Role of anterior segment optical coherence tomography angiography in assessing limbal vasculature in acute chemical injury of the eye

PurposeTo study the role of two anterior segment optical coherence tomography angiography (AS-OCTA) systems in eyes with acute chemical injury.MethodsProspective study in subjects with unilateral chemical injuries. Sequential slit-lamp assessment with spectral domain (SD) (AngioVue, Optovue, USA) and swept source (SS) (Plex Elite, Zeiss, Carl Zeiss Meditec, Dublin, California, USA) AS-OCTA was performed in both eyes within 24–48 hours of injury. Subjects were managed with a standard clinical protocol and followed-up for 3 months. We assessed limbal disruption (loss of normal limbal vessel architecture), limbal vessel density measurements and agreement (kappa coefficient, κ) between masked assessors of limbal disruption based on AS-OCTA scans and slit-lamp assessment.ResultsTen subjects with median age 31 (25–33) years, 20% women, 60% suffered alkali injuries (Roper-Hall grade 1.5±0.7, Dua grade 2.3±1.2) at presentation. Mean limbal vessel density was lower in quadrants of affected eyes compared with controls detected by SD AS-OCTA (9.4%±2.0% vs 15.5%±1.8%, p<0.001) and SS AS-OCTA (8.8%±2.5% vs 13.9%±1.3%, p=0.01). There was substantial agreement when assessing limbal disruption on AS-OCTA (κ=0.7) compared with slit-lamp evaluation (κ=0.4). Overall, we found good agreement between SD and SS AS-OCTA systems in assessing limbal vessel density in eyes with chemical injury at presentation (mean paired difference: −1.08, 95% CI −3.2 to 0.5; p=0.189).ConclusionsIn this pilot study, AS-OCTA provided objective, non-contact, rapid assessment of limbal vasculature involvement in eyes with acute chemical injury. Further studies are required to establish the role of AS-OCTA in determining the prognosis of eyes with chemical injury.

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Anterior segment optical coherence tomography angiography for iris vasculature in pigmented eyes

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2020-316930 ◽

2020 ◽

pp. bjophthalmol-2020-316930

Author(s):

Marcus Ang ◽

Kavya Devarajan ◽

Anna CS Tan ◽

Mengyuan Ke ◽

Bingyao Tan ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Anterior Segment ◽

Mean Difference ◽

Vessel Density ◽

Optical Coherence ◽

Swept Source ◽

Density Measurements ◽

Stage 1 ◽

Swept Source Octa

PurposeTo compare anterior segment optical coherence tomography angiography (AS-OCTA) systems in delineating normal iris vessels and iris neovascularisation (NVI) in eyes with pigmented irides.MethodsProspective study from January 2019 to June 2019 of 10 consecutive patients with normal pigmented iris, had AS-OCTA scans with a described illumination technique, before using the same protocol in five eyes with NVI (clinical stages 1–3). All scans were sequentially performed using a spectral-domain OCTA (SD-OCTA), and a swept-source OCTA (SS-OCTA, Plex Elite 9000). Images were graded by two masked observers for visibility, artefacts and NVI characteristics. The main outcome measure was iris vessel density measurements comparing SS-OCTA and SD-OCTA systems.ResultsThe median age of subjects was 28 (20–35) years, and 50% were female. The paired mean difference of iris vessel density measurements was 11.7 (95% CI 14.7 to 8.1; p=0.002), SS-OCTA detecting more vessels than SD-OCTA. The inter-rater reliability for artefact score (κ=0.799, p<0.001) and visibility score (κ=0.722; p<0.001) were substantial. Both AS-OCTA systems were able to detect NVI vessels with a fair agreement (κ=0.588), with clearer NVI characteristics in stage 1/2 compared to stage 3 NVI (mean difference NVI score: 2.7±0.4, p=0.009).ConclusionThe SS-OCTA was better able to delineate iris vessels in normal pigmented irides compared to SD-OCTA. Both AS-OCTA systems identified NVI characteristics based on its atypical configuration or location, but further improvements are needed to allow for more accurate objective, serial quantification for clinical use.

