Treatment of Chronic Recalcitrant or Unresponsive Central Serous Chorioretinopathy Via Electromagnetic Stimulation And Platelet- Rich Plasma

Central serous chorioretinopathy (CSCR) is a retinal disorder that is mostly unilateral, and predominantly affects young and middle-aged male patients who are otherwise healthy. It is characterized by leaking fluid through a dysfunctional retinal pigment epithelium (RPE) to submacular area resulting in serous neuroretinal detachment. The main risk factors for CSCR include emotional stress, systemic arterial hypertension, pregnancy, use of corticosteroids, and the presence of pachychoroid under the RPE layer.

Although several clinical presentations are described, two forms of CSCR can be distinguished: acute and chronic. Acute CSCR usually presents with sudden visual loss of central vision, disturbed color vision and dark adaptation, central or paracentral scotoma, metamorphopsia, and/or micropsia caused by the rapid accumulation of subretinal fluid (SRF). While spontaneous resolution is common and self-limiting with little or no residual damage in the acute variant, the chronic variant is usually progressive with persistence of SRF. Persistent serous detachment for more than 3 months can result in progressive photoreceptor (PR) compromise, which explains the worsening visual outcomes versus the acute form.

The chronic form of CSCR is characterized by diffuse multifocal irregular hyper-fluorescence seen on fluorescein angiography (FA) and indocyanine green angiography (ICGA) in addition to widespread RPE changes. B-scan optical coherence tompgraphy (OCT) shows elongated PR outer segments and a shallow heterogenous RPE detachment surrounded by subretinal fluid containing fibrin/fluorophore. Widespread diffuse RPE abnormalities including RPE atrophy, intraretinal fluid, and cystic retinal changes, retinal atrophy, subretinal fibrinous accumulation, subretinal fibrosis, and secondary choroidal neovascularization (CNV) are late complications that can lead to permanent visual loss.

The etiology of this disease remains incompletely understood with systemic associations and a complex pathogenesis that involves diffuse dysfunction of the RPE cells, the choroid, or both. Various treatment modalities have been used nowadays with varying success rates. These are selected according to the stage of the disease and diffusiveness and presence of CNV. Examples include acetazolamide, mineralocorticoid receptor antagonists, intravitreal anti-VEGF injections, photodynamic therapy (PDT), and subthreshold micropulse lasers (MPL). However, some of the CSCR cases are recalcitrant or unresponsive to currently available therapy modalities. The disease can be recurrent in 15-50% of cases or bilateral in approximately one-third of cases. Secondary CNV is an important vision-threatening complication of longstanding CSCR with an incidence ranging from 2% to 9%. Thus, new treatment options and approaches, addressing the complex nature of the etiopathogenesis are necessary in patients who would otherwise be disabled.

Platelets are anucleated cells containing many types of growth factors (GFs) such as epithelial growth factor (EGF), fibroblast growth factor (FGF), transforming growth factor (TGF), nerve growth factor (NGF), platelet-derived growth factor (PDGF), and insulin-like growth factor (IGF). These growth factors and their receptors are expressed in epithelial and endothelial cells and play a key role in tissue healing. EGF stimulates the proliferation and migration of epithelial cells. NGF is a neurotrophin that stimulates growth and survival of intraretinal glial cells, Müller's cells, and neurons; it can restore the function of injured neurons. NGF also plays a key role in the integrity and function of the both epithelial cells and nerve fibers. Autologous platelet-rich plasma (aPRP) that contains many GFs has been used to treat retinitis pigmentosa and deep retinal capillary ischemia with promising clinical functional and structural improvements.