title: Decision support system for age-related macular degeneration using discrete wavelet transform.
abstract: Age-related macular degeneration (AMD) affects the central vision and subsequently may lead to visual loss in people over 60 years of age. There is no permanent cure for AMD, but early detection and successive treatment may improve the visual acuity. AMD is mainly classified into dry and wet type; however, dry AMD is more common in aging population. AMD is characterized by drusen, yellow pigmentation, and neovascularization. These lesions are examined through visual inspection of retinal fundus images by ophthalmologists. It is laborious, time-consuming, and resource-intensive. Hence, in this study, we have proposed an automated AMD detection system using discrete wavelet transform (DWT) and feature ranking strategies. The first four-order statistical moments (mean, variance, skewness, and kurtosis), energy, entropy, and Gini index-based features are extracted from DWT coefficients. We have used five (t test, Kullback-Lieber Divergence (KLD), Chernoff Bound and Bhattacharyya Distance, receiver operating characteristics curve-based, and Wilcoxon) feature ranking strategies to identify optimal feature set. A set of supervised classifiers namely support vector machine (SVM), decision tree, [Formula: see text]-nearest neighbor ([Formula: see text]-NN), Naive Bayes, and probabilistic neural network were used to evaluate the highest performance measure using minimum number of features in classifying normal and dry AMD classes. The proposed framework obtained an average accuracy of 93.70%, sensitivity of 91.11%, and specificity of 96.30% using KLD ranking and SVM classifier. We have also formulated an AMD Risk Index using selected features to classify the normal and dry AMD classes using one number. The proposed system can be used to assist the clinicians and also for mass AMD screening programs.
authors.affiliation: Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Clementi, 599489, Singapore, mkm2@np.edu.sg.
authors.forename: Muthu Rama Krishnan
authors.initials: MR
authors.lastname: Mookiah
authors.forename: U Rajendra
authors.initials: UR
authors.lastname: Acharya
authors.forename: Joel E W
authors.initials: JE
authors.lastname: Koh
authors.forename: Chua Kuang
authors.initials: CK
authors.lastname: Chua
authors.forename: Jen Hong
authors.initials: JH
authors.lastname: Tan
authors.forename: Vinod
authors.initials: V
authors.lastname: Chandran
authors.forename: Choo Min
authors.initials: CM
authors.lastname: Lim
authors.forename: Kevin
authors.initials: K
authors.lastname: Noronha
authors.forename: Augustinus
authors.initials: A
authors.lastname: Laude
authors.forename: Louis
authors.initials: L
authors.lastname: Tong
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001499:Bayes Theorem; D005103:Expert Systems / Q000295:instrumentation*; D005654:Fundus Oculi; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008268:Macular Degeneration / Q000175:diagnosis*; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012984:Software; D060388:Support Vector Machine; D058067:Wavelet Analysis
references.citation: Invest Ophthalmol Vis Sci. 2012 Dec 17;53(13):8310-8
references.pmid: 23150624
references.citation: Invest Ophthalmol Vis Sci. 2011 Jul 29;52(8):5862-71
references.pmid: 21666234
references.citation: Med Biol Eng Comput. 2002 Jan;40(1):2-13
references.pmid: 11954703
references.citation: N Engl J Med. 2006 Oct 5;355(14):1474-85
references.pmid: 17021323
references.citation: IEEE Trans Med Imaging. 2001 Dec;20(12):1321-33
references.pmid: 11811832
references.citation: Med Biol Eng Comput. 2005 Nov;43(6):756-63
references.pmid: 16594303
references.citation: J Med Syst. 2010 Feb;34(1):1-13
references.pmid: 20192050
references.citation: Med Biol Eng Comput. 1997 Nov;35(6):626-32
references.pmid: 9538538
references.citation: Comput Biol Med. 2008 May;38(5):611-9
references.pmid: 18402931
references.citation: BMJ. 2003 Mar 1;326(7387):485-8
references.pmid: 12609947
references.citation: Prog Retin Eye Res. 2001 Mar;20(2):227-53
references.pmid: 11173253
references.citation: Med Image Anal. 2003 Mar;7(1):95-108
references.pmid: 12467724
references.citation: Annu Int Conf IEEE Eng Med Biol Soc. 2010;2010:4100-3
references.pmid: 21096627
references.citation: Med Biol Eng Comput. 2004 Jul;42(4):516-23
references.pmid: 15320461
references.citation: Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:6236-41
references.pmid: 22255764
references.citation: IEEE Trans Inf Technol Biomed. 2012 Jan;16(1):80-7
references.pmid: 22113813
references.citation: Comput Biol Med. 2013 Dec;43(12):2136-55
references.pmid: 24290931
references.citation: J Digit Imaging. 1998 Nov;11(4):193-200
references.pmid: 9848052