Frequency Domain Optical Coherence Tomography Research Articles

TiO2 nanoparticles as exogenous contrast agent for 1 µm swept source optical coherence tomography: an in vitro study

Optical coherence tomography (OCT) is a rapidly evolving, robust technology that has profoundly changed the practice of medical imaging. Swept source OCT (SSOCT) combines the standard time domain and the spatially encoded frequency domain OCT. We have employed a high-speed SSOCT system that utilizes a swept source laser with an A-scan rate of 100 kHz and a central wavelength of 1060 nm for the imaging of the tissue. SSOCT at 1060 nm allows for high penetration in the tissue. TiO2 nanoparticles (NPs) are mostly used for various experimental purposes as an exogenous imaging contrast agent. The in vitro imaging of chicken breast tissue is performed with and without the application of TiO2 NPs for exogenous contrast. Characterization of the chemically synthesized TiO2 NPs was done with dynamic light scattering and a scanning electron microscope method. The effect of TiO2 is studied at different exposure times. A significant improvement in the contrast to noise ratio has been observed through the in vitro imaging of a TiO2 treated tissue.

Early vascular responses to everolimus-eluting cobalt\u2013chromium stent in the culprit lesions of st-elevation myocardial infarction: results from a multicenter prospective optical coherence tomography study (MECHANISM-AMI 2-week follow-up study)

The use of cobalt–chromium everolimus-eluting stents (CoCr-EES) for ST-segment elevation myocardial infarction (STEMI) reduces the incidence of stent thrombosis compared with bare metal stents, and a substantial difference is apparent in the initial 2 weeks. However, vascular behavior during this early period remains unclear. This was a prospective study (MECHANISM-AMI-2W) to investigate early vascular responses in STEMI patients immediately after CoCr-EES implantation and at 2-week follow-up using frequency domain-optical coherence tomography (FD-OCT). The study enrolled 52 patients (age 63.7 ± 11.7 years, male 85.0%), of whom 44 patients were available for complete serial FD-OCT analyses. Both % uncovered struts and % malapposed struts were improved at 2-week follow-up (63 ± 20 vs. 21 ± 14%, p < 0.0001 and 7.3 ± 9.0 vs. 4.7 ± 5.9%, p = 0.005, respectively). Thrombus was decreased, with significant changes in longitudinal length to stent (28.8 ± 27.7 vs. 18.1 ± 20.2%, p = 0.0001) and maximal area (0.93 ± 0.84 vs. 0.65 ± 0.63 mm2, p = 0.034). As a result, the average lumen area was significantly larger at 2 weeks (6.49 ± 1.82 vs. 6.71 ± 1.89 mm2, p = 0.048, respectively). The number of dissection flaps was lower (0.86 ± 1.11 vs. 0.52 ± 0.90%, p = 0.024). In conclusion, this study showed early vascular responses to CoCr-EES for STEMI lesions—including a significant reduction of thrombus—that resulted in lumen enlargement, earlier progression of strut coverage, and improvements in strut apposition and dissection. The combination of these factors may therefore be responsible for the safety of CoCr-EES within the initial 2 weeks.

Correlation between frequency-domain optical coherence tomography and fractional flow reserve in angiographically-intermediate coronary lesions

BackgroundThe decision-making process of patients with angiographically-intermediate coronary lesions (ICL) is clinically challenging and may benefit from adjunctive invasive techniques. Fractional-flow-reserve (FFR) represents the gold standard to evaluate ICL but frequency-domain optical-coherence-tomography (OCT) is a novel, promising, high resolution coronary imaging technique, which allows physiopathologic assessment of coronary plaque. We investigated the possible relation between OCT and FFR in selected ICL patients. MethodsStable or unstable patients with ICL who underwent both FFR and OCT assessment at two large tertiary centers were retrospectively enrolled. FFR was performed according to standard methodology. OCT images were (on blind to clinical and FFR results) analyzed to assess minimal lumen area (MLA), percentage area stenosis (AS), thrombus and plaque ulceration. ResultsForty patients were identified (62±10years, 93% symptomatic, 35% acute presentation, 93% left-anterior-descending artery ICL). Percentage diameter stenosis at quantitative coronary angiography was 40±12% and FFR was 0.85±0.07. MLA (p=0.009), AS (p<0.001) and plaque ulceration (p=0.02) were significantly associated with FFR values. An integrated assessment of AS (≥ or <70%), MLA (≥ or <2.5mm2) and presence or absence of thrombus and plaque ulceration was found to have the potential to accurately (sensitivity 91%, specificity 93%) predict FFR results. ConclusionIn patients with ICL, a combination of different OCT parameters may help predict FFR results. These findings suggest that only a comprehensive assessment of lesion features by OCT can allow an accurate prediction of lesion severity assessed by FFR.

