Investigation of alterations in multifractality in optical coherence tomographic images of in vivo human retina.
Optical coherence tomography (OCT) enables us to monitor alterations in the thickness of the retinal layer as disease progresses in the human retina. However, subtle morphological changes in the retinal layers due to early disease progression often may not lead to detectable alterations in the thickness. OCT images encode depth-dependent backscattered intensity distribution arising due to the depth distributions of the refractive index from tissue microstructures. Here, such depth-resolved refractive index variations of different retinal layers were analyzed using multifractal detrended fluctuation analysis, a special class of multiresolution analysis tools. The analysis extracted and quantified microstructural multifractal information encoded in normal as well as diseased human retinal OCT images acquired <italic<in vivo</italic<. Interestingly, different layers of the retina exhibited different degrees of multifractality in a particular retina, and the individual layers displayed consistent multifractal trends in healthy retinas of different human subjects. In the retinal layers of diabetic macular edema (DME) subjects, the change in multifractality manifested prominently near the boundary of the DME as compared to the normal retinal layers. The demonstrated ability to quantify depth-resolved information on multifractality encoded in OCT images appears promising for the early diagnosis of diseases of the human eye, which may also prove useful for detecting other types of tissue abnormalities from OCT images.
Indian Institute of Science Education and Research Kolkata, Mohanpur 741 246, India.
Nandan Kumar
NK
Das
Indian Institute of Science Education and Research Kolkata, Mohanpur 741 246, IndiabNanoscope Technologies Pvt. Ltd., New Town Rajarhat 700156, India.
Sabyasachi
S
Mukhopadhyay
Indian Institute of Science Education and Research Kolkata, Mohanpur 741 246, India.
Nirmalya
N
Ghosh
L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, Banjara Hills, Hyderabad 500 034, India.
Jay
J
Chhablani
L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, Banjara Hills, Hyderabad 500 034, India.
Ashutosh
A
Richhariya
Bhabha Atomic Research Centre Facility, Photonics and Nanotechnology Section, Autonagar, Visakhapatnam 530012, India.
Kompalli
K
Divakar Rao
Bhabha Atomic Research Centre, Atomic and Molecular Physics Division, Trombay, Mumbai 400085, India.
Naba Kishore
NK
Sahoo
D003930:Diabetic Retinopathy / Q000000981:diagnostic imaging; D017709:Fractals; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008269:Macular Edema / Q000000981:diagnostic imaging; D012160:Retina / Q000000981:diagnostic imaging*; D012815:Signal Processing, Computer-Assisted; D041623:Tomography, Optical Coherence / Q000379:methods*