scholarly journals Optical Coherence Tomography Angiography Imaging to monitor Anti-VEGF treatment of Corneal Vascularization in a Rabbit Model

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kavya Devarajan ◽  
Hon Shing Ong ◽  
Nyein C. Lwin ◽  
Jacqueline Chua ◽  
Leopold Schmetterer ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Imaging Technique ◽  
Anterior Segment ◽  
Rabbit Model ◽  
Saline Group ◽  
Optical Coherence ◽  
Conjunctival Injection ◽  
Anti Vegf ◽  
Significant Difference

AbstractOptical coherence tomography angiography (OCTA) is a well-established non-invasive retinal vascular imaging technique. It has been recently adapted to image the anterior segment and has shown good potential to image corneal vascularisation. The purpose of the study is to evaluate the usefulness of OCTA to monitor regression of corneal vessels following anti-VEGF (vascular endothelial growth factor) treatment using a previously established corneal vascularisation rabbit model. The regression of vessels following the treatment with aflibercept and ranibizumab anti-VEGFs using both topical instillation and sub-conjunctival injection was quantified using OCTA and compared with ICGA (indocyanine green angiography). Overall vessel density measurements using OCTA showed good correlation (r = 0.988, p < 0.001) with ICGA, with no significant difference between the two treatment groups (p = 0.795). It was also shown that OCTA provided good repeatability outcomes of the quantitative measurements. Using Bland-Altman plots, vessel growth density values between anti-VEGF treatments were compared to control saline group. It was observed that aflibercept provided longer lasting effect than ranibizumab. We also observed that in both drugs, the topical route of administration topical provided longer regression outcomes compared to one-time sub-conjunctival injection. Thereby, with this pilot study, it was demonstrated that OCTA is a reliable imaging technique to follow-up and monitor corneal vascularisation and its treatment quantitatively.

Optical Coherence Tomography Angiography for Anterior Segment Vasculature Imaging

Ophthalmology ◽  
2015 ◽  
Vol 122 (9) ◽  
pp. 1740-1747 ◽  
Author(s):  
Marcus Ang ◽  
Dawn A. Sim ◽  
Pearse A. Keane ◽  
Chelvin C.A. Sng ◽  
Catherine A. Egan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Anterior Segment ◽  
Optical Coherence

scholarly journals Swept Source Optical Coherence Tomography Angiography for Contact Lens-Related Corneal Vascularization

2016 ◽  
Vol 2016 ◽  
pp. 1-3 ◽  
Author(s):  
Marcus Ang ◽  
Yijun Cai ◽  
Anna C. S. Tan
Keyword(s):  
Optical Coherence Tomography ◽  
Image Quality ◽  
Contact Lens ◽  
Optical Coherence Tomography Angiography ◽  
Quality Score ◽  
Image Quality Score ◽  
Optical Coherence ◽  
Swept Source ◽  
Corneal Vascularization ◽  
Significant Difference

Purpose. To describe a novel technique of adapting a swept-source optical coherence tomography angiography (OCTA) to image corneal vascularization.Methods. In this pilot cross-sectional study, we obtained 3 × 3 mm scans, where 100,000 A-scans are acquired per second with optical axial resolution of 8 μm and lateral resolution of 20 μm. This was performed with manual “XYZ” focus without the anterior segment lens, until the focus of the corneoscleral surface was clearly seen and the vessels of interest were in focus on the corresponding red-free image. En face scans were evaluated based on image quality score and repeatability.Results. We analyzed scans from 10 eyes (10 patients) with corneal vascularization secondary to contact lens use in 4 quadrants, with substantial repeatability of scans in all quadrants (mean image quality score 2.7 ± 0.7;κ=0.75). There was no significant difference in image quality scores comparing quadrants (superior temporal: 2.9 ± 0.6, superior nasal: 2.8 ± 0.4, inferior temporal: 2.5 ± 0.9, and inferior nasal: 2.4 ± 1.0;P=0.276) and able to differentiate deep and superficial corneal vascularization.Conclusion. This early clinical study suggests that the swept-source OCTA used may be useful for examining corneal vascularization, which may have potential for clinical applications such as detecting early limbal stem cell damage.

scholarly journals Repeatability of ocular surface vessel density measurements with optical coherence tomography angiography

