AIM: To study the changes of the red blood cell volume distribution width(RDW)level and the correlation between them in patients with primary angle-closure glaucoma(PACG).

METHODS: Retrospective case-control study was conducted. A total of 306 PACG patients in Eye & ENT Hospital of Fudan University from February 2019 to October 2020 were selected as the case group and 126 healthy patients who received physical examination at the hospital during the same period were selected as the control group. The PACG patients were divided into three subgroups according to the mean defect of visual field(MD): mild(MD≤6dB), moderate(612dB). The detailed eye and physical examinations information of the two groups were collected from the medical data platform of Eye & ENT Hospital of Fudan University. The blood sample parameters were detected by automated hematology and biochemistry analyzers. Independent sample t-test, Chi-square test, one-way ANOVA test, Pearson correlation analyses and multiple linear regression analyses were performed in this research.

RESULTS: There was no significant difference between the PACG group and the control group in age, gender, body mass index and blood pressure(P>0.05). Based on the laboratory results, the mean RDW level was significantly higher(t=2.132, P=0.034)in the PACG group(12.64%±0.96%)than that in the control group(12.45%±0.49%). Moreover, the mean RDW level and the mean hemoglobin(HG)level was significantly lower(P<0.05)in the mild PACG subgroup than that in the moderate and severe PACG subgroups. The Pearson correlation analyses showed a positive correlation between the MD and the RDW level(r=0.141, P=0.013), a significantly positive correlation between the IOP and the RDW level(r=0.148, P=0.002), and a negative correlation between the MS and the RDW level(r=-0.154, P=0.007)in patients with PACG. After adjusting for the confounding factors, multiple linear regression analyses showed a positive association between between the MD and the RDW level in patients with PACG(β=1.405, P=0.018, 95% CI=0.240-2.570).

CONCLUSION: The RDW level of PACG patients is higer than normal. The RDW level may help to predict the PACG patients' conditions for better treatments.