Optical Coherence Tomography Findings Research Articles

Atypical macular hole formation after Anti-VEGF therapy for neovascular age-related macular degeneration: Coincidence or consequence?

Age-related macular degeneration (AMD) is the primary cause of blindness in developed countries, particularly in older adults. Anti-vascular endothelial growth factor (anti-VEGF) intravitreal injection is the current standard treatment for neovascular form of AMD. Studies reporting macular hole (MH) formation following anti-VEGF treatment are limited, and the exact pathogenesis is still under discussion. With the present study, we aim to analyse the clinical features of eyes developing MH after anti-VEGF therapy for neovascular AMD. Patients were treated with intravitreal anti-VEGF agents for at least one year and stable for at least six months. Best-corrected visual acuity (BCVA) and optical coherence tomography findings were evaluated. Nineteen eyes of 18 patients were included in this study. Patients had an average age of 77.7 years at first visit and eight were female. The average number of injections before the MH formation was four. MH developed after a mean follow-up of 5.1 months after the last injection. Sixteen eyes had (84.2%) had choroidal neovascular membrane without any abnormal vitreomacular traction. Eleven eyes (57.8%) had retinal pigment epithelium detachment (PED), two (10.5%) had an epiretinal membrane (ERM), and one (5.2%) had retinal pigment epithelium (RPE) tear. The mean first and last BCVA was 1.07±0.48 LogMAR (0.3-1.8) and 1.16±0.38 logMAR (0.4-1.8), respectively. A macular hole can be observed in AMD patients receiving anti-VEGF therapy. Increased fibrovascular scar tissue due to subretinal fluid resolution, neovascular membrane contraction, and the presence of PED, RPE tear, and ERM may contribute to MH formation.

Diabetic retinopathy: neurovascular disease requiring neuroprotective and regenerative therapies.

Diabetic retinopathy: neurovascular disease requiring neuroprotective and regenerative therapies.

Characteristics of Optic Disc and Visual Field Changes in Patients with Thyroid-Associated Orbitopathy and Open-Angle Glaucoma.

This study aimed to characterize the changes in the visual field (VF) patterns and disc morphology of patients with thyroid-associated orbitopathy (TAO) and open-angle glaucoma (OAG). A retrospective review of the medical records at the Tri-Service General Hospital in Taiwan identified 396 eyes of 198 patients with thyroid-associated glaucoma. A final follow-up of VF examination in 140 eyes revealed 114 eyes with VF defects, indicating disease progression. The characteristics of and changes in disc morphology, optical coherence tomography findings, and VF defects were statistically analyzed. The most common VF defects at the initial diagnosis and the end of the follow-up period were inferior partial arcuate (17%) and paracentral (15%) defects, respectively. The most common VF defect in patients with unspecific disc signs was an unspecific scotoma (13%). The most common optic disc feature was disc cupping (51%), followed by parapapillary atrophy (48%). The most frequent location of nerve fiber layer thinning was the inferotemporal region (48%). VF defects showed a significantly more pronounced progression in the non-nerve fiber bundle group than in the nerve fiber bundle group (p < 0.001). This study details the characteristics and progression of disc morphology and VF defects in patients with TAO and OAG.

Contrast sensitivity and quality of life following intravitreal ranibizumab injection for central retinal vein occlusion

Synopsis/precisWe investigated the relationship between contrast sensitivity (CS) and vision-related quality of life (VR-QOL) in patients with central retinal vein occlusion following ranibizumab intravitreal injection; CS showed a stronger association...

