Abstract
Purpose: :
To describe a new non-invasive en face spectral domain optical coherence tomography (SD-OCT) imaging technique to visualize areas of occult choroidal neovascularization (CNV) without fluorescein angiography, using a prototype Minimum Intensity Projection (MinIP) analysis.
Methods: :
Observational case series. Eleven eyes of 11 subjects with CNV due to AMD; and 6 eyes serving as controls, including two subjects with diabetic macular edema, two fellow eyes with drusen, one eye with geographic atrophy, and one normal eye. Study participants were enrolled prospectively with CNV due to AMD who required anti-VEGF treatment after their clinical evaluation. Subjects were imaged on the day of study entry with color, red-free black and white fundus photographs, fluorescein angiography, and Cirrus OCT (Carl Zeiss Meditec, Inc., Dublin, CA). The en face fundus images generated by the Minimum Intensity Prototype software were compared qualitatively to the corresponding color, red-free fundus photographs, and fluorescein angiography in enrolled eyes and their controls.Main outcome measures were 1) Qualitative analysis of the white signal provided by the MinIP Software and its capability to identify occult CNV on fluorescein angiography; 2) Qualitative analysis of the black signal provided by the MinIP Software and its agreement with the location of intraretinal or subretinal fluid on OCT B-scans.
Results: :
MinIP images in eyes with CNV showed a white area similar in shape, often slightly larger, but apparently more easily defined than the pattern of occult CNV on fluorescein angiography which usually was not detectable on fundus photographs. The analysis also disclosed darkened areas that corresponded with the location of intraretinal or subretinal fluid visible on OCT B-scans.
Conclusions: :
This new non-invasive prototype software appears to detect the extent of occult CNV usually visualized on fluorescein angiography but not color or red-free fundus photographs. MinIP images potentially could be used to identify onset of CNV without fluorescein angiography, and potentially guide identification of growth of CNV following anti-VEGF therapy of CNV.
Keywords: choroid: neovascularization • age-related macular degeneration • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)