Central serous chorioretinopathy

Description

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 localized 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

Central serous chorioretinopathy 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- 6/12). As elevation of the retina often causes hypermetropia (long-sightedness), vision may be improved with positivedioptre lenses. Amsler grid examination may reveal central or paracentral scotomata 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. Central serous retinopathy (CSR) typically affects men aged between 20 and 50 years, although it may also occur in women 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 neovascularization; choroidal tumors.

See also

Pregnancy; Systemic lupus erythematosus; Hypertensive retinopathy.

Management

Investigations CSCR is usually diagnosed clinically. Fluorescein angiography is indicated when the diagnosis is unceri:ain, 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, and then extends to outline the area of serous detachment. Ocular coherence tomography (OCT) may also be used to confirm the diagnosis (Fig. 24.2).

Advice The condition is usually selflimiting. Most patients recover normal or near-normal acuity within 3 months. Recurrences occur in approximately 20 percent of patients, usually within a year of the initial presentation. A minority experience multiple recurrences, prolonged attacks and permanent visual impairment.

Review In most cases, patients are reviewed at 6-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 the following situations:

• Serous detachment persisting for longer than 3 months
• Recurrence, when previous episodes have resulted in a permanent visual deficit
• When prompt restoration of vision is important (e.g. 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.