Clinical and Experimental Ophthalmology 2006; 34: 137–140 doi:10.1111/j.1442-9071.2006.1171.x
Original Article Optical coherence tomographic pattern of fluorescein angiographic leakage site in acute central serous chorioretinopathy Nazimul Hussain MS DNS,1 Arumugam Baskar B.Opt,2 LS Mohan Ram Oph. Tech.1 and Taraprasad Das MD FRCS1 1
Smt. Kanuri Santhamma Retina Vitreous Centre, and 2Bausch and Lomb school of optometry, L.V. Prasad Eye Institute, Andhra Pradesh, India
ABSTRACT Purpose: To study the optical coherence tomography (OCT) pattern of the fluorescein angiographic leakage in acute central serous chorioretinopathy (CSCR). Methods: This is a non-interventional pilot case study. OCT line scan was performed over the fluorescein angiographic leak site in eyes clinically diagnosed acute CSCR. Clinical fundus photograph, site of leakage on fundus fluorescein angiography and corresponding OCT were analysed. Results: The mean age of 10 consecutive patients was 38.8 ± 6.9 years. Six patients were male and the mean duration of symptom was 7 days. Six eyes (60%) showed a characteristic dipping pattern of neurosensory retina with intervening hyper-reflective echoes suggestive of fibrin over the leakage site. All these eyes had ink-blot leak and subretinal fibrin. Conclusions: Ink-blot leak in acute CSCR with subretinal fibrin generates a dipping morphological pattern on OCT. Key words: central serous chorioretinopathy, leakage, optical coherence tomography, subretinal fibrin.
INTRODUCTION Central serous chorioretinopathy (CSCR) is a common disorder characterized by serous detachment of the neurosensory retina in the macula. Subretinal fibrin (see Fig. 1a), seen as yellow white deposits between the retinal pigment epithelium (RPE) and the neurosensory retina together with fluorescein angiographic leakage at the level of RPE, is very characteristic.1–3 Currently optical coherence tomography
(OCT) is used to evaluative and monitor the progress of CSCR.1,2 Two types of leaks – the smoke stack and ink-blot leaks – are described in fundus fluorescein angiography (FFA) of CSCR. This leakage site is used for thermal laser photocoagulation when such is decided. The typical OCT appearances of CSCR are neurosensory elevation at the macula and a hyper-reflective bridging membranous structure secondary to subretinal fibrin has been described.1,2 It is not known whether this OCT character correlates with the FFA leak. This pilot study was carried out to characterize the OCT appearance of the leak demonstrated in FFA in acute CSCR.
METHODS Ten consecutive patients who satisfied the following criteria were recruited in the study: • •
Acute attack of CSCR, defined as duration of ≤2 months At least one leak on FFA.
The CSCR was diagnosed clinically from the characteristic symptoms (recent reduction of central vision and or metamorphopsia) and signs (improvement of vision with hypermetropic correction, serous detachment of macula observed by indirect ophthalmoscopy or biomicroscopy). The exclusion criteria were: • • • •
Absence of leakage on FFA Fluorescein angiographic leak outside the macula Conditions that may masquerade a CSCR Media opacity that may impair the image quality of OCT.
Correspondence: Dr Nazimul Hussain, Smt. Kanuri Santhamma retina vitreous centre, L.V. Prasad Eye Institute, L.V. Prasad Marg, Banjara Hills, Hyderabad – 500 034, Andhra Pradesh, India. Email:
[email protected] Received 10 March 2005; accepted 6 September 2005. © 2006 Royal Australian and New Zealand College of Ophthalmologists
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All patients received a detailed ophthalmic examination including clinical history, applanation tonometry, slit-lamp biomicroscopy and binocular fundus examination with 90 D and indirect ophthalmoscopy. Visual acuity was measured with Snellen vision acuity chart under standard conditions. Colour fundus photography and digital FFA (Zeiss digital FA, Carl Zeiss, Gmbh, Germany) and OCT (stratus OCT III, Carl Zeiss) were performed on all patients. Images were captured at 0–60 s, 2–3 min and 5 min after the injection of fluorescein. The leakage pattern and location with respect to the fovea was recorded. Optical coherence tomography was performed using line scan through the point of leakage seen on FFA. Six line scan was passed through the study point and recorded.
RESULTS The age range of 10 patients was from 29 to 47 years (mean 38.8 ± 6.9). Six patients were male. The duration of symptoms ranged from 4 to 46 days (mean 7 days). The visual acuity at presentation was ≥6/12 in three patients (30%), 6/15–6/37.5 in four patients (40%) and ≤6/60 in three patients (30%) (Table 1). All eyes had serous elevation of the macula and six eyes (60%) had focal subretinal deposits of fibrin, seen as yellowish white lesion (Fig. 1a). FFA images revealed active leakage in the macular area – nine eyes had ink-blot pattern of leakage and one eye had smoke stack pattern. Seven eyes had extrafoveal leakage, two had subfoveal and one had juxtafoveal leakage. The OCT in all eyes showed neurosensory detachment with subretinal fluid involving the fovea irrespective of the type of leakage. Six eyes (60%) showed posterior layer dipping of the neurosensory retina (dipping pattern) on to the RPE with intervening high reflectivity, probably suggesting the corresponding subretinal fibrin over the leakage point. This pattern was observed in all six eyes with ophthalmoscopic subretinal fibrin (Fig. 1b–e). We believe that the morphological changes correlate to the point of leakage. All eyes, which showed this particular pattern on OCT, had inkblot pattern of leakage on FFA.
