The Weiss ring, a major confounding factor for measurements of peripapillary retinal nerve fiber layer thickness

Author(s): Min-Woo Lee (1), Min-Su Kim (2), Hwa-Young Yu (1), Kee-Sup Park (1), Young-Hoon Lee (1), Jung-Yeul Kim (3)

1 Department of Ophthalmology, Konyang University College of Medicine, Daejeon, Republic of Korea.
2 Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Republic of Korea.
3 Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Republic of Korea. Electronic address: kimjy@cnu.ac.kr.

PURPOSE: To identify how the Weiss ring affects the measurement of mean and sectoral peripapillary retinal nerve fiber layer (pRNFL) thicknesses.

DESIGN: Retrospective cross-sectional study.

METHODS: Subjects were divided into two groups: controls (control group) and subjects in which a Weiss ring was visible on optical coherence tomography fundus images (WR group). Mean and sectoral pRNFL thicknesses were compared between the two groups.

RESULTS: A total of 205 eyes were enrolled: 131 eyes in the control group and 74 eyes in the WR group. The mean pRNFL thicknesses of the control group and WR group were 97.2 ± 6.7 and 94.6 ± 10.8 μm, respectively (P = 0.042). In sectoral thickness, the inferior sector of the WR group was 112.1 ± 23.2 μm, which was significantly thinner than that of the control group (125.5 ± 13.3 μm, P < 0.001). The Weiss ring was located in 10 eyes (13.5 %) in the superior sector, 7 eyes (9.5 %) in the temporal sector, 40 eyes (54.1 %) in the inferior sector, and 17 eyes (23.0 %) in the nasal sector. In analyses of reproducibility, the coefficient of variation and intraclass coefficient of the inferior sector measurement was 10.90 % and 0.409, respectively, indicating low reliability of the measurement.

CONCLUSIONS: Eyes with a Weiss ring showed thinner mean and inferior pRNFL thicknesses than normal controls, which would be a measurement error caused by the Weiss ring. This could be a major confounding factor for analyses of pRNFL changes, especially in glaucoma patients.

Copyright © 2022. Published by Elsevier Inc.

Am J Ophthalmol. 2022 Jan 13;S0002-9394(22)00003-4. doi: 10.1016/j.ajo.2022.01.001. Online ahead of print.

PMID: 35038416 DOI: 10.1016/j.ajo.2022.01.001

Keywords: Weiss ring; retinal nerve fiber layer; spectral domain optical coherence tomography

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