Effect of drug-coated balloon on stent restenosis, neointimal proliferation, and coronary dissection

The aim of this study was to assess the acute and mid-term effects of drug-coated balloon (DCB) in terms of the healing process of non-flow-limiting dissections and changes in the neointimal area after DCB treatment using frequency domain optical coherence tomography (FD-OCT). Thirty-six consecutive patients with in-stent restenosis pretreated with a scoring balloon were evaluated (19 and 17 patients with and without a DCB, respectively). FD-OCT was performed before and after each procedure during percutaneous coronary intervention and at 6 months of follow-up. Clinical characteristics and baseline FD-OCT findings were comparable between the two groups. No patient required stent implantation because of low-pressure DCB-related dissections. In the acute phase, the DCB distributed paclitaxel to the vessel wall without increasing dissections. The DCB did not reduce the neointimal area by itself. At 6 months, more dissections healed in the DCB group (-4.5±2.3 vs. -2.7±1.3, P=0.02). The DCB group showed less change in the neointimal area (-0.04±0.92 vs. 1.06±1.57 mm, P=0.03). The low-pressure DCB was not intended to expand the lumen, but instead to attach paclitaxel to the vessel wall by using FD-OCT examination. The DCB reduced the number of dissections and prevented neointimal proliferation during the mid-term follow-up.

Difference in plaque characteristics of coronary culprit lesions in a cohort of Egyptian patients presented with acute coronary syndrome and stable coronary artery disease: An optical coherence tomography study

AimsThis study was designed to utilize frequency-domain optical coherence tomography (FD-OCT) for assessment of plaque characteristics and vulnerability in patients with acute coronary syndrome (ACS) compared to stable coronary artery disease (SCAD).Methods and resultsWe enrolled 48 patients; divided into an ACS-group (27 patients) and SCAD-group (21 patients) according to their clinical presentation. Hypertension and diabetes mellitus were more prevalent in SCAD group. Patients with ACS showed higher frequency of lipid-rich plaques (96.3% vs. 66.7%, P = .015), lower frequency of calcium plaques (7.4% vs. 57.1%, P < .001), and fibrous plaques (14.8% vs. 81%, P < .001) when compared with SCAD patients. The TCFA (defined as lipid-rich plaque with cap thickness <65 μm) identified more frequently (33.3% vs. 14.3%, P = .185), with a trend towards thinner median fibrous cap thickness (70 (50–180) µm vs. 100 (50–220) µm, P = .064) in ACS group. Rupture plaque (52% vs. 14.3%, P = .014), plaque erosion (18.5% vs. 0%, P = .059) and intracoronary thrombus (92.6% vs. 14.3%, P < .001) were observed more frequently in ACS group, while cholesterol crystals were identified frequently in patients with SCAD (0.0% vs. 33.3%, P = .002).ConclusionThe current FD-OCT study demonstrated the differences of plaque morphology and identified distinct lesion characteristics between patients with ACS and those with SCAD. These findings could explain the clinical presentation of patients in both groups.

Quantified frequency-domain optical coherence tomography analysis for the thin-high signals on restenotic tissue after paclitaxel-coated balloon angioplasty.

