Alteration of perivascular reflectivity on optical coherence tomography of branched retinal vein obstruction.

This study aimed to evaluate perivascular reflectivity in patients with branched retinal vascular obstruction (BRVO) using en-face optical coherence tomography (OCT). The study retrospectively analyzed 45 patients with recurrent BRVO, 30 with indolent BRVO, and 45 age- and sex-matched controls. Using a 3.0 × 3.0-mm deep capillary plexus slab on macular scans, OCT angiography (OCTA) and structural en-face OCT scans were divided into four quadrants. Obstructive quadrants of OCTA scans were binarized using a threshold value of mean + 2 standard deviation. The selected area of high signal strength (HSS) was applied to the structural en-face OCT scans, and the corrected mean perivascular reflectivity was calculated as the mean reflectivity on the HSS area/overall en-face OCT mean reflectivity. The same procedure was performed in the quadrants of the matched controls. Regression analysis was conducted on several factors possibly associated with corrected perivascular reflectivity. The perivascular reflectivity in the obstructive BRVO quadrant was significantly higher than in the indolent BRVO and control quadrants (P = 0.009, P = 0.003). Both univariate and multivariate regression analyses showed a significant correlation between the average number of intravitreal injections (anti-vascular endothelial growth factor or dexamethasone implant) per year and refractive errors and image binarization threshold and perivascular reflectivity (P = 0.011, 0.013, < 0.001/univariate; 0.007, 0.041, 0.005/multivariate, respectively). En-face OCT scans of the deep capillary plexus slab revealed higher perivascular reflectivity in recurrent BRVO eyes than in indolent BRVO and control eyes. The results also indicate a remarkable correlation between perivascular reflectivity and the average number of intravitreal injections, suggesting a link to recurrence rates.

Morphologic analysis of the foveal avascular zone for prediction of postoperative visual acuity in advanced idiopathic epiretinal membrane.

To investigate the preoperative morphology of the foveal avascular zone (FAZ) for prediction of the postoperative visual acuity in advanced idiopathic epiretinal membrane (ERM). 28 patients (28 eyes) with unilateral idiopathic ERM who underwent pars plana vitrectomy with internal limiting membrane peeling were included. Superficial FAZ was measured preoperatively in both eyes using optical coherence tomography angiography. Area, perimeter, and circularity of FAZ were achieved, and the differences between the ERM eyes and the contralateral eyes were evaluated to analyze the degree of FAZ distortion in diseased eyes. The best-corrected visual acuity (BCVA) and central foveal thickness (CFT) were measured at baseline and more than 6 months after surgery. The correlations of the preoperative FAZ with BCVA and CFT were assessed. The FAZ in the eyes with ERM was significantly reduced, and the BCVA was significantly correlated with the FAZ area (FAZa) (P = 0.001) and the FAZ perimeter (FAZp) (P < 0.001) before surgery. LogMAR BCVA and CFT were significantly improved from 0.550 ± 0.221 to 0.354 ± 0.229 (P = 0.008), and from 524.393 ± 93.575 µm to 400.071 ± 75.979 µm (P < 0.001) after surgery. The preoperative FAZa and FAZp were significantly associated with letter score gain (P < 0.001, P < 0.001) and the postoperative final BCVA (P = 0.026, P = 0.006). The preoperative FAZp had correlation with ratio of postoperative to preoperative CFT (P = 0.016). The preoperative FAZp is a predictor of visual acuity and morphological prognosis after surgery in advanced idiopathic ERM.

En-face optical coherence tomography hyperreflective foci of choriocapillaris in central serous chorioretinopathy.

