Purpose
To describe the spectrum of ultra-widefield autofluorescence (AF) and indocyanine green (ICG) angiographic findings in central serous chorioretinopathy (CSC).
Design
Retrospective observational case series.
Methods
In 37 patients, 65 eyes with CSC from 2 vitreoretinal clinical practices were imaged using ultra-widefield AF and 24 of these eyes with ultra-widefield ICG angiography. Images were correlated with clinical findings and spectral-domain optical coherence tomography (OCT).
Results
In 37 (57%) eyes, a variety of altered AF patterns, including gravitational tracts, extended beyond the posterior 50 degrees of retina. Hyper-AF corresponded to areas of subretinal fluid (SRF) on spectral-domain OCT and was found to persist in 44 (70%) eyes for up to 8 years despite resolution of SRF. These areas corresponded to outer retinal atrophy with viable retinal pigment epithelium (RPE) on spectral-domain OCT and may be explained by the unmasking of normal background RPE AF. Ultra-widefield ICG angiography revealed dilated choroidal vessels and choroidal hyperpermeability in areas corresponding to altered AF on ultra-widefield AF in all 24 eyes. In 20 (83.3%) eyes, dilated vessels were observed in association with 1 or more congested vortex veins ampullas, suggesting that outflow congestion may be a contributing factor to the pathogenesis of CSC.
Conclusions
Ultra-widefield AF and ICG angiography in CSC revealed more widespread disease in a single image than with standard field imaging and may be useful for identifying peripheral areas of previous or ongoing SRF and choroidal hyperpermeability that can assist in the diagnosis of CSC, surveillance of recurrent disease and treatment of active disease.
Central serous chorioretinopathy (CSC) is a disease characterized by exudative macular detachment due to focal or multifocal leakage at the level of the retinal pigment epithelium (RPE). One of the most common retinal disorders causing vision loss, CSC predominantly affects males between the ages of 30 and 50 years with type A personalities who may also have a history of corticosteroid use. Although most cases of CSC are acute and self-limited, with complete resolution of macular detachment and excellent visual prognosis, a subset may be recurrent or chronic with long-standing serous retinal detachment and widespread alteration of the RPE and outer retina, leading to permanent visual decline.
Retinal and choroidal imaging advancements have provided invaluable insight into the mechanisms and prognoses of disease and have guided therapy for CSC. Fundus autofluorescence (AF) imaging employs the stimulated emission of light from endogenous fluorophores to show characteristic pathologic changes in CSC and may even predict visual acuity in this disorder, whereas indocyanine green (ICG) angiography has demonstrated hydrostatic dysfunction of the choroid. Choroidal hyperpermeability has been postulated to lead to serous pigment epithelial detachments or decompensation of the RPE, which may result in neurosensory detachments.
Traditionally, analysis of the retina in CSC has been limited to the posterior 50 degrees. Novel ultra-widefield imaging systems have expanded our viewing capability to 200 degrees, allowing detailed evaluation of the peripheral retina. With ultra-widefield imaging tools for AF and ICG angiography, we are able to study an expanded spectrum of CSC and broaden our understanding of this disease.
Methods
The retrospective study was approved by the Western Institutional Review Board and is compliant with the Health Insurance Portability and Accountability Act.
We conducted a retrospective review of patients seen by 2 physicians (KBF and DS) in vitreoretinal referral practices located in New York City, New York (KBF) and Los Angeles, California (DS). Eyes of patients with a diagnosis of acute or chronic CSC who had undergone imaging with ultra-widefield AF with or without ultra-widefield ICG angiography were included. Diagnosis was established based on clinical history, examination and imaging.
All patients underwent complete ocular examinations, including Snellen visual acuity, slit-lamp biomicroscopy and ophthalmoscopy as well as ocular imaging, including color fundus photography, ultra-widefield AF, and spectral-domain optical coherence tomography (OCT). A subset of these patients also underwent ultra-widefield ICG angiography. Ultra-widefield AF imaging was obtained by the Optos 200Tx (Optos 200Tx; Optos, Dunfermline, Scotland, United Kingdom), which enables imaging up to 200 degrees, or 82% of the retina, in a single image acquisition. The Optos 200Tx has an excitation wavelength of 532 nm, a cut-off of 540 nm in the barrier filter, and a transmission wavelength extending to the infrared range (approximately 900 nm). Ultra-widefield ICG angiographic images were acquired with a modified prototype of the Optos 200Tx with similar 200 degrees of field, excitation wavelengths at approximately 800 nm, a cut-off at 807 nm in the barrier filter, and a transmission wavelength extending beyond 900 nm. Spectral domain-OCT images were obtained using the Heidelberg Spectralis (Spectralis; Heidelberg Engineering, Heidelberg, Germany). The study period, which started at the time each eye was first imaged by the Optos 200Tx, extended from April 2012 to September 2013.
Acute CSC was defined as the presence of visual symptoms and neurosensory macular detachment with subretinal fluid (SRF) of less than 4 months duration and focal RPE leakage withfluorescein angiography. Chronic CSC was defined as persistent or recurrent serous retinal detachment documented for greater than 4 months, with multifocal or diffuse RPE alteration.
