Purpose
To investigate the characteristics of subretinal exudation and consequent morphologic changes in acute central serous chorioretinopathy (CSC) using spectral-domain optical coherence tomography (OCT).
Design
Prospective, observational, cross-sectional case series.
Methods
Patients with CSC with symptom duration of fewer than 3 months underwent visual acuity measurement, fundus observation and spectral-domain OCT examinations and then were evaluated for subretinal exudation and other changes.
Results
A total of 123 patients (123 eyes) were included, all showing various retinal pigment epithelium (RPE) abnormalities on OCT. OCT also showed subretinal exudation (65 eyes, 52.8%); retinal dipping (14 eyes, 11.4%); and photoreceptor layer defects (88 eyes, 71.5%). Without exception, the locations of these pathologic changes were closely related to the abnormal sites in the RPE. Those with subretinal exudation showed shorter durations of symptoms, whereas those with photoreceptor layer defects showed longer durations. In most eyes with retinal dipping, exudation connected it to RPE abnormalities. The defects of the photoreceptor layer, which involved the photoreceptor outer segment in 68 eyes, the photoreceptor inner segment in 20 eyes, and the outer nuclear layer as well, were likely to be the consequence of retinal dipping.
Conclusions
OCT findings suggested that in eyes with acute CSC subretinal exudation, which indicated fibrin leakage through the RPE defects, might cause retinal dipping, thus leading to photoreceptor layer defects, and that spectral-domain OCT could provide a better understanding of the pathologic changes in acute CSC.
Central serous chorioretinopathy (CSC), a common macular disease, always presents a well-circumscribed serous retinal detachment in the macular region on clinical examination and shows 1 or several leakage points at the level of the retinal pigment epithelium (RPE) on fluorescein angiography (FA). With the advent of optical coherence tomography (OCT), it is now possible to obtain high-resolution cross-sectional images of the retina in a noninvasive manner and thus to characterize many forms of pathologic retinal features. The typical pathologic changes, such as serous retinal detachment and pigment epithelial detachment (PED), were clearly demonstrated in eyes with CSC by using OCT. Afterward, the RPE defects in the PED were detected, and they corresponded precisely to the leakage point shown by FA, and also exudation in the subretinal space was reported in acute CSC. However, there has been limited information concerning the characteristics of subretinal exudation in acute CSC. In the current study, we used high-speed spectral-domain OCT to investigate the subretinal exudation and consequent morphologic changes so that we could characterize further the features of acute CSC.
Methods
The research protocol and the collection of clinical data and OCT images for this prospective observational cross-sectional study were approved by the ethics committee of the Eye and Ear Nose Throat Hospital, Fudan University (KJ2009-16). Informed consent was obtained from each patient.
In the current study, we enrolled patients with consecutive acute CSC who visited the clinic of Eye and Ear Nose Throat Hospital of Fudan University, Shanghai, between January and June 2013. The clinical diagnosis of CSC was based on ocular histories of decreased visual acuity with or without metamorphopsia and micropsia for fewer than 3 months, as well as on the results of clinical examinations showing a focal serous retinal detachment on both fundus and OCT examinations, and leakage points at the level of the RPE as shown by FA. Excluded were those with clinical signs of or with histories of other intraocular diseases such as glaucoma and iridochoroiditis; those with histories of intraocular surgery or any steroids use; and those with clinical signs of other macular abnormalities, such as drusen and age-related macular degeneration.
A collection of information was performed; it included best-corrected visual acuity (BCVA), measured using a standard Snellen chart and converted to logarithm of the minimum angle of resolution (logMAR) for statistical analysis, and the details of clinical examinations. All OCT images were obtained through a dilated pupil by spectral-domain OCT (Cirrus HD-OCT, Carl Zeiss Meditec, Dublin, California, or Heidelberg Spectralis OCT, Heidelberg Engineering, Heidelberg, Germany). The acquired images were observed and analyzed. Statistical analysis was performed using IBM SPSS Statistics 19 (IBM, Chicago, Illinois). The Student t test was applied to BCVA, and a comparison was made of symptom duration between the eyes with and without subretinal exudation and other manifestations. A P value of <.05 was considered statistically significant.
