Superficial Foveal Avascular Zone Area Research Articles

The Recovery of Microvascular Status Evaluated by Optical Coherence Tomography Angiography in Patients after Successful Macular Hole Surgery

Purpose: The aim of this study was to evaluate the optical coherence tomography angiography (OCTA) features of patients who underwent successful macular hole (MH) surgery. Methods: Nineteen patients who underwent surgery in a single eye due to MH and 13 healthy subjects as a control group were included in the study. Vascular densities, flow indexes, and the foveal avascular zone (FAZ) area in superficial and deep retinal capillary plexuses were evaluated by OCTA in the right eyes of the control group, and both the surgical and healthy fellow eyes of the patients. Results: The mean vascular densities of the superficial and deep capillary plexuses were significantly lower in the surgical eyes than in the control group (44.1 vs. 49.6%, p = 0.002, and 47.3 vs. 59.1%, p = 0.009, respectively). The mean superficial and deep capillary flow indexes were significantly lower in the surgical eyes than in the control group (0.85 vs. 1.35, p = 0.003, and 0.57 vs. 1.45, p = 0.001, respectively), while the mean superficial and deep FAZ area were significantly greater in the surgical eyes in comparison to the control group (0.55 vs. 0.32, p < 0.001, and 0.64 vs. 0.37, p = 0.001, respectively). There was no difference between the flow indexes of both layers of the healthy fellow eyes and the control group. Conclusions: These preliminary results may be an explanation for unsatisfactory visual gain after surgery, despite the successful anatomical closure of the MH.

CORRELATION OF MICROVASCULAR STRUCTURES ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY WITH VISUAL ACUITY IN RETINAL VEIN OCCLUSION.

To analyze the correlation of superficial and deep capillary plexuses using optical coherence tomography (OCT) angiography with visual acuity in eyes with retinal vein occlusion (RVO). We retrospectively reviewed the medical records of 33 patients with retinal vein occlusion (RVO; branch retinal vein occlusion in 21 patients, central retinal vein occlusion in 12 patients) and included 33 healthy subjects as a control group, who were evaluated by OCT angiography. The OCT angiography was performed on a 3 mm × 3-mm region centered on the fovea and parafoveal area. The foveal avascular zone (FAZ), and foveal and parafoveal vascular density (VD) in superficial and deep vascular plexuses were analyzed using OCT angiography. The area of superficial and deep FAZ in eyes with RVO were larger than those in fellow eyes and control eyes (P = 0.034, P = 0.018). The superficial and deep parafoveal VDs in eyes with RVO were significantly lower than those in fellow eyes and control eyes (P = 0.001, P< 0.001). The area of superficial FAZ was negatively correlated with best-corrected visual acuity, and the superficial and deep parafoveal VDs were positively correlated with best-corrected visual acuity. Eighteen of the total 21 eyes with branch retinal vein occlusion (85.7%) showed a high concordance rate with respect to the location of branch retinal vein occlusion and the lowest parafoveal VD area. The multivariate analysis showed that the deep parafoveal VD was associated with best-corrected visual acuity. The OCT angiography allows to detect FAZ enlargement, increased parafoveal capillary nonperfusion, and decreased parafoveal VD in eyes with RVO. The area of superficial FAZ and the parafoveal VD are correlated with best-corrected visual acuity in eyes with RVO.

The quantitative measurements of foveal avascular zone using optical coherence tomography angiography in normal volunteers

PurposeTo provide normative data of foveal avascular zone (FAZ) and thickness. MethodsIn this cross-sectional study both eyes of each normal subject were scanned with optical coherence tomography angiography (OCTA) for foveal superficial and deep avascular zone (FAZ) and central foveal thickness (CFT) and parafoveal thickness (PFT). ResultsOut of a total of 224 eyes of 112 volunteers with a mean age of 37.03 (12–67) years, the mean superficial FAZ area was 0.27 mm2, and deep FAZ area was 0.35 mm2 (P < 0.001), with no difference between both eyes. Females had a larger superficial (0.32 ± 0.11 mm2 versus 0.23 ± 0.09 mm2) and deep FAZ (0.40 ± 0.14 mm2 versus 0.31 ± 0.10 mm2) (P < 0.001) than males. By multivariate linear regression analysis, in normal eyes, superficial FAZ area varied significantly with the gender, CFT, and deep FAZ. Deep FAZ varied with the gender and CFT. ConclusionThe gender and CFT influence the size of normal superficial and deep FAZ of capillary network.

SUPERFICIAL FOVEAL AVASCULAR ZONE DETERMINED BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY BEFORE AND AFTER MACULAR HOLE SURGERY.

To determine the size of the superficial foveal avascular zone (FAZ) by optical coherence tomography angiography before and after surgery for an idiopathic macular hole. A retrospective, observational case series, in which 16 eyes of 16 patients with an idiopathic macular hole were studied. Pars plana vitrectomy was performed with internal limiting membrane peeling. The foveal retinal vasculature was examined by optical coherence tomography angiography, and the area of the superficial FAZ was determined before, and at 1 and 3 months after the surgery. The area of the macular hole was also measured in the en face optical coherence tomography images. The central foveal thickness was measured to determine the relationship between the size of the superficial FAZ and foveal shape. The unaffected fellow eyes were used as controls. The mean age of the patients was 68.9 years. The average preoperative superficial FAZ area was 0.45 ± 0.14 mm, which was significantly reduced to 0.23 ± 0.08 mm at 1 month (P < 0.001) and 0.25 ± 0.08 mm at 3 months postoperatively (P < 0.001). The size was smaller than that of the control eyes (0.36 ± 0.12 mm, P = 0.003). There was a significant inverse correlation between the area of the postoperative superficial FAZ and the central foveal thickness (r = -0.589, P = 0.016). The correlations between the visual acuity and the area of the superficial FAZ at 1 and 3 months postoperatively were not significant (P = 0.369 and 0.285). The significant decrease in the superficial FAZ after the macular hole surgery indicates that there was a centripetal movement of the foveal tissue postoperatively.

