%0 Journal Article
%T The role of Müller cells in tractional macular disorders: an optical coherence tomography study and physical model of mechanical force transmission.
%A Govetto A
%A Hubschman JP
%A Sarraf D
%A Figueroa MS
%A Bottoni F
%A dell'Omo R
%A Curcio CA
%A Seidenari P
%A Delledonne G
%A Gunzenhauser R
%A Ferrara M
%A Au A
%A Virgili G
%A Scialdone A
%A Repetto R
%A Romano MR
%J Br J Ophthalmol
%V 104
%N 4
%D 04 2020
%M 31326893
%F 5.908
%R 10.1136/bjophthalmol-2019-314245
%X To 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.<BR>In 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).<BR>In tractional lamellar macular holes, there was a significant reduction of the angle θ towards the foveal centre (p<0.001). By contrast, there were no significant differences in θ in myopic foveoschisis (p=0.570). R2 segments were more vertical in myopic foveoschisis. There was a significant association between lower θ angles at 200 µm temporal and nasal to the fovea and lower BCVA (p<0.001 and p=0.005, respectively). The stiffness of parafoveal Müller cells was predicted to be function of the angle θ , and it grew very rapidly as the θ decreased.<BR>Parafoveal 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.