Abstract
Abstract: :
Purpose:Choroidal neovascularisation (CNV) in age–related macular degeneration (AMD) results in severe visual loss. CNV are subdivided into classic and occult based on their appearance on fluorescein angiography (FFA). Although FFA remains the diagnostic method of choice, it is invasive and does not show the anatomical location of the CNV. Furthermore, in some cases, the distinction of the classic and occult component in a mixed lesion can be difficult. We have evaluated the potential of using non–invasive optical coherence tomography (Carl Zeiss Stratus OCT–3) to identify whether there are differences in appearances between classic and occult CNV. Methods:Consecutive patients with classic and occult CNV underwent FFA non–invasive imaging with OCT–3. Masked observers were asked to interpret the FFA and OCT findings separately and the two were then compared. Results:Sub–retinal fluid is present in both classic and occult CNV. However, OCT–3 is able to identify discreet sub–retinal lesions above the retinal pigment epithelium in classic CNV, a feature infrequently found in occult CNV. Conclusion:The improved resolution of this latest OCT imaging system has allowed us to describe features that characterise certain differences between classic and occult CNV. OCT–3 imaging may be a useful adjunct to FFA in the diagnosis and classification of CNV type in AMD as well as confirming the previously held belief that classic CNV tends to occupy the sub–retinal space. The potential benefits also include a useful diagnostic tool in cases where FFA may be equivocal.
Keywords: age–related macular degeneration • choroid: neovascularization • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)