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Vascular Density of the Anterior Segment of the Eye Determined by Optical Coherence Tomography Angiography and Slit-Lamp Photography

Ophthalmic Research ◽

10.1159/000506953 ◽

2020 ◽

Vol 63 (6) ◽

pp. 572-579

Author(s):

Nina Teresa Aicher ◽

Katsuya Nagahori ◽

Makoto Inoue ◽

Yuji Itoh ◽

Akito Hirakata

Keyword(s):

Optical Coherence Tomography ◽

Cataract Surgery ◽

Optical Coherence Tomography Angiography ◽

Anterior Segment ◽

Vascular Density ◽

Optical Coherence ◽

Slit Lamp ◽

Swept Source ◽

Vascular Flow ◽

Imagej Software

Objective: To determine the vascular density of the anterior segment (AS) of the eye from optical coherence tomography angiography (OCTA) images and slit-lamp photographs. Methods: A swept-source OCTA (Plex Elite 9000; Carl Zeiss) device modified with a +10-diopter lens was used to record the vasculature of the AS. Twenty eyes, including 4 eyes of 4 healthy subjects and 16 eyes of 12 patients scheduled for cataract surgery or combined vitrectomy and cataract surgery, were studied. The slit-lamp photographs of the AS were acquired concurrently with the AS-OCTA images. The vascular density was measured preoperatively and postoperatively in the nasal, temporal, superior, and inferior quadrants after binarization with ImageJ software. Results: Acceptable AS-OCTA images were obtained of 65% (superior), 80% (nasal), 70% (inferior), and 80% (temporal) of the eyes. The percentage of acceptable images was significantly lower in the superior quadrant among the AS-OCTA images than among the AS photographs (100%; p = 0.004). The vascular density determined by AS-OCTA was higher than that determined in the AS photographs in all quadrants (p = 0.011 to <0.001). The AS-OCTA B-mode images showed that vascular flow was identified mainly between the conjunctiva and sclera but not in the ciliary body. The vascular density increased significantly after cataract surgery in the superior quadrant, which was significantly correlated with the location of the surgical incision (p = 0.03). Conclusion: AS-OCTA can obtain images with higher vascular density of the conjunctiva and sclera than slit-lamp photographs, and AS-OCTA images can show a postoperative increase in vascular density.

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Macular vessel density in diabetes and diabetic retinopathy with swept-source optical coherence tomography angiography

Graefe s Archive for Clinical and Experimental Ophthalmology ◽

10.1007/s00417-020-04832-3 ◽

2020 ◽

Vol 258 (12) ◽

pp. 2671-2679

Author(s):

Naiqiang Xie ◽

Yan Tan ◽

Sen Liu ◽

Yining Xie ◽

Shaoshuai Shuai ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Diabetic Retinopathy ◽

Optical Coherence Tomography Angiography ◽

Vessel Density ◽

Optical Coherence ◽

Swept Source

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Additive Role of Optical Coherence Tomography Angiography Vessel Density Measurements in Glaucoma Diagnoses

Korean Journal of Ophthalmology ◽

10.3341/kjo.2019.0016 ◽

2019 ◽

Vol 33 (4) ◽

pp. 315 ◽

Cited By ~ 4

Author(s):

Hye Ji Kwon ◽

Junki Kwon ◽

Kyung Rim Sung

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Vessel Density ◽

Optical Coherence ◽

Density Measurements

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Reproducibility of macular and optic nerve head vessel density measurements by swept-source optical coherence tomography angiography

European Journal of Ophthalmology ◽

10.1177/1120672119834472 ◽

2019 ◽

Vol 30 (4) ◽

pp. 756-763 ◽

Cited By ~ 7

Author(s):

José Ignacio Fernández-Vigo ◽

Bachar Kudsieh ◽

Ana Macarro-Merino ◽

Pedro Arriola-Villalobos ◽

José María Martínez-de-la-Casa ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Optic Nerve ◽

Optic Nerve Head ◽

Optical Coherence Tomography Angiography ◽

Central Zone ◽

Vessel Density ◽

Optical Coherence ◽

Outer Retina ◽

Swept Source ◽

Capillary Plexus

Purpose: To assess the reproducibility of swept-source optical coherence tomography angiography (SS-OCTA) for macular and optic nerve head (ONH) vessel density (VD). Methods: Cross-sectional study using the Triton OCTA (Topcon, Tokyo, Japan), for VD (%) measurements in 40 eyes of 40 healthy subjects on two 6 × 6 mm scans of the macula and ONH across five subfields (central, superior, inferior, temporal, and nasal) at different segmentation levels: superficial capillary plexus (SCP), deep capillary plexus (DCP), outer retina, and choriocapillaris. Reproducibility values were summarized as intraclass correlation coefficients (ICCs) and coefficients of variations (CV). Results: ICCs for the macular VD measurements in the central zone were 0.874, 0.770, 0.575, 0.718 at the levels SCP, DCP, outer retina, and choriocapillaris, respectively, while worse ICCs were obtained for the parafoveal subfields (ICC ⩽ 0.589); CVs were 2.8%–6.7%. The reproducibility of the ONH superficial VD was ICC = 0.941 for the papillary region and was ICC = 0.499–0.853 for the peripapillary zone; CVs ranged from 4.8% to 17%. Peripapillary VD showed an ICC = 0.533–0.770 in the DCP layer, and 0.572–0.828 in the choriocapillaris. Lowest VD were obtained for the macular SCP and DCP (23% and 22%, respectively), in the foveal zone, while greatest VD were recorded in the nasal and temporal peripapillary subfields at the level of the choriocapillaris (both 68%). Conclusions: The new SS-OCTA software served to quantify macular and ONH VD with a reproducibility that was good in the central zones (foveal and papillary, respectively) and moderate in the peripheral zones (parafoveal and peripapillary).

