Diabetic macular ischemia (DMI) is one of the manifestation of diabetic retinopathy (DR). It could be associated with diabetic macular edema (DME), which may affect the vision of DR patients. FFA is the gold standard for the diagnosis of DMI, but with the advent of OCT angiography, a more convenient and diversified method for the evaluation of DMI has been developed, which makes more and more researchers start to study DMI. Intravitreal injection of anti-VEGF has become the preferred treatment for DME. When treating with DME patients, ophthalmologists usually avoid DMI patients. But if intravitreal anti-VEGF should be the contradiction of DME is still unclear. To provide references to the research, this article summarized the risk factors, assessment methods and influence of DMI. This article also analyzed the existing studies, aiming to offer evidences to a more reasonable and effective treatment decision for DME individual.
ObjectiveTo observe the changes of macular structure and microvessels in eyes with diabetes macular ischemia (DMI). MethodsA retrospective case study. From January 2023 to July 2023, 23 patients of 31 eyes diagnosed with DMI at Tangshan Ophthalmological Hospital were included in this study. Among them, there were 14 males with 23 eyes; Female cases with 8 eyes. Age were (59.5±4.6) years old. According to the DMI grading standard formulated by the research group for early treatment of diabetes retinopathy, the patients were divided into mild DMI group, moderate DMI group, and severe DMI group, with 8, 12, and 11 eyes respectively. The blood flow density (VD), perfusion area (FA), small vessel VD (SVD), inner retinal capillary plexus VD, FA, and outer retinal, choroidal, and ganglion cell complex (GCC) thickness within 1 mm of the macular fovea in retinal superficial vascular plexus (SVP)were measured using a scanning frequency light source optical coherence tomography instrument. The changes in macular structure and microvasculature in the affected eyes of different degrees of DMI groups were compared and observed. Inter group comparisons were conducted using one-way ANOVA or Kruskal Wallis H-test. Spearman correlation analysis was used to analyze the correlation between DMI severity and GCC, outer retina, choroid thickness, VD, FA and SVP VD, SVD and FA in inner retina. ResultsThe GCC (F=70.670), outer retinal thickness (H=12.393), VD (F=105.506), SVD (H=25.300), FA (F=107.655), and VD (H=24.098) and FA (H=25.300) of the retinal SVP in the mild, moderate, and severe DMI groups were compared, and the differences were statistically significant (P＜0.05). There was no statistically significant difference in choroidal thickness (H=2.441, P＞0.05). Pairwise comparison between groups: VD, SVD, FA of GCC thickness and SVP, and VD of inner retina were statistically significant between severe DMI group and moderate DMI group, and between moderate DMI group and mild DMI group (P＜0.05). The thickness of outer retina was statistically significant between severe DMI group and moderate DMI group (P＜0.05). Inner retinal FA: there were statistically significant differences between severe DMI group, moderate DMI group and mild DMI group (P＜0.05). The correlation analysis results showed that GCC (rs=－0.918), outer retinal thickness (rs=－0.448), and inner retinal VD (rs=－0.894) and FA (rs=－0.918), as well as VD (rs=－0.919), SVD (rs=－0.924), and FA (rs=－0.939) of retinal SVP, were all negatively correlated with the degree of DMI (P＜0.05). There was no correlation between choroidal thickness and degree of DMI (rs=－0.081, P＞0.05). ConclusionThe thickness of GCC, outer retina and choroid, the VD, SVD, and FA of the retinal SVP, the VD and FA of inner retina are all reduced in eyes with different degrees of DMI, while all of them are negatively correlated with the degree of DMI, except for choroid thickness.