We came across a piece of French research (published in September 2011) that is very timely in reminding professionals that ICG – Indocyanine Green Angiography (green dye is injected into blood stream and quickly reaches the blood vessels at the back of the eye, which can then be photographed) is still a very useful tool for people with Birdshot as it can identify leakages that are hard to see by other methods such as Optical Coherence Technology (OCT).
This is yet another example of an ‘old’ method that, although superseded by a range of new methods, still has a part to play in our disease and should remain as one of the several monitoring and diagnostic tools used for Birdshot.
Here is an abstract from that research:
Desmettre T, Cohen SY, Devoisselle JM, Gaudric A
“A full interpretation of indocyanine green angiography images involves not only optical issues but also pharmacokinetic and biochemical aspects. These issues may involve biochemical changes in the fluorescence yield and the affinity of the molecule for lipoproteins and phospholipids. For age-related macular degeneration (AMD), the advent of photodynamic therapy and especially anti-VEGF drugs has increased the use of OCT in assessing treatment response and guiding retreatment. The ease and advantages of OCT have become increasingly associated with a decreasing interest in ICG angiography, which is becoming less well suited for the current management of AMD. An aging population, the efficacy of anti-VEGF drugs and the relative rarity of polypoidal choroidal vasculopathy (PCV) in Europe are factors contributing to our proportional increase in AMD patients. However, aside from AMD, the indications for ICG angiography remain little changed over the last decade: it remains important in diagnosing PCV and choroidal hemangiomas, since their prognosis and treatment are specific. Similarly, for certain inflammatory conditions such as Multiple Evanescent White Dot Syndrome (MEWDS) or Birdshot chorioretinitis, the value of ICG angiography remains significant. In addition, for the treatment of chronic Central Serous Chorioretinopathy, ICG angiography helps to find sites of leakage which otherwise might have been missed. The ICG angiographic appearance in this setting may also have prognostic value. Although the indications for ICG angiography are currently decreasing for AMD, these other conditions represent a large enough number of patients to justify the continued use of this original test, which remains complementary to other chorioretinal imaging techniques.”
The full article can be found at: http://www.ncbi.nlm.nih.gov/pubmed/21907446?dopt=Citation