Dr. Shroff Rahul Ashok, S05342, Dr. Shroff Ashok C, Dr. Anand A Shroff
Introduction – Central serous chorioretinopathy (CSCR) is characterized by serous retinal detachment (SRD) with detachment of the retinal pigment epithelium(RPE). Multimodal imaging has shown that subretinal fluid accumulation results from thickened, congested hyperpermeable choroidal leaking fluid through a dysfunctional RPE. Previous studies have examined blood flow using FA/ICG imaging and have observed choriocapillary congestion. OCT angiography is a non-invasive device that detects movements of blood cells, instead of serum extravasation or staining of vessel walls. The aim of the study was to compare the findings of OCT Angiography in acute and chronic Central serous chorioretinopathy (CSCR)
Purpose – To evaluate changes in choroidal blood flow on OCT Angiography (OCTA) in eyes with acute, chronic and resolved Central Serous Chorioretinopathy (CSCR).
Method – Retrospective analyses of 12 eyes of 9 patients with acute or chronic CSCR were included. All patients underwent best-corrected visual acuity (BCVA), slit-lamp examination, 78D fundus biomicroscopy, SD-OCT of macula and OCT angiography of macula. 6X6 scans of OCTA were used. Evaluation was done by one single observer.
Results and discussion – 8 eyes had acute CSCR and 4 eyes had chronic CSCR. The mean age of the patients was 36yrs in acute CSCR group and 48yrs in chronic CSCR group. 8 patients were male and 1 patient was female. The mean BCVA in acute CSCR group was 6/9(logmar1.6+/-0.075) and in chronic CSCR group was 6/12(logmar0.35+/-0.22). The mean OCT thickness was 548+/-95 microns in the acute group and 190+/-17 micron in chronic group. 4 eyes of 3 patients showed complete resolution of submacular fluid at 3 months followup. Areas of Hypoperfusion (Hypofluorescence) surrounded by Hyperperfusion (Hyperfluorescence) in the choriocapillaris layer was seen in 7 of 8 eyes with acute Central Serous Chorioretinopathy (CSCR).These did no correlate well with the height of the serous retinal detachment. Leakage point was no identified in any eye in both the acute or chronic groups in inner, medium , outer retina or choriocapillaris. Similar studies have shown that leakage point cannot be identified. This is because the leakage point in acute Central serous chorioretinopathy (CSCR) has a very low flow rate that is too small for the difference in fliud extension between two images at two different time points to be visualized. Rarefaction of vessels in deep plexus with vessel wipeout in area of serous retinal detachment was seen in 6 of 8 eyes in Acute Central Serous Chorioretinopathy (CSCR). This did not correlate with the height of the serous retinal detachment and no study has shown a proper explanation for this observation. Patches of Hypoperfusion surrounded by Hyperperfusion in choriocapillarary layer were seen and aberrant choriocapillary flow with irregular choriocapillary texture was seen in 4 of 4 (100%) eyes in the chronic Central Serous Chorioretinopathy (CSCR) group. This is because the choriocapillary flow pattern on OCT Angiography appear as focally increased or decreased pixel values. Other earlier studies have shown focal filling defects in the choriocapillaries with dilated and tortuous feeding arterioles and dilated venules. This may be due to reduced blood perfusion in the choriocapillaries surrounded by reactive hyperperfusion, leading to disintegrity of the continuity of RPE and SRF leakage. Abnormal (aberrant) choriocapillary flow persisted in the choriocapillary layer in 4 of 4 eyes with resolved submacular fluid even after complete resolution of the Central Serous Chorioretinopathy (CSCR).
Conclusion – OCT angiography shows characteristic changes of choroidal blood flow in acute and chronic Central Serous Chorioretinopathy (CSCR) which persist even after absorbtion of the submacular fluid, suggestive of foci of ischaemia surrounded by reactive choroidal hyperperfusion as an important factor in the pathogenesis of chronic Central serous chorioretinopathy (CSCR). However it does not show leakage point in either the outer retina or choriocapillaries.
References –
1) OCT Angiography Findings in Acute Central Serous Chorioretinopathy ;Nikolaus Feucht, MD; Matthias Maier, MD; Chris P. Lohmann, MD; Lukas Reznicek, MD; Ophthalmic Surg Lasers Imaging Retina. 2016;47:322-327
2) OCT Angiography Compared to Fluorescein and Indocyanine Green Angiography in Chronic CentralSerous Chorioretinopathy Michel M. Teussink,1 Myrte B. Breukink,1 Mark J. J. P. van Grinsven,2 Carel B. Hoyng,1 B. Jeroen Klevering,1 Camiel J. F. Boon,3 Eiko K. de Jong,1 and Thomas Theelen1; Invest Ophthalmol Vis Sci.2015;56:5229–5237. DOI:10.1167/iovs.15-17140
3) Spaide RF, Hall L, Haas A, et al. Indocyanine green videoangiography of older patients with central serous chorioretinopathy.Retina. 1996;16:203–213
4) Iida T, Kishi S, Hagimura N, Shimizu K. Persistent and bilateral choroidal vascular abnormalities in central serous chorioretinopathy.Retina. 1999;19:508–512.
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