Background: A pigment epithelial detachment (PED) is an exudative manifestation of late age-related macular degeneration (AMD). Its long-term unfavourable prognosis is influenced by the association of a neovascular membrane. Seemingly identical PEDs in ophthalmoscopy can be further differentiated by fluorescein and indocyanine green angiography. The purpose of this prospective follow-up study was to determine the most reliable angiographic classification to distinguish PEDs in AMD and to evaluate their outcome.
Material and methods: 73 eyes of 68 patients with a PED in AMD were examined with simultaneous angiography with fluorescein and indocyanine green. 34 eyes were additionally scanned by retinatomography. Fluorescein angiographic classification comprises 4 types: 1. early hyperfluorescent type, 2. late hyperfluorescent type, 3. drusen type, 4. irregular fluorescent type. Indocyanine green angiographic classification consists of the following three groups: 1. angiographically no vascularisation, 2. associated choroidal neovascularisation, 3. associated polypoidal choroidal vasculopathy.
Results: Both classifications show statistically significant correlation with visual acuity (fluorescein classification: P = 0.0112, ICG-classification: P = 0.0004) and area of the PEDs (fluorescein classification: P = 0.0002, ICG-classification: P < 0.0001). ICG-classification additionally is significantly associated with the volume (P = 0.0008). Both classifications correlate (P = 0.0001). Factors influencing visual acuity are: age (P = 0.0044), associated neovascular membrane (P = 0.0004), area (P < 0.0001), volume (P = 0.0077) and height (P < 0.0001).
Conclusions: PEDs in AMD can best be classified by indocyanine green angiography on the basis of an associated prognostically important neovascular membrane, which can only be further distinguished into choroidal neovascularisation or polypoidal choroidal vasculopathy by indocyanine green angiography. Statistical analysis shows qualitatively and quantitatively more significant results for the indocyanine green angiographic classification.