| disease | Central Serous Chorioretinopathy |
| alias | Central Serous Chorioretinopathy (CSCR), Zentrale Rezidiverende Retinitis, Central Serous Chorioretinopathy, Recurrent Central Retinitis |
Central serous chorioretinopathy (CSC), also known as "central serous retinopathy," was first described by von Graefe in 1866 as "zentrale rezidiverende retinitis." Over the following century, numerous reports on this condition emerged worldwide. The incidence of CSC is relatively high in China, making it one of the most common fundus diseases. It predominantly affects young and middle-aged men, with the onset typically occurring between ages 25 and 50, peaking around age 40. The male-to-female ratio is approximately 5:1 to 10:1. Over 90% of cases involve only one eye, with no preference for either the left or right eye. Most patients recover spontaneously within 3 to 6 months, as it is a self-limiting condition. However, the disease is prone to recurrence, and repeated episodes may lead to irreversible vision damage.
bubble_chart Etiology
The exact disease cause of this condition remains unclear. In the past, some believed it to be inflammation of the retina or choroid membrane retina; others thought it was caused by vascular spasms, but none of these theories were widely accepted due to insufficient evidence. In 1951, Mitsui and Maumenee conducted detailed observations under a slit-lamp microscope and concluded that the essence of central serous chorioretinopathy (CSC) is a localized shallow detachment of the macular region or its adjacent myopia retinal neural epithelial layer. In the early 1960s, Gass used fundus fluorescein angiography to demonstrate that the sub-neural epithelial layer fluid accumulation is caused by increased permeability of the choroid membrane capillaries. The fistula disease fluid passes through Bruch membrane and initially accumulates under the pigment epithelial layer, forming a pigment epithelial detachment, then crosses the pigment epithelial layer to enter the sub-neural epithelial layer. However, Tsukahara et al., after extensive fluorescein angiography, found that in CSC, the serous fistula disease fluid from the choroid membrane capillaries mostly enters directly under the neural epithelial layer, unlike Gass's earlier claim that pigment epithelial detachment must occur first.
It is a well-known clinical fact that this condition is often triggered by mental stress and excessive fatigue. As for how these triggers lead to increased permeability of the choroid membrane capillaries—whether it is due to hemodynamic or vascular regulatory dysfunction, or whether it is caused by impaired venous blood flow in the choroid membrane affecting its thermal regulation—there is still no consensus. Additionally, the pigment epithelial cells are tightly connected by zonula occludens, forming a robust barrier between the choroid membrane and the neural epithelial layer. The pigment epithelial cells also have a physiological pump function that directs serous fluid toward the choroid membrane capillaries. Only when this barrier and pump function are compromised can serous fistula disease fluid accumulate under the neural epithelial layer, leading to CSC (Gass, 1977). Whether the disruption of these physiological mechanisms in the pigment epithelial layer during the onset of CSC is primary to the choroid membrane capillary leakage or secondary to it remains uncertain.bubble_chart Clinical Manifestations
1. Changes in visual function and examination findings
(1) Central vision: The central vision of the affected eye suddenly declines. If the eye was originally emmetropic, the uncorrected visual acuity is generally no lower than 0.5, and at worst, no lower than 0.2. Temporary hyperopia of 0.50D to 2.50D often occurs. In the early stages of the disease, vision can be corrected to a better level, or even fully corrected, with lenses. This phenomenon is interpreted as being caused by the forward displacement of the macular retinal detachment.
(2) Central scotoma: Patients subjectively experience blurred vision and dimming of the visual field in the affected eye. Some patients also report a disc-shaped shadow in the central visual field. A relative scotoma corresponding roughly in size and shape to the lesion in the posterior pole can be detected in the central visual field. If not detected, smaller or blue test targets can be used, or the background brightness of the perimeter can be reduced. Alternatively, the patient can be instructed to blink frequently or gaze at a white wall for several minutes before self-examination, which may reveal the scotoma. If the central relative scotoma is examined under different background brightness levels, the area of the scotoma will vary, being larger under lower brightness than under higher brightness.
