Purpose:
Tears of the retinal pigment epithelium (RPE) may cause severe visual loss and occur either spontaneously or during anti-VEGF therapy of neovascular age-related macular degeneration (AMD). We determined morphological alterations at various layers with high-resolution imaging and assessed fundus autofluorescence (FAF) abnormalities in the border zone.
Methods:
Serial examinations in patients with RPE tears were performed using simultaneous confocal scanning laser ophthalmoscopy (cSLO) and spectral-domain optical coherence tomography (SD-OCT). Retinal thickness was quantified by two independent readers over the area of ripped RPE using image processing methods. Qualitative evaluations included corresponding subneuroretinal alterations in volume scans covering the entire affected area. Abnormalities in the border zone on FAF images (exc. 488nm, em. >500nm) were compared to previously described patterns of abnormal FAF in eyes with RPE loss due to geographic atrophy associated with AMD.
Results:
A total of 14 eyes of 14 patients (mean age 76,75±4,97 years) with longitudinal recordings ranging from 1 to 48 months (mean 13 months) were retrospectively analysed. The mean maximal extrafoveal thickness of the neuroretina over the area of torn RPE was 239±51µm (range 178 to 333 µm). In the area of denuded Bruch’s membrane development of diffuse, continuous hyperreflective structures of variable vertical extensions was observed in 10 eyes (71 %), while 2 eyes additionally had focal accumulations of reflective material in the subretinal space. These phenomenons were associated with integrity of corresponding neuroretinal layers in 8 out of 10 eyes. On FAF imaging the lesion boundaries were identified when complicating haemorrhages were absent. The junctional zone showed either no increased FAF signal or single or multifocal signal increments.
Conclusions:
The results indicate a remodelling process in the area of denuded Bruch’s membrane following the acute occurence of an RPE tear secondary to AMD. Given the corresponding preserved retinal microarchitecture in some of these eyes, the findings may support previous assumptions of proliferations of cells with RPE-like functions able to maintain survival of outer retinal layers. Abnormalities on FAF imaging of the junctional zone overall differed from previously described patterns associated with primary geographic atrophy indicating a different cellular and molecular response to lacking neighbouring RPE cells.
Keywords: age-related macular degeneration • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • regeneration