Optical Coherence Tomography Evaluation Research Articles

Acute eclipse retinopathy: A small case series

We present four young patients with acute severe solar retinopathy after observation of the total eclipse on January 4, 2011 without appropriate eye protection. Funduscopic findings were accompanied by optical coherence tomography (OCT) investigation of the macula. All our patients were young (range 14–29 years). In three of the four patients we have been able to repeat OCT evaluation revealing that the retinal changes were reversible, but delineating mild pathology in the retinal pigment epithelium and photoreceptors. Best-corrected visual acuity in the fourth case was 6/24. In addition, macular edema, which has been previously described in literature, could not be demonstrated by OCT. In the two cases we performed an early fluorescein angiogram, no pathology was seen.

SUPRA CHOROIDAL BUCKLING IN MANAGING MYOPIC VITREORETINAL INTERFACE DISORDERS

To evaluate the efficacy of supra choroidal buckling procedure using a supra choroidal catheter, as a new approach in treating myopic vitreomacular interface disorders specially in difficult cases of myopic traction maculopathy with or without macular hole retinal detachment in posterior staphyloma depending on the concept of indenting the choroid only, from a 1-year data study. A newly developed supra choroidal catheter was used to deliver stabilized, cross-linked, long-acting hyaluronic acid as a filler in the supra choroidal space in the area of the staphyloma forming a choroidal indenting effect. Before the injection, pars plana vitrectomy was performed without internal limiting membrane peeling to avoid the risk of break of the roof of foveal detachment in case of foveoschisis. This indentation was used to treat 11 patients with myopic foveoschisis and 12 patients with myopic macular hole retinal detachment, 5 of whom had failed primary repair by vitrectomy before inclusion in this trial. Clinical and optical coherence tomographic evaluations of these patients were performed over 1-year follow-up. Retinal layer restoration was achieved in all 11 eyes with myopic foveoschisis. This was gradual over a period of 2 to 6 weeks postoperatively. No recurrence over the 12-month follow-up was observed. Visual acuity improved by 1 line or more in 9 eyes (81.8%). Of the 12 eyes, 10 with macular hole detachment (83%) showed closure of the holes in association with the resolution of the detachment; 2 eyes showed resolution of the detachment and flatting of the edge of the holes but with incomplete closure on optical coherence tomography. Eight eyes (66.6%) showed improvement in visual acuity by 1 or more lines with no recurrence of retinal detachment over the 12-month follow-up period. The indentation effect was sufficient over the 12-month follow-up period. The indentation effect achieved by supra choroidal approach can be used as a method of managing myopic foveoschisis and myopic macular hole with detachment even in eyes with failed primary vitrectomy, counteracting the role of posterior staphyloma in the role of the disease. The indentation effect is sufficient for first year of follow-up.

Frequency-domain optical coherence tomography evaluation of a patient with Kawasaki disease and severely calcified plaque

Frequency-domain optical coherence tomography evaluation of a patient with Kawasaki disease and severely calcified plaque

Optical coherence tomography imaging of non-melanoma skin cancer undergoing photodynamic therapy reveals subclinical residual lesions

BackgroundPhotodynamic therapy with methyl aminolaevulinate (MAL–PDT) is a widely used non-invasive treatment modality for non-melanoma skin cancer (NMSC). The outcome of MAL–PDT is usually primarily evaluated clinically. Optical coherence tomography (OCT) is a non-invasive imaging technology based on interferiometry. OCT has been proven to provide high accuracy in identifying NMSC lesions and performing thickness measurements of thin tumours. ObjectivesTo describe the OCT morphology in in-vivo NMSC lesions during MAL–PDT treatment and to investigate the use of OCT in evaluating the response of MAL–PDT treated NMSC lesions. MethodsA total of 18 biopsy-proven basal cell carcinomas and actinic keratoses were monitored by OCT during 2 sessions of MAL–PDT treatment. At 3-months follow-up the patients were assessed both by OCT and clinically. If the clinical and OCT evaluation came to different conclusions on recurrence of the lesion, patients were followed more closely at clinical appointments for up to one year after the PDT treatment. ResultsAll lesions displayed at least one OCT characteristic before MAL–PDT treatment. At 3 months follow-up, recurrence was suspected clinically in 5/18 cases, with OCT in 7/18 cases. OCT correctly identified all of the partial responses also found by the clinical examinations. In both cases where recurrence was only found in OCT, this was subsequently confirmed by histology. ConclusionsOur study suggests that OCT identified 29% more recurrences than clinical examination alone. OCT can detect subclinical residual NMSC lesions after MAL–PDT treatment and may therefore be an accurate tool for early detection of residual lesional tissue.

