Central serous retinopathy

Summary

Central serous retinopathy (CSR) is an idiopathic disorder involving a localised serous detachment of the sensory retina at the macula due to leakage from the choriocapillaris through sites of increased permeability on the retinal pigment epithelium (RPE).

Background

Central serous retinopathy (CSR) is an idiopathic disorder involving a localised serous detachment of the sensory retina at the macula due to leakage from the choriocapillaris through sites of increased permeability on the retinal pigment epithelium (RPE).

There are two forms of CSR:

1. Acute: lasting 3-6 months, then self-resolving, with return to near-normal or normal vision. This occurs in 〜80% of patients. Recurrence is seen in up to 1/2 of patients

2. Chronic: 〜15% of patients have chronic CSR lasting ≥12 months

CSR is the 4th most common retinopathy after age-related macular degeneration, diabetic retinopathy, and branch retinal vein occlusion.

Epidemiology

CSR is typically unilateral, affecting males more than females (with a 3:1 male to female ratio), of young-to-middle age (in their 20s to 50s). Females with CSR tend to be older.

Many risk factors for CSR and associations have been proposed, importantly:

• A single nucleotide polymorphism (SNP) on chromosome 1 involving the compliment factor H confers a predisposition to the chronic form of CSR in white patients.

• Steroids (both endogenous and exogenous), including Cushing’s syndrome, have the strongest known association with CSR

• Helicobacter pylori infection

• Renal dialysis

• Hypertension

• Psychological stress

• Pregnancy

Clinical features

Symptoms:

• Acute/subacute unilateral blurred vision. This is typically central visual loss/distortion, with a possible central scotoma

• Metamorphopsia (a type of visual distortion where straight lines specifically appear distorted or warped)

• Micropsia (where objects are perceived to be smaller than they actually are)

• Mild dyschromatopsia (a deficiency in colour vision)

Signs:

• Visual acuity is usually 6/9 to 6/18, but might improve with a low-strength convex lens (this corrects the acquired hypermetropia from retinal elevation)

• Round or oval detachment of the sensory retina at the macula

• The subretinal fluid may be clear (often in early lesions) or turbid. Precipitates may be seen on the posterior surface of the retina

• One or more depigmented RPE foci (often small pigment epithelial detachments, PDEs)

• Chronic lesions may be associated with atrophic changes. With prolonged detachment of the sensory retina, there is gradual photoreceptor and RPE degeneration —> permanently reduced vision. Multiple recurrent episodes of CSR may give rise to similar consequences

• Cystoid macular oedema (CMO), choroidal neovascularisation (CNV) or RPE tears develop in a small proportion of patients

💡 In acute CSR, visual acuity can be improved with a convex lens (plus lens), and usually self-resolves within 3-6 months

Fundus picture showing CSR with central pigment epithelial changes with overlying sub-retinal fluid. Image courtesy of Gregory et al.

Here are fundal images (top) and fundus autoflourescence images (bottom) from a patient with bilateral multifocal CSR. In the fundal image, note the slightly yellowish, translucent, raised lesions of various sizes throughout the fundi bilaterally. In the fundus autofluorescence images, the areas of autofluorescence (the white areas) correspond with the detached sensory retina. Image courtesy of Gkotsi et al.

Investigations

• Amsler grid testing: to demonstrate metamorphopsia corresponding to the neurosensory detachment

• Ocular coherence tomography (OCT): will show neurosensory elevation. OCT may also reveal smaller RPE detachment(s), thickened choroid, precipitates on the posterior surface of the detached retina, and degenerative changes (in chronic/recurrent cases)

• Fluorescein angiography (FA): shows an early hyperfluorescent spot that gradually enlarges (an ‘ink blot’), followed by diffusion throughout the detached area. Multiple focal leaks or diffuse areas of leakage may be seen in chronic/recurrent disease

• Fundus autofluorescence (FAF): shows a focal decrease in fundus autofluorescence at the leakage site and at sites of previous lesions

• Indocyanine green angiography (ICGA): can show dilated/compromised choroidal vessels at the posterior pole (in the early phase) or areas of hyperfluorescence due to choroidal hyper-permeability (in the middle stage of the disease)

Management

Many cases will not require intervention, and can instead be observed. This is because 〜80% of acute cases will self-resolve, and it is important to bear in mind that all treatments are associated with risks, such as RPE tear formation (which can also occur spontaneously). However, any possible risk factors should be mitigated, including discontinuing exogenous steroids if possible.

If treatment is required, there are several options:

• Oral spironolactone —> faster respiration of subretinal fluid than no treatment in acute CSR

• Laser photocoagulation: sub threshold (micro pulse) diode laser to the RPE site of leakage

• Photodynamic therapy (PDT): can lead to complete resolution, including in chronic severe cases

• Intravitreal anti-VEGF agents are showing promise

💡 Patients should immediately stop taking any steroids, as these are a risk factor for the development of CSR

References

1. Salmon, John F., and Jack J. Kanski. Kanski’s Clinical Ophthalmology: A Systematic Approach. Ninth Edition, Elsevier, 2020.

2. ‘What Is Central Serous Chorioretinopathy?’ American Academy of Ophthalmology, 21 Sept. 2022, https://www.aao.org/eye-health/diseases/what-is-central-serous-retinopathy.

3. Gregory, D. L., et al. ‘Acute Visual Loss Induced by Dexamethasone During Neoadjuvant Docetaxol’. Clinical Medicine. Oncology, vol. 2, Feb. 2008, pp. 37–42. PubMed Central, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3161640/.

4. Gkotsi, Despoina, et al. ‘Alcoholic Liver Disease and Bilateral Multifocal Central Serous Retinopathy: A Case Report’. Journal of Medical Case Reports, vol. 7, Feb. 2013, p. 43. PubMed, https://doi.org/10.1186/1752-1947-7-43.

5. Bousquet, Elodie, et al. ‘SPIRONOLACTONE FOR NONRESOLVING CENTRAL SEROUS CHORIORETINOPATHY: A RANDOMIZED CONTROLLED CROSSOVER STUDY’. Retina (Philadelphia, Pa.), vol. 35, no. 12, Dec. 2015, pp. 2505–15. PubMed, https://doi.org/10.1097/IAE.0000000000000614.