2. Findings on ophthalmoscopy and slit-lamp microscopy In the early stages of the disease, ophthalmoscopy reveals one (occasionally two or three) round or horizontally oval, well-demarcated, shallow detachment area of the neurosensory layer in the macula or its vicinity, measuring approximately 1–3 disc diameters (PD). The detached area appears slightly darker, mildly elevated, with irregular peripheral reflex, and the foveal reflex is absent. These changes are more pronounced when examined with red-free light.
At this stage, if a narrow slit beam is used with a slit-lamp microscope equipped with a precorneal lens or contact lens, the light section of the neurosensory layer appears as an arched elevation. The retinal pigment epithelial layer also shows a light section. The space between these two light sections appears optically empty due to the completely transparent fluid. If the light section is moved onto retinal blood vessels elevated with the neurosensory layer, the shadow of the vessels can be seen projected onto the pigment epithelial layer.
In some cases, beneath the shallow detachment of the neurosensory layer, one or more detachments of the pigment epithelial layer may be observed. These detachments are round or oval, approximately 1/4 to 1/3 PD in size, appearing dull in color with steep edges under ophthalmoscopy. Narrow-beam examination reveals a slightly concave, dark-red light section on the detachment surface, with no visible light section at the base. The fluid in the detachment cavity is relatively bright. When present at the periphery without accompanying neurosensory layer detachment, it is termed serous detachment of the retinal pigment epithelium.
In the advanced stage of the disease, the sub-neurosensory fluid resolves, and visual function recovers. The macula may exhibit marbled pigmentary disturbances or fine pigmentary spots. In recurrent cases, such pigmentary changes may already be visible through the transparent sub-neurosensory fluid during the initial or first stage of recurrence.
3. Findings on Fundus Fluorescein Angiography The retinal pigment epithelium (RPE) acts as a barrier between the choroid and the neurosensory retina. Fluorescein leaks from the choroidal capillaries through Bruch's membrane and diffuses beneath the RPE. Due to the tight junctions of the zonulae occludentes between RPE cells, fluorescein cannot pass into the subneurosensory space. Only when these tight junctions are disrupted can fluorescein enter the subneurosensory space through the gaps between RPE cells. In cases with associated RPE detachment, this fluorescein leakage may appear as small, well-defined, round or oval sub-RPE cystoid fluorescence in the early arteriovenous phase. The fluorescence intensifies over time, and by the venous phase, the dye can be seen entering the subneurosensory space from beneath the RPE, spreading in an inkblot or smokestack pattern throughout the neurosensory detachment cavity, outlining a poorly defined disciform detachment. At this stage, the angiogram reveals a large area of faint fluorescence in the neurosensory detachment, with a more concentrated, sharply demarcated RPE detachment within it. In most cases of central serous chorioretinopathy (CSCR) without RPE detachment, fluorescein passes directly from the choroidal capillaries through damaged RPE into the subneurosensory fluid. This fluorescein leakage begins in the arteriovenous phase or early venous phase, initially appearing as one or several small fluorescent dots, which then expand in an inkblot or smokestack pattern, gradually diffusing throughout the serous space and outlining a disciform contour.
Inkblot diffusion (indbot diffusion) and smokestack-like spreading, also known as the smokestack phenomenon, are both manifestations of fluorescein dye leakage into the sub-neuroepithelial layer in fistula disease. The difference in presentation is generally attributed to the stage and characteristics of the disease. In the initial stage [first stage] of fistula disease, cases with low viscosity of exudate, high permeability of the pigment epithelial layer, and severe detachment often exhibit smokestack-like spreading. Conversely, in cases with a longer disease duration, higher viscosity of fistula disease exudate, and milder detachment, inkblot diffusion is more commonly observed.
In approximately 20% of cases, although serous detachment of the neuroepithelial layer is visible under an ophthalmoscope or slit-lamp microscope, no fluorescein leakage is detected in fluorescein angiography. For such cases, performing a water-loading test (such as drinking large amounts of water or intravenous infusion of isotonic solution) before angiography can increase the positive rate of fluorescein dye leakage in fistula disease.