Optical coherence tomography evaluation of late strut coverage patterns between first‐generation drug‐eluting stents and everolimus‐eluting stent

To compare strut coverage patterns between everolimus-eluting stent (EES) and first-generation drug-eluting stents (DES) at more than 12 months after successful implantation, using optical coherence tomography (OCT). No sufficient OCT data has been reported comparing late strut coverage patterns between EES and first-generation DES. The favorable late results after EES implantation could be related to lower rates of uncovered and malapposed struts. A total of 66 DES (21 EES, 23 SES, and 22 PES) that were implanted at least 1 year in advance in 40 patients and met good late angiographic results were evaluated by OCT. The percentage of uncovered and malapposed struts, calculated as the ratio of uncovered or malapposed struts to total struts in all cross-sectional images per stent, was compared among the three groups. A total of 35,061 struts were analyzed: 11,967 from EES, 11,855 from SES, and 11m239 from PES. The average tissue coverage thickness of the struts per stent was greater in EES than in SES and PES (109 ± 40 µm vs. 72 ± 27 µm and 83 ± 26 µm, respectively; P = 0.001). The percentage of uncovered struts (1.9 ± 4.1% in EES vs. 11.6 ± 12.7% in SES, P = 0.01 and vs. 7.1 ± 5.2% in PES, P < 0.001) and malapposed struts (0.1 ± 0.3% in EES vs. 1.8 ± 3.5% in SES, P = 0.01 and vs. 3.5 ± 5.1% in PES, P = 0.02) was much lower in EES than in first-generation DES, with no significant differences between SES and PES. Late strut coverage patterns are not similar between EES and first-generation DES. EES showed a lower percentage of uncovered and malapposed struts.

Fourier-domain optical coherence tomography evaluation of retinal and optic nerve head neovascularisation in proliferative diabetic retinopathy

AimTo describe the in vivo spatial and morphological vitreoretinal relationships associated with diabetic retinal neovascularisation using Fourier-domain optical coherence tomography (FD-OCT).MethodsQualitative assessment of macula, retina and optic disc head FD-OCT...

Metrological reliability of optical coherence tomography in biomedical applications

Optical coherence tomography (OCT) has been proving to be an efficient diagnostics technique for imaging in vivo tissues, an optical biopsy with important perspectives as a diagnostic tool for quantitative characterization of tissue structures. Despite its established clinical use, there is no international standard to address the specific requirements for basic safety and essential performance of OCT devices for biomedical imaging. The present work studies the parameters necessary for conformity assessment of optoelectronics equipment used in biomedical applications like Laser, Intense Pulsed Light (IPL), and OCT, targeting to identify the potential requirements to be considered in the case of a future development of a particular standard for OCT equipment. In addition to some of the particular requirements standards for laser and IPL, also applicable for metrological reliability analysis of OCT equipment, specific parameters for OCT's evaluation have been identified, considering its biomedical application. For each parameter identified, its information on the accompanying documents and/or its measurement has been recommended. Among the parameters for which the measurement requirement was recommended, including the uncertainty evaluation, the following are highlighted: optical radiation output, axial and transverse resolution, pulse duration and interval, and beam divergence.

Evaluation of Macular Thickness after Uncomplicated Cataract Surgery using Optical Coherence Tomography

To evaluate central macular thickness (CMT) after cataract surgery in selected groups of patients. The study comprised 4 groups-patients with epiretinal membrane, patients with high myopia, patients with diabetes without retinopathy, and healthy subjects-who underwent phacoemulsification and intraocular lens implantation. Central macular thickness was measured with spectral domain optical coherence tomography (OCT) using the 3D macular cube scan. The OCT evaluation was performed preoperatively and 1, 6, 15, 30, 60, 90, and 360 days after surgery. Visual acuity was measured preoperatively and after 6 and 360 days after surgery. The study included 258 patients, 164 women and 94 men, with a mean age of 74 (SD 7.6) years. A statistically significant increase in CMT was observed from day 30 in patients with epiretinal membrane (p = 0.010) and diabetic patients (p = 0.026), reaching its maximum thickness at day 60 (p = 0.001 and p = 0.001), while it was observed only on day 360 in healthy subjects (p = 0.018) and those with high myopia (p = 0.003). The correlation between CMT and visual acuity was statistically significant only in the diabetic group (r = 0.61, p<0.01). Following cataract surgery, CMT changes according to characteristic patterns in the different groups studied. These changes did not prevent an optimal recovery of visual function.

