|
|
|
| Effect of Different Scanning Signal Strength of Optical Coherence
Tomography on the Analysis of Optic Disc RNFL Thickness |
| Ziyang Li, Sha Li, Xiaoyong Huang |
| Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical
University), Chongqing 400038, China |
|
|
|
| Guide |
|
|
Abstract Objective: To collect optic disc retinal nerve fiber layer (RNFL) thickness by optical coherence
tomography (OCT) in different signal strength (SS), and compare the differences between them, discuss the
influence of SS on it, and provide basis for accurate analysis of optic disc RNFL. Methods: This case series
stude included 90 patients with RNFL analysis in 90 eyes who had undergone OCT optic disc scanning in
Department of Ophthalmology, South west Hospital, from December 2018 to August 2019 were selected,including 30 eyes in the RNFL normal group, 30 eyes in the RNFL thinning group, and 30 eyes in the
RNFL thickening group. Age (41.8±18.0) years old. All patients have clear refractive media. Scan images
of different SS have been acquired during the collection process, Signal strength 0-3 is regarded as low SS,
signal strength 4-6 is medium SS, signal strength 7-10 is high SS. The average value of 3.46 mm diameter
RNFL and the number of abnormal quadrants of RNFL abnormal group under low SS and high SS were
counted. The average age between groups was compared by single-factor ANOVA, the gender differences
between different groups were compared by Chi square test, to compare the difference between the mean
RNFL between different signal groups, the results were single-factor repeated measures ANOVA and those
that did not conform to the normal distribution were tested by Friedman rank-sum test, and the abnormal
RNFL distribution between the low signal group and the high signal group was analyzed by the kappa
consistency test, and the kappa
0.75 indicated that the consistency was good, and the kappa
0.4. indicated
the consistency difference. Results: The difference in the average thickness of RNFL under different signal
strength is statistically significant, in the normal RNFL group (F=137.78, P<0.001), in the thinning RNFL
group (F=66.91, P<0.001), in the RNFL thickening group (χ
2=60.00, P<0.001). In the analysis of RNFL
thinning group, the distribution of abnormal quadrants under low signal strength and high signal strength
was highly consistent (kappa=0.88, P<0.001). In the analysis of RNFL thickening group, the distribution
of abnormal quadrants under low signal strength and high signal strength was not significantly consistent
(kappa=0.20, P=0.009). Conclusion: The average RNFL value of the optic disc OCT scan is correlated
with the SS. The higher the SS, the higher the reliability of the result. At low SS, the quadrant distribution
of thinned RNFL can be determined, but the distribution of thickened RNFL cannot be determined
accurately.
|
|
Received: 24 November 2021
|
|
|
| Fund: |
|
Corresponding Authors:
Xiaoyong Huang, Department of Ophthalmdogy, Southwest Hospital, Army
Medical University (Third Military Medical University), Chongqing 400038, China (Email: huangxy_yk@
hotmail.com)
|
|
|
|
|
|
|