After the sub-neuroepithelial fluid accumulation resolves, fluorescein angiography no longer shows fluorescein leakage in fistula disease, but transmitted fluorescence may still be observed, indicating damage to the pigment epithelium.
1. It is more common in young and middle-aged men, with recurrent episodes and a tendency to self-heal.
2. Blurred vision, decreased central vision, presence of fixation shadows, metamorphopsia, and dyschromatopsia. Amsler grid examination reveals central scotoma and distorted curves.
3. Fundus examination: ① Macular area shows edema, dark red coloration, round or oval elevation surrounded by a reflective halo, disappearance of the foveal reflex, and typical white exudate spots visible within the edematous area. ② After repeated episodes, residual gray-yellow hard exudates may remain, with pigment loss and free pigment. The foveal reflex often gradually recovers.
4. Fluorescein angiography: During the venous phase, a pinpoint leakage point can be observed, gradually expanding like a smoke plume or spreading outward like ink. In the late stage [third stage], the leakage area is clearly defined, showing persistent strong fluorescence.
bubble_chart Treatment Measures
1. Laser Photocoagulation Laser photocoagulation of the leaking points is the preferred treatment for this disease. Approximately one week after photocoagulation, the serous detachment of the neuroepithelium begins to subside and completely disappears within 2–3 weeks. However, this condition is a self-limiting disease with a tendency to heal spontaneously. Improper use of laser photocoagulation may instead cause catastrophic outcomes for the patient. Therefore, the correct application of laser photocoagulation is extremely important. Based on domestic and international literature, the indications are as follows.
(1) Obvious fluorescein leakage, with the leaking points located outside the optic disc-macular fiber bundle and more than 250μm from the central fovea, and severe serous detachment;
(2) Large-area neuroepithelial detachment accompanied by pigment epithelial detachment with a diameter of more than 1 PD;
(3) Fluorescein leakage persisting for more than three months, along with sustained serous detachment.
2. Drug Therapy Medications such as vitamin C, E, rutin, and adrenobazone, which reduce capillary permeability, may be tried. For patients with poor sleep, oral sedatives can be administered.
Adrenocortical hormones may induce this disease or exacerbate subneuroepithelial serous leakage, even leading to bullous retinal detachment, and are therefore contraindicated. The mechanism is unclear, but it has been speculated that hormones may loosen the tight junctions between pigment epithelial cells.
3. Lifestyle Management Avoiding excessive mental and physical fatigue is also of significant importance in the treatment and prevention of recurrence of this disease.
This disease is a self-limiting condition, with most cases resolving spontaneously. Central vision typically recovers within about three months, while symptoms such as distorted vision, micropsia, and darkened scenery gradually disappear over approximately six months. However, some cases may persist and recur, leading to irreversible visual impairment. The macula may exhibit pigmentary disturbances with a dull and discolored appearance. Fluorescein angiography reveals transmitted fluorescence and extremely slow leakage of small dye spots, known as chronic central serous chorioretinopathy, which may result from decompensation of the retinal pigment epithelium.
Based on the above clinical manifestations, the diagnosis of this disease is not difficult, but it should be differentiated from the following conditions.
1. Inferior peripheral retinal detachment, which may also involve the macula and be mistaken for this disease. If relying solely on the findings of a small-pupil ophthalmoscopic examination, misdiagnosis is common. Therefore, if shallow detachment of the neurosensory layer is found in the macula, especially with radiating folds inferiorly, it is essential to perform a dilated fundus examination of the peripheral retina.
2. Intermediate uveitis, also known as peripheral uveoretinitis or pars planitis, where toxic pathological products from the posterior chamber spread through Berger's space and along Cloquet's canal to the macula, causing edema and symptoms such as micropsia and metamorphopsia, which resemble those of central serous chorioretinopathy. However, this condition presents with dust-like opacities in the anterior vitreous, sometimes accompanied by a small number of keratic precipitates; behind the posterior lens capsule (i.e., within Berger's space), there are yellowish-brown inflammatory exudates resembling rice crusts. After full dilation, examination with a three-mirror lens may reveal inflammatory exudates, hemorrhages, and retinal vascular sheathing near the ora serrata.
