Leukemia is a disease caused by the abnormal and uncontrolled proliferation of hematopoietic stem cells due to rare mutations during hematopoiesis [1]. Previous studies reported that 9% to 90% of patients with leukemia had ophthalmic lesions, including leukemic retinopathy and leukemic optic neuropathy, and these ophthalmic lesions are more frequently seen in acute leukemia (AL) [2]. To date, the pathogenesis of ocular lesions in AL is not clearly understood but is hypothesized to be related to ischemia and hypoxia caused by focal retinal capillary rupture with central platelet or leukemic cell plugs [3], [4], [5], which may lead to macular and peripapillary microvascular changes in the early stage of AL.

Optical coherence tomography angiography (OCTA), a modern noninvasive imaging system, can reconstruct the retinal capillary network by detecting changes in blood flow signals [6], and it has previously been used to describe the retinal vasculature in various ocular and systematic diseases, such as glaucoma, diabetic retinopathy, retinal vein occlusion, AMD, TAO and leukemia retinopathy [7], [8], [9], [10], [11]. Recent research [7] on OCTA showed that patients with AL had reduced vessel density (VD) in the macular area. However, VD changes in the peripapillary region were not detected in their study. This result may not be consistent with our previous assumption. Because leukemic retinopathy and optic neuropathy are the common ocular manifestations in AL [12], [13], [14], there is a rational reason to speculate that VD in the peripapillary region may undergo subtle changes at the early stage. To investigate this, we recruited AL patients and normal subjects to undergo OCTA to evaluate the peripapillary capillaries and analyze the correlation between the changes and the blood laboratory parameters.