Abstract
Purpose :
The examination of the histological differences and characteristics of drusen of the retinal pigment epithelium (RPE) in the macula and RPE drusen in the parapapillary alpha zone.
Methods :
With light microscopy human eyes, enucleated due to uveal melanoma or secundary angle-closure glauocma, were examined and drusen (periodic-acid-schiff positive material) of the retinal pigment epithelium (RPE) located between the basal membrane of the RPE and the inner collagenous layer of Bruchs membrane were histomorphometrically analysed.
Results :
106 human eyes were included (age:62.6±15.2 years) with RPE drusen in the parapapillary region (n=29) and in the macula region (n=7). 70 eyes had no drusen in the sections available. All of the drusen had periodic-acid-schiff (PAS) positive material located between Bruch's membrane and the RPE. Macula drusen compared to parapaillary drusen were lower in height (15.2±10.1µm versus 34.3±19.8µm;P=0.003). There was no significant difference in width between the two groups with drusen (74.0±36.3µm versus 108.7±101.0µm;P=0.95). Comparing eyes with macular drusen and eyes without drusen there was no difference in Bruch's membrane (BM) thickness (2.74±0.44 µm versus 2.55±0.88µm;P=0.57) and RPE cell density (35.4±10.4 cells/480µm versus 32.8±7.5 cells/480µm;P=0.53). But the same parameter were elevated in eyes with parapapillary drusen (RPE cell density: 56.9±26.8 cells/480µm;P=0.005; BM thickness: 4.60±1.490µm;P<0.001). Between all three groups there was no significant difference in choriocapillary thickness (P>0.1) and density (P>0.3).
Conclusions :
RPE drusen of the macula and the parapapillary region shared similar characteristics of the PAS positive material and did not significantly differ in morphology of the choriocapillaris. The density of RPE cellsand BM thickness were significantly higher in eyes with parapapillary drusen.
Future studies may elucidate the pathogenesis and possible differences of the drusen.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.