Purpose: Are there any morphological parameters in pigment epithelial detachment (PED) in eyes with age-related macular degeneration (AMD), which could identify the development of tears (RIP) in the retinal pigment epithelium (RPE) before initiation of anti-vascular endothelial growth factor (VEGF) therapy?
Methods: Retrospectively, the spectral domain optical coherence tomography (SD-OCT), FLA and near infrared (NIR) images of 98 eyes with PED in exudative AMD before treatment (ranibizumab or bevacizumab) were analyzed. Eyes in which a tear in the RPE (RIP group) could be observed during treatment were compared to eyes without the development of RIP (PED group) in the following morphological parameters of PED: height, number of peaks, presence of hyporeflective fissures at the base of the PED, structure of the RPE, presence of floating structures in the PED with maximum hyperreflectivity, amount and localization of hyperreflectivity in the PED and hyperreflectivity in the NIR images.
Results: In the 80 eyes of the PED group the mean PED height was 373.7± 197 µm and in the 18 eyes of the RIP group the mean PED height was higher (694.2± 284.3 µm, p < 0.0001). A difference was also seen in the number of peaks per PED (PED group 43%, RIP group 72%, p = 0.039) and in the hyperreflectivity in NIR images (PED group 68%, RIP group 94%, p = 0.033). There were no significant differences in the other morphological parameters. A classification into four types of PED was found by the parameters height and number of peaks. The PED type with a height > 350 µm and one peak (RIP 43%) developed tears more often (p = 0.001) than the PED type < 350 µm with one peak (RIP 0%, p = 0.001). A trend in the visual acuity over 156 weeks was seen: in PED types with heights > 350 µm there was a lower increase in the visual acuity than in PED types < 350 µm (rm ANOVA p = 0.18; ɛ HH = 0.88). Furthermore, in PED types > 350 µm with multiple peaks the total number of injections necessary was higher than in the other PED types (p = 0.032).
Conclusion: Morphological parameters, such as PED height, number of peaks per PED in OCT images and hyperreflectivity in NIR images are prognostic factors for RPE tears in exudative AMD. The PED height and number of peaks per PED are useful for classification of PED in the daily routine.