Parapapillary Choroidal Research Articles

Parapapillary Choroidal Microvasculature Predicts Diabetic Retinopathy Progression and Diabetic Macular Edema Development: A Three-Year Prospective Study

To determine the predictive value of the microcirculation of the optic nerve head by swept-source optical coherence tomography angiography for identifying individuals with high risk of diabetic retinopathy (DR) progression and diabetic macular edema (DME) development. Prospective observational cohort study. A total of 946 patients (1879 eyes) with type 2 diabetes mellitus were recruited who had no DR or mild nonproliferative DR at baseline, and no DME. All subjects underwent 3×3 mm swept-source optical coherence tomography angiography centered on the optic nerve head to generate angiograms in 4 layers: radial peripapillary plexus, superficial retinal capillary plexus (SCP), deep retinal capillary plexus, and choriocapillaris (CC). The CC flow deficit percentage (CC FD%), vessel density (VD), and perfusion density (PD) were quantified. During the 3 consecutive years of follow-up, 312 eyes (16.60%) experienced DR progression and 115 eyes (6.12%) developed DME. The DR progression was related to a lower VD of the SCP (relative risk per standard deviation decrease, 95% confidence interval): 1.30, 1.14-1.48; P < .001), a lower PD of the SCP (1.41, 1.24-1.60; P < .001), a lower VD of the radial peripapillary plexus (1.23, 1.08-1.40; P=.002), and an elevated CC FD% (1.62, 1.40-1.88; P < .001). The DME occurrence was associated with a lower VD of SCP (1.35, 1.09-1.66; P=.005), a lower PD of SCP (1.29, 1.05-1.59; P=.016), and a higher CC FD% (1.29, 1.03-1.61; P < .001). The CC FD% significantly improved the predictive power, with the increase of the C-statistic for DR progression and DME occurrence by 3.83% (P=.002) and 5.24% (P < .001), respectively. This study provides the first longitudinal evidence suggesting that peripapillary CC FD% can improve the prediction of DR progression and DME development beyond traditional risk factors.

Parapapillary Choroidal Microvasculature Dropout in Branched Retinal Vein Occlusion and Glaucoma.

PurposeTo investigate parapapillary choroidal microvasculature dropout (MvD) in branch retinal vein occlusion (BRVO) patients and compare them with open-angle glaucoma (OAG) patients using optical coherence tomography angiography (OCT-A).MethodsIn total, 85 eyes of BRVO patients and 85 eyes of OAG patients, matched by age, spherical equivalent, and baseline mean deviation (MD) of the visual field (VF), were assessed. MvD was defined as complete loss of microvasculature within the choroidal layer on OCT-A. Linear regression analysis was used to obtain the slope of the MD change of the VF.ResultsThe presence of MvD on OCT-A was significantly more frequent in OAG eyes (63.1%) compared to BRVO eyes (31.8%). BRVO eyes with MvD showed worse baseline MD of the VF than BRVO eyes without MvD (−10.19 ± 8.50 and −7.77 ± 6.46 dB, respectively; P = 0.045). The presence of MvD was the only factor significantly associated with MD change of the VF in OAG eyes. Lower baseline average RNFL thickness, greater MvD angle, and lower macular superficial vessel density were significantly associated with MD change of the VF in BRVO eyes.ConclusionsOCT-A of the parapapillary area showed choroidal microvasculature impairment in both BRVO and OAG patients. However, the frequency was higher in glaucoma patients with similar degrees of VF damage, which suggests that the glaucomatous process contributes to MvD development. The effect of MvD on VF change was different between BRVO and OAG, suggesting that the underlying pathogenesis may also be different.

Automated Evaluation of Parapapillary Choroidal Microvasculature in Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma

To determine whether parapapillary choroidal microvasculature (PPCMv) density as measured by optical coherence tomography angiography differs between pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG). Cross-sectional study. One hundred ninety-two eyes of 120 subjects from 2 academic referral institutions were enrolled. Automated PPCMv density was calculated using custom Matlab software in inner and outer annuli around the optic nerve region in addition to peripapillary superficial vasculature. Linear modeling was used to compare vessel densities among groups. Data from 64 eyes with PXS, 84 eyes with PXG, and 44 eyes healthy control subjects were analyzed. The differences of visual field mean deviation and peripapillary retinal nerve fiber layer thickness among study groups were statistically significant with lower values in PXG eyes compared with the PXS and control groups. Peripapillary superficial retinal vessel densities were significantly reduced in patients with PXG compared with patients with PXS and normal control subjects (all P < .001) without a difference between PXS and control eyes. Customized outer annular PPCMv density in the PXG group with a value of 11.1% (SD 5.1%) was lower than that in PXS with a value of 13.2% (SD 5.3%; P= .001). Similarly, PXS values were lower than those of control eyes with a value of 18.6% (SD 5.1%; P < .001). A progressive decrease in outer PPCMv from the control group to those with PXS without glaucoma to those with PXS and glaucoma (PXG) showed deep peripapillary vasculopathy in pseudoexfoliation syndrome. Choroidal vessel density may be affected early in the course of pseudoexfoliation before glaucoma develops.

Glaucoma-like Parapapillary Choroidal Microvasculature Dropout in Patients with Compressive Optic Neuropathy

To characterize peripapillary choroidal microvasculature dropout (MvD) in patients with compressive optic neuropathy (CON) as compared with those with open-angle glaucoma (OAG) using OCT angiography (OCTA). Cross-sectional, observational study. Eighty-eight eyes of 44 patients with CON; 88 eyes of 88 patients with OAG matched by age, spherical error, and OCT-determined retinal nerve fiber layer thickness (RNFLT); and 88 eyes of 44 control participants matched by age and spherical error. Peripapillary microvasculature was evaluated, and peripapillary vessel density was measured in en face images segmented into inner-retinal and choroidal layers using swept-source OCTA. An MvD was defined as a focal sectoral capillary dropout with no visible microvascular network in the choroidal layer. Comparative characteristics of MvD in eyes with CON and OAG. Microvasculature dropout was observed in 30 eyes (34.1%) of 22 patients (50.0%) with CON, and in 48 eyes of 48 patients (54.5%) with OAG (P= 0.011). All MvDs in the CON group were located in the temporal parapapillary sector, whereas MvDs in the OAG group were located in the temporal-inferior (n= 36) and temporal-superior (n= 4) sectors. At their locations, MvDs in the CON group were accompanied by significant reductions in retinal vessel density and RNFLT, but this was not observed in the OAG group. The presence of MvD was associated significantly with female gender (P= 0.020) and thinner global retinal nerve fiber layer (P= 0.006) in the CON group, but not in the OAG group. OCT angiography of the peripapillary area showed retinal and choroidal microvasculature impairment in patients with both CON and OAG. However, the features and associated characteristics of MvD differed between these groups, suggesting that the pathogenesis of peripapillary microvascular impairment may be diverse.

Anterior Optic Nerve Head Perfusion is Dependent on Adjacent Parapapillary Choroidal perfusion

Recent studies reported that parapapillary microvascular dropout (MvD) was significantly associated with glaucoma and glaucoma progression. To understand the clinical relevance/importance of MvD, it is essential to know the exact vascular anatomy of optic nerve head (ONH). Although it is known that parapapillary choroid and the deep ONH structure including prelaminar tissue are both supplied by branches of short posterior ciliary artery, it remains controversial whether parapapillary choroid provides a major contribution to the prelaminar tissue perfusion. This study investigated perfusion within and around the ONH using indocyanine green angiography. Thirty-three eyes from 33 patients with primary open-angle glaucoma and 10 eyes from 10 normal subjects were included. The temporal sequence of dye appearance in various tissues was analyzed. We also sought the microvessels directly responsible for blood supply to the prelaminar tissue. The perfusion of the prelaminar tissue, which occurred in a sectoral fashion, was dependent on the dye appearance in the adjacent parapapillary choroid. In addition, microvessels crossing over the optic disc margin from the parapapillary choroid to the ONH were found. The findings suggest that the centripetal flow from the parapapillary choroid is an important source of prelaminar tissue perfusion.

