A Novel Method for the Objective Identification of Hyperautofluorescent Ring in Retinitis Pigmentosa Using
Yohei Hashimoto1, Tatsuya Inoue1, Takashi Ono1
1Department of Ophthalmology, University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
Translational Vision Science & Technology
|February 19, 2019
Summary
A new binarization algorithm precisely identifies the autofluorescent ring in retinitis pigmentosa (RP). This objective method offers superior precision and accuracy compared to subjective visual inspection for assessing retinal function.
Area of Science:
- Ophthalmology
- Medical Imaging
- Computational Biology
Background:
- Retinitis pigmentosa (RP) is a group of inherited disorders that affect photoreceptor cells.
- The hyperautofluorescent ring (AF ring) is a key indicator of retinal function in RP.
- Accurate identification of the AF ring is crucial for disease monitoring and management.
Purpose of the Study:
- To evaluate the precision and accuracy of a novel objective algorithm for AF ring identification in RP.
- To compare the performance of this algorithm against subjective visual inspection.
Main Methods:
- Ultra-widefield fundus autofluorescence (AF) images from 23 RP eyes were analyzed.
- A semiautomatic binarization algorithm in Fiji software was used to define AF ring borders.
- Precision was assessed using Jaccard indices (JIs) for intra- and interrater agreement.
- Classification performance was compared with subjective freehand methods using percent agreement and weighted kappa statistics.
Main Results:
- The binarization algorithm demonstrated significantly higher interrater (0.94-0.95 vs. 0.73-0.78) and intrarater (0.95 vs. 0.68-0.71) JIs compared to the freehand method (P < 0.005).
- Classification agreement between methods was high (percent agreement = 0.94, weighted kappa = 0.94, P < 0.001).
- Retinal sensitivity decreased significantly with increasing distance from the AF ring.
Conclusions:
- The binarization algorithm provides a highly precise and accurate method for defining the AF ring in RP.
- This objective approach offers advantages over subjective visual inspection.
- The method facilitates quantitative analysis of the AF ring, aiding in the assessment of retinal function in RP.
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