Optical coherence tomography tissue coverage and characterization at six months after implantation of bioresorbable scaffolds versus conventional everolimus eluting stents in the ISAR-Absorb MI trial

PurposeData regarding vessel healing by optical coherence tomography (OCT) after everolimus-eluting bioresorbable scaffolds (BRS) or everolimus-eluting metallic stent (EES) implantation in acute myocardial infarction (AMI) patients is scarce. We compared OCT findings after BRS or EES implantation in patients with AMI enrolled in a randomized trial.MethodsIn ISAR-Absorb MI, AMI patients were randomized to BRS or EES implantation, with 6–8 month angiographic follow-up. This analysis includes patients who underwent OCT during surveillance angiography. Tissue characterization was done using grey-scale signal intensity analysis. The association between OCT findings and target lesion failure (TLF) at 2 years was investigated.ResultsOCT was analyzed in 103 patients (2237 frames, 19,827 struts) at a median of 216 days post-implantation. Of these, 70 were treated with BRS versus 32 with EES. Pre-(92.8 vs. 68.7%, p = 0.002) and post-dilation (51.4 vs. 12.5%, p < 0.001) were more common in BRS as compared to EES. Strut coverage was higher in BRS vs. EES (97.5% vs. 90.9%, p < 0.001). Mean neointimal thickness was comparable in both groups [85.5 (61.9, 124.1) vs. 69.5 (32.7, 127.5) µm, respectively, p = 0.20]. Mature neointimal regions were numerically more common in BRS (43.0% vs. 24.6%; p = 0.35); this difference was statistically significant in ST-elevation myocardial infarction patients (40.9% vs. 21.1%, p = 0.03).At two-years, 8 (7.8%) patients experienced TLF. Mean neointimal area [0.61 (0.21, 1.33) vs. 0.41 (0.11, 0.75) mm2, p = 0.03] and mean neointimal coverage [106.1 (65.2, 214.8) vs. 80.5 (53.5, 122.1) µm, p < 0.01] were higher, with comparable tissue maturity, in lesions with versus without TLF.ConclusionsIn selected patients who underwent OCT surveillance 6–8 months after coronary intervention for AMI with differing implantation characteristics depending on the device type used, vessel healing was more advanced in BRS compared with EES, particularly in the STEMI subgroup.

Long-term Clinical Course of Korean Patients Diagnosed with Macular Telangiectasia Type 2

Purpose: To evaluate long-term visual prognosis and changes in the retinal microstructure in patients with macular telangiectasia type 2.Methods: Retrospective analysis of medical records were performed for 61 eyes (32 patients) diagnosed with macular telangiectasia type 2. The visual acuity at diagnosis was compared with that at the final visit. In addition, cases were classified into three grades based on optical coherence tomography (OCT) findings: grade 1, inner retinal cavities only; grade 2, outer retinal cavities with ellipsoid zone disruption; and grade 3, ellipsoid zone disruption with proliferation of retinal pigment epithelium. Change in the grade during the follow-up was verified. In addition, visual acuities were compared between eyes with and without a change in grade.Results: The mean follow-up period was 41.5 ± 33.2 months. Visual acuity had deteriorated significantly from the mean logarithm of the minimal angle of resolution 0.23 ± 0.26 at diagnosis to a mean of 0.31 ± 0.31 at the final visit (p &lt; 0.001). When classified using OCT, 65.6%, 22.9%, and 11.5% were grades 1, 2, and 3, respectively, at diagnosis and 47.5%, 36.1%, and 16.4% at the final visit. Progression of grade was noted in 22.9%. A higher degree of visual deterioration was noted in eyes showing progression than in eyes without (p = 0.002).Conclusions: During the long-term follow-up period, visual deterioration was noted in patients with macular telangiectasia type 2. However, the degree of deterioration was not high. Progression in the disruption of the retinal microstructure was the likely cause of visual deterioration.