Optical Coherence Tomography Angiography Evaluation of the Parafoveal Vasculature and Its Relationship With Ocular Factors

To determine the size and characteristics of the superficial and deep foveal avascular zone (FAZ) in healthy adults by using optical coherence tomography angiography (OCT-A), and to ascertain the effects of demographic and ocular parameters on the FAZ size. In a prospective cohort study of 117 healthy volunteers, foveal-centered 3 × 3-mm OCT-A scans were manually graded by certified graders to determine the size of the superficial and deep FAZ. Multiple linear regression analyses were performed to evaluate the impact of demographics and ocular factors, including central retinal thickness (CRT), choroidal thickness, axial length (AL), and spherical equivalent (SE) on superficial and deep FAZ areas. The mean age of the participants was 22.5 years, with mean AL of 25.4 mm and mean SE of -4.3 diopters. The mean CRT was 262.8 μm (range, 220-316 μm). The mean superficial FAZ area was 0.24 mm2, while the deep FAZ area was 0.38 mm2 (P < 0.001). Females had a larger superficial (P < 0.001) and deep FAZ (P < 0.001). On univariate linear regression, both superficial and deep FAZ areas had significant correlations with CRT, sex, AL, and SE, but not with age. By multiple linear regression analysis, in normal eyes, superficial FAZ area varied significantly with CRT and sex. Among eyes with high myopia, both superficial and deep FAZ varied significantly with CRT, sex, and choroidal thickness. The superficial and deep FAZ areas varied significantly among healthy eyes. Factors such as CRT, sex, SE, AL, and choroidal thickness influence the size of the FAZ.

Optical Coherence Tomography Angiography in Central Retinal Vein Occlusion: Correlation Between the Foveal Avascular Zone and Visual Acuity.

To investigate the relationship between best-corrected visual acuity (BCVA) and the foveal avascular zone (FAZ) in patients with central retinal vein occlusion (CRVO) evaluated with optical coherence angiography (OCT-A). The study was a prospective consecutive case series including 24 patients with CRVO. All patients received either aflibercept or ranibizumab intravitreal injections prior to analysis. Best-corrected visual acuity and FAZ were evaluated in eyes without macular edema. The FAZ areas were evaluated with OCT-A in both the superficial and deep capillary plexus layers by using 3 × 3-mm images of the macula. Disruption of the ellipsoid zone (EZ) was also analyzed. The mean superficial FAZ area measured 0.76 mm2 (95% confidence interval [CI] 0.50-1.13). The mean deep FAZ area measured 1.12 mm2 (95% CI 0.77-1.47). In a multivariable analysis a negative correlation was found between the BCVA and the superficial FAZ area (r = -0.54, P = 0.03). The correlation between the BCVA and deep FAZ area did not meet statistical significance (r = -0.43, P = 0.09). In a multivariable analysis, disruption of the ellipsoid zone was significantly correlated to a larger superficial FAZ area (r = 0.68, P = <0.001) and poor visual acuity (r = 0.75, P < 0.001). Optical coherence tomography-A is a novel technique that allows segmented evaluation of the FAZ in patients with CRVO providing additional prognostic information. The FAZ areas were enlarged both in the superficial and the deep capillary networks. A significant correlation was found between BCVA and the FAZ area in CRVO patients without macular edema (ClinicalTrials.gov, number NCT02274259).

CORRELATION OF FOVEAL AVASCULAR ZONE SIZE WITH FOVEAL MORPHOLOGY IN NORMAL EYES USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

To analyze the foveal avascular zone (FAZ) in normal eyes using optical coherence tomography angiography. Prospective noncomparative case series. The parafoveal region of 70 eyes from 67 healthy subjects was imaged using optical coherence tomography angiography to visualize the superficial and deep capillary plexuses and correlated with standard macular volume scans using spectral domain optical coherence tomography to determine foveal morphology. In all 70 eyes imaged, 2 vascular plexuses could be detected within the retina: a superficial plexus within the ganglion cell layer and a deep plexus within the inner nuclear layer. A measurable FAZ was visualized in both plexuses in all imaged eyes. The FAZ area was variable in the study population with a mean of 0.266 mm² ± 0.097 mm² in the superficial plexus (range: 0.071 mm²-0.527 mm²) and a mean of 0.495 mm² ± 0.227 mm² in the deep plexus (range: 0.160 mm²-0.795 mm²). The FAZ area was significantly larger in the deep plexus (P < 0.0001) compared with superficial plexus. The FAZ area in both plexuses correlated inversely with central macular thickness and central macular volume (P < 0.0001). No significant correlation was found between superficial plexus FAZ area and age (P = 0.55) or sex (P = 0.34). In the same manner, no significant correlation was found between deep plexus FAZ area and age (P = 0.13) or sex (P = 0.13). Optical coherence tomography angiography provides a noninvasive method to visualize and measure the superficial and deep plexus FAZ in a normal population. The FAZ can vary in size and shape, with the FAZ area significantly larger in the deep compared with the superficial plexus. Both superficial and deep FAZ area correlate inversely with foveal thickness and volume.