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. 2018 Feb;32(1):38-44.
doi: 10.3341/kjo.2017.0031. Epub 2018 Jan 25.

Factors Affecting ISNT Rule Satisfaction in Normal and Glaucomatous Eyes

Jayoon Moon  1   2 , Ki Ho Park  1   2 , Dong Myung Kim  1   2 , Seok Hwan Kim  1   3
Affiliations

Factors Affecting ISNT Rule Satisfaction in Normal and Glaucomatous Eyes

Jayoon Moon et al. Korean J Ophthalmol. 2018 Feb.

Abstract

Purpose: To determine the factors that influence the satisfaction of the 'ISNT rule' (neural rim width: inferior ≥ superior ≥ nasal ≥ temporal) in normal and glaucomatous eyes.

Methods: The medical records of patients that visited Boramae Medical Center, Seoul, Korea, were reviewed. Each group of normal and glaucomatous eyes was divided into subgroups based on whether or not they satisfied the ISNT rule. ISNT rule assessment was performed by measuring the rim width with stereoscopic optic disc photographs using ImageJ software. Logistic regression analysis was performed to determine the factors that affect ISNT rule satisfaction.

Results: Seventy-seven normal eyes and 97 glaucomatous eyes were included in the study. The ISNT rule was intact in 59 (76.6%) of the normal eyes and was violated in 71 (73.2%) of the glaucomatous eyes. Logistic regression analysis revealed a significant influence of axial length in violation of the ISNT rule in the normal eye group, while the mean deviation value was a significant factor for violation of the ISNT rule in the glaucomatous eye group.

Conclusions: The ISNT rule should be cautiously applied when evaluating normal eyes with long axial lengths. In addition, the ISNT rule might not be as effective for detecting early glaucoma.

Keywords: Axial length; Glaucoma; Nerve fibers; Optic disk; Optic nerve diseases.

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Conflict of interest statement

No potential conflict of interest relevant to this article was reported.

Figures

Fig. 1
Fig. 1. Clinical assessment of the normal optic disc. Optic disc center was defined as the intersection of the longest diameter (LD) and shortest diameter (SD) of the optic disc. Superior (S) and inferior (I) rims were defined as the vertical line that passes through the optic disc center. Nasal (N) and temporal (T) rims were defined as the horizontal line that passes through the optic disc center.
See this image and copyright information in PMC

References

    1. Quigley HA, Katz J, Derick RJ, et al. An evaluation of optic disc and nerve fiber layer examinations in monitoring progression of early glaucoma damage. Ophthalmology. 1992;99:19–28. - PubMed
    1. Sommer A, Quigley HA, Robin AL, et al. Evaluation of nerve f iber layer assessment. Arch Ophthalmol. 1984;102:1766–1771. - PubMed
    1. Jonas JB, Fernandez MC, Sturmer J. Pattern of glaucomatous neuroretinal rim loss. Ophthalmology. 1993;100:63–68. - PubMed
    1. Tuulonen A, Airaksinen PJ. Initial glaucomatous optic disk and retinal nerve fiber layer abnormalities and their progression. Am J Ophthalmol. 1991;111:485–490. - PubMed
    1. Chan EW, Liao J, Wong R, et al. Diagnostic performance of the ISNT rule for glaucoma based on the Heidelberg Retinal Tomograph. Transl Vis Sci Technol. 2013;2:2. - PMC - PubMed

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