Visual Acuity Is Correlated with the Area of the Foveal Avascular Zone in Diabetic Retinopathy and Retinal Vein Occlusion

Citation: Kwon J, Choi J, Shin JW, Lee J, Kook MS. Alterations of the foveal avascular zone measured by optical coherence tomography angiography in glaucoma patients with central visual field defects. Invest Ophthalmol Vis Sci. 2017;58:163758: -164558: . DOI: 10.1167 PURPOSE. To investigate whether the area and shape of the foveal avascular zone (FAZ) as assessed by optical coherence tomography angiography (OCTA) are altered in glaucomatous eyes with central visual field defects (CVFDs). METHODS.A total of 78 patients with open-angle glaucoma with central or peripheral visual field defects (PVFDs) confined to a single hemifield were studied retrospectively. Foveal avascular zone area and circularity were measured using OCTA images from the superficial retinal layer. Central retinal visual field (VF) sensitivity using Swedish Interactive Threshold Algorithm 24-2 VF and macular ganglion cell-inner plexiform layer (mGCIPL) thickness were measured. The FAZ area between VF-affected hemimacular segments and VF-unaffected hemimacular segments in eyes with CVFDs and matched hemimacular segments of eyes with PVFDs were compared. Factors associated with the presence and severity of CVFD at initial presentation were determined. RESULTS.Eyes with CVFDs showed a significantly larger FAZ area, lower FAZ circularity, and lower mGCIPL thickness than the PVFD group. The mean hemi-FAZ area of VF-affected hemimaculas in eyes with CVFDs was significantly larger than that of the PVFD group (0.256 6 0.07 mm 2 vs. 0.184 6 0.07 mm 2 ) and the VF-unaffected hemimaculas of the CVFD group (0.179 6 0.06 mm 2 ; P < 0.05). Age, mean deviation, mGCIPL thickness, FAZ area, and circularity were associated with CVFDs (P < 0.05).CONCLUSIONS. Microcirculatory alterations in the perifovea are spatially correlated with central VF loss. Loss of FAZ circularity was significantly associated with presence of CVFD, whereas FAZ area was significantly associated with severity of CVFD.Keywords: foveal avascular zone, central visual field defects, optical coherence tomography angiography G laucoma is a leading cause of irreversible blindness and is characterized by progressive retinal ganglion cell (RGC) death and axonal loss.1,2 Ocular blood flow (OBF) impairment and/or abnormal microcirculation along with elevated IOP may play an important role in glaucoma, particularly in normaltension glaucoma (NTG) [3][4][5][6][7] ; however, the exact pathogenesis of glaucoma is still unknown. To assess the vascular integrity of OBF, different types of imaging modalities have been introduced, including fluorescein angiography (FA), Heidelberg retina flowmeter, and color Doppler. Although FA remains the gold standard for detecting vascular pathology in the retina, it is invasive and requires exposure to an exogenous contrast agent. Moreover, the axial and lateral resolution of FA allows for limited visualization of capillaries, especially in macula in which there are overlapping capillary networks. 8 Recently, noninvasive retinal microvascular imaging has become availab...

Section: Discussionmentioning

confidence: 99%

Alterations of the Foveal Avascular Zone Measured by Optical Coherence Tomography Angiography in Glaucoma Patients With Central Visual Field Defects

Kwon

Choi²,

Shin

et al. 2017

“…FAZ enlargement is related to worse vision in diabetic retinopathy and retinal vein occlusions. 26,27 Capillary density of both plexuses is correlated to visual loss in diabetic retinopathy, 28 branch retinal vein occlusion, 29,30 and idiopathic macular telangiectasia type 1 (MacTel1). 31 In addition, several investigators have shown that decreased perfusion is more frequent in the deep than superficial plexus, in central or branch vein occlusion, 32-34 diabetic retinopathy, 35 and MacTel1.…”

Section: Discussionmentioning

confidence: 99%

Radiation Maculopathy After Proton Beam Therapy for Uveal Melanoma: Optical Coherence Tomography Angiography Alterations Influencing Visual Acuity

