Diagnostic ability of vessel density measured by spectral-domain optical coherence tomography angiography for glaucoma in patients with high myopia

Abstract

Although early glaucoma detection is important to prevent visual loss due to disease progression, its clinical diagnosis in highly myopic eyes is still difficult. Many studies using optical coherence tomography (oct) angiography (octA) reported decreased vessel density (VD) in glaucomatous eyes compared to normal eyes. We evaluated the diagnostic ability of peripapillary VD and macular VD measured by octA, comparing them with conventional valuables such as peripapillary retinal nerve fibre layer (RNFL) thickness and macular ganglion cell-inner plexiform layer (GCIPL) thickness measured by OCT. We also calculated the average VD ratio (VDR) (average outer macular VD/average inner macular VD), superior VDR (superior outer macular VD/average inner macular VD), and inferior VDR (inferior outer macular VD/average inner macular VD). Totally, 169 eyes from 169 subjects were enrolled. Among OCTA measurements, the best diagnostic parameters were average VDR (AUROC: 0.852 and 0.909) and inferior VDR (AUROC: 0.820 and 0.941) in nonhighly and highly myopic eyes, respectively. inferior VDR showed better diagnostic ability than most of the other oct measurements including peripapillary RNFL thickness and macular GCIPL thickness in highly myopic eyes. Accordingly, OCTA measurements can be useful for diagnosing glaucoma in highly myopic eyes, especially when using calculated indices such as average VDR or inferior VDR.Glaucoma is a progressive optic neuropathy characterised by retinal ganglion cell loss and visual field (VF) change 1 . Early detection of glaucoma is important to prevent visual loss caused by disease progression. However, clinical diagnosis of glaucoma in myopic eyes is often difficult 2 . The evaluation of the optic disc is especially difficult in highly myopic eyes because of considerable morphologic variations 3 . The retinal nerve fibre layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) can also be mistaken for glaucoma as they increase in thinness as the axial length increases 4,5 .Spectral-domain optical coherence tomography (SD-OCT) has grown in importance in diagnosing glaucoma, allowing clinicians to assess structural changes in the optic disc and macula 6-10 . Further, recent studies have shown that peripapillary vessel density (VD) and macular VD, as measured by OCT angiography (OCTA), in glaucoma eyes are reduced 11,12 . Interestingly, a recent study reported that peripapillary VD well correlated with VF defects in both non-highly and highly myopic eyes 13 . Therefore, peripapillary VD or macular VD could be useful for glaucoma detection in highly myopic eyes, despite reports that macular VD measurements are not better than macular GCIPL thickness measurements for glaucoma detection in non-highly myopic eye 14 . To the best of our knowledge, few studies have compared the diagnostic ability of peripapillary VD and macular VD for glaucoma detection in highly myopic eyes.In this study, we compared the diagnostic ability of peripapillary VD and macular VD for glaucoma and compared it with that of...

Longitudinal Changes in Macular Optical Coherence Tomography Angiography Metrics in Primary Open-Angle Glaucoma With High Myopia: A Prospective Study

“… 10 Thus the deep retinal layer microvasculature in highly myopic eyes may have decreased retinal function and oxygen consumption and is then more vulnerable to blood flow reduction. Because glaucoma mainly affects macular VD in the superior and inferior sectors, 25 the baseline superior and inferior VD showed closer correlation with the rate of change in VD.…”

“…Early glaucomatous damage could affect the macula; macular VD was shown to have better discriminative performance than peripapillary VD in glaucomatous eyes with high myopia. 25,26 This study aimed to evaluate the longitudinal changes in the macular OCTA metrics in the SCP and DCP of POAG eyes with and without high myopia, and to investigate whether baseline structural and functional measurements were related to subsequent changes in macular OCTA metrics. (5) comorbid systemic hypertension or diabetes.…”

Optical Coherence Tomography Angiography Compared With Optical Coherence Tomography for Detection of Early Glaucoma With High Myopia

“…Vessel density parameters measured by OCT angiography (OCTA) in the peripapillary and macular regions in the glaucomatous eyes were significantly lower than those in the healthy eyes (10)(11)(12)(13). Peripapillary/macular vessel density changes have been reported to be useful for differentiating between glaucoma and healthy eyes, especially in HM patients because vessel density measurement is less affected by the low reflectance of the RNFL or optic disc deformation (14,15). That is, if the vessel density changes are more prominent than other structural changes at the early stage of glaucoma in HM, it would be helpful for this challenging early glaucoma diagnosis.…”

Optical coherence tomography angiography in glaucoma

“…In addition, vessel density correlated well with visual fields in both highly and non-highly myopic glaucoma eyes (38). Lee et al also (55) showed reduction in peripapillary vessel density measurements in the outer area (3-6 mm around optic nerve) in highly myopic eyes than in non-highly myopic eyes and in glaucomatous eyes compared to unaffected eyes, suggesting that myopic changes might affect the outer area around the optic disc, but not the inner region (<3 mm). While the average outer macular vessel density was different between normal and glaucomatous eyes in both non-highly and highly myopic eyes, inner macular vessel density was not.…”