Thin-high signals (THS), detectable by optical coherence tomography (OCT), represent the paclitaxel coverage of in-stent restenotic tissue. This study was conducted to assess the relationship between THS and angiographic outcomes by means of quantified post-procedural frequency-domain OCT (FD-OCT) analysis. From January 2014 to July 2016, 41 patients underwent FD-OCT-guided percutaneous coronary intervention using paclitaxel-coated balloon (PCB) to prevent in-stent restenosis. Of these, we retrospectively enrolled 32 patients (38 lesions) who underwent a 6- to 9-month follow-up angiogram. THS were assessed quantitatively, as THS length and lumen perimeter length were measured using semi-automated software; %THS was calculated by the following formula; total THS area/lumen perimeter area×100. THS were detected in all 38 lesions that had undergone PCB angioplasty. THS and %THS were significantly higher in lesions without binary restenosis (3.34±2.11 vs. 11.48±8.53mm2, p=0.001 and 1.49±0.73 vs. 4.42±2.71%, p=0.001, respectively). Values for THS, which indicates the paclitaxel coverage on restenotic tissue, are associated with reducing restenosis after PCB for in-stent restenosis.

Thickness measurement of frequency domain OCT on photoreceptor cell layer in diabetic retinopathy

Thickness measurement of frequency domain OCT on photoreceptor cell layer in diabetic retinopathy

Optical Coherence Tomography Findings in Patients With Coronary Stent Thrombosis: A Report of the PRESTIGE Consortium (Prevention of Late Stent Thrombosis by an Interdisciplinary Global European Effort).

Stent thrombosis (ST) is a serious complication following coronary stenting. Intravascular optical coherence tomography (OCT) may provide insights into mechanistic processes leading to ST. We performed a prospective, multicenter study to evaluate OCT findings in patients with ST. Consecutive patients presenting with ST were prospectively enrolled in a registry by using a centralized telephone registration system. After angiographic confirmation of ST, OCT imaging of the culprit vessel was performed with frequency domain OCT. Clinical data were collected according to a standardized protocol. OCT acquisitions were analyzed at a core laboratory. Dominant and contributing findings were adjudicated by an imaging adjudication committee. Two hundred thirty-one patients presenting with ST underwent OCT imaging; 14 (6.1%) had image quality precluding further analysis. Of the remaining patients, 62 (28.6%) and 155 (71.4%) presented with early and late/very late ST, respectively. The underlying stent type was a new-generation drug-eluting stent in 50.3%. Mean reference vessel diameter was 2.9±0.6 mm and mean reference vessel area was 6.8±2.6 mm2. Stent underexpansion (stent expansion index <0.8) was observed in 44.4% of patients. The predicted average probability (95% confidence interval) that any frame had uncovered (or thrombus-covered) struts was 99.3% (96.1-99.9), 96.6% (92.4-98.5), 34.3% (15.0-60.7), and 9.6% (6.2-14.5) and malapposed struts was 21.8% (8.4-45.6), 8.5% (4.6-15.3), 6.7% (2.5-16.3), and 2.0% (1.2-3.3) for acute, subacute, late, and very late ST, respectively. The most common dominant finding adjudicated for acute ST was uncovered struts (66.7% of cases); for subacute ST, the most common dominant finding was uncovered struts (61.7%) and underexpansion (25.5%); for late ST, the most common dominant finding was uncovered struts (33.3%) and severe restenosis (19.1%); and for very late ST, the most common dominant finding was neoatherosclerosis (31.3%) and uncovered struts (20.2%). In patients presenting very late ST, uncovered stent struts were a common dominant finding in drug-eluting stents, and neoatherosclerosis was a common dominant finding in bare metal stents. In patients with ST, uncovered and malapposed struts were frequently observed with the incidence of both decreasing with longer time intervals between stent implantation and presentation. The most frequent dominant observation varied according to time intervals from index stenting: uncovered struts and underexpansion in acute/subacute ST and neoatherosclerosis and uncovered struts in late/very late ST.

Optical Coherence Tomography in the Diagnosis of Skin Cancer.

Optical coherence tomography (OCT) has emerged as a novel noninvasive imaging device that allows for the real-time, invivo, cross-sectional imaging of skin morphology. OCT has increased imaging depth and field of view compared with reflectance confocal microscopy, at the cost of decreased cellular resolution. Frequency domain OCT, dynamic OCT (D-OCT), and high-definition OCT (HD-OCT) are useful in the diagnosis, treatment planning, and treatment monitoring of nonmelanoma skin cancers. Research is currently underway to assess the utilization of these devices in distinguishing between malignant and benign melanocytic lesions based on vascular patterns on D-OCT and cellular information on HD-OCT.

