2. CLASSIFICATION OF DIABETIC MACULAR
EDEMA USING COLORED FUNDUS IMAGE
PRESENTED BY:
MUHAMMAD ZUBAIR
SUPERVISED BY:
Dr. SHOAB AHMED KHAN
3. GUIDANCE AND EVALUATION COMMITTEE
GEC Members
Dr. Ubaid Ullah Yasin (Co-Supervisor)
(Asst. Prof. AFPGMI, Eye specialist AFIO)
Dr. Aasia Khanum
Dr. Ali Hassan
4. AGENDA
Motivation and problem statement
Introduction
Literature review
Proposed System
Evaluation and Results
Conclusion and Future work
References
7. MOTIVATION
Diabetes Mellitus is a fast growing global disease
In 2007 survey by International Diabetic Federation
(IDF) Pakistan was at 7th in top 10 countries having
diabetic population [1]
This number may rise from 6.9 million in 2007 to
11.5 million in 2025 by IDF [1], almost double
8. STATISTICAL CHART BY IDF
2007 2025
Country Persons
(millions)
Country Persons
(millions)
1 India 40.9 1 India 69.9
2 China 39.8 2 China 59.3
3 USA 19.2 3 USA 25.4
4 Russia 9.6 4 Brazil 17.6
5 Germany 7.4 5 Pakistan 11.5
6 Japan 7.0 6 Mexico 10.8
7 Pakistan 6.9 7 Russia 10.3
8 Brazil 6.9 8 Germany 8.1
9 Mexico 6.1 9 Egypt 7.6
10 Egypt 4.4 10 Bangladesh 7.4
9. MOTIVATION …
DME can lead to complete irreversible blindness
Early stage detection is rare
Doctor to patient ratio is very low in Pakistan
Screening is hectic in populated areas
Sparse resources in rural areas
10. PROBLEM STATEMENT
To develop an automated CAD system to help
ophthalmologists in mass screening by
Identification of abnormalities (exudates),
Finding out their exact location and area within
the macular region,
Stage classification of the disease
11. PUBLICATIONS
CONFERENCES
“Classification of Diabetic Macular Edema and Its Stages Using
Color Fundus Image” (Registered and to be presented in 2013 3rd
International conference on Signal, Image Processing and
Applications (ICSIA))
“Automated Detection of Optic Disc for the Analysis of Retina
Using Color Fundus Image” (Accepted in 2013 IEEE International
conference on Imaging Systems And Techniques (IST))
“Automated Segmentation of Exudates Using Dynamic
Thresholding in Retinal Photographs” (Accepted in 16th IEEE
International Multi Topic Conference (INMIC) 2013)
JOURNALS
“Automated Grading of Diabetic Macular Edema Using Colored
Fundus Photographs” (Submitted in Journal of Digital Imaging)
13. HUMAN EYE
Retinal layer of human eye comprises:
o Optic Disc (Head of optic nerve)
o Macula (Central portion of retina)
o Fovea (Center of macula)
o Network of Blood vessels
15. DIABETIC MACULAR EDEMA
DME is the swelling of the macula
Leaked fluid accumulates on the retina
Leakage within the macula causes swelling
16. SCREENING TESTS FOR DME
Fundus Fluorescein Angiography (FFA)
Retinal image acquisition process
2D colored and red free images
Optical Coherence Tomography (OCT)
3D high resolution image acquisition process
Provides a cross-sectional image
Used as optical biopsy by the ophthalmologists
22. Aquino et al.*
Detect OD using edge detection
Circular Hough transform
Feature extraction
Morphological operations
Accuracy achieved was 86%
A. Aquino, M. E. G. Arias and D. Marin, “Detecting the Optic Disc Boundary in Digital Fundus Images Using
Morphological, Edge Detection and Feature Extraction Techniques,” IEEE TRANSACTIONS ON MEDICAL IMAGING, Vol.
