Tuesday, March 26, 2024

PERIPAPILLARY RETINOSCHISIS IN GLAUCOMA


 

Peripapillary changes on OCT scans are being increasingly reported in glaucoma patients. This could be due to better awareness of these changes or improvement in the instrumentation.

Peripapillary retinoschisis (PPRS) is more than 10 times commoner in glaucoma patients, compared to healthy controls.

This condition is defined as the visible splitting of the inner or outer neurosensory retinal layers.




The condition is often seen along an existing RNFL bundle defect.




In a study by Sung et. al, the schisis appeared on OCT cross-sections as splitting of the superficial prelaminar tissue. It is usually accompanied with floating retinal vessels which are cleaved from the underlying prelaminar structures.




PPRS is attributed to differential shear forces exerted by lateral tension, causing deformation and remodeling of the load-bearing tissues in the ONH. It also impacts distant tissues through the retinal vessels, internal limiting membrane (ILM) and macroglia (Muller cells).




Lowry found PPRS was commoner in eyes with thinner minimum rim width and a deeper cup.

This condition is regarded as a possible risk factor for further glaucomatous damage.

PPRS can cause artifacts in OCT image segmentation and diagnostic metrics, leading to overestimation of the rim tissue thickness and underestimation of the cup depth.

REFERENCES:

Lowry EA, Mansberger SL, Gardiner SK, Yang H, Sanchez F, Reynaud J, Demirel S, Burgoyne CF, Fortune B. Association of Optic Nerve Head Prelaminar Schisis With Glaucoma. Am J Ophthalmol. 2021 Mar;223:246-258. doi: 10.1016/j.ajo.2020.10.021. Epub 2020 Nov 6. PMID: 33166501; PMCID: PMC7979447.

Fortune B. Pulling and Tugging on the Retina: Mechanical Impact of Glaucoma Beyond the Optic Nerve Head. Invest Ophthalmol Vis Sci. 2019 Jan 2;60(1):26-35. doi: 10.1167/iovs.18-25837. PMID: 30601928.

Sung:  https://www.ajo.com/article/S0002-9394(21)00329-9/abstract

Steven L. Mansberger: https://ark.meetingfiles.com/my-ark/view-session/?sid=5ae8ad13-a6c4-4c45-9865-547a51e0c811



PERIPAPILLARY RETINOSCHISIS IN GLAUCOMA

  Peripapillary changes on OCT scans are being increasingly reported in glaucoma patients. This could be due to better awareness of these ch...