Dynamic and quantitative analysis of choroidal neovascularization by fluorescein angiography.
OBJECTIVE
In this study, the authors sought to develop and characterize techniques for measuring changes in choroidal neovascularization (CNV) lesion size and fluorescence over time for quantitative analysis of fluorescein angiograms.


METHODS
Initial assessment of the quantitative technique was made by retrospectively analyzing digital fluorescein angiograms taken before and 3 months after photodynamic therapy (PDT) for CNV (6 patients, group 1). The method was then applied prospectively to digital fluorescein angiograms (baseline and day 71) obtained on 12 patients taking part in a clinical trial investigating the effect of vascular endothelial growth factor (VEGF) Trap in CNV (group 2). Two masked observers, with the use of image processing, measured the area of hyperfluorescence and fluorescence intensity above background. Values for each image were plotted against time after dye injection to generate curves, and each area under the curve (AUC) was calculated.


RESULTS
The physician who treated the patients in group 1 judged the condition of three patients to be improved and of three to be worse 3 months after PDT. Masked retrospective grading of fluorescein angiograms showed an 11% decrease in AUC for fluorescence area and a 32% decrease in AUC for fluorescence intensity in the three patients whose conditions clinically improved but increases of 131% and 292% in the three patients whose conditions clinically worsened. In group 2, a 38% decrease in AUC for fluorescence intensity and a 19% decrease in AUC for fluorescence area were observed in patients who received VEGF Trap compared with increases of 66% (P = 0.004, Mann-Whitney U test) and 21% (P = 0.07) for patients who received placebo. Macular volume decreased by 11% in VEGF Trap-treated patients and increased by 10% in placebo-treated patients (P = 0.03).


CONCLUSIONS
This study reports a technique for analysis of change in fluorescence area and intensity over time during fluorescein angiography (FA) using a continuous scale and its application in a clinical setting and a clinical trial. Compared with previous techniques making use of categorical scales, this approach provides an advantage for evaluating responses to treatment that may improve the value of FA as an outcome measure in clinical trials.
Shah
Syed Mahmood
SM
Retinal Imaging Research and Reading Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-9277, USA.
Tatlipinar
Sinan
S
Quinlan
Edward
E
Sung
Jennifer U
JU
Tabandeh
Homayoun
H
Nguyen
Quan Dong
QD
Fahmy
Ahmed S
AS
Zimmer-Galler
Ingrid
I
Symons
R C Andrew
RC
Cedarbaum
Jesse M
JM
Campochiaro
Peter A
PA
D020256:Choroidal Neovascularization / Q000175:diagnosis* / Q000188:drug therapy; D005451:Fluorescein Angiography; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis* / Q000188:drug therapy; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D017978:Receptors, Growth Factor / Q000627:therapeutic use; D011993:Recombinant Fusion Proteins / Q000627:therapeutic use; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence
D017319:Photosensitizing Agents; D017978:Receptors, Growth Factor; D011993:Recombinant Fusion Proteins; C460365:VEGF Trap R1R2 protein