Dataset Information

Optical coherence tomography angiography reveals progressive worsening of retinal vascular geometry in diabetic retinopathy and improved geometry after panretinal photocoagulation.

ABSTRACT:

Purpose

To quantify vessel tortuosity and fractal dimension of the superficial capillary plexus (SCP) of the macula in different stages of diabetic retinopathy (DR), and following panretinal photocoagulation (PRP) using optical coherence tomography angiography (OCTA).

Methods

75 eyes of 75 subjects were divided into five groups; healthy controls, diabetes with no clinical DR, non-proliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR) and patients who received PRP for PDR (PDR+PRP).For vessel tortuosity, SCP slabs from 3x3 mm macular OCTA scans were processed using imageJ (NIH, USA), where large perifoveal vessels were traced and their length was measured with tortuosity calculated as the ratio between the actual length and the straight Euclidean length. For fractal dimension, SCP slabs were processed and imported to Fractalyse (ThéMA, France), where box-counting analyses produced fractal dimension values.

Results

We found a significant difference in vessel tortuosity and fractal dimension between the five groups (one-way ANOVA, p < 0.001both). NPDR and PDR had significantly more tortuous vessels and lower fractal dimension compared to healthy controls (Tukey HSD: p = 0.02, 0.015,0.015 and <0.001, respectively). Fractal dimension was also significantly lower in NPDR and PDR compared to eyes with no clinical DR (p <0.001 both), and in PDR compared to NPDR (p = 0.014). Following PRP, vessel tortuosity was significantly lower and fractal dimension was higher in PDR+PRP compared to PDR (p = 0.001 and 0.031, respectively).

Conclusions

We used macular OCTA scans to demonstrate significantly higher perifoveal large vessel tortuosity, and lower fractal dimension in NPDR and PDR compared to healthy controls. Vessel tortuosity shows more dramatic normalization than fractal dimension and could be explored as a sensitive marker for successful PRP.

SUBMITTER: Fayed AE

PROVIDER: S-EPMC6936773 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

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Publications

Optical coherence tomography angiography reveals progressive worsening of retinal vascular geometry in diabetic retinopathy and improved geometry after panretinal photocoagulation.

Fayed Alaa E AE Abdelbaki Ahmed M AM El Zawahry Omar M OM Fawzi Amani A AA

PloS one 20191230 12

<h4>Purpose</h4>To quantify vessel tortuosity and fractal dimension of the superficial capillary plexus (SCP) of the macula in different stages of diabetic retinopathy (DR), and following panretinal photocoagulation (PRP) using optical coherence tomography angiography (OCTA).<h4>Methods</h4>75 eyes of 75 subjects were divided into five groups; healthy controls, diabetes with no clinical DR, non-proliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR) and patients who r ...[more]

PMID: 31887149

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Project description:PURPOSE:To compare rates and identify predictive factors for events that represent worsening of proliferative diabetic retinopathy (PDR) in eyes treated with panretinal photocoagulation (PRP) or ranibizumab. DESIGN:Randomized clinical trial (55 United States sites). PARTICIPANTS:Three hundred ninety-four study eyes from 305 adults with PDR, visual acuity (VA) 20/320 or better, and no history of PRP. INTERVENTION:Panretinal photocoagulation or intravitreous ranibizumab injections (0.5 mg/0.05 ml). MAIN OUTCOME MEASURES:Time from randomization to a composite PDR-worsening outcome defined as the first occurrence of vitreous hemorrhage, retinal detachment, anterior segment neovascularization, or neovascular glaucoma. RESULTS:Through 2 years, the cumulative probability of worsening PDR was 42% (PRP) versus 34% (ranibizumab; hazard ratio [HR], 1.33; 99% confidence interval [CI], 0.90 to 1.98; P = 0.063). Worse baseline levels of diabetic retinopathy severity (Early Treatment Diabetic Retinopathy Study scale) were associated with increased risk of worsening PDR, regardless of treatment group (64% [high-risk PDR or worse] vs. 23% [moderate PDR or better]; HR, 3.97; 99% CI, 2.48 to 6.36; P < 0.001). In the PRP group, eyes receiving pattern scan versus conventional single-spot PRP also were at higher risk for worsening PDR (60% vs. 39%; HR, 2.04; 99% CI, 1.02 to 4.08; P = 0.008), regardless of the number of spots placed or the number of sittings to complete the initial PRP. Eyes in both groups with vision-impairing (VA 20/32 or worse) center-involved diabetic macular edema (DME) at baseline were required to receive ranibizumab for center-involved DME. Therefore the composite outcome was compared by treatment in the subgroup of eyes that did not have vision-impairing center-involved DME at baseline. For these eyes, the rate of PDR-worsening was greater with PRP than ranibizumab (45% vs. 31%; HR, 1.62; 99% CI, 1.01 to 2.60; P = 0.008). CONCLUSIONS:In eyes with PDR, ranibizumab resulted in less PDR worsening compared with PRP, especially in eyes not required to receive ranibizumab for center-involved DME. Although anti-vascular endothelial growth factor therapy requires a more frequent visit schedule than PRP, these findings provide additional evidence supporting the use of ranibizumab as an alternative therapy to PRP for PDR, at least through 2 years.

Project description:Macular ischemia is a key feature of diabetic retinopathy (DR). Quantification of macular ischemia has potential as a biomarker for DR.To assess the feasibility of automated quantification of capillary nonperfusion as a potential sign of macular ischemia using optical coherence tomography (OCT) angiography.An observational study conducted in a tertiary, subspecialty, academic practice evaluated macular nonperfusion with 6?×?6-mm OCT angiography obtained with commercially available 70-kHz OCT and fluorescein angiography (FA). The study was conducted from January 22 to September 18, 2014. Data analysis was performed from October 1, 2014, to April 7, 2015. Participants included 12 individuals with normal vision serving as controls and 12 patients with various levels of DR.Preplanned primary measures were parafoveal and perifoveal vessel density, total avascular area, and foveal avascular zone as detected with 6?×?6-mm OCT angiography and analyzed using an automated algorithm. Secondary measures included the agreement of the avascular area between the OCT angiogram and FA.Compared with the 12 healthy controls (11 women; mean [SD] age, 54.2 [14.2] years), the 12 participants with DR (4 women; mean [SD] age, 55.1 [12.1] years) had reduced parafoveal and perifoveal vessel density by 12.6% (95% CI, 7.7%-17.5%; P?<?.001) and 10.4% (95% CI, 6.8%-14.1%; P?<?.001), respectively. Total avascular area and foveal avascular zone area were greater in eyes with DR by 0.82 mm2 (95% CI, 0.65-0.99 mm2; P?=?.02) and 0.16 mm2 (95% CI, 0.05-0.28 mm2; P?<?.001). The agreement between the vascular areas in the OCT angiogram and FA had a ? value of 0.45 (95% CI, 0.21-0.70; P?<?.001). Total avascular area in the central 5.5-mm-diameter area distinguished eyes with DR from control eyes with 100% sensitivity and specificity.Avascular area analysis with an automated algorithm using OCT angiography, although not equivalent to FA, detected DR reliably in this small pilot study. Further study is necessary to determine the usefulness of the automated quantification in clinical practice.

Dataset Information

Optical coherence tomography angiography reveals progressive worsening of retinal vascular geometry in diabetic retinopathy and improved geometry after panretinal photocoagulation.

Purpose

Methods

Results

Conclusions

Publications

Optical coherence tomography angiography reveals progressive worsening of retinal vascular geometry in diabetic retinopathy and improved geometry after panretinal photocoagulation.

Similar Datasets

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