Peripapillary Perfused Capillary Density in True Versus Pseudoexfoliation Syndrome: An OCTA Study

Abstract

PurposeTo compare peripapillary perfused capillary density (PCD) among eyes with true exfoliation syndrome (TEX), eyes with pseudoexfoliation syndrome (PEX), and healthy control eyes.Materials and MethodsIn this observational cross-sectional study, eyes with and without TEX or PEX were assessed by optical coherence tomography angiography (OCTA) imaging. Bilateral OCTA images (4.5 · 4.5 mm2) centered at the optic nerve head were obtained using a commercial spectral domain OCTA system. Optic nerve head perfusion was quantified using the split-spectrum amplitude decorrelation angiography algorithm. Categorical and continuous variables were compared using the chi-squared test and one-way analysis of variance, respectively. The generalized estimating equation was used to adjust for confounding factors and determine inter-ocular associations.ResultsWe enrolled 39 eyes with TEX, 31 eyes with PEX, and 32 control eyes. There were no significant differences among the three groups regarding age, intraocular pressure, cup-to-disc ratio, blood pressure, or axial length (all p>0.05). There were significant differences in global PCD among the three groups (p=0.01). There were significant differences in annular PCD between the TEX and PEX groups (p=0.027).ConclusionsWhile both global and annular PCDs did not differ between the TEX and control groups, greater loss of annular PCD in the PEX group than in the TEX and control groups suggests more pronounced microvascular disturbance in PEX.Synopsis/PrecisGreater microvascular attenuation in PEX compared with TEX and normal control measured by OCTA.

The Role of Vessel Density as Measured by Optical Coherence Tomography Angiography in the Evaluation of Pseudoexfoliative Glaucoma: A Review of the Literature

“…Three cross-sectional studies compared eyes with PXS with age-matched control eyes [20,28,37]. Regarding VD in the macular area, there was consistency in that a significant decrease in superficial VD was observed in eyes with PXS compared to controls [28,37], accompanied by a significant enlargement in the FAZ area in both the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in eyes with PXS compared to control eyes [28].…”

“…Regarding VD in the macular area, there was consistency in that a significant decrease in superficial VD was observed in eyes with PXS compared to controls [28,37], accompanied by a significant enlargement in the FAZ area in both the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in eyes with PXS compared to control eyes [28]. However, the findings related to peripapillary VD seemed to be contradictory, with Tangtammaruk et al reporting a significant decrease in peripapillary perfused capillary density in eyes with PXS versus controls [20], in line with Suwan et al [23], while Gu ¨r Gu ¨ngo ¨r et al found no significant difference in peripapillary VD between the two groups [37].…”

“…Various methods have been used to measure optic nerve head perfusion in both POAG and PXS [18]. Fluorescein angiography has been applied to measure vascular blood flow; however, it is both invasive and inaccurate for the measurement of optic nerve head perfusion, while laser speckle flowmetry and Doppler imaging are operator-dependent and do not provide adequate visualization [19,20]. Optical coherence tomography angiography (OCTA) is a relatively new noninvasive imaging technology, allowing visualization of the retinal microcirculation, also providing quantitative analysis of the peripapillary and macular microvasculature [21,22].…”

“…Optical coherence tomography angiography (OCTA) is a relatively new noninvasive imaging technology, allowing visualization of the retinal microcirculation, also providing quantitative analysis of the peripapillary and macular microvasculature [21,22]. Since it has been hypothesized that impaired vascular supply may also be involved in the pathogenesis of PXG, several studies have used OCTA to investigate peripapillary and macular microcirculation in eyes with PXG and PXS [20,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. Based on the above, the purpose of this review is to assess the peripapillary and macular vessel density (VD) as measured using OCTA in eyes with PXG, as well as to compare these OCTA parameters in eyes with PXG with those of either eyes with POAG or normal eyes, based on findings reported in the existing literature.…”