DISCUSSION Optical coherence tomography is currently used to evaluate and monitor the resolution of CSCR.1,2 Iida et al. have shown that 17.3% (4 out of 23 eyes) of acute CSCR can show a pattern on OCT characterized by moderately or highly reflective mass bridging the detached neurosensory retina and RPE in the area of greyish white lesion seen in the area of serous elevation.1 And this corresponded to the leakage point in FFA. They further noted that the outer layer of the detached retina was more highly reflective in these eyes and the RPE was focally detached beneath the subretinal reflective mass in three of the four eyes. Rezai and Elliot also noted that this highly reflective material, presumably fibrin, disappeared after resolution of the serous detachment.4 The present study also demonstrated and confirmed the OCT findings of the reported studies1,3 of a tenting down of the neurosensory retina in association with the reflective mass bridging the detached neurosensory retina and the RPE (Fig. 2). We have named this ‘the dipping sign’. We observed that this pattern was present in eyes with acute CSCR that had associated subretinal fibrin and an inkblot leakage on FFA. This was consistently seen in six of nine eyes with ink-blot leak and all these six eyes had subretinal fibrin deposits. The hyper-reflective echoes between the tented neurosensory retina and RPE is due to the presence of fibrinous exudates. We believe that this OCT pattern is characteristic of eyes with subretinal fibrin and an associated ink-blot type of leak. Montero and Ruiz-Moreno have also described two different patterns of OCT in patients with idiopathic CSCR.5 One of the findings was highly characteristic of this condition. Acute and multiepisodic forms of idiopathic CSCR showed in all cases empty subretinal spaces. In most of them, bulges protruded from the RPE under a detached retina. This probably meant activity of the disease as this correlated to the angiographic leakage. We also believe that this characteristic OCT pattern cannot be used to apply laser. The reason is that it cannot provide the dynamic information of leakage, whether it is actively leaking or resolving, and also the exact location of
Table 1. Demographic, clinical presentation and optical coherence tomography (OCT) characteristics Case 1 2 3 4 5 6 7 8 9 10
Age/sex
Eye
Duration (years)
Fundus
FFA leak
VA
OCT
46/M 42/M 45/F 42/M 39/F 30/F 30/M 29/F 47/M 38/M
OD OD OS OS OD OS OS OS OS OD
7 5 7 4 7 7 10 10 46 7
Fibrin positive Fibrin positive Fibrin positive Serous elevation Serous elevation Serous elevation Fibrin positive Fibrin positive Serous elevation Fibrin positive
Ink-blot, extrafoveal Ink-blot, subfoveal Ink-blot, extrafoveal Ink-blot, extrafoveal Ink-blot, juxtafoveal Smokestack, subfoveal Ink-blot, extrafoveal Ink-blot, extrafoveal Ink-blot, extrafoveal Ink-blot, extrafoveal
6/24 6/120 6/37.5 6/9 6/24 6/9 6/120 6/120 6/12 6/30
Dipping pattern Dipping pattern Dipping pattern Serous elevation Serous elevation Serous elevation Dipping pattern Dipping pattern Serous elevation Dipping pattern
F, female; FFA, fundus fluorescein angiography; M, male; OD, right eye; OS, left eye; VA, visual acuity. © 2006 Royal Australian and New Zealand College of Ophthalmologists
Morphologic pattern of angiographic leakage
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a
b
c
d
e
Figure 1. (a) Colour fundus photograph of the right eye of a 42-year-old man (case 2) showing a serous elevation of the macular region with yellowish grey subretinal discoloration (arrow) in the foveal region suggestive of subretinal fibrin exudates. (b and c) Fundus fluorescein angiography image in the mid (b) and late (c) phase with active ink-blot pattern foveal leakage. (d and e) Optical coherence tomography line scan, corresponding to b and c, respectively, through the leakage point shows posterior layer dipping pattern (red arrowhead) of the neurosensory retina with intervening high reflective echoes suggestive of fibrin (yellow arrow).
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a
b
Figure 2. (a) Optical coherence tomography (OCT) line scan of case 8 showing dipping of the posterior layer of the elevated neurosensory retina (arrowhead) and intervening fibrin seen as hyper-reflective lesion (arrow). (b) OCT line scan of case 1 showing a dipping pattern (arrowhead) along with pigment epithelial detachment and intervening fibrin (arrow).
leakage. However, in a clinical setting, this information can be used with caution in patients contraindicated for FFA to apply laser. However, one could possibly use this information to monitor the progressive changes in the nature of resolution and the leak site in acute CSCR. In conclusion, OCT is a non-invasive tool to evaluate and monitor CSCR and can possibly correlate to the site of leakage in certain group of active CSCR.
REFERENCES 1.
Iida T, Hagimura N, Sato T, Kishi S. Evaluation of central serous chorioretinopathy with optical coherence tomography. Am J Ophthalmol 2000; 129: 16–20.
2.
Hee MR, Puliafito CA, Wong C et al. Optical coherence tomography of central serous chorioretinopathy. Am J Ophthalmol 1995; 120: 65–74. 3. Otsuka S, Ohba N, Nakao K. A long-term follow up study of severe variant of central serous chorioretinopathy. Retina 2002; 22: 25–32. 4. Rezai KA, Elliot D. Optical coherence tomographic findings in pregnancy – associated central serous chorioretinopathy. Graefes Arch Clin Exp Ophthalmol 2004; 242: 1014–16. 5. Montero JA, Ruiz-Moreno JM. Optical coherence tomography characterization of idiopathic central serous chorioretinopathy. Br J Ophthalmol 2005; 89: 562–4.
© 2006 Royal Australian and New Zealand College of Ophthalmologists
