Correlation of Visual Field With Peripapillary Vessel Density Through Optical Coherence Tomography Angiography in Normal-Tension Glaucoma

Abstract

Purpose To investigate the retinal vessel density (VD) in healthy and normal-tension glaucoma (NTG) eyes through optical coherence tomography angiography (OCTA) and to determine the correlation between VD and the retinal nerve fiber layer (RNFL) thickness and functional visual field (VF) defects for different locations. Methods A total of 74 NTG eyes and 24 healthy eyes were included. OCTA VD at 4.5 × 4.5 mm peripapillary region and 3.0 × 3.0 mm macula area, RNFL thickness, and VF pattern deviation results were individually analyzed on the basis of the Garway-Heath sectorization. Correlations between VD and VF/RNFL and VF were compared. Results In the NTG group, peripapillary VD, superficial macula VD, RNFL thickness, and ganglion cell complex thickness were significantly lower. In the whole peripapillary area and inferotemporal sector, anatomic correlations between VD and VF pattern deviation values were significantly higher than those between the RNFL thickness and VF values. In the subgroup analysis, VD was anatomically correlated with VF in early-, moderate-, and severe-stage NTG eyes, whereas the RNFL thickness was correlated with VF in moderate- and severe-stage NTG eyes. Conclusions We observed VD reduction in the peripapillary retina and superficial macula area in NTG eyes. The microvascular dropout of VD in the peripapillary retina, especially in the inferotemporal sector, provided a more accurate anatomic correlation with functional VF defects than that of the RNFL thickness, especially in early-stage NTG eyes. Translational Relevance In patients who cannot comply VF exam, VD is a good tool for disease detection.

A Global and Sector-Based Comparison of OCT Angiography and Visual Field Defects in Glaucoma

“…We found similar vascular-anatomic change patterns present in glaucomatous eyes as seen in other studies on OCTA, corroborating data showing that ST and IT areas of the ONH are more vulnerable to nerve damage in patients with glaucoma [ 11 – 14 ]. Of note, some other studies have shown higher correlational values across sectors than what we demonstrated; however, most of these studies were analyzing one or two types of glaucoma and were mostly composed of homogeneous populations [ 7 , 12 , 21 ]. Future studies aimed at inspecting the utility of OCTA with more diverse populations should be implemented to validate a more universal utility for OCTA imaging in glaucoma.…”

“…These results show that the superotemporal, superonasal, and inferotemporal sector changes of the ONH have the highest correlation with visual field pattern deviation changes [ 11 – 14 ]. However, many studies designed to evaluate OCTA only include subjects with primary open angle glaucoma (POAG) and normal tension glaucoma (NTG) [ 5 – 7 , 10 – 12 , 14 , 15 ]. Furthermore, some of these previous studies only measured differences between the people of European and African descent [ 5 – 7 , 15 ] or studied a racially or ethnically homogeneous population [ 10 – 14 ].…”

Normal‐tension glaucoma: Current concepts and approaches‐A review

“…[89][90][91] Another recent study using OCT-A also demonstrated vessel density (VD) reduction in the peripapillary retina and superficial macula area in NTG eyes. 92 The microvascular dropout of VD in the peripapillary retina, especially in the inferotemporal sector, provided a more accurate anatomic correlation with functional VF defects than that of the RNFL thickness, especially in early-stage NTG eyes. 92 On the other hand, data in vascular geometry in NTG, are lacking.…”

“…92 The microvascular dropout of VD in the peripapillary retina, especially in the inferotemporal sector, provided a more accurate anatomic correlation with functional VF defects than that of the RNFL thickness, especially in early-stage NTG eyes. 92 On the other hand, data in vascular geometry in NTG, are lacking. Our group therefore sets out to investigate, using OCT-A, the correlation between cpVD, circumpapillary fractal dimension (cpFD), and severity of NTG.…”

“…NTG is a significant disease entity worldwide: the proportion of NTG amongst primary open angle glaucoma (POAG) was reported to be as high as 92.3% in Japan (the Tajimi Study), 3 84.6% in Singapore (the Singapore Malay Eye Study), 4 83.58% in northern China (the Handan Eye Study), 5 82% in south India (the Chennai Glaucoma Study), 6 79.3% in southern China (the Liwan Eye Study), 7 77% in South Korea (the Namil Study), 8 57.1% in South Africa (Zululand), 9 46.9% in Iran (the Yazd Eye Study), 10 38.9% in Netherlands (the Rotterdam Study), 11 31.7% in United States of America (the Beaver Dam Eye Study), 12 31.0% in Iceland (the Reykjavik Eye Study), 13 and 30% in Italy (the Egna-Neumarkt Study). 14 We can therefore see that there appeared to be a trend, with Asians in general having a higher prevalence of NTG, followed by Africans, and to a lesser extent in Caucasians.…”