Matet

Daruich

Zografos

2017

PURPOSE. To analyze microvascular and structural changes in radiation maculopathy and their influence on visual acuity (VA), using optical coherence tomography (OCT) and OCT angiography (OCTA).METHODS. This was a retrospective analysis of consecutive patients with radiation maculopathy, 12 months or more after proton-beam irradiation for uveal melanoma, imaged with fluorescein angiography, OCT, and OCTA. Clinical parameters potentially affecting VA were recorded, including OCTA-derived metrics: foveal avascular zone (FAZ) area, vascular density, and local fractal dimension of the superficial (SCP) and deep capillary plexuses (DCP). Nonirradiated fellow eyes served as controls. RESULTS.Ninety-three patients were included. FAZ was larger, while SCP/DCP capillary density and local fractal dimension were lower in the 35 irradiated than in the 35 fellow eyes (P < 0.0001). Microvascular alterations graded on fluorescein angiography (minimally damaged/ disrupted/disorganized) were correlated to FAZ area and SCP/DCP density on OCTA (P < 0.01). By univariate analysis, worse VA was associated to macular detachment at presentation (P ¼ 0.024), total macular irradiation (P ¼ 0.0008), higher central macular thickness (CMT) (P ¼ 0.019), higher absolute CMT variation (P < 0.0001), cystoid edema (P ¼ 0.030), ellipsoid zone disruption (P ¼ 0.002), larger FAZ (P < 0.0001), lower SCP (P ¼ 0.001) and DCP capillary density (P < 0.0001), and lower SCP (P ¼ 0.009) and DCP local fractal dimension (P < 0.0001). Two multivariate models with either capillary density or fractal dimension as covariate showed that younger age (P ¼ 0.014/0.017), ellipsoid zone disruption (P ¼ 0.034/0.019), larger FAZ (P ¼ 0.0006/0.002), and lower DCP density (P ¼ 0.008) or DCP fractal dimension (P ¼ 0.012), respectively, were associated with worse VA.CONCLUSIONS. VA of eyes with radiation maculopathy is influenced by structural and microvascular factors identified with OCTA, including FAZ area and DCP integrity.

“…The visual improvement after treatment of macular edema significantly correlates with better retinal perfusion and less retinal ischemia in patients with RVO. [16][17][18][19][20][21] Therefore, the effects of repeated anti-VEGF therapy to the retinal perfusion should be investigated for a better longterm management of RVO. Optical coherence tomography angiography (OCTA) enables noninvasive visualization of different retinal layers, such as the superficial and deep retinal capillaries by segmentation of each layer.…”

mentioning

confidence: 99%

Changes in Retinal Microvasculature and Visual Acuity After Antivascular Endothelial Growth Factor Therapy in Retinal Vein Occlusion

Winegarner

Wakabayashi

Fukushima

et al. 2018

PURPOSE. To investigate the changes in the retinal microvasculature during the course of anti-VEGF therapy in eyes with macular edema due to retinal vein occlusion (RVO) and their association with visual outcomes.METHODS. The vessel density (VD) and foveal avascular zone (FAZ) area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were quantitatively measured by optical coherence tomography angiography (OCTA) in 48 consecutive eyes with RVO before and 1, 3, 6, 9, and 12 months after anti-VEGF therapy. Anti-VEGF therapy was performed either with ranibizumab or aflibercept following a pro re nata (PRN) regimen. The correlation between post-treatment best-corrected visual acuity (BCVA) and changes in the retinal microvasculature evaluated by OCTA were assessed.RESULTS. The BCVA improved significantly at 12 months (P < 0.001). Better BCVA at 12 months was significantly associated with a better VD in the SCP and DCP both at baseline (R 2 ¼ 0.524, P < 0.001 and R 2 ¼ 0.457, P < 0.001, respectively) and at 12 months (R 2 ¼ 0.521, P < 0.001 and R 2 ¼ 0.662, P < 0.001, respectively). Overall, both VD and FAZ did not change significantly during the 12 months. However, the progression of nonperfusion was observed in the SCP in 6 (13%) eyes and in the DCP in 10 (21%) eyes. The number of macular edema recurrence was significantly associated with a decrease in the VD (P ¼ 0.006 [SCP] and P < 0.001 [DCP]) and less visual gain (P ¼ 0.02) after treatment.CONCLUSIONS. Anti-VEGF therapy maintains retinal perfusion in most patients with RVO. Preserving retinal perfusion is crucial for better visual outcomes.