The role of Müller cells in tractional macular disorders: an optical coherence tomography study and physical model of mechanical force transmission

BackgroundTo explore the role of foveal and parafoveal Müller cells in the morphology and pathophysiology of tractional macular disorders with a mathematical model of mechanical force transmission.MethodsIn this retrospective observational study, spectral-domain optical coherence tomography images of tractional lamellar macular holes and patients with myopic foveoschisis were reviewed and analysed with a mathematical model of force transmission. Parafoveal z-shaped Müller cells were modelled as a structure composed of three rigid rods, named R1, R2 and R3. The angle formed between the rods was referred to as θ . R1, R2 and R3 lengths as well as the variation of the angle θ were measured and correlated with best corrected visual acuity (BCVA).ResultsIn tractional lamellar macular holes, there was a significant reduction of the angle θ towards the foveal centre (pConclusionParafoveal Müller cells in the Henle fibre layer may guarantee structural stability of the parafovea by increasing retinal compliance and resistance to mechanical stress. Small values of the angle θ were related to worse BCVA possibly due to damage to Müller cell processes and photoreceptor’s axons.