Therapeutic potential of human neural precursor cells in diabetic retinopathy—preclinical model

Abstract Background Considering the expressive number of individuals being diagnosed with diabetes worldwide, it is relevant to find medicines and treatments, in order to achieve diabetes complications, as diabetic retinopathy (DR) long-awaited regression and/or cure. The study aimed to evaluate cell therapy with human neural precursor cells (hNPCs) on induced diabetic retinopathy (DR) in Wistar rats. Methods Wharton's Jelly Mesenchymal stem cells (WJ-MSCs) were isolated, expanded, and seeded onto a biopolymer substrate without growth factors to develop neurospheres, then hNPCs were obtained and characterized by immunocytochemistry. The animals were divided into three groups; non-diabetic (ND) n = 4; diabetic without treatment (DM) n = 9; diabetic with cell therapy (DM + hNPCs) n = 9. Cells were transplanted by intravitreal injection (1 x 106 cel/µL) into each of Streptozotocin (STZ) induced diabetes rats. Evaluations by Optical Coherence Tomography (OCT) and Electroretinography (ERG) were done before and after diabetes induction and post cell therapy. Four weeks after treatment, eye enucleation allowed histopathological and immunohistochemistry (IHC) analysis. Results hNPCs increased the number of retina ganglion cells, ameliorated the photoreceptor layer, and decreased the microvessel points, evidenced by ERG, OCT, histopathological, and IHC findings. The most relevant differences in morphological analysis (treated vs untreated), exhibit the retinal improvement in many layers, notably in the retinal pigment epithelium and photoreceptors. Conclusions hNPCs reduced DR progression, as demonstrated by a neuroprotective effect and promotion of retinal regeneration.

Best practice patterns: how to effectively use OCT in pediatric ophthalmology

As optical coherence tomography (OCT) technology has advanced, and become more widely available, it is being used more commonly in pediatric ophthalmology. As the technology demonstrates value as an integral part of the evaluation of the pediatric eye, it is critical for pediatric ophthalmologists to understand how to incorporate OCT into their clinical flow, interpret results, and make clinical decisions based on OCT findings. The purpose of this workshop is to review basic OCT interpretation and discuss recent advances in OCT technology, including OCT angiography. We will discuss the pearls and pitfalls in utilizing OCT in the evaluation and management of pediatric glaucoma, genetics, and retina.

Anterior segment optical coherence tomography (AS-OCT) findings in the Infant Aphakia Treatment Study (IATS)

Anterior segment optical coherence tomography (AS-OCT) findings in the Infant Aphakia Treatment Study (IATS)

Impact of Intracoronary Optical Coherence Tomography in Routine Clinical Practice: A Contemporary Cohort Study

Background/purposeGuidelines recommend intracoronary optical coherence tomography (OCT) to assess stent failure and guide percutaneous coronary intervention (PCI) but OCT may be useful for other indications in routine clinical practice. Methods/materialsWe conducted an international registry of OCT cases at two large tertiary care centers to assess clinical indications and the potential impact on decision making of OCT in clinical routine. Clinical indications, OCT findings, and their impact on interventional or medical treatment strategy were retrospectively assessed. ResultsOCT was performed in 810 coronary angiography cases (1928 OCT-pullbacks). OCT was used for diagnostic purposes in 67% (N = 542) and OCT-guided percutaneous coronary intervention in 50% (N = 404, 136 cases with prior diagnostic indication). Most frequent indications for diagnostic OCT were culprit lesion identification in suspected ACS (29%) and stent failure assessment (28%). OCT findings in the diagnostic setting influenced patient management in 74%. OCT-guided PCIs concerned ACS patients in 45%. Among the 55% with chronic coronary syndrome, long lesions >28 mm (19%), left main PCI (16%), and bifurcation PCI with side-branch-stenting (5%) were the leading indications for PCI-guidance. Post-procedural OCT findings led to corrective measures in 52% (26% malapposition, 14% underexpansion, 6% edge dissection, 3% intrastent mass, 3% geographic plaque miss). ConclusionsOCT was most frequently performed to identify culprit lesions in suspected ACS, for stent failure assessment, and PCI-guidance. OCT may impact subsequent treatment strategies in two out of three patients.

Spectral Domain Optical Coherence Tomography in Retinal Vasculopathy With Cerebral Leukoencephalopathy and Systemic Manifestations: A Monogenic Small Vessel Disease.

Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S) is a monogenic small vessel disease caused by mutations in TREX1. Several organs, including retina and brain, are affected. Analyzing retinal anatomy is increasingly used as a biomarker for ophthalmological and neurological disorders (due to the shared embryological origin of retina and brain). Optical coherence tomography (OCT) provides a noninvasive cross-sectional visualization of optic disc and macula. We aimed to use OCT to investigate retinal layer thickness in RVCL-S. Cross-sectional, 17 TREX1 mutation carriers (34 eyes) and 9 controls (18 eyes) underwent comprehensive ophthalmologic assessment followed by spectral domain OCT for measuring peripapillary retinal nerve fiber layer (pRNFL) thickness and total macular volume (TMV). Secondary outcomes included measuring thickness of individual macular retinal layers and peripapillary sectors. Findings were analyzed using generalized estimating equations to account for intereye correlation. TREX1 mutation carriers had decreased pRNFL thickness (median [interquartile range] 76 [60-99] vs 99 [87-108] µm, P < 0.001) and TMV (8.1 [7.4-8.5] vs 8.7 [8.4-8.8] mm3, P = 0.006) compared with controls. With the exception of the temporal sector, the thickness of all peripapillary sectors was decreased in TREX1 mutation carriers. Ganglion cell layer (30 [22-37] vs 39 [36-41] µm, P < 0.001) and inner plexiform layer (27 [24-34] vs 34 [31-35], P = 0.001) were thinner in TREX1 mutation carriers. Notably, in 9 of 12 eyes with normal funduscopic examination, retinal thinning was already detected. RVCL-S, which may serve as a vascular retinopathy model, is associated with retinal thinning in the peripapillary and macular area. OCT findings can potentially serve as early biomarkers for RVCL-S and other vascular retinopathies.

A comparison of posterior segment optical coherence tomography findings in full-term and preterm children without retinopathy of prematurity

Purpose:Structural differences have been described in the retina of prematurely born children, including increased macular thickness caused by failed migration of the inner retina during development and retinal nerve fiber layer (RNFL) thinning related to low birth weight. The present study aimed to evaluate the differences in macular and RNFL optical coherence tomography (OCT) findings between full-term and preterm children without retinopathy of prematurity (ROP).Methods:Thirty-four premature (study group) and 43 full-term patients (control group)—aged 3 to 8 years—were studied. All children underwent a complete ophthalmological exam and OCT of the macula and optic nerve in both eyes to determine macular and RNFL thickness and morphology. Correlation analysis between central macular thickness, age, and visual acuity was also performed.Results:Central macular thickness was greater in the study group than in the control group; a difference of 14.2 μm was observed for the right eye (P = 0.002) and 12.16 μm for the left eye (P = 0.019). The thickness of the parafoveal and the perifoveal zones was consistently greater in the study group. 44.3% of eyes in the study group had mild forms of foveal hypoplasia (grades 1a and 1b) in qualitative description. No correlation between central macular thickness and visual acuity was found. There was no difference in RNFL thickness between both groups.Conclusion:Statistically significant structural differences were found in the macula of premature children, with a greater foveal thickness possibly reflecting retention of the inner retina during development, with no repercussion over visual acuity. RNFL thickness was similar in both groups.

Cognitive Decline in Multiple Sclerosis Is Related to the Progression of Retinal Atrophy and Presence of Oligoclonal Bands: A 5-Year Follow-Up Study.