The purpose of this study is to evaluate choroidal hyperreflective foci (HRF) changes in central serous chorioretinopathy (CSC) on en-face optical coherence tomography (OCT). Retrospective analysis of 42 patients with unilateral CSC (84 eyes, including fellow eyes for controls) and 42 age- and sex-matched controls. With 4.5 × 4.5 mm macular scans, structural en-face OCT choriocapillaris (CC) slabs were used to calculate the density and number of HRF in acute CSC eyes with serous retinal detachment (SRD), resolved CSC eyes without SRD, unaffected fellow eyes, control eyes, and 1-year follow-up eyes. Based on the 2-disc diameter (3000 µm), the en-face OCT scan was divided into foveal and perifoveal lesion and analyzed to consider the impact of SRF in HRF measurement. Regression analyses were performed on the several factors with HRF number and density in the acute and resolved CSC eyes. The perifoveal density and number of CC HRF was significantly lower in the resolved CSC eyes when compared to the acute CSC eyes (P = 0.002, both), fellow eyes (P = 0.042/density, 0.028/number), and controls (P = 0.021/density, P = 0.003/number). There was no significant difference between the acute CSC eyes, fellow eyes, controls, and 1-year follow-up eyes. As subfoveal choroidal thickness decreased and choroidal vascularity (CVI) increased, the perifoveal density and number of HRF was measured higher with a significant correlation in univariate regression analysis of the acute and resolved CSC eyes (all, P < 0.05). The authors hypothesized that stromal edema induced by choroidal congestion and hyperpermeability has the greatest influence on HRF measurement, possibly affected by inflammatory cells and materials extravasation.

Serial choriocapillaris flow changes in eyes with branched retinal vascular obstruction (BRVO).

PURPOSE: To evaluate the choriocapillaris (CC) flow changes in branched retinal vascular obstruction (BRVO) on optical coherence tomography angiography (OCTA). METHODS: Retrospective analysis of 29 patients with unilateral BRVO (58 eyes, including unaffected fellow eyes for controls). 4.5 x 4.5 mm macular scans were divided into 4 quadrants. Serial analyses were conducted on CC flow voids of the opposite quadrant to the active occluded area in BRVO eyes. Each of the quadrants were also compared to the occluded quadrant of resolved eyes and the contralateral quadrant of fellow eyes by matched data analysis. A regression analysis was performed on the several parameters (Choroidal thickness; CT, Choroidal vascularity index; CVI, Central macular thickness; CMT, The number of intravitreal injections) and CC flow voids. RESULTS: The CC flow void increased sequentially: The uninvolved quadrant of acute BRVO-affected eyes, that of resolved eyes after 3-month/1-year, the contralateral quadrant of fellow eye, the involved (occluded) quadrant of resolved eyes. There were significant correlations between initial CMT, the number of injections and the CC flow void of uninvolved quadrants (P = 0.025, 0.031, respectively), and between the involved (occluded) quadrants and fellow CT (P = 0.029). CONCLUSION: CC flow void of uninvolved macular areas decreased significantly in eyes with acute BRVO, suggesting that CC changes were limited to the blocked area and a compensatory mechanism would work in surrounding areas.

Quantitative analysis of choroidal blood flow parameters in optical coherence tomography and angiography in central serous chorioretinopathy.

PURPOSE: To evaluate the choriocapillaris (CC) flow in central serous chorioretinopathy (CSC) and determine the relationship between CC flow void with the choroidal thickness (CT) and choroidal vascularity index (CVI). METHODS: Retrospective analysis of 20 patients with CSC (40 eyes, including unaffected fellow eyes) and 20 age- and sex-matched controls. After compensation with optical coherence tomography (OCT) en-face structural image, the CC flow void (%) was measured using the phansalkar threshold with a window radius of 3 and 15 pixels. The mean CC flow voids of acute CSC, recovered-acute CSC, unaffected fellow, and control eyes were compared by matched data analysis. A regression analysis was performed on the choroidal parameters (CT and CVI) and CC flow voids. RESULTS: The CC flow void had an increasing tendency in the following order: control, fellow, recovered-acute CSC, and acute CSC eyes. Acute/recovered comparison showed a significant P value (0.008) in the foveal lesion. Recovered/fellow and fellow/control presented significant P values regardless of location to fovea (all <0.05). There were significant positive correlations between CT and CC flow void (P < 0.05) in the acute CSC, recovered-acute CSC eyes. CONCLUSION: The CC flow on OCT angiography decreased in acute CSC eyes, especially in the foveal lesion, with a published compensation method. The findings suggest that unmodulated choroidal blood flow contributed to partially reversible diminished CC flow.

