Abstract
Purpose: :
To determine if a single or combination of clinical signs allow accurate differentiation of polypoidal choroidal vasculopathy (PCV) from age-related macular degeneration (AMD) without the need for indocyanine green angiography (ICGA)
Methods: :
Fundus photographs of patients with exudative maculopathy who were suspected to have either AMD or PCV were graded in a masked fashion for clinical signs according to a standardized protocol modified from the Wisconsin AMD Grading scale. These include the presence or absence of drusen (type and area), atrophic disciform scar, pigment epithelial detachment, hard exudates, subretinal fibrosis, hemorrhage (area and level), retinal pigment epithelium changes (hypopigmentation or hyperpigmentation and area involved). ICGA was performed in all cases and graded for PCV by two retinal specialists separately, based on the Japanese Study Group guidelines. Pairwise test was performed to compare the prevalence of each sign between AMD and PCV group, and classification and regression tree analysis (CART) models were built to determine if combination of signs may accurately differentiate PCV from AMD. Area under curve (AUC) was calculated to assess the efficiency of our model.
Results: :
A total of 55 eyes (n=27 for PCV and n=28 for AMD) were analysed. Comparison of single signs showed that only large hemorrhage area differentiated PCV from AMD (p=0.006). In CART model, a combination of three signs: total hemmorhage area (≥5.544 disc area), presence of subretinal fibrosis and RPE hyperpigmentation resulted in a model with AUC of 0.693 (95%CI: 0.571 - 0.814, P value=0.002), sensitivity of 0.778 (95%CI: 0.577 - 0.914) and specificity of 0.607 (95%CI: 0.406 - 0.785) for PCV.
Conclusions: :
In Asian eyes with exudative maculopathy, a combination of total hemmorhage area, subretinal fibrosis and RPE hyperpigmentation differentiated PCV from AMD with 69% accuracy. These data may be useful to guide clinical diagnosis and possible treatment options for exudative maculopathy (e.g., anti-VEGF versus photodynamic therapy), particularly if ICGA is not available.
Keywords: age-related macular degeneration • imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)