Abstract
Purpose :
To verify if Segmented Swept Source Optical Coherence Tomography Angiography (SS OCT-A) can provide additional information on morphology and pathophysiology of macular fibrosis in Coats’ patients.
Methods :
Case Report of three male patients (5,7 and 15 years old), with macular fibrosis (stage 2b-2 patients, 3b-1patient) due to Coat’s disease.
All patients underwent SS OCT-A (Deep Range Imaging (DRI) Triton®, Topcon Corporation, Tokyo, Japan, software version: IMAGEnet® 6.0); 3x3mm macular scans of clinically healthy eyes.
We have established an in-house protocol for modified segmentation (Fig1)
1.Inner boundary was placed at internal limiting membrane
2.Outer boundary for superficial plexus- just above dense hyperreflective layer
3.Inner boundary for inner hyperreflective portion of the lesion- at the level between higher and lower hyperintensity
4.Outer portion of the lesion-from relatively decreased hyperintensity to choriocapillaris
5.Boundaries of the choriocapillaris were conducted as extension of neighbouring automated layers, as due to shadow effect no signal from the area under the lesion was obtainable
For the purpose of vascular analysis we defined a narrow layer with an inner boundary as denoted by point 2 and an outer boundary parallel to it, but 55 micrometers lower. This layer was then moved thorough the lesion to observe course of vessels. SS OCT-A B-scans were analyzed for cross-sections of vessels.
Analysis was performed by 2 independent retinal specialists. Motion and projection artifacts were taken into account.
Results :
In all 3 cases SS OCT-A imaging displayed vascular structure within lesion (Fig. 2). There was associated loss of foveal avascular zone (FAZ). Inner portion of macular fibrosis displayed dense network of vessels, continuing to deeper layer. Outer portion was difficult to analyze due to shadow effect.
We have noted cross-sections of vessels at different levels on B-scans. Also, vessels penetrating deeper to the lesion were observed.
This structure was similar to retinal angiomatous proliferations (RAP).
Conclusions :
Macular fibrosis has distinct vascular structure, revealed by SS OCT-A.
The imaging results suggest vascular origin of the lesion with elements resembling RAP.
SS OCT-A enables to reveal additional information about structure and pathophysiology of macular fibrosis.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.