Abstract
Purpose: :
The EVEREST Study was the first randomized controlled trial comparing verteporfin photodynamic therapy (PDT) with/without ranibizumab, vs ranibizumab monotherapy for polypoidal choroidal vasculopathy (PCV). For the purpose of the trial, standardized imaging protocol and diagnostic criteria were applied, providing a standardized image set whereby the lesions could be systematically characterized and described.
Methods: :
This study describes the baseline indocyanine green angiography (ICGA) findings of cases recruited. All ICGA were captured using confocal scanning laser ophthalmoscope (CSLO) technology (Heidelberg Retinal Angiogram (HRA), Heidelberg Engineering, Heidelberg, Germany). All dynamic images (first 30 seconds) and still stereoscopic pairs (at 1, 3, 5, 10 and 20 minutes from injection) were read using Heidelberg Eye Explorer (version 1.6.2.0) on a pair of calibrated high resolution LCD monitors, aided by stereoscopic viewer (ScreenVu®). Measurements of polyp diameters were made using the 'best-fit circle' tool of Eye Explorer.
Results: :
Of the 95 cases referred to the Central Reading Center (CRC), 61 were confirmed PCV and considered treatable by PDT. All showed early focal hyperfluorescence (before 6 minutes), 69% had hypofluorescent halo, 6.7% was pulsatile and 92% was nodular upon stereoscopic viewing of CSLO-ICGA. The smallest polyp measured 149 microns, the largest 1450 microns (mean 265 microns, 95% CI: 244, 287 microns). The number of 'typical' polyps ranged from 1-9 in each eye (average 4). The polyps were 'solitary' in 26%, arranged in a 'ring' in 51%, a 'cluster' in 20% and mixed in 2%. Sixty-seven percent was associated with a branching vascular network (BVN), of which 63% showed 1 or more feeder vessels. The mean filling time of the BVN was 18.0 seconds, that of the first polyp 21.9 seconds. Pulsatile polyps tended to fill earlier, but not statistically significantly different from non-pulsatile cases (p=0.09, ANOVA). Lower quarter (early) fillers, compared to upper quarter (later) fillers, tended to present with massive submacular hemorrhage, compared to serous/sero-sanguinous presentation, but the difference did not reach statistical significance (p=0.09, Chi-square test).
Conclusions: :
The EVEREST Study provided one of the first standardized image sets of PCV using CSLO-ICGA. Larger standardized image sets of PCV is needed to further characterize and subtype the lesion, which may provide further insights into its pathogenesis.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00674323
Keywords: age-related macular degeneration • imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)