Reduced Macular Vascular Density in Myopic Eyes / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Morphological changes of the vasculature system in patients with myopia have been observed by Doppler ultrasound and fundus fluorescein angiography (FFA); however, these studies have limitations. Doppler ultrasound provides low-resolution images which are mainly obtained from visualized large vessels, and FFA is an invasive examination. Optic coherence tomography (OCT) angiography is a noninvasive, high-resolution measurement for vascular density. The purpose of this study was to investigate the change of vascular density in myopic eyes using OCT angiography.</p><p><b>METHODS</b>This cross-sectional study includes a total of 91 eyes from 47 participants including control, moderate, and high myopia that were evaluated by OCT angiography. Patients with myopia were recruited from the Refractive Department, Shenzhen Aier Eye Hospital, from August 5, 2015 to April 1, 2016. Emmetropic eyes were from healthy volunteers. The vascular density at macula and optic disc regions, ganglion cell complex (GCC) thickness, and retinal nerve fiber layer (RNFL) thickness were measured. Their relationships with axial length (AL) and refractive error were analyzed. One-way analysis of variance (ANOVA), Pearson's correlation, and generalized estimating equation were used for statistical analysis.</p><p><b>RESULTS</b>Both superficial and deep macular vascular density were highest in control (25.64% ± 3.76% and 37.12% ± 3.66%, respectively), then in moderate myopia (21.15% ± 5.33% and 35.35% ± 5.50%, respectively), and lowest in high myopia group (19.64% ± 3.87% and 32.81% ± 6.29%, respectively) (F = 13.74 and 4.57, respectively; both P < 0.001). Both superficial (β = -0.850 and 0.460, respectively) and deep (β = -0.766 and 0.396, respectively) macular vascular density were associated with AL and spherical equivalent (all P < 0.001). Superficial macular vascular density was associated with GCC thickness (β = 0.244, P = 0.040), independent of spherical equivalent. The vascular density in optic disc region had no difference among the three groups, and it was not associated with AL, spherical equivalent, or RNFL thickness.</p><p><b>CONCLUSION</b>Our results suggested that with the increase of myopia, the vascular density decreased in macular region, but not in optic disc region.</p>

Relationship between subfoveal choroidal thickness and both choroidal hemodynamic index and glycosylated hemoglobin in diabetic subjects / 国际眼科杂志(Guoji Yanke Zazhi)

AlM: To investigate the relationship between the subfoveal choroidal thickness ( SFCT) and both choroidal hemodynamic index and glycosylated hemoglobin in diabetic subjects.METHODS:Seventy-eight type 2 diabetic patients (156 eyes) from ophthalmology and endocrinology ward of our hospital were enrolled in this study, including 39 females and 39 males, with a mean age of (59. 8±6. 2)years. According to early treatment diabetic retinopathy study ( ETDRS) grading method, all samples were divided into diabetic retinopathy ( DR ) group, mild or moderate nonproliferative diabetic retinopathy group, severe nonproliferative diabetic retinopathy ( NPDR) group and proliferative diabetic retinopathy ( PDR ) group. The SFCT and choroidal hemodynamic index were measured by enhanced depth imaging optical coherence tomography ( EDl-OCT ) and Color Doppler lmaging. Recording glycosylated hemoglobin content of all samples. Using multivariate linear regression to analyse the relationship between the SFCT and both choroidal hemodynamic index and glycosylated hemoglobin.RESULTS: The end diastolic velocity ( EDV ) was significant higher and the SFCT was significant thinner in no diabetic retinopathy ( NDR) group than other groups. There was no significant difference of peak systolic velocity ( PSV ) between four groups. The resistance index ( Rl) was significant higher in severe NPDR group than NDR group and mild or moderate group, the Rl in PDR group was hihgest than other group with statistically significance. The SFCT was correlated positively ( b =0. 540,P<0. 001) with the glycosylated hemoglobin. No significant correlation was found between the SFCT and the choroidal hemodynamic index (DR,P=0. 341;PSV,P=0. 770;EDV,P=0. 131;Rl,P=0. 084).CONCLUSlON: Our results suggest that there is no significant correlations between the SFCT and the choroidal hemodynamic index; glycosylated hemoglobin is one of the factors that affect the SFCT in diabetic patients.