Indian Journal of Ophthalmology

: 2018  |  Volume : 66  |  Issue : 8  |  Page : 1181--1182

Smokestack leak on indocyanine green angiography in acute central serous chorioretinopathy

Apoorva Ayachit1, Vinod Kumar2, Nimmy Raj2, Guruprasad Ayachit1,  
1 Department of Vitreoretina, M M Joshi Eye Institute, Hubballi, Karnataka, India
2 Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India

Correspondence Address:
Dr. Vinod Kumar
Dr. Rajendra Prasad Centre for Ophthlamic Sciences, All India Institute of Medical Sciences, New Delhi


How to cite this article:
Ayachit A, Kumar V, Raj N, Ayachit G. Smokestack leak on indocyanine green angiography in acute central serous chorioretinopathy.Indian J Ophthalmol 2018;66:1181-1182

How to cite this URL:
Ayachit A, Kumar V, Raj N, Ayachit G. Smokestack leak on indocyanine green angiography in acute central serous chorioretinopathy. Indian J Ophthalmol [serial online] 2018 [cited 2022 Dec 6 ];66:1181-1182
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Full Text

Smokestack leak (SSL) is pathognomonic feature of central serous chorioretinopathy (CSC) seen on fundus fluorescein angiography (FFA). The fluorescein dye leaks through choriocapillaris and is then restricted by outer blood-retina barrier (retinal pigment epithelium [RPE]). In the setting of CSC, the leaked fluorescein dye from hyperpermeable choriocapillaris reaches the subretinal space through a breach in outer blood-retina barrier. Since indocyanine green (ICG) dye is almost completely protein bound (98%), the dye does not leak across the choriocapillaris; and therefore, the characteristic patterns of leak seen on FFA are not seen on ICG angiography (ICGA). We report SSL on ICGA in two eyes of two patients with acute CSC.

 Case Report

Two patients of acute CSC underwent simultaneous FFA and ICGA (Heidelberg Spectralis, Heidelberg, Germany) using 25 mg ICG dye and 3 ml of 20% fluorescein sodium. A typical SSL on FFA was seen in both the cases. Interestingly, the ICGA also showed an SSL. The SSL seen on ICGA, however, appeared later than that of FFA [Figure 1] and [Figure 2]. Areas of choroidal hyperpermeability were seen in addition, in the late phases of ICGA in both the cases. Spectral domain optical coherence tomography (OCT) showed a large neurosensory detachment (NSD) in both the cases. Irregular, flat pigment epithelial detachments (PEDs) and a dip in the neurosensory retina were also seen on OCT through the area of the leak in both eyes [Figure 3] and [Figure 4].{Figure 1}{Figure 2}{Figure 3}{Figure 4}


SSL is due to differential osmotic pressures of fluorescein dye and subretinal fluid in CSC causing a rise of leaked fluorescein dye inside the NSD.[1] The reported ICGA findings in CSC include arterial filling delay, venous dilatation, dilated choroidal vessels and hyperpermeability, and choroidal lobular ischemia.[2] SSLs on ICGA have not been described in CSC and indicate leakage of ICG dye across the choriocapillaris as well as RPE into the subretinal space. PEDs are known to show late pooling on ICGA suggesting that some amount of ICG dye leaks through the choriocapillaris. A vigorous leak of ICG dye across choriocapillaris in certain patients may explain leak of dye across choriocapillaris. An RPE micro-rip may explain the entry of leaked ICG dye (in the PED) into subretinal space.[3] Although we could not identify the RPE micro-rip in either of our cases, its presence is supported by the presence of large NSDs in both the cases.


SSLs may be seen on ICGA in patients with acute CSC with large neurosensory detachments and may result from a combination of vigorous leak from choriocapillaris and RPE micro-rip.

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Conflicts of interest

There are no conflicts of interest.


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