29, No. 11, pp.1860-1869, 2010
23. Siddalingaswamy et al.*
Exudates detection using clustering
Morphological techniques
Exudates location based severity level
Sensitivity achieved 95% and specificity 96%
No publically available database used
Use only 148 local fundus images
P.C. Siddaligaswamy, K. G. Prabhu, “Automatic Grading of Diabetic Maculopathy Severity Levels”, Proceedings of
2010 International Conference on Systems in Medicine and Biology, pp. 331-334, 2010
24. Lim et al.*
Segmentation of exudates using watershed transform
External and internal markers used
Classification done as normal, stage1 and stage2
Use only 88 images of MESSIDOR
Sensitivity and Specificity achieved 80.9%, 90.2%
respectively
Accuracy achieved was 85.2 percent
S.T. Lim, W.M.D.W. Zaki, A. Hussain, S.L. Lim, S. Kusalavan, “Automatic Classification of Diabetic Macular Edema in Digital Fundus
Images", 2011 IEEE Colloquium on Humanities, Science and Engineering (CHUSER), pp. 265-269, 2011.
25. Giancardo et al.*
Unsupervised technique for exudates segmentation
Background estimation used
Image normalization used
8 neighbor connectivity used
Used local database images
No Stage classification was done
L. Giancardo, F. Meriaudeau, T.P. Karnowski, K. W. Tobin Jr, E. Chaum, MD, “AUTOMATIC RETINA EXUDATES SEGMENTATION
WITHOUT A MANUALLY LABELLED TRAINING SET”, IEEE Transactions on Medical Imaging, Vol. 21, No. 5, pp. 1396-1400, 2011
27. PROPOSED SYSTEM
Preprocessing of image
Optic disc elimination
Dynamic Thresholding
All possible exudates detection
Classification of the stage
28. FLOW CHART OF PROPOSED TECHNIQUE
Input Colored Fundus Image
Resizing of Image
Green Component
Preprocessing
OD Removal
Fovea
localization
Grayscale
Classifier
29.
30. Input Colored Image
Green Channel of Image
Contrast Limited Adaptive Histogram Equalization
Contrast Stretching Transform
PREPROCESSING OF IMAGE
31. PREPROCESSING OF IMAGE
CLAHE
Contrast Limited Adaptive Histogram Equalization
(CLAHE)
To make the components visually distinct
Distinction of foreground objects from background
CLAHE used iteratively to get the desired result
33. PREPROCESSING OF IMAGE
CONTRAST STRETCHING TRANSFORM
Expands the range of intensity of the image
Range span is defined by the user
Improves the overall contrast of the image
Increases the contrast b/w dark and lights
Stretches the intensity domain histogram
36. OPTIC DISC (OD) ELIMINATION
OD becomes prominent after preprocessing
Detection on basis of highest intensity value pixels
Extended minima transform applied
Detect all candidate OD regions
Morphological operations to extract real OD
38. OPTIC DISC (OD) ELIMINATION
EXTENDED MINIMA TRANSFORM
Computes the regional minima
Regional minima are connected components of
pixels with constant intensity value
The external boundary pixels have high value
8-neighbor connectivity used
Selects all possible candidate regions for OD
41. MORPHOLOGICAL OPERATIONS
Morphological Erotion
To remove all non OD candidate regions
Structuring element (SE) having size less than OD size
SE chosen is of the size one fourth of the radius of OD
Erotion also shrinks the actual OD region
42. MORPHOLOGICAL OPERATIONS
Morphological Dilation
To get the actual size of OD after erotion
SE is of the size approx. equal to the radius of OD
Dilation restores the size and shape of actual OD
False OD are no more in the image
45. DYNAMIC THRESHOLDING
Fundus images are taken in different illumination
All images have different intensity levels
Intensity based parameters chosen for dynamic
thresholding
Mean and standard deviation of the image is used
Threshold value is set using these parameters
46. CALCULATION OF THRESHOLD VALUE
USING MEAN AND STANDARD DEVIATION
Mean Standard deviation Threshold value
30.05 33.35 2.8
31.25 34.6 2.8
31.25 35.4 2.8
31.9 35.7 2.9
32.45 36.2 2.9
32.55 35.92 3.0
32.84 35.96 3.0
35.08 38.6 3.2
35.09 40.2 3.3
35.49 39.38 3.3
35.85 39.40 3.3
35.95 39.46 3.3
37.15 41.87 3.4
37.35 41.56 3.4
38.57 42.27 3.4
41.00 46.65 3.6
41.22 47.1 3.65
41.53 47.06 3.65
43.10 48.48 3.7
43.07 48.05 3.75
43.27 47.71 3.75
44.58 49.58 3.9
45.56 51.30 3.95
48.20 53.50 4.3
49.4 54.51 4.4
48. DETECTION OF EXUDATES
Exudates are bright lesions
