Posters

Radiation effect on the optic nerve observed in eyes enucleated after failed choroidal melanoma Iodine 125 brachytherapy

Poster Details

First Author: S.Aghabaklou IRAN

Co Author(s):    A. Mohammadzadeh                    

Abstract Details

Purpose:

In this study, we evaluated radiation effect on the optic nerve observed in eyes enucleated after failed choroidal melanoma Iodine 125 brachytherapy.

Setting:

retrospective study

Methods:

In the study, the incidence of optic neuropathy and visual acuity after failed choroidal melanoma Iodine 125 Brachytherapy was studied. Twenty-one enucleated eyes were fixed in buffered formalin and embedded in paraffin. They were sectioned at 6 mm in the sagittal plane through the optic nerve. Sections were then immunohistochemically stained using the Neurofilament [figure1]. The areas of decreased immunoreactivity to NF protein considered the areas of axonal loss and degeneration.

Results:

Percentage of positive neurofilament immunostaining to the total optic nerve surface area is 60.1 in the control group and 63.7 % in the non-irradiated melanoma group in compared to 37.8% in the irradiated group [figure2].Myelination of the nerve fibers increased susceptibility to the radiation. The critical distance of plaque to the optic nerve head that may associate with less optic nerve damage is 2mm.

Conclusions:

Plaque radiation to the juxta-papillary melanomas is more likely to cause irreversible vision loss secondary to the optic atrophy; however, the amount of visual loss is not correlated with the percentage of optic atrophy.

Financial Disclosure:

None