P2355Dual quantitative coronary angiography accurately quantifies intracoronary thrombotic burden in patients with acute coronary syndrome: comparison with frequency-domain optical coherence tomography

P2355Dual quantitative coronary angiography accurately quantifies intracoronary thrombotic burden in patients with acute coronary syndrome: comparison with frequency-domain optical coherence tomography

High-Throughput Photonic Time-Stretch Optical Coherence Tomography with Data Compression

Photonic time stretch enables real-time high-throughput optical coherence tomography (OCT), but with massive data volume being a real challenge. In this paper, data compression in high-throughput optical time-stretch OCT has been explored and experimentally demonstrated. This is made possible by exploiting the spectral sparsity of an encoded optical pulse spectrum using a compressive sensing approach. Both randomization and integration have been implemented in the optical domain avoiding electronic bottleneck. A data compression ratio of 66% has been achieved in high-throughput OCT measurements with 1.51-MHz axial scan rate using greatly reduced data sampling rate of 50 MS/s. Potential to improve compression ratio has been exploited. In addition, using a dual pulse integration method, capability of improving frequency measurement resolution in the proposed system has been demonstrated. A number of optimization algorithms for the reconstruction of the frequency-domain OCT signals have been compared in terms of reconstruction accuracy and efficiency. Our results show that the $l_1$ magic implementation of the primal-dual interior point method offers the best compromise between accuracy and reconstruction time of the time-stretch OCT signal tested.

Clinical observation of vitrectomy combined with internal limiting membrane peeling and scleral shortening for myopic foveoschisis

Objective To observe the efficacy of vitrectomy combined with internal limiting membrane (ILM) peeling and scleral shortening for myopic foveoschisis (MF). Methods Prospective and non-randomized concurrent control study. A total of 35 MF patients (35 eyes) were enrolled in this study. The patients were divided into 2 groups according to surgery, including group A (18 eyes) and group B (17 eyes), all received vitrectomy combined with ILM peeling, but group A also received scleral shortening. The best corrective visual acuity (BCVA) examination using the Snellen vision chart was converted to the minimum resolution logarithm (logMAR). Ocular axis length (AL) was measured by Zeiss IOL-Master or A-scan ultrasound (Quantel Medical, France). The maximal value of retinal foveoschisis (MxFT) was measured by frequency-domain optical coherence tomography (Heidelberg, Germany). Multifocal electroretinogram (mfERG) responses were obtained with the RETIscan system (Roland Consult, Gemany).There was no statistically significant difference between the two groups (P>0.05) in age (t=0.460), AL (t=1.520), diopter (t=0.020), logMAR BCVA (t=−2.280), MxFT(Z=−4.179) and b-wave ERG amplitude (Z=−0.198). The changes of BCVA, AL, MxFT and b wave amplitude were followed-up for 3-12 months. Results At the last follow-up, the height of MF was decreased in 18 eyes of group A, and MF was completely disappeared in 4 eyes. The logMAR BCVA (t=7.272, 5.951), MxFT (Z=−3.724, −3.622) and b- wave ERG amplitude (Z=−3.223, −3.243) in both groups A and B were statistically improved (P=0.000, 0.000, 0.000, 0.000, 0.001, 0.001) compared to pre-operational results. There was significant difference of logMAR BCVA (t=−2.280) and MxFT (Z=−4.179) between the two groups (P=0.029, 0.000). But there was no significant difference in the amplitude of b-wave (Z=−0.198, P=0.843). The AL in group A was shortened after surgery, the difference was statistically significant (t=10.017, P=0.000). During the follow-up, there was no ocular hemorrhage, endophthalmitis and other complications. Conclusion PPV combined with ILM peeling and scleral shortening can shorten AL significantly for MF patients, and gain relative normal anatomical structure of the fovea, thus improve the vision. Key words: Myopia, degenerative/complications; Myopia, degenerative/surgery; Retinal perforations/surgery; Vitreoretinal surgery; Scleroplasty

