Central serous chorioretinopathy (CSC) is a common macular disease in which a serous detachment of the neuroretina occurs, often in the macula, with subsequent vision loss [
1]. The disease usually presents with visual symptoms including decreased visual acuity, diminished contrast vision and/or metamorphopsia. Middle-aged men are most often affected, while the use of corticosteroids has been described to be the most important exogenous risk factor for the development of CSC [
2]. Although the exact aetiology of CSC is unknown, the choroid is presumed to be primarily affected. Choroidal congestion and hyperpermeability have been found to induce damage to the retinal pigment epithelium (RPE) which may lead to atrophic RPE abnormalities (pachychoroid pigment epitheliopathy). In typical CSC, accumulation of subretinal fluid (SRF) occurs when fluid leaks through a defect in the outer blood-retinal barrier of the RPE [
3]. Multimodal imaging consisting of optical coherence tomography (OCT), fluorescein angiography (FA), indocyanine green angiography (ICGA), are pivotal for diagnosing CSC and OCT angiography can aid in detecting subretinal neovascularisation in cases of CSC or diseases mimicking CSC. While OCT is important to detect SRF, FA is of additional value since it provides information on leakage sites and the extent of atrophic RPE alterations. Using ICGA, the extent of underlying choroidal abnormalities can be assessed. Based on the findings on multimodal imaging and the duration of symptoms, CSC is often categorized into acute CSC and chronic CSC (cCSC), although the classification is subject of debate [
4]. While acute CSC usually resolves spontaneously within 4 months after the start of symptoms, cCSC can lead to irreversible visual impairment and a decreased quality of life [
5,
6]. For cCSC, several subtypes have been described including for example cCSC with focal or diffuse leakage on FA, severe cCSC cases with diffuse atrophic RPE alterations and/or cCSC with posterior cystoid retinal degeneration (PCRD) [
7‐
10]. Treatment in cCSC patients is recommended in order to reduce the duration of the serous detachment, to improve vision and to reduce the recurrence rate [
5,
11,
12]. The first large randomized controlled trial in cCSC, the PLACE trial, reported superiority of half-dose PDT over treatment with high-density subthreshold micropulse laser [
13]. Currently, most evidence on efficacy is available for half-dose (or half-fluence) photodynamic therapy, which is therefore considered to be the treatment of choice for cCSC [
11].
Retrospective data suggest that PDT may be the best option also in severe cases of cCSC, with multifocal leakage points, more extensive RPE atrophy and/or PCRD, but robust data on the outcome of treatment in this severe end of the disease spectrum are scarce [
9,
10]. The presence of (foveal) RPE atrophy in cCSC may be suggestive of a prolonged serous detachment and/or RPE and choroidal dysfunction and is associated with a worse visual outcome [
5,
14,
15]. However, no clear definition exists and no data on treatment outcome are available in this specific subgroup of cCSC patients. While half-dose and half-fluence PDT in uncomplicated cCSC are highly effective and safe, it is unknown if the presence of fovea-involving atrophy may influence the efficacy and visual outcome of PDT in cCSC, which may in turn have important clinical implications with regard to counselling. The aim of this study is to report the outcome of PDT in cCSC patients with pre-existent fovea-involving RPE atrophy.