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Sijie Cai ◽  
Fengping Zhao ◽  
Chixin Du
Keyword(s):  
Optical Coherence Tomography ◽  
Ocular Surface ◽  
Optical Coherence Tomography Angiography ◽  
Imaging System ◽  
Intraclass Correlation ◽  
Vessel Density ◽  
Optical Coherence ◽  
Significant Difference ◽  
Surface Vessel ◽  
Healthy Eyes

Abstract Background To determine the repeatability of measurements of ocular surface vessel density in normal and diseased eyes using optical coherence tomography angiography (OCTA). Methods Ten normal eyes, 10 pinguecula eyes, and 10 pterygium eyes of 30 volunteers were subjected to OCTA (AngioVue Imaging System, Optovue, Inc.). For scanning, we used the corneal adapter module. Each eye was scanned three times in the nasal and temporal directions, separately. AngioVue software was used to generate the ocular surface vessel density. Ocular surface vessel density was defined as the proportion of vessel area with blood flow to the total measurement area (3 × 3 mm2). Intersession repeatability of the measurement was summarized as the coefficient of variation (CV), and intraclass correlation coefficients (ICC) were calculated by variance component models. Results The CVs were less than 5% in all subjects, and the ICCs exceeded 0.9; thus, all measurements showed good repeatability. The nasal vessels densities differed significantly between healthy eyes and eyes with pterygium (P < 0.05); however, there was no significant difference between healthy eyes and eyes with pinguecula (P = 0.466). Conclusions These results suggest that measurement of ocular surface vessel density by OCTA in normal eyes and eyes with pterygium and pinguecula is repeatable. This preliminary research describes a quantitative and visual method for assessing vessel density of the ocular surface with a high level of consistency.

scholarly journals Comparison of two different optical coherence tomography angiography devices in detecting healthy versus glaucomatous eyes – an observational cross-sectional study

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
A. R. Kee ◽  
V. C. H. Yip ◽  
E. L. T. Tay ◽  
C. W. Lim ◽  
J. Cheng ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diagnostic Accuracy ◽  
Optic Disc ◽  
Optical Coherence Tomography Angiography ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
Retest Reliability ◽  
Significant Difference ◽  
Test Retest Reliability

Abstract Background To understand the differences between two different optical coherence tomography angiography (OCTA) devices in detecting glaucomatous from healthy eyes by comparing their vascular parameters, diagnostic accuracy and test-retest reliability. Methods A cross-sectional observational study was performed on healthy and glaucoma subjects, on whom two sets of OCTA images of optic disc and macula were acquired using both AngioVue (Optovue, USA) and Swept Source (Topcon, Japan) OCTA devices during one visit. A novel in-house software was used to calculate the vessel densities. Diagnostic accuracy of the machines in differentiating healthy versus glaucomatous eyes was determined using area under the receiver operating characteristic curve (AUROC) and test-retest repeatability of the machines was also evaluated. Results A total of 80 healthy and 38 glaucomatous eyes were evaluated. Glaucomatous eyes had reduced mean vessel density compared to healthy controls in all segmented layers of the optic disc and macula using AngioVue (p ≤ 0.001). However, glaucomatous eyes had higher mean vessel density on optic disc scans using Swept Source, with lack of statistically significant difference between healthy and glaucomatous eyes. The AUROC showed better diagnostic accuracy of AngioVue (0.761–1.000) compared to Swept Source (0.113–0.644). The test-retest reliability indices were generally better using AngioVue than Swept Source. Conclusions AngioVue showed better diagnostic capability and test-retest reliability compared to Swept Source. Further studies need to be undertaken to evaluate if there is any significant difference between the various machines in diagnosing and monitoring glaucoma.

scholarly journals Optical Coherence Tomography Reveals New Insights into the Accommodation Mechanism

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mahmoud Mohamed Farouk ◽  
Takeshi Naito ◽  
Kayo Shinomiya ◽  
Hiroshi Eguchi ◽  
Khulood Mohammed Sayed ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Outcome Measures ◽  
Anterior Segment ◽  
Case Series ◽  
Optical Coherence ◽  
Anterior Pole ◽  
Forward Movement ◽  
Anterior Segment Oct ◽  
Lens Thickness ◽  
Significant Difference

