Eliminate blood vessels from retinal image

I am trying to eliminate the blood vessels from a retinal image and remain the exudates using edge detection technique 'Kirsch's Templates' but still some parts of the unwanted blood vessels and optic disc 'the circular shape' on the left side of the image remain. I wonder if there is a better solution to perfectly eliminate these or adding some other techniques?

Main :

clc;
clear all;
close all;

%Read Input Retina Image
inImg = imread('image013b.png');
dim = ndims(inImg);
if(dim == 3)
    %Input is a color image
    inImg = rgb2gray(inImg);
end

%Extract Blood Vessels
Threshold = 6;
bloodVessels = VesselExtract(inImg, Threshold);

%Output Blood Vessels image

figure;
subplot(121);imshow(inImg);title('Input Image');
subplot(122);imshow(bloodVessels);title('Extracted Blood Vessels');

VesselExtract.m:

function bloodVessels = VesselExtract(inImg, threshold)

%Kirsch's Templates
h1=[5 -3 -3;
    5  0 -3;
    5 -3 -3]/15;
h2=[-3 -3 5;
    -3  0 5;
    -3 -3 5]/15;
h3=[-3 -3 -3;
     5  0 -3;
     5  5 -3]/15;
h4=[-3  5  5;
    -3  0  5;
    -3 -3 -3]/15;
h5=[-3 -3 -3;
    -3  0 -3;
     5  5  5]/15;
h6=[ 5  5  5;
    -3  0 -3;
    -3 -3 -3]/15;
h7=[-3 -3 -3;
    -3  0  5;
    -3  5  5]/15;
h8=[ 5  5 -3;
     5  0 -3;
    -3 -3 -3]/15;

%Spatial Filtering by Kirsch's Templates
t1=filter2(h1,inImg);
t2=filter2(h2,inImg);
t3=filter2(h3,inImg);
t4=filter2(h4,inImg);
t5=filter2(h5,inImg);
t6=filter2(h6,inImg);
t7=filter2(h7,inImg);
t8=filter2(h8,inImg);

s=size(inImg);
bloodVessels=zeros(s(1),s(2));
temp=zeros(1,8);

%

for i=1:s(1)
    for j=1:s(2)
        temp(1)=t1(i,j);temp(2)=t2(i,j);temp(3)=t3(i,j);temp(4)=t4(i,j);
        temp(5)=t5(i,j);temp(6)=t6(i,j);temp(7)=t7(i,j);temp(8)=t8(i,j);
        if(max(temp)>threshold)
            bloodVessels(i,j)=max(temp);
        end
    end
end