Prospective Evaluation of Optical Coherence Tomography in Lower Limb Arteries Compared with Intravascular Ultrasound

PurposeTo compare in a prospective noninferiority study optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in popliteal and infrapopliteal vessels. Materials and MethodsOCT and IVUS images of 112 popliteal and infrapopliteal arterial segments were prospectively obtained from 16 patients with peripheral arterial occlusive disease. Three observers evaluated the corresponding OCT and IVUS images for image quality, artifact frequency, discriminability of vessel wall layers, and plaque composition. Measurements of the lumen, vessel, and plaque areas were compared for both modalities. ResultsThe intrareader and interreader reproducibility of plaque tissue discrimination (0.88 vs 0.75), overall image quality, and vessel wall layer discriminability were significantly higher for OCT (all P < .001). Artifact frequency was higher in OCT, constraining the imaging of the tibioperoneal trunk. The results of measurements of the lumen and vessel area were comparable for both modalities (correlation > 0.9, P < .001). Plaque area measurements differed (correlation 0.8, P < .01) because OCT underestimated it. The OCT procedure caused vessel spasms in two patients. ConclusionsOCT imaging of infrapopliteal arteries is feasible and safe and provides high image quality. It enables an accurate assessment of vessel lumen, wall, and plaque. Compared with IVUS, OCT images provide excellent image quality and superior visualization of vessel wall layers and different plaque components. The penetration depth of OCT restricts its use to suitable vessel regions.

Analysis of residual thrombotic burden after thrombus aspiration in acute myocardial infarction: an optical coherence tomographic evaluation

Purpose: Thrombus aspiration (TA) is recommended in patients with ST segment elevation myocardial infarction (STEMI) to improve myocardial perfusion during percutaneous coronary intervention (PCI). However, the angiographic assessment of residual thrombotic burden following TA has several inaccuracies. Optical coherence tomography (OCT) allows excellent discrimination between the thrombotic and atherosclerotic plaque components. We assessed the feasibility of quantification of residual thrombotic burden by OCT and its relation to angiographic results of TA. Methods: Patients with acute STEMI (symptoms onset ≤ 12 hours) who underwent TA were screened for inclusion. OCT was performed in patients with successful TA (TIMI flow=3+ chest pain cessation+ ST elevation resolution). Culprit lesion was analyzed by quantitative coronary angiography (QCA) and TIMI flow was measured before and after TA. Thrombus surface, thrombus length, thrombotic score, minimal luminal area (MLA) and cross sectional area (CSA) were quantified by serial area measurement within the athero-thrombotic culprit lesion in 1 mm intervals. The absolute residual thrombotic volumes (absThV) and thrombotic volume indexed to artery volume (indThV) were then calculated. Results: A total of 30 patients were included in the study (mean age: 58.4±3 y; 77% men; 47% anterior localization). OCT was feasible in all cases and did not induce any complication (including embolization, artery re-occlusion or dissection). Residual thrombotic material was present in all cases, irrespective of the angiographic result: the residual absThV, indThV and thrombotic score were respectively 19.8±4.3 mm3, 45.9±8.2% and 23.7±3.3. AbsThV and indThV highly correlated to the values of thrombotic score (respectively r=0.86 and 0.79, p<0.001), but not with post-TA QCA values. Patients were divided into 2 groups according to the post-TA angiographic analysis: optimal (QCA ≤ 70%) and sub-optimal (QCA >70%) result. We didn't observe any significant difference in the thrombus characteristics between the two groups, confirming that QCA accuracy for prediction of thrombus burden in STEMI is limited. Conclusion: OCT can be safely performed in patients presenting with STEMI treated with primary PCI and allows quantification of residual thrombotic material. A significant discrepancy remains between angiographic result of TA and OCT data.

