Q&A: Elon van Dijk on central serous chorioretinopathy.

Photo of Elon van Dijk, MD, PhD, FEBOphth, at the 2025 EURETINA meeting

Elon van Dijk, MD, PhD, FEBOphth, an ophthalmologist from the Netherlands working at Leiden University Medical Center and Rotterdam Eye Hospital, delivered a comprehensive presentation on central serous chorioretinopathy (CSC). He discussed the evolving understanding of CSC's pathogenesis during the 2025 EURETINA meeting in Paris, France.

Note: The following conversation has been lightly edited for clarity.

Ophthalmology Times: You are presenting here at the 2025 EURETINA meeting. Can you share what you will be discussing?

Elon van Dijk, MD, PhD, FEBOphth: I'm indeed involved in the EBO AMD, CSC course. So within the EBO program, there are lots of courses during the day, and I'm the lucky one to be involved in the last part of the day. I will mainly talk about the paragenesis, the differential diagnosis, and the optimal treatment of CSC, central serous chorioretinopathy.

OT: What should attendees know about CSC?

van Dijk: So first of all, I think recent developments within the pathogenesis of CSC has been found. So it used to be the people used to think that it was only a choroidal disease. So based on choroidal abnormalities, damage to the retinal pigment epithelium occurs with the subsequent accumulation of subretinal fluid. However, recently, there were some other thoughts regarding its pathogenesis, mainly that there are, let's say, changes within that choroidal outflow. So there are changes in the venous outflow of the choroid, and that eventually leads to the disease. Moreover, there are also, let's say, scleral changes. Recently found out, so it seems to be important that some scleral outlet problem, which has its effect on the choroid, subsequently leading to the subretinal fluid accumulation.

I think that mind shift mainly occurs because the fact that the retinal imaging has improved. So because of the beautiful OCT scans, OCT-A scans, we can make we, yeah, we found out more about that, let's say magnificent choroid, or that strange choroid that has its role in CSC. But also imaging techniques have improved in order to find out more about the sclera. So I think it's mainly attributed to the fact that the imaging and modalities are improving over time. So I think also thinking about the differential diagnosis of CSC, it's an extremely broad differential diagnose of the serous subretinal fluid in the macula. That differential diagnosis is broadening every year, and I will try to, let's say, obtain or provide information to all the attendants in order to learn more about the differential diagnosis.

In recent years, several new diagnoses were established, and that's important to be aware of those diagnoses, because it has implications for the treatment and also the prognosis for your patient. Then I've also been involved in designing evidence based treatment guideline for CSC, in which we make a clear distinction between acute CSC and chronic CSC.

OT: What do those treatment guidelines include?

van Dijk: For both diseases, there are, let's say the most important treatment to be used is half-dose photodynamic therapy. Both in acute CSC and chronic CSC, the effect of that treatment is quite good, both on the short term and on the long term. I think in terms of, let's say the reimbursement of the photodynamic therapy, I would happily encourage everyone in order to speak to the government, to other, let's say, official organizations within their country, in order to try to make it happen that the fertporine that is needed for the photodynamic therapy will be reimbursed. When you compare that treatment, for example, to intravitreal anti-VEGF injections, the photodynamic therapy is relatively cheap. So it only cost a few 1000 euros, and then hopefully, the patient won't need any treatment in the future anymore, which is totally different compared to the anti-VEGF treatment, because patients would need them every 4 weeks, or 6 weeks, or 8 weeks.

So if needed, I'm happily to assist. I'm happy to assist people with their, let's say, problems or challenges, with several governments, because it can be a challenging process in order to get that reimbursement happening. So I would say in the first instance, you should really go to your local society to try to obtain as many information, as much information as possible. So that PDT really works in CSC the literature can be helpful in that, but also experiences from the ophthalmologists from several countries is really important. As your local society, you are way more powerful than an ophthalmologist on your own, and when you are together with your local society, I think you can really try to make it happen at the government, for example, in your country.