Optical coherence tomography guidance for the management of angiographically intermediate left main bifurcation lesions: Early clinical experience

BackgroundLeft main (LM) atherosclerotic lesions affect clinical outcomes. Frequency domain-optical coherence tomography (FD-OCT) allows detailed characterization of non-ostial coronary atherosclerotic lesions. The clinical impact of FD-OCT assessment of LM bifurcation disease on the revascularization decision is unknown. MethodsPatients who underwent FD-OCT assessment to guide management of angiographically intermediate distal LM stenosis were retrospectively selected. The FD-OCT LM criteria for percutaneous or surgical revascularization were:–LM area stenosis (AS)≥75%–LM AS >50%<75% with minimum lumen area<4mm2 or plaque ulceration–critical FD-OCT ostial stenosis on the left anterior descending or circumflex arteries.Clinical follow-up was obtained to evaluate the occurrence of target vessel failure (TVF) defined as cardiac death and/or acute myocardial infarction (AMI) not related to other vessel and/or target vessel revascularization. ResultsOut of 131 patients underwent FD-OCT assessment of LM, 122 patients (93%) entered the study. Based on FD-OCT features, 58 (48%) patients were conservatively managed, while the remaining 64 (52%) were revascularized by stenting (n=48) or surgery (n=16). After a mean follow-up of 18months, TVF-free survival was not different between patients undergoing conservative management vs. revascularization (HR 0.40, CI 95% 0.10–1.61, P=0.20). Of note, two patients only in the conservative management group had TVF (elective LM stenting, no death or myocardial infarction). ConclusionsThis preliminary experience suggests that a FD-OCT based management for patients with angiographically-intermediate LM bifurcation stenosis may help identify patients in whom revascularization could be deferred. Such observation calls for further evaluations by appropriately designed trials.

A novel hybrid approach for reconstruction of coronary bifurcations using angiography and OCT.

The aim of this study is to present a new method for three-dimensional (3D) reconstruction of coronary bifurcations using biplane Coronary Angiographies and Optical Coherence Tomography (OCT) imaging. The method is based on a five step approach by improving a previous validated work in order to reconstruct coronary arterial bifurcations. In the first step the lumen borders are detected on the Frequency Domain (FD) OCT images. In the second step a semi-automated method is implemented on two angiographies for the extraction of the 2D bifurcation coronary artery centerline. In the third step the 3D path of the bifurcation artery is extracted based on a back projection algorithm. In the fourth step the lumen borders are placed onto the 3D catheter path. Finally, in the fifth step the intersection of the main and side branches produces the reconstructed model of the coronary bifurcation artery. Data from three patients are acquired for the validation of the proposed methodology and the results are compared against a reconstruction method using quantitative coronary angiography (QCA). The comparison between the two methods is achieved using morphological measures of the vessels as well as comparison of the wall shear stress (WSS) mean values.

The cause analysis and clinical characteristics of macular light damage

Objective To explore the the etiology and clinical characteristics of macular light damage. Methods The clinical data of 34 eyes of 25 cases with macular light damage from Jan. 2009 to Dec.2014 were collected and retrospectively analyzed. The data of first 3 years and the last 3 years were comparied.The frequency domain optical coherence tomography, fundus photography and fluorescein fundus angiography were used to observe and analyze the clinical characteistics of macular light damage. Results The first 3 years, from 2009 to 2011, 11 cases of macular light damage, sex ratio was 4.5: 1 (9/2). The last 3 years, from 2012 to 2014, macular light damage in 14 cases, the male to female ratio was 2.5: 1 (10/4). The main cause was welding damage(electric arc) in 14 eyes(41.18%) of 10 cases. The second cause was the solar eclipse injury and ultraviolet of sunlight on plateau in 12 eyes of 7 cases (35.29%). The light damage of computer and mobile phone of the light-emitting diode in 5 eyes of 5 cases (14.71%). In all cases , the macula had obvious clinical changes. Frequency domain optical coherence tomography showed that the high reflection signals of macula cones inside and outside layer plate and part of the retinal pigment cells layer were abnormal and even fracture, some accompanied by retinal layers low reflective dark cavity. Conclusion The last 3 years, more women occurr macular light injuries. Frequency domain optical coherence tomography is helpful for the diagnosis of macular light damage. It is a fast and optimal technology, can show significant morphologic changes. Key words: Macula; Light damage; Optical coherence tomography, frequency domain