Evaluation of Parapapillary Choroidal Microvasculature Dropout and Progressive Retinal Nerve Fiber Layer Thinning in Patients With Glaucoma

Parapapillary choroidal microvasculature dropout (MvD) is considered one of pathophysiological manifestations of glaucomatous damage. To evaluate the longitudinal change in the parapapillary choroidal MvD in patients with primary open-angle glaucoma (POAG), and to determine whether this change is associated with progressive retinal nerve fiber layer (RNFL) thinning. This prospective observational case series was conducted at a tertiary referral center in Korea and included 68 patients with POAG who exhibited parapapillary choroidal MvD in en face optical coherence tomography (OCT) angiography (OCTA) images who were enrolled from the ongoing Investigating Glaucoma Progression Study from January 1, 2016, through July 31, 2018. The mean (SD) follow-up period was 2.5 (0.2) years and observers were masked to the clinical characteristics of the participants for measurements. The OCTA images were obtained twice at an interval of at least 2 years, during which the RNFL thickness was measured at least 4 times in serial OCT examinations. Microvasculature dropout was defined as a focal sectoral capillary dropout with no visible microvascular network identified in the choroidal layer. The MvD area was measured in the OCTA images obtained at the baseline and the final follow-up. The significance of changes in the MvD area was defined using the 95% Bland-Altman limits of agreement. The rate of RNFL thinning was determined by linear regression of the serial OCT RNFL thickness measurements. The association between the change in the MvD area and the rate of RNFL thinning. Of 68 Korean participants, 37 (54.5%) were women, and the mean (SD) age was 54.3 (13.1) years. Among 68 eyes, 22 (32.4%) showed increases in the MvD area during the follow-up. Faster global RNFL thinning was associated with a larger baseline parapapillary atrophy β-zone (β = -0.55; 95% CI, -0.96 to -0.14; P = .01), disc hemorrhage detection during the follow-up period (β = -0.75; 95% CI, -1.67 to -0.34; P = .001), and a larger increase in the MvD area (β = -4.74; 95% CI, -7.72 to -1.75; P = .002). The MvD area was not associated with the rate of RNFL thinning at baseline or the final follow-up. Microvasculature dropout enlargement was associated with progressive RNFL thinning in POAG.

Association Between Parapapillary Choroidal Vessel Density Measured With Optical Coherence Tomography Angiography and Future Visual Field Progression in Patients With Glaucoma

ImportanceInvestigating the vascular risk factors of glaucoma progression is important to individualize treatment; however, few studies have investigated these factors because the available methods have proven insufficient to evaluate the vascular features of patients with glaucoma. Recently, the advent of optical coherence tomography angiography (OCT-A) allowed both qualitative and quantitative microvascular data to be obtained, to in turn evaluate the perfusion status of different retinal layers.ObjectiveTo determine whether baseline parapapillary choroidal vessel density (VD) as measured by OCT-A was associated with future glaucoma progression.Design, Setting, and ParticipantsA prospective, observational, comparative study was conducted at Seoul St Mary’s Hospital of The Catholic University of Korea from March 1, 2016, to December 31, 2018, for 108 glaucomatous eyes in which the retinal nerve fiber layer thickness and mean deviation were measured by at least 5 serial OCT and visual field (VF) examinations. The participants underwent OCT-A at baseline. Vessel density was measured using the en face image of the choroidal map of OCT-A within the β-zone parapapillary atrophy region.Main Outcomes and MeasuresParapapillary choroidal VD, retinal nerve fiber layer thinning rate, mean deviation rate, and progression of glaucoma as measured by OCT and VF.ResultsAmong 108 patients (74 women and 34 men; mean [SD] age, 59.2 [13.1] years), 38 (35.2%) showed progression of glaucoma as measured by OCT and 34 (31.5%) showed progression of glaucoma as measured by VF at the last follow-up. The mean (SD) follow-up duration was 2.6 [2.3] years. The presence of disc hemorrhage (odds ratio, 5.57; 95% CI, 3.18-8.29; P = .001), baseline mean deviation (odds ratio, 0.83; 95% CI, 0.71-0.97; P = .02), and parapapillary choroidal VD (odds ratio, 1.18; 95% CI, 1.09-1.28; P = .01) were associated with progression of glaucoma as measured by VF, but not with progression of glaucoma as measured by OCT. Baseline parapapillary choroidal VD (β, 1.08; 95% CI, 1.02-1.13; P < .001) was associated with progression of glaucoma as measured by VF using Cox proportional hazards regression analysis.Conclusions and RelevanceThese data suggest that lower parapapillary choroidal VD within the β-zone parapapillary atrophy at baseline among individuals with glaucoma could play some role in the risk of progression of glaucoma as measured by VF. The findings suggest that patients with glaucoma with lower parapapillary choroidal VD within the β-zone parapapillary atrophy at baseline warrant careful monitoring for progression of glaucoma as measured by VF.

