Paton lines (PL) refer to the ophthalmoscopic finding of radiating lines around the optic disc. It includes a structural display of tensile, compressive, or shearing  stress that causes mechanical strain from pressure changes arising from pathological optic disc edema. The disc edema dislodges surrounding structures to cause bulging, which appears as lines or folds.
There is a multitude of causes for PL. The most prominent and clinically relevant is papilledema from intracranial hypertension but they may be seen in other causes of optic disc edema including non-arteritic anterior ischemic optic neuropathy ; some maculopathies; orbital and intraocular tumors; orbital, choroidal, or scleral infiltrative and inflammatory diseases; ocular hypotony; retinal detachment, scleral buckles, epiretinal membranes; and even microgravity space flight associated neuro-ocular syndrome. Optical coherence tomography (OCT) can identify and differentiate the various types of ophthalmoscopically visible lines in the fundus including peripapillary wrinkles (PPW), retinal folds (RF), choroidal folds (CF), and the various entities referred to in the pre-OCT era as PL. Clarifying the specific location of the folds can help determine the etiology of the pathological disc edema.
PL refers to several types of lines or folds in different locations. They may be found in the retina (i.e., RF), choroid (i.e., CF), or in the retina nerve fiber layer (RNFL). PL in the retina are either intraretinal or on the surface. Three distinct ophthalmoscopic patterns of PL in the retina have been described including concentric, spiral, or radial lines. RF, CF or PPW can be found exclusively or concurrently with each other. These patterns are associated with distinct forms of stress.
The concentric, spiral, and radial patterns of RF are located in or on the retina. The most specific pattern of RF due to papilledema is radial RF.
CF are undulations of the choroid, which in contrast to retinal folds, are located deeper and beneath the overlying retina. CF display clinically as alternating yellow and dark bands most commonly located near the posterior pole. CF can be found in papilledema but can also occur in the setting of an orbital mass or ocular hypotony. 
PPW are demonstrated on OCT as lines flowing up and down as “hair pins”.
Paton and Holmes first described PL in their 1911 paper on the pathophysiology of papilledema, arguing that papilledema was a consequence of intracranial hypertension rather than inflammation. The paper included observations of “greyish-white lines” in the fundus in the described papilledema. These retinal folds originally related to the displaced retina in a concentric pattern due to disc edema. The histopathological photographs show displaced peripapillary intra-retinal folds that did not include the retinal nerve fiber layer or the choroid.
PL are best imaged using OCT of the retina, specifically spectral domain (SD)-OCT, rather than fundus photographs alone due to higher sensitivity. SD-OCT can also demonstrate the cross-sectional images of the folds and thus can differentiate which layer (retinal nerve fiber layer, retina, or choroid) from which the ophthalmoscopic folds are originating.
Treatment of the underlying etiology of the folds (e.g., lowering intracranial pressure, surgical removal of tumor, etc.) is based on the underlying cause, because the lines themselves are not usually vision threatening. Improvement in PL has been demonstrated after treatment of IIH with acetazolamide.
- Lee AG. Paton's Lines. Neuro-Ophthalmology with Dr. Andrew Lee. https://www.youtube.com/watch?v=5Wj1cJCk8ck. Published April 8, 2020. Accessed June 1, 2020.
- Sibony PA, Kupersmith MJ, OCT Substudy Group of the NORDIC Idiopathic Intracranial Hypertension Treatment Trial. "Paton's Folds" Revisited: Peripapillary Wrinkles, Folds, and Creases in Papilledema. Ophthalmology. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4877233/. Published June 2016. Accessed June 2, 2020.
- Kupersmith M, Sibony P, Dave S. Nonarteritic Anterior Ischemic Optic Neuropathy Induced Retinal Folds and Deformations. Investigative Ophthalmology & Visual Science. 2017;58(10):4286. doi:10.1167/iovs.17-22140
- Sibony PA., Kupersmith MJ, Feldon S., Wang JK, Garvin M. The OCT Substudy Group for the NORDIC Idiopathic Intracranial Hypertension Treatment Trial. Retinal and choroidal folds in papilledema. Invest Ophthalmology Vis Sci. 2015; 56: 670-680.
- Choroidal folds. EyeRounds.org: Online Ophthalmic Atlas. https://webeye.ophth.uiowa.edu/eyeforum/atlas/pages/choroidal-folds.html. Published August 10, 2017. Accessed June 3, 2020.