Background: Brain atrophy, which is associated with cognitive impairment and retinal nerve fiber layer (RNFL) atrophy, is the main biomarker of neurodegeneration in multiple sclerosis (MS). However, data on the relationship between inflammatory markers, such as oligoclonal bands (OCBs) in the cerebrospinal fluid (CSF), and cognition, RNFL atrophy, and brain atrophy are scarce. The aim of this study was to assess the influence of RNFL thickness, brain atrophy markers, intrathecal OCBs, and the immunoglobulin G (IgG) index on cognitive decline over a 5-year period in patients with MS.Methods: This prospective, single-center, observational cohort study included 49 patients with relapsing MS followed up over 5 years. At baseline, the patients underwent brain magnetic resonance imaging (MRI). Cognitive evaluation was performed using the Brief International Cognitive Assessment for MS (BICAMS), and RNFL thickness was assessed using optical coherence tomography (OCT). OCBs and IgG levels in the CSF were evaluated at baseline. The BICAMS, OCT, and MRI findings were re-evaluated after 5 years.Results: A significant reduction in information processing speed, visual learning, temporal RNFL thickness, the Huckman index, and third ventricle mean diameter was found in all 49 patients with relapsing MS over the observation period (p < 0.05). Of the patients, 63.3% had positive OCBs and 59.2% had elevated IgG indices. The atrophy of the temporal segment and papillomacular bundle and the presence of OCBs were significantly related to a decline in information processing speed in these patients (p < 0.05). However, brain atrophy markers were not found to be significant on the general linear models.Conclusions: RNFL atrophy and the presence of OCBs were related to cognitive decline in patients with MS over a 5-year follow-up period, thereby suggesting their utility as potential biomarkers of cognitive decline in MS.

English

BACKGROUND Optical Coherence Tomography (OCT) is a commonly used non invasive imaging instrument useful for the diagnosis and follow up of macular disorders, but it has its own share of drawbacks in the presence of media opacities like corneal oedema, dense cataract and vitreous haemorrhage. We wanted to study and interpret the various patterns of common macular diseases on optical coherence tomography. METHODS 100 patients having macular diseases with no other ocular pathology were selected by simple random sampling. The patients were studied and followed up from day 1 of OPD during the period from January 2019 to December 2019 in rural hospital at Latur. All patients suspected of any macular disorder by slit lamp bio-microscopy with 78D or 90D examination were subjected to OCT evaluation. RESULTS On observation, out of 100 cases of macular pathology, 44 % (44 patients) with age related macular degeneration(ARMD), diabetic macular oedema ( DME) 36 % (36 patients), central serous retinopathy (CSR) 10 % (10 patients), myopic maculopathy (MM) 7 % (7 patients), macular hole (MH) 3 % (3 patients) were found in our study. In ARMD patients our OCT findings were hard drusens in retinal pigment epithelium (RPE), detachment of neurosensory retina and retinal pigment epithelium whereas in patients of DME our OCT findings were cyst like hyporeflective spaces within the retina, with retinal thinning and loss of foveal depression. In patients of CSR our findings were separation of sensory retina from RP, in myopic maculopathy our OCT findings were presence of macular retinoschisis and in patients of MH our findings were showing attachment of the posterior hyaloids to the fovea, separation of a small portion of the sensory retina from RPE in the foveolar region and intraretinal cystic changes. CONCLUSIONS OCT plays a crucial role when added along with the clinical examination in the diagnosis and interpretation of common macular disorders. KEYWORDS Optical Coherence Tomography, Age Related Macular Degeneration, Macular Hole, Myopic Maculopathy

Influence of one or two horizontal muscle surgeries on OCT findings

ABSTRACT We investigate the effects of differences between one or two horizontal rectus muscle surgeries (recession ± resection) on the central macular thickness (CMT), subfoveal choroidal thickness (SFCT), and retinal nerve fiber layer (RNFL). Measurements of the CMT, SFCT, and RNFL in patients who underwent horizontal rectus muscle surgery were obtained using optical coherence tomography (OCT). Patients were grouped as those who had undergone rectus muscle recession surgery (Group 1) and those who had undergone rectus muscle recession + resection surgery (Group 2). The CMT, SFCT, and RNFL in patients were measured preoperatively and 1 day, 1 week, 1 month, 3 months, and 6 months postoperatively. A total of 65 eyes of 50 patients were analyzed retrospectively. The average age of the 25 patients in Group 1 was 8.96 ± 7.966 years (min 3, max 38). The average age of the 25 patients in Group 2 was 15.17 ± 6.806 years (min 2, max 34). The comparison of the preoperative and the 1-day and 1-week postoperative values revealed an increase in CMT and SFCT in Group 1 and Group 2. There were no significant differences between the two groups. It was observed that this increase reached the preoperative values after 1–3 months and 6 months in both groups. There was no statistically significant change in the RNFL. Rectus muscle surgery (recession±resection) caused an increase in CMT and SFCT in the early stage, which was possibly caused by the altered choroidal microcirculation resulting from mechanical traction during surgery and by postoperative inflammation. There was no difference between one or two muscle surgeries.

