Central serous chorioretinopathy (CSCR) appears to occur when fluid leaks from the choroid into the subretinal space through a defect in the retinal pigment epithelium (RPE).
This results in localised elevation and detachment of the retina. As the macula is involved in more than two-thirds of cases, central vision is usually affected. Patients often describe significant psychosocial stressors preceding the disease onset, and it is suspected that increased serum corticosteroid or catecholamine levels may play a role.
Animal studies, as well as an increased incidence in patients taking steroid medications, support this proposition.
Symptoms
CSCR is usually unilateral. Common symptoms are blurred vision, micropsia (objects appearing unusually small) and metamorphopsia (distorted shapes).
Signs
Acuity is usually moderately reduced (6/9 to 6/12). As elevation of the retina often causes hypermetropia, vision may be improved with positive-dioptre lenses. Amsler grid examination may reveal central or paracentral scotomas and distortion of straight lines.
Retinal examination is best conducted with a slit lamp. Areas of serous detachment appear as shallow, round or oval elevations of the sensory retina with glistening margins. Detachment of the sensory retina can often be confirmed when its blood vessels cast shadows on the underlying RPE. Fine yellow precipitates are sometimes present on the posterior surface of the elevated retina.
In some cases, RPE detachment is visible within (or slightly above) the serous detachment. This appears as a small, circumscribed, yellow-grey area of elevation.
Areas of RPE irregularity or atrophy may be present at sites of previous episodes. In rare, severe cases, multiple areas of serous detachment coalesce and result in a large, bullous, retinal detachment.
Prevalence
Uncommon. CSR typically affects men between the ages of 20 and 50 years, although it may also occur in female and elderly patients.
Significance
A minority of patients experience multiple recurrences, prolonged attacks or permanent visual impairment.
Differential Diagnosis
Age-related macular degeneration; Optic nerve head pit (with serous retinal detachment); Retinal detachment – rhegmatogenous; Choroidal neovascularisation; Choroidal tumours.
See also
Systemic lupus erythematosus; Hypertensive retinopathy.
Management
Investigations
CSCR is usually diagnosed clinically. Fluorescein angiography is indicated when the diagnosis is uncertain, or when laser treatment is being considered. Fluorescein leaks through the defective blood-retina barrier, resulting in a focal dot of hyperfluorescence.
This often ascends to the superior limit of the detachment in a characteristic ‘smokestack’ pattern, then extends to outline the area of serous detachment. Ocular coherence tomography (OCT) may also be used to confirm the diagnosis (Figure 2).
Advice
The condition is usually self-limiting. Most patients recover normal or near-normal acuity within three months. Recurrences occur in approximately 20 per cent of patients, usually within a year of the initial presentation. A minority experience multiple recurrences, prolonged attacks or permanent visual impairment.
Review
In most cases, patients are reviewed at six-week intervals until disease resolution.
Laser treatment
Laser treatment to the site of leakage (provided it is at least 500µm from the fovea) is indicated in these situations:
? Serous detachment persisting for longer than three months
? Recurrence, when previous episodes have resulted in a permanent visual deficit
? When prompt restoration of vision is important (eg for occupational reasons).
Laser treatment has been shown to shorten disease duration and lower the recurrence rate. However, it has not been shown to affect the final visual outcome, and may adversely affect contrast sensitivity.