Role of the choroidal vascularity index in branch retinal vein occlusion (BRVO) with macular edema.

PURPOSE: To assess choroidal vasculature changes in eyes with branch retinal vein occlusion (BRVO) and macular edema (ME) using the choroidal vascularity index (CVI) and evaluate the effectiveness of CVI as a prognostic biomarker. METHODS: 35 patients with monocular BRVO and ME were analyzed retrospectively. Luminal and stromal areas in choroids of swept-source optical coherence tomography were calculated using the image binarization technique. The CVI was calculated as the ratio of the luminal to total choroidal area. The CVI of BRVO and ME eyes were compared with that of the unaffected fellow and post anti-vascular endothelial growth factor (VEGF) injected eyes. A regression analysis was performed on the choroidal parameters, logMAR visual acuity (VA) two years post disease onset and central macula thickness (CMT). RESULTS: The CVI of BRVO and ME eyes was significantly lower than the fellow and post-injected eyes (p<0.05). The regression analysis showed a strong association between two years after logMAR VA and the CVI of fellow eyes (R2 = 0.433, p<0.001). Remarkable correlations were observed in the CVI and subfoveal choroidal thickness of BRVO and ME eyes (R2 = 0.189, 0.155, respectively, p<0.05). The CMT of diseased eyes were also significantly associated with the CVI of unaffected fellow eyes (R2 = 0.113, p<0.05). CONCLUSIONS: The alteration of CVI in BRVO and ME suggests that choroidal vasculature might be affected by extracellular fluid shift and VEGF changes. The fellow eye CVI could be a useful supplementary prognostic biomarker.

Clinical Clues to Predict the Presence of Parafoveal Scotoma on Humphrey 10-2 Visual Field Using a Humphrey 24-2 Visual Field.

PURPOSE: To investigate characteristics related to the presence of parafoveal scotoma on Humphrey 10-2 visual field (VF) in early glaucoma patients. DESIGN: Prospective, cross-sectional study. METHODS: participants: Ninety-one eyes from 91 patients with glaucomatous optic neuropathy were prospectively tested with a 10-2 VF test. OBSERVATION PROCEDURES: Glaucoma patients were classified into eyes with or without parafoveal scotoma on 10-2 VF based on pattern deviation plot. The central 10 degree region of Humphrey 24-2 VF test comprised 12 points and any abnormal VF points depressed <5%, <2%, <1%, or <0.5% from the normal database on pattern deviation plot were analyzed. Various factors related to the presence of parafoveal scotoma on 10-2 VF were analyzed. MAIN OUTCOME MEASURES: Abnormal 24-2 VF points, macular ganglion cell-inner plexiform layer thickness. RESULTS: The presence of abnormal 24-2 VF points <0.5% was significantly different between eyes with and without parafoveal scotoma on 10-2 VF (P < .01). The minimum macular ganglion cell-inner plexiform layer thickness (P = .04), any central 12 points depressed <0.5% on 24-2 VF (P < .01), and any central 12 points depressed <5% on 24-2 VF that spatially corresponds to macular ganglion cell-inner plexiform layer thinning (P < 0.01) were related factors to the presence of parafoveal scotoma on 10-2 VF. CONCLUSIONS: Glaucomatous eyes with any abnormal 24-2 VF points on the central 10 degree region that are depressed <0.5% or <5% that correlates to macular ganglion cell-inner plexiform layer thinning should receive attention and be further evaluated with a 10-2 VF test.