Improved visualisation of choroidal neovascularisation by scanning laser ophthalmoscope using image averaging.
OBJECTIVE
To improve visualisation of angiographic features in patients with age related macular degeneration associated with choroidal neovascularisation (CNV) and related complications. To evaluate if image averaging can achieve this goal.


METHODS
27 eyes of 20 sequential patients with age related macular degeneration over a 3 month period were studied. Indocyanine green angiograms (ICGA), fluorescein angiograms (FA), and oral fluorescein angiograms were recorded with a confocal scanning laser ophthalmoscope. Software was used to average multiple images from a 10-20 image series (over 0.5-1.0 seconds). Image quality was assessed by two masked observers and graded on a scale of 0-3. A more quantifiable grading method was devised by adding a variable amount of Gaussian noise to the improved image until the original and image averaged image appeared equal.


RESULTS
Masked review showed mild to strong improvement of visualisation of structures including borders of CNV. Improvement varied depending on the type and phase of the angiogram. Improvement was highest in late phase FA, mid and late phase ICGA, and all phases of oral FA.


CONCLUSIONS
Image averaging using software based algorithms improves the quality of angiographic images, particularly late ICGA images and oral FAs. This method may assist in the visualisation of choroidal neovascularisation in age related macular degeneration.
Bartsch
D U
DU
Jacobs Retina Center, Department of Ophthalmology, University of California San Diego, 9415 Campus Point Drive, La Jolla, CA 92093-0946, USA. dbartsch@ucsd.edu
El-Bradey
M H
MH
El-Musharaf
A
A
Freeman
W R
WR
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D020256:Choroidal Neovascularization / Q000175:diagnosis* / Q000209:etiology; D004396:Coloring Agents; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007208:Indocyanine Green; D008268:Macular Degeneration / Q000150:complications / Q000175:diagnosis*; D009887:Ophthalmoscopy / Q000379:methods
D004396:Coloring Agents; D007208:Indocyanine Green