Mechanical impact of epiretinal membranes on the retina utilizing finite element analysis

• Published in: Computer methods and programs in biomedicine 2024-03, Vol.245, p.108020-108020, Article 108020
• Main Authors: Naftali, Sara, Della Rocca, Keren, Gershoni, Assaf, Ehrlich, Rita, Ratnovsky, Anat
• Format: Article
• Language: English
• Subjects: 3D numerical simulation; Epiretinal membrane; Finite element method; Fovea metamorphopsia; Mechanical stresses; Optical coherence tomography; Vitrectomy surgery
• ISSN: 0169-2607; 1872-7565
• DOI: 10.1016/j.cmpb.2024.108020

•Epiretinal membranes (ERMs) cause traction forces on the retinal surface that produce mechanical excitation that led to fovea thickening.•Treatment options include watchful monitoring or vitrectomy surgery without any certain criteria for the need of early surgery.•The developed three-dimensional geometrical model of ERM on a retina shows that the increase in ERM contractility level increase the developed stress at the fovea, which spread and advance towards its base.•Asymmetric stretching produced non-uniform deformations distribution that distort the fovea structure.•High and asymmetric ERM contractility is a risk for ERM worsening and should be consider as a factor for early vitrectomy surgery to avoid irreversible visual loss. Epiretinal membrane (ERM) is a transparent membrane that forms on the surface of the neurosensory retina, causing tangential traction on the retinal surface, which may contribute to cell proliferation and contraction. Epiretinal membranes (ERMs) may be asymptomatic in some patients, while in others the membranes can progress, resulting in macular thickening and macular traction, thus distorting and inducing loss of central visual function and metamorphopsia. Currently, treatment options include follow-up or pars plana vitrectomy with an ERM peel, aiming to relieve the macular traction and improve vision and metamorphopsia. No specific criteria exist for predicting which patients might progress and need early surgery to improve and maintain good vision. The decision for surgery is based on the individual's symptoms and the physician's judgment. This study aimed to evaluate the mechanical impact in terms of stress and deformations of the ERM and to qualitatively compare them with the clinical progression of fovea thickening observed through optical coherence tomography (OCT) images. Numerical simulation on a three-dimensional geometrical retina and ERM model was applied to isolate factors that can be used to predict its progression and prognosis. OCT images of 14 patients with ERM were used to derive the fovea thickness progression before and after vitrectomy surgery with ERM peeling. The results clearly show that the increase in ERM contractility level increases the developed stress at the fovea, which spreads and advances toward its base. The highest stress level (2.1 kPa) was developed at the highest and asymmetric contractility, producing non-uniform distributed deformations that distort the fovea structure. These findings imp