When interpreting RNFL OCT scans, attention should be paid to the presence of peripapillary retinoschisis

Peripapillary retinoschisis (PPRS) occurs significantly more frequently in glaucoma patients (1%-6%) compared to healthy subjects (0.5%) (1). The B-scan of the OCT shows splitting of the RNFL with strut-like structures remaining in the schisis area. A reliable assessment of the RNFL thickness is not possible in such areas. The finding can persist for months to years but eventually resolves spontaneously (2). In RNFL analysis, the onset of PPRS is characterized as a sudden, localized increase in RNFL thickness that may mask a pre-existing localized thinning of the RNFL. Conversely, as a PPRS resolves, there is a sudden decrease in RNFL, which can be misinterpreted as rapid progression of glaucoma (2, 3).

Irrespectively, there is evidence that PPRS per se can be a sign of progression (1, 4). However, the exact relationship remains yet to be clarified. When interpreting an OCT RNFL scan, attention should be paid to the presence of a PPRS, and RNFL findings at respective areas should be interpreted cautiously over time.

Contributor: Cornelia Hirn, FEBO, FEBOS Glaucoma, Hanusch Hospital, Vienna, Austria

References:
1) Lee EJ, Kee HJ, Han JC, Kee C. The Progression of Peripapillary Retinoschisis May Indicate the Progression of Glaucoma. Invest Ophthalmol Vis Sci. 2021 Feb 1;62(2):16.
2) Hwang YH, Kim YY, Kim HK, Sohn YH. Effect of peripapillary retinoschisis on retinal nerve fibre layer thickness measurement in glaucomatous eyes. Br J Ophthalmol. 2014 May;98(5):669-74.
3) Dhingra N, Manoharan R, Gill S, Nagar M. Peripapillary schisis in open-angle glaucoma. Eye (Lond). 2017 Mar;31(3):499-502.
4) Fortune B, Ma KN, Gardiner SK, Demirel S, Mansberger SL. Peripapillary Retinoschisis in Glaucoma: Association With Progression and OCT Signs of Müller Cell Involvement. Invest Ophthalmol Vis Sci. 2018 Jun 1;59(7):2818-2827.

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