Abstract
Purpose :
For diagnosis of myopic choroid neovascularisation (mCNV) in eyes with high myopia fluorescein angiography (FAG) is the current gold standard. Due to the specific anatomy of highly myopic eyes, high-quality images are often difficult to generate, and challenging with time-sensitive recording techniques (FAG). The purpose of this essay was to compare mCNV imaging with FAG with optical coherence angiography (OCT-A) and describe the advantages and disadvantages.
Methods :
14 eyes with mCNV were examined on the same day with FAG and OCT-A. Then the recordings were compared with one another and compared according to the following criteria: quality of imaging, mCNV detectable, mCNV vessels can be demarcated, activity can be assessed (leakage in FAG vs. flow in OCTA, aided by SD-OCT)
Results :
Of the 14 eyes, 2 could not be used in OCT-A due to poor imaging quality. In these cases, snapshot of leakage were possible during late phase FAG.
In 10 eyes, a diffuse CNV complex with leakage was visible in FAG and a corresponding areas with increased flow were visible in 9 eyes with OCT-A. In one case, the CNV complex was very small and could only be determined clearly in late phase FAG thanks to leakage, while in OCT-A we were not able to separate the CNV network from the physiological choroid flow.
Demarcated vessels were only visible in one case with FAG versus 6 in OCT-A (see example in annex).
Signs of activity were detectable in FAG with all 14 eyes. In OCT-A pathological flow detection was measurable in 11 cases and corresponded to FAG findings.
Conclusions :
OCT-A allows an accurate assessment of mCNV in patients with high myopia, often superior in the presentation of blood vessel networks compared to FAG. Since OCT-A allows a layered presentation of the retinal vessels, in myopic eyes with large atrophy areas, clear imaging without choroid blooming is possible. In 11 out of 14 cases OCT-A allowed a precise diagnosis, with similar relevance for therapy decisions. In the future the detailed vascular demarcation provided by OCT-A might be a precise and fast follow-up parameter for the diagnosis of mCNV.
However OCT-A alone does not appear to be a sufficient diagnostic tool in all cases of mCNV and thus should be used in combination with SD-OCT and FAG in challenging cases. Technical advances as well as the unlimited ability to repeat acquisition can partially compensate for these disadvantages.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.