Quantitative depth analysis of optic nerve head using stereo retinal fundus image pair.

Area of Science:

• Ophthalmology
• Medical Imaging
• Computational Vision

Background:

• Glaucoma diagnosis relies on early detection of optic nerve head (ONH) changes.
• Accurate quantitative depth measurement of the ONH is crucial for assessing glaucoma progression.
• Existing methods may require specialized equipment or complex procedures.

Purpose of the Study:

• To develop and validate an automatic method for quantitative depth measurement of the optic nerve head (ONH) using stereo retinal fundus images.
• To assess the feasibility of using stereo fundus imaging for routine glaucoma screening and diagnosis.
• To compare the accuracy of the proposed depth measurement technique against a gold-standard imaging modality.

Main Methods:

• A five-step automatic reconstruction method was developed, including ONH region cutout, stereo image registration, disparity measurement, noise reduction, and depth calculation.
• Stereo retinal fundus images were acquired from 12 normal eyes.
• Depth measurements were performed using the proposed stereo imaging method and compared with those obtained from a Heidelberg Retina Tomograph (HRT).

Main Results:

• The proposed automatic method successfully reconstructed quantitative depth values of the ONH from stereo retinal fundus images.
• Depth measurements from the stereo fundus image pair showed high accordance with HRT measurements (r=0.80+/-0.15).
• The method demonstrated good performance in depth assessment of the ONH cup.

Conclusions:

• The developed automatic reconstruction method provides a reliable and quantitative measure of ONH depth from stereo retinal fundus images.
• This technique shows potential as an easy-to-handle tool for routine ophthalmological diagnosis and glaucoma screening.
• Stereo fundus imaging offers a promising, accessible approach for assessing ONH morphology relevant to glaucoma.