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Acute macular neuroretinopathy: pathogenetic insights from optical coherence tomography angiography

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2018-312197 ◽

2018 ◽

Vol 103 (3) ◽

pp. 410-414 ◽

Cited By ~ 10

Author(s):

Giuseppe Casalino ◽

Alessandro Arrigo ◽

Francesco Romano ◽

Marion R Munk ◽

Francesco Bandello ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Pigment Epithelium ◽

Retinal Pigment ◽

Vessel Density ◽

Control Group ◽

Optical Coherence ◽

Cross Sectional ◽

Swept Source ◽

Acute Macular Neuroretinopathy

AimTo describe the optical coherence tomography angiography (OCT-A) features of patients affected by acute macular neuroretinopathy (AMN).Methods This is a prospective, observational, cross-sectional study. Multimodal imaging, including spectral domain OCT (Spectralis HRA+OCT; Heidelberg Engineering, Heidelberg, Germany) and 6×6 mm swept source OCT-A (ZEISS PLEX Elite 9000; ZEISS, Dublin, California), was performed on all patients. The primary outcome measure was assessment of the vascular alterations of the superficial (SCP) and deep (DCP) capillary plexuses and choriocapillaris (CC). A segmentation of the AMN lesions using enface OCT images of photoreceptors-retinal pigment epithelium complex was used to discriminate intralesional and extralesional regions on the OCT-A enface slabs of the DCP and CC reconstructions. Each OCT-A slab was imported into ImageJ V.1.50 and digitally binarised for quantitative analyses.ResultsOverall, seven patients (mean age 19.4±3.2 years, six women) affected by AMN were included. The mean best-corrected visual acuity was 0.00±0.00 logarithm of the minimum angle of resolution. Twelve healthy age-matched subjects (mean age 22±3.4 years, 10 women) represented the control group. The quantitative analysis of global vessel densities showed that the CC vessel density was significantly lower in patients with AMN (0.495±0.03) compared with the age-matched controls (0.545±0.02) (corrected p=0.0003). The intralesional vessel density of the DCP was 0.349±0.04 in AMN and vs 0.497±0.02 in the controls (corrected p=0.0002).ConclusionsOur study confirmed inner choroidal vascular flow void as a possible pathogenetic mechanism of AMN. We also found a focal impairment of the DCP within the AMN lesions. Future studies are needed to clarify which is the primary location of the vascular insult in this condition.

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Role of anterior segment optical coherence tomography angiography in the assessment of acute chemical ocular injury: a pilot animal model study

Scientific Reports ◽

10.1038/s41598-021-96086-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kai Yuan Tey ◽

Jinyuan Gan ◽

Valencia Foo ◽

Bingyao Tan ◽

Meng Yuan Ke ◽

...

Keyword(s):

Animal Model ◽

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Anterior Segment ◽

Ocular Injury ◽

Optical Coherence ◽

Chemical Injury ◽

Highly Correlated ◽

A Prospective Study ◽

And Control

AbstractTo examine the use of anterior segment-optical coherence tomography angiography (AS-OCTA) in the assessment of limbal ischemia in an animal model chemical ocular injury. We conducted a prospective study using an established chemical ocular injury model in 6 rabbits (12 eyes), dividing the cornea limbus into 4 quadrants. Chemical injury grade was induced based on extent of limbal injury (0 to 360 degrees) and all eyes underwent serial slit-lamp with AS-OCTA imaging up to one month. Main outcome measure was changes in AS-OCTA vessel density (VD) comparing injured and control cornea limbal quadrants within 24 h and at one month. AS-OCTA was able to detect differences in limbal VD reduction comparing injured (3.3 ± 2.4%) and control quadrants (7.6 ± 2.3%; p < 0.001) within 24 h of ocular chemical injury. We also observed that AS-OCTA VD reduction was highly correlated with the number of quadrants injured (r = − 0.89; p < 0.001; 95% CI − 5.65 to − 1.87). Corneal vascularization was detected by AS-OCTA in injured compared to control quadrants (10.1 ± 4.3% vs 7.0 ± 1.2%; p = 0.025) at 1 month. Our animal pilot study suggests that AS-OCTA was able to detect limbal vessel disruption from various severities of acute chemical insult, and in the future, could potentially serve as an adjunct in providing objective grading of acute ocular chemical injury once validated in a clinical trial.

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