Patients with acute leukemia may exhibit a decrease in vessel density seen on OCT-A.
Patients with acute leukemia may exhibit a decrease in vessel density seen on OCT-A. Photo: Julie Rodman, OD. Click image to enlarge.

A recent longitudinal study examined retinal circulation among patients with active acute leukemia to better understand the retinal microvasculature of this cohort. The analysis included 22 eyes from 12 acute leukemia patients and healthy eyes as controls.

Optical coherence tomography angiography (OCT-A) was conducted at baseline and repeated in case of morphological leukemia remission. Participant ages ranged from 37 to 74, and all patients had 20/20 vision. Seven eyes (32%) of five patients had clinically visible leukemic retinopathy, the study authors reported.

Vascular alterations in the macula and the peripapillary region were detected by OCT-A in all acute leukemia patients, according to the investigators. The data also showed that, regardless of the presence of leukemic retinopathy, leukemia patients had lower vessel density in the superficial capillary plexus compared with their healthy counterparts.

The researchers observed that lower vessel density was correlated with lower white blood cell and platelet counts. Additionally, disease remission was associated with the reappearance of small capillaries and a reduction in vessel diameter as well as an increase in both vessel density and fractal dimension.

“A significant subclinical reduction in blood vessel density along with vasodilation and loss in branching complexity seems to occur in patients with active acute leukemia,” the study authors stated. “These changes partially revert with regression of the disease; we hypothesize a reduction of blood velocity as a cause of OCT-A perfusion metric alterations, more evident in the superficial retinal vessels.”

“The decrease in vessel density was associated with lower white blood cells and platelets, in the context of bone marrow function failure,” they concluded. They noted that further research is required to shed light on the functional implications, systemic associations and prognostic significance of these findings.

Cicinelli MV, Mastaglio S, Menean M, et al. Retinal microvascular changes in patients with acute leukemia. Retina. April 18, 2022. [Epub ahead of print].