Ophthalmic Research – Tiara IAO

IAO Wai U Tiara



  • Msc, The Chinese University of Hong Kong
  • BMed, Nanjing Medical University

Research Areas:

  1. Optical coherence tomography imaging in thyroid associated orbitopathy
  2. Electrophysiological studies in thyroid associated orbitopathy



Research Highlights:

(1) Identifying dysthyroid optic neuropathy with spectral domain OCT

The most severe complication of thyroid associated orbitopathy (TAO) is dysthyroid optic neuropathy (DON). Similar to other types of optic neuropathy, DON presents with nerve fibre layer thinning and visual field loss. Besides clinical diagnosis, the use of investigational devices serves as a role in detecting DON. We are studying the potential use of optical coherence tomography (OCT) to identify specific features of RNFL loss in DON.

Figure 1. Cirrus OCT Optic Disc Cube 200×200 scans – The RNFL Thickness Map and RNFL Deviation Map showing the location of RNFL thinning in an eye with DON.


(2) Electrophysiological studies in assessing thyroid associated optic nerve dysfunction

Proposed mechanisms of DON include optic nerve compression by enlarged extraocular muscles at the orbital apex and mechanical stretch of optic nerve due to proptosis, leading to structural change as well as functional change of the eye. Apart from visual field test, electrophysiological studies are alternative methods to evaluate DON. Visual evoked potential (VEP) is one of the electrophysiological studies which directly assess optic nerve function. We are investigating the use of VEP to detect change in visual function throughout the course of DON.

Figure 2. Multifocal VEP test – A 60 sectors map showing interocular comparison of optic nerve function in DON eye.