Evaluation of the novel novolimus-eluting bioresorbable vascular scaffold for the treatment of de novo coronary artery stenosis: serial optical coherence tomography analysis of the DESolve NX study

Purpose: The DESolve system is a novel Poly-L-Lactide (PLLA)-based scaffold, designed to provide both temporary vessel support along with neointimal suppression, followed by full bioresorption between one and two years. In the present study, we aim to present the first serial optical coherence tomography (OCT) evaluation of the novel PLLA-based novolimus-eluting DESolve bioresorbable scaffold investigated in the DESolve NX study. Methods: The DESolve NX study enrolled 126 patients with single de novo native coronary lesions at 13 sites. A serial (baseline and 6-month follow-up) analysis of the first 25-patient subset who underwent OCT examination will be presented. All OCT images were analyzed by an independent core laboratory at 0.6-mm interval. At baseline, lumen, scaffold, plaque prolapse and incomplete scaffold apposition (ISA) areas were determined. At follow-up, serial changes in lumen and scaffold dimensions and degree of neointimal hyperplasia (NIH) formation on top of the struts will be assessed. Frequency of covered struts and NIH thickness on top of each covered strut will also be examined. OCT imaging end-points were scaffold expansion and structural integrity post-procedure and neointimal obstruction and degree of strut coverage at six-month follow-up. Results: At baseline, overall adequate scaffold expansion (93.75±9.21%) was obtained. A mean of 30.44±5.16 cross-sections were analyzed per scaffold. Mean lumen and scaffold areas measured 6.80±1.35 mm2 and 6.95±1.32 mm2, respectively, with a minimum scaffold area post-procedure of 5.71±1.15 mm2. In average, plaque prolapse accounted for a very small area of lumen reduction post-procedure (0.03±0.02 mm2). ISA was detected at baseline in 9 (36%) scaffolds, but it was in average very small (0.07±0.13 mm2). A total of 9,871 struts were analyzed at baseline, and the frequency of malapposed struts per patient was 0.43±0.98%. All 25 patients have already completed 6-month OCT evaluation, and the images are currently under analysis. The complete serial OCT results will be available at the meeting. Conclusions: The novel PLLA-based novolimus-eluting bioresorbable scaffold demonstrated an excellent acute performance, tolerating very good expansion with virtually no structural deformity concerns. Good vessel wall conformability was also demonstrated, resulting in minimal areas of scaffold malapposition. Six-month OCT analysis is being conducted and will be presented at the meeting.

Three-dimensional optical coherence tomography evaluation of a left main bifurcation lesion treated with ABSORB® bioresorbable vascular scaffold including fenestration and dilatation of the side branch

Three-dimensional optical coherence tomography evaluation of a left main bifurcation lesion treated with ABSORB® bioresorbable vascular scaffold including fenestration and dilatation of the side branch

Serial optical coherence tomography evaluation of the novel DESolve myolimus-eluting bioresorbable vascular scaffold for the treatment of de novo coronary artery lesions

Serial optical coherence tomography evaluation of the novel DESolve myolimus-eluting bioresorbable vascular scaffold for the treatment of de novo coronary artery lesions

How to organise the follow‐up of patients with macular edema?

AbstractThe results of clinical trials have demonstrated significant visual and anatomic benefits to intravitreal agents in the treatment of the macular edema (MO) related to retinal ischemic microangiopathies. Following the evaluation of non‐perfused capillary areas, on fluorescein angiography, spectral domain optical coherence tomography (OCT) helps to quantify the amount of cystoid macular edema. The clinical examination include VA assessment, biomicroscopy and OCT. Important differences exist in the protocols evaluating treatment for Diabetic MO, from the mandatory monthly anti VEGF injections, to either protocol, requiring injections during the first 4 study visits and prompt or deferral laser or in trials, where patients, after 3 mandatory monthly injections, had both a variable dose and injection, based on VA and OCT evaluation. The MO related to RVO should be monitored monthly for the first 3 months, and then every 2 months for the first year. During this monitoring period, patients should be instructed to return promptly whenever they notice a decrease in vision, a possible indication of macular edema, or the conversion to ischemia. Follow‐up after the initial 6 months will be required

Optical coherence tomography analysis of strut coverage in biolimus- and sirolimus-eluting stents: 3-Month and 12-month serial follow-up

