Abstract
Purpose:
There is not any experimental model for ARMD yet. Chronic retinal phototoxicity as risc factor of ARMD had been emphasized in the epidemiological studies. It has been well known the importance of RPE, Bruch’s membrane, and choriocapillaris layers in the histopathology of ARMD. We aimed to clarify phototoxic effects of light on the rabbits RPE, Bruch’s membrane and choriocapillaris endothelium ultra structurally if there was any contribution in explaining ARMD etiology.
Methods:
We conducted 2 studies with 3 groups. After one hour application of blue(488 nm), green (532 nm) and red light (640 nm) exposure via a slit lamp to a single eye of each of four grey chinchilla rabbits eyes were enucleated in the first group after 48 hours in the second group after 72 hours. Following enucleations ultrastructural changes were evaluated with light microscopy and transmission electron microscopy.
Results:
Following blue light and red light exposure, we have seen important deteriorations of RPE basal invaginations, breaks of Bruch’s membrane, and new collagen synthesis areas and deposits were observed in the area of Bruch’s membrane. We have seen same changes in human eye. In red light group we have also seen eosinophyl degranulation and trombocytes aggregation collagen synthesis areas in adjacent to new collagen synthesis areas very similar to ARMD.
Conclusions:
The blue and the red light induced changes in rabbit eyes and white light induced changes in human eye of Bruch’s membrane and RPE were very similar ultra structurally those changes had been seen in eyes with ARMD. These findings support that this ARMD model may play an important role in understanding the etiology and pathogenesis of ARMD. Additional red light changes with phototoxicity deserves further investigation about the links between phototoxicity and intravascular immunity and thrombosis like eosinophyl degranulations and trombocyte aggregation and also new collagen synthesis areas deserves new long term studies to enlighten the drusen formation and neovascularization process of ARMD.
Keywords: 412 age-related macular degeneration