Study on the correlation between the visual acuity and the changes of retinal structure of the macular in eyes with contusion

Objective To investigate the correlation between the visual acuity and the changes of retinal structure of the macular in eyes with contusion. Methods Sixteen eyes of 16 patients with ocular contusion were collected in this study. Frequency domain optical coherence tomography (SD-OCT) were used to measure the changes of shape and structure of the macular.The difference was observed between contusion eyes and contralateral normal eyes.The relationship between the degree of impaired BCVA and the foveal change was analysed. Results The average thickness of central macula in contusion eyes was thinner than in contral eyes, the difference was statistically significant(P=0.003). The difference in macular volume between contusion eyes and contralateral eyes was statistically significant(P=0.008, 0.001, 0.002, 0.017, 0.020, 0.010, 0.002, 0.014) in all other areas except the ring side, below the nose and temporal. Macular volume, macula paracentral inner ring volume and average central macular retinal thickness were negatively correlated with vision (P=0.000, 0.044, 0.008). Macular total volume showed no correlation with vision(P=0.194). The length of ellipsoid interrupted had a positive correlation with vision(P=0.043). Multiple linear regression analysis showed, visual acuity was drop with decreasing of the volume of macular (Y=-9.636X+ 2.471, R2=0.896, Rad2=0.878, P=0.000). Conclusion After ocular contusion, the changes of retinal morphology and structure such as macular volume, foveal thickness, the length of retinal internal reflection band are closely related to the degree of retinal damage. Macular retinal region volume can reflect the severity of the damage of visual function. Key words: Ocular contusion; Macular structure; Visual acuity; Tomography, optical coherence; Volume, retinal, central macular

The impact of blood pressure variability on coronary plaque vulnerability in stable angina: an analysis using optical coherence tomography.

Blood pressure variability (BPV), especially visit-to-visit BPV, has been reported to be a risk factor for cardiovascular disease. The impact of BPV on coronary plaque vulnerability remains uncertain. The aim of this study was to investigate the relationship between BPV and coronary plaque vulnerability. From August 2013 to May 2014, 36 patients with both hypertension and stable angina pectoris who underwent a percutaneous coronary intervention guided by frequency-domain optical coherence tomography were investigated retrospectively. The size of the lipid cores and the thickness of the fibrous cap covering the lipid core were measured by frequency-domain optical coherence tomography, and we calculated the blood pressure coefficient of variation (CV) and SD as intraindividual visit-to-visit BPV. Both SD and CV of systolic blood pressure (SBP) correlated positively with lipid arc (SBP-SD: r=0.68, P<0.01; SBP-CV: r=0.64, P<0.01) as well as average SBP (r=0.48, P<0.01). Fibrous cap thickness did not correlate with blood pressure variables or BPV. BPV is related to coronary plaque volume, but not to coronary plaque vulnerability. In addition to conventional coronary risk factors, BPV may be a therapeutic target for coronary atherosclerosis.

The influence of coronary plaque morphology assessed by optical coherence tomography on final microvascular function after stenting in patients with ST-elevation myocardial infarction.

