Optical coherence tomography characteristics and their relationship with vision prognosis in central serous chorioretinopathy patients with different symptom duration before and after photodynamic therapy

Abstract

Objective To observe the characteristics of optical coherence tomography (OCT) in central serous chorioretinopathy (CSC) patients with different symptom duration before and after photodynamic therapy (PDT), and investigate its relationship with vision prognosis. Methods 93 CSC patients (103 eyes) who had undergone the treatment of PDT were enrolled in this study. The eyes were divided into 3 groups according to symptom duration including group A ( 6 months, 33 eyes). The best corrected visual acuity (BCVA) and OCT were performed before and after treatment. Before the treatment, the percentage of patients with regular retinal pigment epithelium (RPE), irregular bump or detachment of RPE and disordered RPE were 63.0%, 37.0%, 0.0% in group A; 41.9%, 53.5%, 4.7% in group B and 24.2%, 57.6%, 18.2% in group C, respectively. The difference of percentage of RPE structure was no significance among the three groups (χ2=19.88, P=0.001). The outer nuclear layer (ONL) thickness was (220.42±49.88), (145.81±19.65), (98.15±33.02) μm in group A, B, C respectively, the difference between three groups was significant (P=0.000). The BCVA differences in different RPE structure and the relationship between ONL thickness and vision prognosis were recorded and analyzed. Results The difference of ONL thickness in eyes with regular RPE and irregular bump or detachment of RPE in group A, B and C were not significant (P=0.599, 0.151, 0.789). The ONL thickness in eyes with disordered RPE were decreased significantly compared to eyes with irregular bump or detachment of RPE in group B and C (P= 0.025, 0.036). The ONL thickness were (139.14±26.23), (119.14±21.09), (97.61±29.92) μm after PDT, respectively. Compared with ONL thickness before PDT, there was statistically significant decreasing after PDT in group A and B (P=0.000, 0.010), but there was no statistically significant difference after PDT in group C (P=0.192). After PDT, BCVA was negatively related to ONL thickness before PDT in group A (r=-0.684, P=0.000), and was positively related to ONL thickness after PDT in group C (r=0.413, P=0.017), but was neither related to ONL thickness before nor after PDT in group C (r=0.278, 0.117; P=0.074, 0.462). Conclusions With the duration of symptom being longer, the rate of irregular bump or detachment of RPE and disordered RPE are increased gradually, ONL thickness is getting thinner. After PDT, the ONL thickness became thinner in eyes with symptom duration less than 6 months and has no difference in eyes with symptom duration more than 6 months. The difference of BCVA in eyes with different RPE structure is significant. The vision prognosis of CSC with duration less than 4 months or more than 6 months are related to ONL thickness. Key words: Central serous chorioretinopathy/therapy; Tomography, optical coherence