Parapapillary Choroidal Microvasculature Dropout Is Associated With the Decrease in Retinal Nerve Fiber Layer Thickness: A Prospective Study.

To explore the correlation between longitudinal changes of peripapillary retinal nerve fiber layer (RNFL) thickness and the presence of parapapillary choroidal microvasculature dropout (MvD). This is a longitudinal cohort study. All patients with normal-tension glaucoma (NTG) were recruited from the Wenzhou Glaucoma Progression Study. The presence of MvD was determined using optical coherence tomography (OCT) angiography and the RNFL thickness was evaluated by spectral-domain OCT. All assessments were performed both at baseline and at every 3-month follow-up for at least 18 months. Seventy-one eyes were included. The presence of MvD was observed in 23 NTG eyes (32.4%). Eyes with MvD had a thinner RNFL (68.8 ± 9.6 vs. 76.2 ± 16.7 μm, P = 0.016) and a faster rate of RNFL loss (-1.2 ± 1.5 vs. -0.4 ± 1.4 μm/y, P = 0.036) compared with those without MvD. In a univariate analysis of rates of RNFL loss, the presence of MvD at baseline (β = -0.83 ± 0.38, P = 0.033) was significantly associated with progressive RNFL loss. After adjusting for age, female sex, mean follow-up IOP, axial length, central corneal thickness, and mean deviation, the presence of MvD at baseline (β = -0.85 ± 0.41, P = 0.041) was significantly associated with faster rates of RNFL loss in the multivariate analysis. There is a significant correlation between the presence of MvD and decrease in RNFL thickness in NTG patients. Our study further supported that the presence of MvD is a predictor of longitudinal RNFL damage in glaucoma.

Parapapillary Choroidal Microvasculature Dropout in Glaucoma: A Comparison between Optical Coherence Tomography Angiography and Indocyanine Green Angiography

To investigate whether the parapapillary choroidal microvasculature dropout (MvD) determined by optical coherence tomography angiography (OCTA) in glaucomatous eyes indicates a true perfusion defect and whether the MvD accurately represents the area of nonperfusion. Observational case series. Thirty primary open-angle glaucoma (POAG) patients with choroidal MvD as determined by OCTA and 13 POAG patients without this dropout. Peripapillary circulation was evaluated using both OCTA and indocyanine green angiography (ICGA). For OCTA, the choroidal microvasculature was evaluated using 4.5×4.5-mm choroid-disc vessel density maps of OCTA images of the optic nerve head. An MvD was identified in OCTA by the presence of a capillary dropout. A filling defect observed in ICGA was defined as a perfusion defect (ICGPD). The topographic correlations between MvD and ICGPD determined based on their circumferential extent, location, and area. The ICGPD was observed as a sectoral filling defect in the 30 POAG patients exhibiting MvD and appeared identical to the MvD in terms of the shape and location. The circumferential extent, location, and area of ICGPD did not differ from those of the MvD (all P > 0.05). The ICGPD was not found in any of the eyes not having the MvD. A localized MvD observed in the parapapillary choroid using OCTA coincided with the ICGPD detected by ICGA. These findings indicate that OCTA accurately images impaired parapapillary choroidal circulation.

Visual-field Deficits Associated with Proton Beam Irradiation for Parapapillary Choroidal Melanoma

A large series of patients treated with proton irradiation for parapapillary choroidal melanoma were reviewed retrospectively to determine the frequency of radiation papillopathy and visual-field loss after treatment. Among 249 patients with proton irradiation for parapapillary choroidal melanoma, the authors identified 59 patients who had visual-field testing performed before treatment and at least 18 months after treatment. The visual fields, color fundus photographs, and charts were reviewed to determine the prevalence of radiation papillopathy and visual-field loss after treatment. Nineteen of the 59 patients reviewed (31%) received a clinical diagnosis of radiation papillopathy. Progressive visual-field loss, defined as enlargement of absolute scotoma of greater than [corrected] or equal to 30 degrees as compared with the pretreatment visual field, was noted in 67% of patients with radiation papillopathy and 73% of patients without papillopathy. In both groups, visual-field loss correlated with the area of the retina predicted to be exposed to irradiation in the majority of patients. Progressive visual-field loss is common after proton irradiation for parapapillary choroidal melanoma. However, the scotoma usually correlates with the area of the retina exposed to irradiation. The development of radiation papillopathy does not appear to be associated with additional visual-field defects in most cases.