Clinical Study Of Macular Vascular Density In Patients With Pterygium By Optical Coherence Tomography Angiography

Purpose: To investigate the retinal vascular network alterations in eyes of patients with pterygium.Method: 18 left eyes from 18 female pterygium patients(pterygium group)and 18 left eyes from 18 female healthy control subjects(healthy control group)were enrolled.Three-dimensional OCTA images were generated with 6×6-mm angiographic OCT scans of the superficial retinal layer(SRL)and deeper retinal layer(DRL)of the macular retina for each eye.The microvascular(MIR)and macrovascular(MAR)densities were calculated and MIR,MAR,and total MIR(TMI)density was compared in the healthy control and pterygium groups separately.We used the ETDRS,Hsmispheric and annular partition(C1-C6)method to analyze retinal vessel density alterations.Correlation analysis were used to examine the association of MIR density and disease course,and area size of the pterygium.Results: In pterygium group,in the SRL,the vascular density in SMIR(superficial MIR),SR(superior right),IR(inferior right),R(right),SC(superficial central annuli)1,SC2 and SC3 decreased significantly in the macular area(P<.05).Furthermore,the vascular density in all those decreased regions except R,was significantly and negatively correlated with the disease course(r=-0.6038 to-0.7762,P=0.0008),and the area size of pterygium(r=-0.6043 to-0.9508,P<0.05).For the DRL,the density of DTMI,DMIR(deeper MIR),SR,IR,R,DC2 and DC3 decreased significantly in macular area of pterygium patients(P<.05).Furthermore,the vascular density in all those decreased regions was significantly and negatively correlated with the disease course(r=-0.6901 to-0.7795,P=0.0015),and the area size of pterygium(r=-0.6043 to-0.9563,P<0.05).No statistically significant differences and correlation was found in other region density(|r|<0.47,P>0.05).Conclusion: OCTA findings suggested that pterygium patients present with decreased retinal MIR density,and the major vascular alterations occurred mainly on the bitamporal side.The vascular density of the superficial SC1,SC2,SC3 in the foveal and deep layer of DC2,DC2 regions,significantly decreased.