Background <p>Diabetic oculomotor neuropathy (DON) is a microcirculatory ischaemic disease. At present, the ratio of albumin to fibrinogen (AFR) is considered as an indicator of microcirculation. Previous studies have reported that low serum albumin and high fibrinogen levels are related to diabetic peripheral neuropathy. There is no research on the relationship between AFR and DON.</p> Objective <p>The study aimed to investigate the association of AFR with DON.</p> Methods <p>In our research, 173 T2D patients with DON from 2011 to 2022 were included, as were 167 randomly chosen patients with T2D (controls) without DON in the same period. We constructed three models to analyze the relationship between AFR and DON through binary logistic regression analysis. After excluding other related risk factors, it is found that AFR is the protective factor of DON, and the lower AFR value is related to the increased risk of DON. When distinguishing between DON patients with DSPN and those without DSPN, receiver operating characteristic (ROC) curve analysis revealed a meaningful area under the curve (AUC).</p> Results <p>In our research, a low AFR was more related to DON. When the AFR is &lt; 10.96, DSPN is more likely to occur.</p> Conclusion <p>Therefore, AFR may be a potential biomarker of DON, at least in T2D patients.</p>