Page 203 - Computational Retinal Image Analysis

CHAPTER

Structure-preserving

guided retinal image 11

filtering for optic disc

analysis

a
a
b
d
c
Jun Cheng , Zhengguo Li , Zaiwang Gu , Huazhu Fu , Damon Wing Kee Wong ,
a
Jiang Liu
a Chinese Academy of Sciences, Cixi Institute of Biomedical Engineering,
Ningbo, Zhejiang, China
b Agency for Science, Technology and Research, Institute for Infocomm Research, Singapore
c Inception Institute of Artificial Intelligence, Abu Dhabi, United Arab Emirates
d Nanyang Technological University, Singapore
1 Introduction

Glaucoma is a chronic eye disease where the optic nerve is progressively damaged.
It is the second-leading cause of blindness predicted to affect around 80 million
people by 2020 [1]. It leads to loss of vision, which often occurs gradually over
a long period of time. As the symptoms of the disease only occur when it is quite
advanced, glaucoma is called the silent thief of sight. Glaucoma cannot be cured, but
its progression can be slowed down by treatment. Therefore, detecting glaucoma in
time is critical. However, more than 50–90% of people are unaware of the disease
until it has reached an advanced stage [2, 3]. Since glaucoma progresses silently,
screening of people at high risk for the disease is vital. Three types of methods
to detect glaucoma exist and are based on the following: (1) raised intraocular
pressure (IOP), (2) abnormal visual field, and (3) damaged optic nerve head. Since
glaucoma can be present with or without increased IOP, the IOP measurement is
not accurate enough to be an effective screening tool. A functional test for vision
loss requires special equipments only present in territory hospitals and therefore
unsuitable for screening. Assessment of the damaged optic nerve head is superior to
IOP measurement or visual field testing for glaucoma screening. Optic nerve head
assessment can be done by a trained professional. However, manual assessment is
subjective, time consuming, and expensive. Therefore, automatic optic nerve head
assessment would be very beneficial.
The optic nerve head or the optic disc (in short, disc) is the location where ganglion
cell axons exit the eye to form the optic nerve, through which visual information of
the photo-receptors is transmitted to the brain. In 2D images, the disc can be divided

Computational Retinal Image Analysis. https://doi.org/10.1016/B978-0-08-102816-2.00011-3 199
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