The index of microcirculatory resistance (IMR) provides a reproducible assessment of the status of coronary microvasculature in patients with ST-elevation myocardial infarction (STEMI). Frequency-domain optical coherence tomography (FD-OCT) enables detailed assessment of the morphology of coronary plaque.We sought to determine the influence of the initial culprit coronary plaque anatomy within the infarct-related artery on IMR after stenting in STEMI. In 25 STEMI patients IMR was measured immediately before and after stent implantation. FD-OCT imaging was performed at the same time points and atherothrombotic volume (ATV) before stenting, prolapsed+floating ATV after stenting and ΔATV was measured using three different strategies. There were no relationships between preprocedural IMR and FD-OCT parameters. Prestenting IMR was related only to pain to wire time (P: 0.02). Irrespective of the method adopted, the final IMR was related to prestenting ATV (ρ: 0.44, P: 0.03 for method I, ρ: 0.48, P: 0.02 for method II and ρ: 0.30, P: 0.06 for method III) and ΔATV (ρ: 0.41, P: 0.04 for method II and ρ: 0.44, P: 0.03 for method III). IMR measured before stenting is independent of the appearances of the culprit coronary plaque within the infarct-related artery. IMR after stenting, and more importantly, the change in IMR after stenting, reflect the degree of distal embolization during stent implantation.

Optical Coherence Tomography and Glaucoma Progression: A Comparison of a Region of Interest Approach to Average Retinal Nerve Fiber Layer Thickness.

To determine whether the change in the retinal nerve fiber layer (RNFL) thickness in a region of interest (ROI) is a better measure of glaucoma progression than the change in average circumpapillary (cp) RNFL thickness. Disc cube scans were obtained with frequency domain optical coherence tomography from 60 eyes of 60 patients (age, 61.7±12.7 y) with early or suspected glaucoma and controlled intraocular pressure. The average time between 2 test dates was 3.2±1.8 years. En-face images of the scans from the 2 tests were aligned based on the blood vessels, and cp images were derived for an annulus 100 μm wide and 3.4 mm in diameter, centered on the disc. An ROI was defined as the portion of the circumpapillary retinal nerve fiber layer (cpRNFL) plot within the temporal disc that extended below the 1% confidence interval for ≥5 degrees. Trend analysis using multilevel mixed-effects models was used to compare the rates of change between ROI width and average cpRNFL thickness. In total, 26 of the 60 eyes had a total of 33 ROIs. The ROI width significantly increased between the 2 test dates (median, 4.9 degrees; Q1=1.03 degrees, Q3=10.5 degrees). In comparison, the average cpRNFL thickness did not decrease significantly over the same period (median, -0.7 μm; Q1=-2.7 μm, Q3=2.7 μm). Mixed-effects linear models confirmed significant ROI progression (P=0.015), but not average cpRNFL (P=0.878). In this population, RNFL thinning in a ROI is a better measure of progression than is average cpRNFL thickness change.

The role of residual intrastent thrombus during primary angioplasty: insights from the COCTAIL II study.

Recent frequency-domain optical coherence tomography studies showed that a complete removal of thrombotic materials is rarely achieved after percutaneous coronary interventions for ST segment elevation myocardial infarction. Residual intrastent thrombus can embolize distally leading to microcirculatory injury. The aim was to find a possible correlation between residual intrastent thrombus and angiographic indexes of myocardial reperfusion. The population consisted of 128 ST segment elevation myocardial infarction patients enrolled in the COCTAIL II trial. Intrastent thrombus at optical coherence tomography was defined as the maximum percentage value of thrombus area (thrombus area/stent area × 100 in the cross-section with largest thrombus). A thrombus area of at least 16% (mean value) was considered indicative of high residual intrastent thrombus. The following angiographic indexes of myocardial reperfusion were evaluated: thrombolysis in myocardial infarction (TIMI) value, corrected TIMI frame count and myocardial blush grade. Angiographic and optical coherence tomography results are available in 119 patients: 64 had a maximum percentage value of thrombus area less than 16%, whereas the remaining 55 had a residual intrastent thrombus at least 16%. No differences were found regarding the microcirculatory indexes at baseline angiogram. After intervention, patients with intrastent thrombus less than 16% showed a significant improvement in the final TIMI value (2.87 ± 0.33 vs 2.67 ± 0.54; P = 0.014), final TIMI frame count (11.71 ± 4.58 vs 18.04 ± 17.32; P = 0.012) and a nonsignificant improvement in the final myocardial blush grade value (2.58 ± 0.58 vs 2.43 ± 0.76; P = 0.255). Data obtained from this ancillary study of the COCTAIL II suggest that the presence of high residual intrastent thrombus in patients undergoing primary angioplasty is associated with worsened final microcirculatory indexes.