Subfoveal choroidal thickness as a potential predictor of treatment response after intravitreal ranibizumab injections for polypoidal choroidal vasculopathy.

OBJECTIVE

To evaluate the impact of subfoveal choroidal thickness (SFCT) and other clinical biomarkers in intravitreal anti-vascular endothelial growth factor response in treatment-naive Caucasian patients diagnosed with polypoidal choroidal vasculopathy (PCV/AT1).

DESIGN

Cross-sectional study.

PARTICIPANTS

Treatment-naive patients diagnosed with PCV/AT1 recruited in a single centre from January 2013 to December 2020.

METHODS

Eligibility was determined in treatment-naive PCV patients who received a loading dose of 3 injections of 0.5 mg ranibizumab. A diagnosis of PCV/AT1 was made based on the diagnostic criteria in the efficacy and safety of verteporfin photodynamic therapy in combination with ranibizumab or alone versus ranibizumab monotherapy in patients with sumptomatic macular polypoidal choroidal vasculopathy study. Choroidal thickness was manually measured by enhanced depth imaging technology in Spectralis spectral domain optical coherence tomography.

RESULTS

Eighty-three eyes of 83 patients were included in this study, 47 patients diagnosed with PCV/AT1 with a good response to 3 intravitreal injections of ranibizumab and 36 with a poor response. The receiver operating characteristic curve of treatment effect against the SFCT revealed that the area under the curve was 0.85 (range, 0.74-0.96). Based on the Youden index, the optimal SFCT cut-off point for predicting a poor response to anti-vascular endothelial growth factor is 257 µm. In the multivariate analysis, the SFCT remained statistically significant (odds ratio 1.02 [range, 1.01-1.04]; P = 0.008). The combined effect of treatment effect against clinical biomarkers produced an area under the curve of 0.90 (range, 0.82-0.98).

CONCLUSION

SFCT is a risk factor for a poor response to the 3 loading injections of ranibizumab in treatment-naive PCV/AT1 Caucasian patients. A cut-off point of 257 µm could be a valuable parameter for defining the population at risk for an inadequate response to ranibizumab.