ObjectiveTo observe and analyze the clinical and imaging features of eyes with cystoid macular degeneration (CMD) secondary to chronic central serous chorioretinopathy (cCSC). MethodsA retrospective clinical study. From February 2018 to June 2023, 9 patients of 15 eyes with cCSC secondary CMD diagnosed by ophthalmology examination in Yunnan University Affiliated Hospital were included in the study. All patients were male. The age was (53.67±3.83) years. The cases of binocular and monocular were 6 and 3 respectively. The visual acuity of the affected eye ranges from 0.02 to 0.1, which cannot be corrected. Visual acuity decreased and the duration of shadow occlusion was ＞1 year. Half dose photodynamic therapy (PDT) was performed on 8 eyes. All the patients underwent the best corrected visual acuity, posterior mydriatic fundus color photography, infrared fundus photography (IR), fundus autofluorescence (AF), fluorescein fundus angiography (FFA), optical coherence tomography (OCT), and multi-wavelength dazzling imaging (MC). The patients who received half dose PDT were followed up until 3 months after treatment. Patients who did not receive treatment were followed up to 2 years after the first diagnosis. ResultsThe light reflection in macular area decreased or disappeared in all eyes, and abnormal macular pigmentation was observed in 12 eyes. IR examination showed diffuse patchy weak fluorescence in the macular area in all affected eyes, and dotted strong fluorescence in the periphery. Fundus AF examination showed disc-like weak AF in the macular area, and scattered small amounts of strong AF in the middle and margins, among which the retinal pigment epithelium (RPE) atrophy trace in the macular area was observed in 7 eyes. By MC examination, the green signal in the macular area of the posterior pole of all affected eyes was uneven and mottled. FFA examination showed that no abnormal fluorescein leakage was observed in 15 eyes and 8 eyes showed strong fluorescence caused by diffuse permeation fluorescence. A small amount of active fluorescein was found in 7 eyes. OCT examination showed that there were several cystic cavities of different sizes in all the affected eyes, RPE atrophied to different degrees, and RPE cell compensatory ridges and tubular structures in the outer retina were seen in 6 eyes; 7 eyes with CMD and active leakage showed signs of subcortical fluid accumulation. Choroidal hypertrophy was seen in all affected eyes, with significant expansion of the great vascular layer and compression of the middle vascular layer and capillary layer. In 8 eyes treated with half-dose PDT, 6 eyes were ineffective at 3 months after treatment. The treatment was effective in 2 eyes. In 7 eyes that did not receive half-dose PDT, CMD structure did not improve significantly after 2 years of follow-up. The visual acuity decreased with the prolongation of the disease. ConclusionsCMD is more common in cCSC with a long course of disease, which has significant effects on vision and poor prognosis. Fundus color photography shows that the reflection in the macular area of the pole is weakened or disappeared, which may be combined with macular abnormal pigmentation. IR and AF examination show uneven fluorescence in macular area. The green signal in macular area is not uniform according to MC inspection. FFA shows strong fluorescence caused by diffuse permeable fluorescence and fluorescein leakage in active lesions. OCT examination shows that multiple small sacs or connections between sacs were broken and fused, and RPE atrophied to varying degrees.