BackgroundNo randomized studies have been conducted to investigate serial changes in optical coherence tomography (OCT) analyses following implantation of biolimus-A9-eluting stents (BES) and sirolimus-eluting stents (SES). MethodsA total of 60 patients fulfilling the study criteria were randomly assigned into BES (n=30) and SES (n=30) implantation groups. Serial OCT evaluation at post-procedure, 3- and 12-month follow-up was performed in 46 patients [BES (n=22) and SES (n=24)]. OCT analyses were compared according to the type of stents and the follow-up time intervals. The percentage of uncovered struts was defined as the ratio of uncovered struts to total struts in all cross-sections. The primary endpoint was the percentage change (Δ) of uncovered struts in the 3- and 12-month follow-up samples. ResultsThe percentage of uncovered struts at the 3-month time period was not significantly different in the BES and SES groups; the median value (interquartile range) was 14.7% (0.0–23.4) versus 8.6% (0.7–21.5) (p=0.98), respectively. However, OCT at the 12-month follow-up showed a significantly lower percentage of uncovered struts [2.6% (0.8–5.6) versus 6.2% (1.7–14.7), (p=0.028), respectively] without significant difference of neointimal thickness. BES showed a greater reduction of percentage Δ of uncovered struts from 3–12months than that of SES [−17.2±14.5% versus −7.7±16.3%, respectively (p=0.043)]. ConclusionsBoth drug-eluting stents showed a high percentage of incomplete strut coverage at 3months. However, BES showed a significantly lower percentage of uncovered struts at 12months compared to that of SES. This was achieved by superior strut coverage from 3 to 12months.

Evaluation of optical coherence tomography as a non‐invasive diagnostic tool in cutaneous wound healing

The monitoring of wound-healing processes is indispensable for the therapeutic effectiveness and improved care of chronic wounds. Histological sections provide the best morphological assessment of wound recovery, but cause further tissue destruction and increase the risk of infection. Therefore, it is reasonable to apply a diagnostic tool that allows a non-invasive and reliable observation of morphological changes in wound healing. Optical coherence tomography (OCT) is an imaging technique for in vivo evaluation of skin diseases with a resolution close to histopathology. The aim of this study was to investigate whether OCT is suited to display the phases of wound healing. For this purpose, six patients with chronic wounds were objectively characterized by OCT during a period of 2 weeks. Comparable results between histological findings and OCT were achieved. OCT allowed the detection of partial loss of the epidermis, vasoconstriction, vasodilatation and epithelialization. Consequently, OCT could be a potential non-invasive diagnostic tool for the characterization and monitoring of cutaneous wound-healing processes over time.

Optical coherence tomography for evaluation of coronary stents in vivo

Coronary optical coherence tomography (OCT) is a light-based imaging modality that emits light in the near-infrared range. Compared with intravascular ultrasound, OCT has an extraordinarily high resolution (nearly tenfold higher), with an axial resolution in the range of 12–15 µm and a lateral resolution of 20–40 µm. The main drawback of OCT is its relatively low penetration power, especially into lipid-rich atherosclerotic tissue. Second-generation OCT systems, known as frequency domain OCT, are now widely available in many catheter laboratories. The hallmark of OCT is its outstanding ability to depict superficial vessel wall structures with high accuracy. In this regard, OCT was used to evaluate stent expansion and stent strut apposition both early and late following stent deployment, as well as neointimal coverage over struts at long-term follow-up. It has discriminated the differences in strut malapposition and strut neointimal coverage among different stent designs and in various strut subsets. Similarly, OCT delineated many forms of vessel wall injury following percutaneous coronary intervention, such as dissections, thrombosis and tissue protrusion between struts. Recently, OCT was used to study the biodegradation of bioresorbable vascular scaffolds. This review focuses on the role of OCT in the in vivo evaluation of coronary stents.

