Researchers have discovered large microvascular abnormalities in patients with diabetic macular edema, thanks to indocyanine green angiography (ICGA). The abnormalities in question, what the researchers involved in the study call “telangiectatic capillaries (TelCaps),” are either isolated globular capillary ecstasies or a cluster of ill-defined capillary abnormalities. 

The study included 35 eyes from 25 consecutive patients with diabetic macular edema. ICGA showed microvascular abnormalities in 63% of DME eyes, and all eyes with circinate hard exudates had spots of late ICGA staining, or TelCaps. The characteristics of these capillary changes include a location that is a median distance of 2,708µm from the fovea with a range between 1,064µm and 4,583µm. Their diameter ranged from 153µm to 307µm. Using ICGA, the researchers discovered 91% of the TelCaps increased their contrast and apparent size in late frames, whereas 79% of microaneurysms showed reduced contrast on late frames. 

The researchers said previous research suggests that targeted photocoagulation of large microvascular abnormalities may be beneficial, but their detection is not routine. 

Farías D, Serrano R, Gancharov J, et al. Indocyanine green angiography for identifying telangiectatic capillaries in diabetic macular oedema. Br J Ophthalmol. July 29, 2019. [Epub ahead of print].