A 48-year-old male patient presented to our clinic with complaints of decreased vision in both eyes since 2022. Although visual symptoms were bilateral, the patient reported more pronounced visual impairment in the left eye over the past three years, for which he had previously received intravitreal injections. He was subsequently referred to our center for further evaluation.
The patient had no history of systemic disease and was not using any regular medications. On ophthalmological examination, best-corrected visual acuity was 0.7 in the right eye and 0.5 in the left eye. Intraocular pressure was within normal limits in both eyes, and anterior segment examination was unremarkable. Fundus examination revealed a round, well-delineated, shallow serous neurosensory detachment at the macula, characteristically surrounded by a subtle halo-like light reflex.
Color fundus photography demonstrates a round or oval, well-circumscribed, shallow serous neurosensory detachment involving the macula and retinal pigment epithelial alterations and pigmentary changes.
Fundus autofluorescence typically reveals a heterogeneous, mottled pattern characterized by alternating areas of hyper- and hypoautofluorescence. Hyperautofluorescent regions reflect ongoing retinal pigment epithelium stress, whereas hypoautofluorescent areas indicate focal RPE atrophy and irreversible photoreceptor damage. These abnormalities usually correspond to the sites of previous or persistent serous neurosensory detachment.
Spectral-domain optical coherence tomography demonstrated a serous neurosensory retinal detachment involving the foveal region and and accompanying retinal pigment epithelial detachment (PED). The outer retinal layers showed mild irregularity, consistent with chronic photoreceptor stress.
Enhanced depth imaging revealed a markedly thickened choroid, measuring approximately 490 µm at the subfoveal region. The choroid exhibited prominent dilated outer choroidal vessels (pachyvessels), particularly within the Haller’s layer, with associated attenuation of the overlying choriocapillaris and Sattler’s layers. These findings are characteristic of pachychoroid spectrum disease and support the diagnosis of chronic central serous retinopathy.
The combination of persistent neurosensory detachment, choroidal thickening, and pachyvessel prominence suggests long-standing choroidal congestion and retinal pigment epithelium dysfunction, as described in previous OCT-based studies of chronic central serous chorioretinopathy (CSC).
The patient underwent half-fluence photodynamic therapy (PDT) as part of the treatment strategy. Following treatment, best-corrected visual acuity improved to 1.0, indicating complete visual recovery. On follow-up fundus examination, the previously observed serous macular detachment had completely resolved, with no residual subretinal fluid detected.
Post-treatment optical coherence tomography demonstrated complete resolution of the serous neurosensory detachment and also PED. Notably, follow-up enhanced depth imaging OCT revealed significant remodeling of the choroidal architecture. Although overall subfoveal choroidal thickness may remain increased or show variable reduction, there was a marked decrease in the caliber and prominence of pachyvessels, indicating structural vascular remodeling rather than simple thickness normalization.
This pachyvessel remodeling reflects the therapeutic effect of photodynamic therapy on choroidal hyperpermeability and venous congestion, which are considered key pathogenic mechanisms in chronic central serous retinopathy. PDT induces selective choroidal vascular hypoperfusion and vascular remodeling, leading to reduced leakage, restoration of choriocapillaris balance, and subsequent retinal pigment epithelium recovery.
Importantly, these findings highlight that the efficacy of PDT in chronic CSC is not solely dependent on choroidal thinning, but rather on qualitative changes in choroidal vascular structure, supporting the concept that PDT acts as a disease-modifying treatment within the pachychoroid spectrum.
Importance of Photodynamic Therapy in the Treatment of Central Serous Retinopathy
Photodynamic therapy has emerged as one of the most effective treatment options for chronic central serous retinopathy, particularly in cases associated with pachychoroid features. Unlike therapies that primarily target subretinal fluid, PDT directly modulates the underlying choroidal pathology by reducing choroidal vascular hyperpermeability and venous congestion.
Accumulating evidence from optical coherence tomography–based studies demonstrates that PDT induces both functional and structural changes within the choroid. These include progressive thinning of the choroid and remodeling of dilated outer choroidal vessels (pachyvessels), which are considered central to the pathogenesis of chronic CSC. Importantly, these qualitative vascular changes may occur even when immediate choroidal thickness reduction is modest, highlighting that PDT acts through vascular normalization rather than simple tissue contraction.
Clinically, these choroidal modifications translate into durable anatomical outcomes, with high rates of sustained subretinal fluid resolution and significant visual improvement. Consequently, PDT is increasingly regarded not merely as a fluid-resolving intervention but as a disease-modifying therapy that targets the core mechanisms of chronic CSC within the pachychoroid spectrum.
Credit: M. Giray Ersoz, MD, FEBO
Memorial Hospital, Department of Ophthalmology, Istanbul, Turkey
Arel University School of Medicine, Department of Ophthalmology, Istanbul, Turkey
Instagram accounts: @retina.review and @retina.dr.girayersoz
and Sepideh Lotfi, MD
Biruni University School of Medicine, Department of Ophthalmology, Istanbul, Turkey
Instagram accounts: @sepidls