Hallazgo de hipertrofia de la capa de fibras nerviosas de la retina en pacientes con ataxia de Charlevoix-Saguenay

Purpose/methodsTo present the neuro-ophthalmology examination in 5 spastic ataxia of Charlevoix-Saguenay (ARSACS) patients showing significant increases in retinal nerve fiber layer (RNFL) thickness. Results/conclusionsAll patients showed abnormal visual fields, normal optic discs with increased visibility of RNFL in color stereo-photographs, normal examination with Heidelberg Retina Tomography instrument, and moderate to markedly increased RNFL thickness in Cirrus Optical Coherence Tomography evaluation (average thickness: 119 to 220 microns). We found evidence that RNFL hypertrophy may be an alternative funduscopic finding to the hypermyelinated retinal fibers in previous reports. A revision of ARSACS diagnostic criteria, particularly with regard to retinal alterations, is necessary.

ASSA13-15-19 A Novel Polymer-Free Sirolimus-Eluting Stent Coated with Anti-CD34 Antibody Shows Less Neointima Formation and Early Recovery of Endothelial Function

<h3>Background</h3> Drug-eluting stents effectively reduce restenosis but may increase late thrombosis and delayed restenosis. Persistent polymer, the drug, or a combination of both could be responsible. <h3>Objective</h3> To study the effect of endothelial progenitor cell (EPC) capture on the vascular response to polymer-free SIROLIMUS- eluting stent (PFSES). This combo stent may reduce neointimal proliferation and address the risk of stent thrombosis by facilitating rapid endothelialisation compared with the permanent-polymer sirolimus-eluting stent (SES) or PFSES alone. <h3>Methods</h3> We compared a combo stent (CS), a polymer-free sirolimus-eluting stent coated with anti-CD34 antibody, with a permanent-polymer sirolimus-eluting stent (SES), a polymer-free sirolimus-eluting stent (PFSES) and a bare-metal stent (BMS) at 14 days and 28 days in a porcine model with optical coherence tomography (OCT) and histological analysis. <h3>Results</h3> At 14 days, via OCT evaluation, there was a reduction in neointimal proliferation by CS and PFSES compared with SES and BMS (neointimal thickness: BMS, 0.44 ± 0.12; SES, 0.42 ± 0.03; PFSES, 0.14 ± 0.11; CS, 0.11 ± 0.06; P &lt; 0.005; BMS/SES &gt; CS/PFSES). At 28 days, both CS and PFSES were associated with reduced neointimal proliferation, whereas SES exhibited increased neointima (neointimal thickness: BMS, 0.62 ± 0.11; SES, 0.63 ± 0.08; PFSES, 0.18 ± 0.06; CS, 0.21 ± 0.06; P &lt; 0.005; BMS/SES &gt; CS/PFSES). The histology evaluation was demonstrated the similar results. At 14days and 28 days, combo stent showed decreased fibrin and inflammation, compared with SES and PFSES. In addition, the combo SES is associated with increased endothelium-dependent relaxation, protected vascular Endothelial Function. <h3>Conclusions</h3> The polymer-free sirolimus-eluting stent modified with anti-CD34 antibody demonstrates equivalent early and superior late reduction of intimal proliferation compared with SES in a porcine model. After implantation of combo stent, delayed arterial healing was minimal, and there was no increased inflammation at 28 days compared with SES implantation. The use of combo stents may have a potential short-term benefit over traditional polymeric-coated drug-eluting stents.

Evaluation of optical coherence tomography for the measurement of the effects of activators and anticoagulants on the blood coagulation in vitro.

Optical properties of human blood during coagulation were studied using optical coherence tomography (OCT) and the parameter of clotting time derived from the 1/e light penetration depth (d(1/e)) versus time was developed in our previous work. In this study, in order to know if a new OCT test can characterize the blood-coagulation process under different treatments in vitro, the effects of two different activators (calcium ions and thrombin) and anticoagulants, i.e., acetylsalicylic acid (ASA, a well-known drug aspirin) and melagatran (a direct thrombin inhibitor), at various concentrations are evaluated. A swept-source OCT system with a 1300 nm center wavelength is used for detecting the blood-coagulation process in vitro under a static condition. A dynamic study of d1/e reveals a typical behavior due to coagulation induced by both calcium ions and thrombin, and the clotting time is concentration-dependent. Dose-dependent ASA and melagatran prolong the clotting times. ASA and melagatran have different effects on blood coagulation. As expected, melagatran is much more effective than ASA in anticoagulation by the OCT measurements. The OCT assay appears to be a simple method for the measurement of blood coagulation to assess the effects of activators and anticoagulants, which can be used for activator and anticoagulant screening.