseline to 268.4±22.4µm at month 3(p=0.0001). CRT was 365.8±84.9µm and 254.9±95.1µm at month 3 (p=0.0002). A MRV of 11.1±0.9 mm3 was measured at baseline and reached 9.7±0.8 mm3at month 3 (p=0.0001). A mean RPE lesion area of 6.0±3.0 mm2 (median: 6.1) was identified at baseline which decreased to 5.0±3.1 mm2 at month 3 (p=0.115).The only significant correlation between anatomy and function was identified between the area of RPE pathology and central retinal sensitivity.
Conclusions: :
In ranibizumab therapy, the condition of the RPE lesion may be more relevant for visual function than the usual OCT parameters e.g. retinal thickness or volume.
Keywords: age-related macular degeneration • imaging/image analysis: clinical • visual acuity