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

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.

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

2021 ◽  
pp. bjophthalmol-2021-318847
Author(s):  
Marcus Ang ◽  
Valencia Foo ◽  
Mengyuan Ke ◽  
Bingyao Tan ◽  
Louis Tong ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Rapid Assessment ◽  
Anterior Segment ◽  
Vessel Density ◽  
Optical Coherence ◽  
Slit Lamp ◽  
Swept Source ◽  
Chemical Injury

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.

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 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.

scholarly journals Optical Coherence Tomography Angiography of Iris Nevus: A Case Report

2016 ◽  
Vol 7 (3) ◽  
pp. 450-456 ◽  
Author(s):  
Davide Allegrini ◽  
Giovanni Montesano ◽  
Alfredo Pece
Keyword(s):  
Optical Coherence Tomography ◽  
Case Report ◽  
Optical Coherence Tomography Angiography ◽  
Anterior Segment ◽  
Ultrasound Biomicroscopy ◽  
Vascular Network ◽  
Optical Coherence ◽  
Early Phases ◽  
Iris Nevus

Iris nevus is common: 6% of patients with suspected iris melanoma have lesions other than melanoma, and 36% of them are nevi. Iris nevus turns into melanoma in approximately 8% of cases at a mean of 15 years. This case report provides the first description of an iris tumor examined with iris optical coherence tomography angiography (OCTA) compared to iris fluorescein angiography (IFA). A 60-year-old man with a diagnosis of iris nevus in the left eye was referred to our department for IFA and iris OCTA. The iris vasculature in IFA was visible only in the early phases, but not clearly. OCTA, however, gave visualization of the vascular network and very precisely defined the vessels of the whole lesion, except for the pupillary portion, which was masked by superficial pigment accumulations. IFA and iris OCTA can add information about the vascular architecture compared to slit-lamp biomicroscopy, ultrasound biomicroscopy, and anterior-segment OCT. However, IFA is time-consuming and invasive and can – very occasionally – cause serious adverse reactions. In contrast, OCTA defines the texture of the iris vasculature better. In conclusion, OCTA is a new method, easy to execute, needing no dye injection, and provides useful information on the vascular network of iris lesions. It could therefore be helpful in the diagnosis and follow-up of these lesions.

scholarly journals Automated Measurement of Iris Surface Smoothness Using Anterior Segment Optical Coherence Tomography  

2021 ◽  
Author(s):  
Mohammad Zarei ◽  
Tahereh Mahmudi ◽  
Hamid Riazi-Esfahani ◽  
Behnam Mousavi ◽  
Nazanin Ebrahimiadib ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Correlation Coefficient ◽  
Anterior Segment ◽  
Control Group ◽  
Optical Coherence ◽  
Interclass Correlation Coefficient ◽  
Interclass Correlation ◽  
Automated Measurements ◽  
And Control ◽  
Fellow Eyes

Abstract Fuchs uveitis (FU) is a chronic and often unilateral ocular inflammation and characteristic iris atrophic changes, other than heterochromia, are common in FU and are key to the correct diagnosis in many cases. With the advent of anterior segment optical coherence tomography (AS-OCT), some investigators attempted to quantitatively study these atrophic changes; mostly by introducing various methods to measure iris thickness in AS-OCT images. We aimed to present an automated method in a observational case series to measure the smoothness index (SI) of iris surface in AS-OCT images. The ratio of the length of the straight line connecting the most peripheral and central points of the anterior iris border (in nasal and temporal sides) to the actual length of this border on AS-OCT images, was defined as SI. In a uveitis referral center twenty-two eyes of 11 patients with unilateral Fuchs uveitis (FU) (7 female) and 22 eyes of 11 healthy control subjects underwent AS-OCT imaging. Image J and a newly developed MATLAB algorithm were used for manual and automated SI measurements, respectively. Agreement between manual and automated measurements was evaluated with Bland-Altman analysis and interclass correlation coefficient. The inter-eye difference of SI was compared between FU group and control group. Automated mean overall SI was 0.868 ± 0.037 and 0.840 ± 0.039 in FU and healthy fellow eyes, respectively (estimated mean difference = -0.028, 95% CI [-0.038, -0.018], p<0.001). Bland- Altman plots showed good agreement between two methods in both healthy and FU eyes. Interclass correlation coefficient between the manual and automated measurements in the FU and healthy fellow eyes was 0.958 and 0.964, respectively. Inter-eye difference of overall SI was 0.029 ± 0.015 and 0.012 ± 0.008 in FU group and control group, respectively (p=0.01). We concluded that he automated algorithm can rapidly and conveniently measure SI with results comparable to manual method.

scholarly journals Evaluation of implanted perforated lacrimal punctal plugs using anterior segment optical coherence tomography

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Raafat Mohyeldeen Abdelrahman Abdallah ◽  
Ahmed Mohamed Kamal Elshafei ◽  
Heba Radi AttaAllah
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Segment ◽  
Tear Film ◽  
Early Postoperative Period ◽  
Optical Coherence ◽  
Proper Position ◽  
Punctal Plugs ◽  
Tear Meniscus ◽  
Tear Meniscus Height ◽  
A Prospective Study

Abstract Purpose Evaluation of the patency and position of perforated lacrimal punctal plugs implanted for treating punctal stenosis together with quantitative assessment of the precorneal tear film using anterior segment optical coherence tomography (AS-OCT). Methods In a prospective study, the lower punctum of 54 eyes of 29 patients implanted with perforated punctal plugs were examined using AS-OCT during the early postoperative period. Preoperative tear meniscus height (TMH) and tear meniscus area (TMA) were evaluated. Postoperatively, the patency of the plug, its position, TMH and TMA were evaluated, and the results were correlated with postoperative epiphora. Munk scale was used for epiphora grading. Results Using AS-OCT, 48 (88.9%) plugs were found in proper position while 6 (11.1%) were rotated. The lumen of the plugs was completely patent in 47 (87%) plugs, partially obstructed in 2 (3.7%) plugs and completely occluded in 5 (9.2%) plugs. There was a statistically significant postoperative decrease of TMH and TMA (P < 0.001) and postoperative epiphora Munk score (P < 0.001). Conclusion AS-OCT is a valuable, reliable, and noninvasive investigative tool that can detect the proper positioning, patency, and contents of the implanted perforated lacrimal punctal plugs in addition to measurement of TMH and TMA. Trial registration ClinicalTrials.gov ID: NCT04624022, https://clinicaltrials.gov/ct2/show/NCT04624022

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

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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