Results
In total, 123 eyes of 123 patients enrolled were studied; 100 of the enrollees were male and 23 were female, 19–76 years of age; the mean age was 42.92 ± 8.87. The mean BCVA (logMAR) was 0.33 ± 0.22 (Snellen 0.47; range, 0.1–1.0) and the mean duration was 24.26 ± 24.41 days (range, 1–90). FA was performed in 48 eyes, showing that each had 1 or several leakage points at the level of the RPE and that 29 eyes presented with typical smokestack dye leaking.
The number, symptom duration and BCVA of the eyes with and without various OCT manifestations are shown in the Table . All 123 eyes presented well-circumscribed serous retinal detachment at the macular region and also showed various RPE abnormalities below the detached retinas: localized RPE detachment was present in 46 eyes, RPE irregularities in 71; and RPE rupture in 54, all of which produced 46 with 2 or more kinds of RPE abnormalities.
| Eyes | n | Symptom Duration (d) | BCVA (logMAR) |
|---|---|---|---|
| With localized RPE detachment | 46 | 18.23 ± 20.29 | 0.36 ± 0.23 |
| With RPE irregularity | 71 | 35.20 ± 35.37 | 0.29 ± 0.20 |
| With RPE rupture | 54 | 21.41 ± 21.97 | 0.38 ± 0.21 |
| With subretinal exudation | 65 | 18.85 ± 21.25 | 0.38 ± 0.23 |
| Without subretinal exudation | 58 | 30.33 ± 26.41 | 0.27 ± 0.19 |
| With retinal dipping | 14 | 12.40 ± 11.17 | 0.35 ± 0.24 |
| Without retinal dipping | 109 | 25.91 ± 25.31 | 0.33 ± 0.22 |
| With PRL defect | 88 | 27.59 ± 25.82 | 0.34 ± 0.23 |
| Defect involving fovea | 14 | 33.36 ± 32.33 | 0.49 ± 0.21 |
| Defect at extra fovea | 74 | 26.50 ± 24.51 | 0.31 ± 0.22 |
| Without PRL defect | 35 | 15.89 ± 18.18 | 0.32 ± 0.21 |
Subretinal exudation was identified in 65 (52.8%) eyes, and most of the exudation was surrounding the site of the RPE abnormality ( Figure 1 , left). Those with subretinal exudation had shorter symptom durations and lower BCVA than those without (t = −2.636, P = .010; and t = 2.828, P = .005, respectively). In 14 of the 65 eyes, retinal dipping was present, and in 11 of 14 eyes, exudation connected the RPE abnormality with retinal dipping ( Figure 1 , middle and right).
A defect in the photoreceptor layer within the detached retina was observed in 88 eyes (71.5%), with 14 involving the fovea. These eyes showed longer symptom duration than those without such abnormalities but indicated similar vision (t = 2.838, P = .006; t = 0.372, P = .710, respectively). However, the 14 eyes with the defect involving the fovea presented worse visual acuity (t = 2.814, P = .006). The defects, which varied from 0.5 to 1.5 papillary diameter in size, were located primarily above the site of the RPE abnormality. In 68 eyes, the defect involved only the photoreceptor outer segment (OS), leaving photoreceptor inner segment (IS) and outer segment junction (IS/OS) intact; in the other 20 eyes, the defect involved the photoreceptor IS, hence a disrupted IS/OS line, but presented an intact external limiting membrane. It is intriguing that in 2 eyes, outer nuclear layer thinning was present despite an intact external limiting membrane ( Figure 2 ). As indicated by the OCT images derived from 1 eye ( Figure 3 ), it was likely that the defect was caused by early retinal dipping.