Results
A total of 65 eyes of 37 patients with CSC were studied. Of the patients, 4 had acute CSC, and the remainder had chronic CSC. The mean age of the patients was 56.3 ± 11.8 years (range, 32–73); 26 (70%) were male and 11 (30%) were female; 4 were Asian, 6 were Hispanic, and the remaining 27 were white. The mean duration since time of CSC diagnosis was 86.2 ± 85.1 months. Average subfoveal choroidal thickness based on enhanced-depth imaging spectral domain-OCT was 423 ± 127 microns. The median visual acuity was 20/50 (range, 20/20-counting fingers).
A wide spectrum of patterns on ultra-widefield AF was observed with varying degrees of altered AF that can be classified by the location: posterior or peripheral. Posterior AF patterns affecting mainly the macula could be hyper-, hypo- or mixed-AF ( Figure 1 ). Peripheral AF patterns usually included gravitational tracts, which could appear as hyper-, hypo- or mixed-AF tracts and either vertical or arched ( Figure 2 ). A summary of these patterns is tabulated in Table .
| Location | AF patterns | Number of eyes | Total | |
|---|---|---|---|---|
| Posterior | Hyper-AF | 11 | 22 | 60 (5 eyes had no AF findings) |
| Hypo-AF | 3 | |||
| Mixed-AF | 8 | |||
| Peripheral | Hyper-AF | 17 | 38 | |
| Hypo-AF | 9 | |||
| Mixed-AF | 12 | |||
| Peripheral with gravitational tract | Vertical | 14 | 32 (6 eyes had no gravitational tract) | |
| Arched | 18 | |||
Ultra-widefield AF revealed more extensive disease than that which could be detected on clinical examination or by standard field AF imaging in 37 of 65 (57%) eyes. Gravitational fluid tracts were present in 32 of 65 (49%) eyes. In 13 eyes of 9 patients, we observed that the direction of the gravitational tract correlated with the side on which they slept; for example, the tract arched to the right if the patient slept on the right side, arched to the left if the patient slept on the left side and descended vertically if the patient slept on the back. In the remaining 19 eyes, this correlation could not be determined because patients were unsure of their usual sleep position.
Of the 65 eyes, 16 eyes had active disease defined by the presence of SRF. These areas of SRF were demonstrated by spectral domain-OCT imaging and corresponded to hyper-AF with ultra-widefield AF imaging ( Figure 3 ). In the eyes with inactive disease, 5 eyes had only hypo-AF patterns. These areas of absent or reduced AF, appearing as black or dark gray, corresponded to areas of RPE atrophy, retinal thinning and photoreceptor loss when correlated with spectral domain-OCT images ( Figure 4 ). In the remaining 44 eyes (70%), there were areas of hyper-AF that persisted despite absence of SRF. These areas corresponded to areas of retinal thinning, outer retinal atrophy and intact RPE as viewed by spectral domain-OCT imaging ( Figure 5 ). Of these 44 eyes with hyper-AF, 17 eyes experienced documented resolution of subretinal fluid in the area corresponding to hyper-AF, with a mean duration of disease inactivity taken as the time from SRF resolution to the most recent follow-up of 38.8 months (range, 4–96 months). Of those eyes, 2 showed development of complete hypo-AF in the same area that had demonstrated hyper AF 3 years earlier, demonstrating that despite resolution of SRF, atrophy of photoreceptors and RPE could occur, resulting in dark hypo-AF patterns.
Ultra-widefield ICG angiography performed on 24 eyes revealed dilated choroidal vessels in the early phase and areas of choroidal hyperpermeability in the late phase of all eyes, which corresponded to the areas of altered AF on ultra-widefield AF. In 20 (83.3%) of these eyes, the dilated choroidal vessels in the early phase were seen to extend along the entire course of the vessel back to 1 or more vortex veins’ ampullas before exiting the sclera, indicating outflow congestion of that draining vortex vein. Of the eyes, 2 showed congestion in 1 vortex vein, 7 eyes in 2 vortex veins ( Figure 6 ), 1 eye in 3 vortex veins ( Figure 7 ), and 10 eyes in all 4 vortex veins ( Figure 8 ). In 10 of 12 patients, there was symmetry of the vortex vein dilation in both eyes despite asymmetry in the severity of clinical manifestations in 8 of these patients.
We present 2 brief cases illustrating how ultra-widefield AF and ultra-widefield ICG angiography enabled the recognition of more extensive disease in CSC than was suspected on clinical examination and that led to discovery of SRF in peripheral retina and confirmation of the diagnosis of CSC in Case 1 and the institution of appropriate treatment with resolution of SRF in Case 2.
Case 1
A 43-year-old Hispanic male presented with a 1-month history of central blurring of vision associated with central relative scotoma in the right eye. Visual acuity was 20/25 in the right eye and 20/20 in the left eye. Examination of the macula showed no evidence of current SRF. However, ultra-widefield AF revealed 2 extrafoveal areas of hyper-AF nasal and inferior to the disc, which prompted spectral domain-OCT imaging and revealed SRF and associated choroidal thickening; this led to confirmation of the diagnosis of CSC. Spectral domain-OCT through the fovea revealed disruption of the ellipsoid, suggesting prior damage caused by subretinal fluid, which had resolved and was likely responsible for his central visual symptoms ( Figure 9 ).
