β thalassemia is a hereditary hemolytic disease caused by the defect of β globin gene. Transfusion-dependent β thalassemia patients need long-term blood transfusion to survive, and a series of systemic and ocular complications will occur in the disease itself and long-term blood transfusion. Retinal blood vessel density decreases, retinal thickness thinned and elastic pseudoxanthoxanoma syndrome are found in fundus due to long-term anemia and side effects of iron chelating agent. At present, there are few reports about eye changes in thalassemia patients, and the cognition is relatively scarce. Therefore, it is necessary to be vigilant for physicians, deeply explore the cause and symptomatic treatment, combined with individual disease characteristics, to provide a more scientific and accurate plan for clinical treatment.
Objective To observe macular vascular density and structural characteristics in children with transfusion-dependent β-thalassemia (TDT). MethodsA retrospective clinical study. From October 2022 to December 2023, 29 TDT children (58 eyes) diagnosed and examined at the Department of Hematology, Affiliated Hospital of Guangdong Medical University were included in the TDT group, along with 29 age- and gender-matched healthy children (58 eyes) as the control group. All participants underwent optical coherence tomography and angiography. Measurements included central macular thickness (CMT), subretinal choroidal thickness (SFCT), choroidal thickness (ChT), choroidal vascularity index, blood flow density in the superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris layer (CC), and choroidal layer of the macular region, as well as the foveal avascular zone (FAZ) area of the SCP and DCP. A generalized estimating equation was used to compare differences in the above parameters between the two groups. Pearson correlation analysis was employed to examine the relationships between fundus structural parameters, blood flow density, and blood indices. ResultsCompared with the control group, the TDT group showed significantly thinner CMT (χ2=6.044) and ChT at 3.0 mm nasal (χ2=4.451) and temporal (χ2=4.767) to the fovea (P＜0.05). The TDT group also demonstrated reduced blood flow density in the inferior DCP (χ2=5.254), whole CC (χ2=3.996), and superior CC (χ2=5.094), as well as enlarged FAZ area in DCP (χ2=4.286) (P＜0.05). Correlation analysis revealed a negative correlation between SFCT and disease duration (r=−0.357, P=0.006). ConclusionsIn children with TDT, CMT and ChT become thinner and the area of FAZ expands. The blood flow densities of DCP and CC in the macular area decreased.