Fundus autofluorescence in retinal disorders

Background Fundus autofluorescence (FAF) is a noninvasive, rapid, and potentially useful imaging modality that continues to evolve. It reflects metabolic changes at the level of retinal pigment epithelium/photoreceptor complex and variation of fluorescence derived from lipofuscin and thus provides an assay of retinal and retinal pigment epithelium function. Aim Demonstration of the technique, concept, and clinical value of FAF. Patients and methods This study was performed on 63 eyes of 41 patients from May 2016 to May 2017 with various retinal diseases (age-related macular degeneration, macular dystrophy, central serous retinopathy) using digital fundus camera TRC-NW8F Plus Topcon with special filter (Spaide filter). Abnormalities in images of FAF were analyzed and correlated with the corresponding alteration in fluorescein angiography and optical coherence tomography findings. Results A broad range of characteristic FAF patterns were observed. Distribution and variation with disease imply that the fluorescence is derived from lipofuscin in the pigment epithelium. Autofluorescence is shown to be abnormally high in certain inherited diseases, and low in the presence of retinal atrophy. Conclusion FAF imaging constitutes a useful additive tool in the diagnosis and follow-up of various retinal diseases and may detect abnormalities beyond those detected on funduscopic examination.

Effect of Periocular Triamcinolone Acetonide on Prevention of Postsurgical Intraretinal Cystoid Changes after Vitrectomy with Membrane Peeling.

Newly developed intraretinal cystoid changes after vitrectomy with membrane peeling for removal of epiretinal membranes have the potential to lead to worse postsurgical results compared to patients without. The aim of the present study was to evaluate the feasibility of additional periocular application of triamcinolone acetonide as a routine adjunct at the end of vitrectomy with membrane peeling, and to compare the presence of postsurgical intraretinal cystoid changes in the first 3 months after surgery among patients with idiopathic epiretinal membranes to a historical group of patients that did not receive triamcinolone acetonide. The medical records of 41 eyes of 41patients that underwent 23 G or 25 G pars plana vitrectomy with membrane peeling for removal of epiretinal membranes and additional periocular triamcinolone acetonide application at the end of surgery were retrospectively reviewed. Optical coherence tomography findings during routine follow-ups at 3 - 5 days, 1 month, and 3 months and visual acuity at 3months after surgery were evaluated and compared to preoperative findings. Furthermore, postsurgical intraocular pressure was assessed. Periocular triamcinolone acetonide at the end of surgery was well tolerated among all patients. In total, 10% of patients had an increased intraocular pressure at least at one follow-up. Best-corrected visual acuity improved in 91% of patients with idiopathic epiretinal membranes with a mean improvement of + 3 ± 2 lines (Snellen) and was comparable to a historic group of patients (p = 0.307). Early transient macular edema could not be detected in any of the patients, while there were cases with this pathology in the historic group of patients, but neither occurrence of newly developed intraretinal cystoid changes nor macular thickness at 3 months after surgery were significantly different between patients with and without triamcinolone acetonide (p = 0.385 and p = 0.879). Periocularly applied triamcinolone acetonide at the end of vitrectomy with membrane peeling was well tolerated and showed prevention of early transient macular edema but did not prevent the development of new postoperative intraretinal cystoid changes.

