2019/07/20 by Andrea Govetto, Jean-Pierre Hubschman, Jean‐Pierre Hubschman +19 · 19 citations
Medicine · Biochemistry, Genetics and Molecular Biology · #Retinal and Macular Surgery #Ocular Disorders and Treatments #Ophthalmology and Visual Impairment Studies
paper · pdf · doi:10.1136/bjophthalmol-2019-314245
BACKGROUND: 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. METHODS: 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). RESULTS: 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. CONCLUSION: 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.