Purpose. To evaluate the movement of the anterior and posterior lens poles during naturally stimulated accommodation in children using anterior segment optical coherence tomography (OCT).Methods. This is a prospective, observational, noncomparative case series including 18 eyes of nine children. Analysis of the anterior segment in the accommodated and unaccommodated state (with cycloplegia) was done using anterior segment OCT. The main outcome measures were the position of the anterior and posterior lens poles (in relation to the cornea) and lens thickness (LT).Results. A Statistically significant forward movement of the anterior lens pole and backward movement of the posterior lens pole with an increase in LT were found during accommodation (P<0.001). There was no significant difference between the degree of movement of the anterior lens pole and the posterior lens pole during accommodation (P=0.944).Conclusions. Anterior segment OCT provides a rapid noncontact method for studying accommodation in children. The backward movement of the posterior lens pole during accommodation nearly equals the forward movement of its anterior pole. These data minimize the theoretical hydraulic effect of the vitreous during accommodation, adding more support to the capsular theory of Helmholtz.

scholarly journals The Role of Optical Coherence Tomography Angiography in Ranibizumab-Treated Choroidal Neovascularization in Choroidal Osteoma

2020 ◽  
Vol 11 (2) ◽  
pp. 370-376
Author(s):  
William J. Carroll ◽  
Yi Stephanie Zhang ◽  
Lee M. Jampol ◽  
Manjot K. Gill
Keyword(s):  
Optical Coherence Tomography ◽  
Visual Acuity ◽  
Choroidal Neovascularization ◽  
Optical Coherence Tomography Angiography ◽  
Initial Evaluation ◽  
Optical Coherence ◽  
Choroidal Osteoma ◽  
Anti Vegf ◽  
Subsequent Response ◽  
Intraretinal Fluid

In this study, we report the initial evaluation of choroidal neovascularization (CNV) secondary to choroidal osteoma and subsequent response to anti-vascular endothelial growth factor (anti-VEGF) treatment monitored with optical coherence tomography angiography (OCT-A). A 38-year-old female presented with an initial visual acuity of 20/150 in the left eye. Clinical examination revealed a choroidal osteoma. OCT demonstrated both subretinal and intraretinal fluid. OCT-A was performed and showed CNV. A course of ten treatments with ranibizumab showed an improvement of visual acuity to 20/30–3, improvement of subretinal and intraretinal fluid, as well as attenuation of CNV. Our report demonstrates OCT-A as a useful tool for both initial evaluation of CNV and following treatment response to anti-VEGF therapy.

Diagnostic performance of optical coherence tomography angiography in glaucoma: a systematic review and meta-analysis

2019 ◽  
Vol 103 (11) ◽  
pp. 1677-1684 ◽  
Author(s):  
Ana I M Miguel ◽  
André B Silva ◽  
Luis F Azevedo
Keyword(s):  
Systematic Review ◽  
Optical Coherence Tomography ◽  
Prospective Studies ◽  
Diagnostic Performance ◽  
Optical Coherence Tomography Angiography ◽  
Meta Analysis ◽  
Optical Coherence ◽  
Manual Search ◽  
Significant Difference ◽  
The Mean

BackgroundCompared with current imaging methods, the diagnostic performance and the advantages and limitations of optical coherence tomography angiography (OCTA) remain unclear. We performed a systematic review and meta-analysis of studies investigating vessel density (VD) in patients with glaucoma using OCTA.MethodsWe conducted a literature search on PubMed, Scopus, Web of Science, ISI Conference Proceedings and Google Scholar, along with a manual search, from January 2006 to March 2018. We included prospective studies that used OCTA to compare the VD in glaucomatous eyes with healthy control eyes.ResultsOf 3045 screened articles, 24 were included in a broad characterisation and 18 in the meta-analysis. We observed a statistically significant reduction in the mean peripapillary VD (MPVD) in glaucoma (MPVD: 57.53%, 95% CI 52.60 to 62.46, p< 0.001) compared with controls (MPVD: 65.47%, 95% CI 59.82 to 71.11; standardised mean difference [SMD], –1.41, 95% CI –1.62 to –1.20, p< 0.001) for 888 glaucomatous and 475 healthy eyes, and also in the mean-whole optic nerve image VD (SMD, –9.63, 95% CI –10.22 to –9.03, p<0.001), mean inside-disc VD (SMD, − 9.51, 95% CI –12.66 to –6.36, p<0.05) and mean parafoveal VD (SMD, –3.92, 95% CI –4.73 to –3.12, p<0.001). Subgroup analyses revealed a significant difference in the MPVD across glaucoma subtypes and OCTA devices.ConclusionThis suggests the diagnostic utility of OCTA in detecting glaucomatous eyes; however, further longitudinal prospective studies are welcomed to characterise vascular changes in glaucoma.

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