Bright yellowish spots in colored fundus image
OD free image is used for exudates detection
Segmentation is done for exudates detection
50. ETDRS STAGING CRITERIA
Early Treatment Diabetic Retinopathy Study
(ETDRS)
Classification of DME is based on the standard
criteria set by ETDRS
Severity level depends upon size and location of
abnormality
Reference point is the center of macula
53. CLASSIFICATION OF STAGES
Normal Condition
No abnormality is found
Less Significant Stage
Abnormality found outside the circular area of 1 Disc
Diameter 1DD radius but within 2DD from the fovea
Moderate Stage
Abnormality found beyond 1/3DD (radius) but within 1DD
of circle
Severe Stage
Abnormality found within 1/3DD circular area from the
center of fovea region
54. STAGE CLASSIFICATION TABLE
Stage Description
Normal No abnormality is found
Severe
Abnormality found within 1/3DD radius circular
area from the center of fovea region
Moderate
Abnormality found beyond 1/3DD radius but
within 1DD radius of circle
Less
significant
Abnormality found outside the circular area of
1DD radius but within 2DD radius from the
fovea region
1Disc Diameter (DD) = 1500µm (1.5mm)
57. RESULTANT MESSAGES DISPLAYED AFTER THE
CLASSIFICATION OF STAGES
If no exudates are found in the image or the abnormality is found outside the
2DD circle, it is declared as normal case. The message will be displayed “No
exudates found: Normal eye”.
If the exudates are found within the outermost 2DD circle the stage is called
insignificant. The message will be displayed “warning: exudates found within
the outermost circle, insignificant stage”.
If the exudates are found in both outermost 2DD and the middle circle 1DD
circle, it is declared as moderate stage. The message will be displayed
“warning: exudates found within the outermost circle and middle circle,
moderate stage”.
If the exudates are found in the middle circle only 1DD circular area it is known
as moderate stage. The message will be displayed “warning: exudates found
within the middle circle, moderate stage”.
If the abnormality (exudates) found within both the middle circle 1DD circular
area and the innermost 1/3DD circle the stage is known as severe stage. The
message will be displayed “warning: exudates found within the middle circle
and the innermost circle, severe stage”.
If the exudates are found within the innermost 1/3DD circle the stage is called
severe stage. The message displayed in this case “warning: exudates found in
the innermost circle, severe stage”.
66. CONCLUSION
Improved performance of the system in terms of
True localization of optic disc and its removal
Detection of exudates and determining their position
Classifying stage of the disease
The System provide accurate results using less but
effective features of the input image
Efficient system for identifying and classifying the DME
The system can be used practically in diagnostic
environment with a sound reliability
67. FUTURE WORK
Classification of DME using OCT (3D) images
Fusion of FFA and OCT results for easy and better
diagnosis
Detection of soft exudates/drusens in fundus
images
69. REFERENCES
[1] International Diabetic Federation Atlas. 2006 showing prevalence of diabetes in 2007
and future projection for 2025. Available from: http://www.idf.org/diabetesatlas. (Updated
in 2012)
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Fundus Images Using Morphological, Edge Detection and Feature Extraction
Techniques,” IEEE TRANSACTIONS ON MEDICAL IMAGING, Vol. 29, No. 11, pp.1860-
1869, 2010
[3] K. S. Deepak and J. Sivaswamy, “Automatic Assessment of Macular Edema From
Color Retinal Images", IEEE Transactions on Medical Imaging, Vol. 31, No. 3, pp. 766-
776, 2012
[4] P.C. Siddalingaswamy, K. G. Prabhu, “Automatic Grading of Diabetic Maculopathy
Severity Levels”, Proceedings of 2010 International Conference on Systems in Medicine
and Biology, pp. 331-334, 2010
[5] L. Giancardo, F. Meriaudeau, T.P. Karnowski, K. W. Tobin Jr, E.
Chaum, MD, “AUTOMATIC RETINA EXUDATES SEGMENTATION WITHOUT A
MANUALLY LABELLED TRAINING SET”, IEEE Transactions on Medical Imaging, Vol.
21, No. 5, pp. 1396-1400, 2011
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