The Optical Coherence Tomographic Findings Which Predict Outcome of Calcified Coronary Lesions after Percutaneous Coronary Intervention: A Serial Follow-up Study

Objective: Imaging modalities such as intravascular ultrasonography or computed tomography or angiography have shown limitations in assessing coronary calcification. In this study, we investigated whether quantitative indices of optical coherence tomography (OCT) in calcified lesions are correlated with the late outcome of a coronary stent.Methods: We consecutively enrolled patients who had more than grade 2 coronary calcification on fluoroscopy. OCT was performed at baseline, immediately after stenting, and at 9 months after stenting. We analyzed qualitative and quantitative characteristics of plaque, calcification, and stent-related indices.Results: All images of 3-time points were available in a total of 10 patients. Calcified lesions were frequently associated with thin cap fibroatheroma (100%), plaque erosion (20%), or rupture (20%) before the procedure. Thrombus was found in 100% of cases in the OCT immediately after stenting. Maximal calcium area before stenting was strongly correlated with late luminal loss assessed by 9-month follow-up OCT (r= 0.766, P= 0.01).Conclusion: Preprocedural OCT assessment on calcified coronary lesion may predict high-risk procedure and late stent outcome. Further studies are warranted to confirm these findings.

High-Resolution Quantitative Mapping of Macaque Cervicovaginal Epithelial Thickness: Implications for Mucosal Vaccine Delivery.

Vaginal mucosal surfaces naturally offer some protection against sexually transmitted infections (STIs) including Human Immunodeficiency Virus-1, however topical preventative medications or vaccine designed to boost local immune responses can further enhance this protection. We previously developed a novel mucosal vaccine strategy using viral vectors integrated into mouse dermal epithelium to induce virus-specific humoral and cellular immune responses at the site of exposure. Since vaccine integration occurs at the site of cell replication (basal layer 100-400 micrometers below the surface), temporal epithelial thinning during vaccine application, confirmed with high resolution imaging, is desirable. In this study, strategies for vaginal mucosal thinning were evaluated noninvasively using optical coherence tomography (OCT) to map reproductive tract epithelial thickness (ET) in macaques to optimize basal layer access in preparation for future effective intravaginal mucosal vaccination studies. Twelve adolescent female rhesus macaques (5-7kg) were randomly assigned to interventions to induce vaginal mucosal thinning, including cytobrush mechanical abrasion, the chemical surfactant spermicide nonoxynol-9 (N9), the hormonal contraceptive depomedroxyprogesterone acetate (DMPA), or no intervention. Macaques were evaluated at baseline and after interventions using colposcopy, vaginal biopsies, and OCT imaging, which allowed for real-time in vivo visualization and measurement of ET of the mid-vagina, fornices, and cervix. P value ≤0.05 was considered significant. Colposcopy findings included pink, rugated tissue with variable degrees of white-tipped, thickened epithelium. Baseline ET of the fornices was thinner than the cervix and vagina (p<0.05), and mensing macaques had thinner ET at all sites (p<0.001). ET was decreased 1 month after DMPA (p<0.05) in all sites, immediately after mechanical abrasion (p<0.05) in the fornix and cervix, and after two doses of 4% N9 (1.25ml) applied over 14 hrs in the fornix only (p<0.001). Histological assessment of biopsied samples confirmed OCT findings. In summary, OCT imaging allowed for real time assessment of macaque vaginal ET. While varying degrees of thinning were observed after the interventions, limitations with each were noted. ET decreased naturally during menses, which may provide an ideal opportunity for accessing the targeted vaginal mucosal basal layers to achieve the optimum epithelial thickness for intravaginal mucosal vaccination.

OCT Findings in MINOCA.

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) is a working diagnosis for patients presenting with acute myocardial infarction without obstructive coronary artery disease on coronary angiography. It is a heterogenous entity with a number of possible etiologies that can be determined through the use of appropriate diagnostic algorithms. Common causes of a MINOCA may include plaque disruption, spontaneous coronary artery dissection, coronary artery spasm, and coronary thromboembolism. Optical coherence tomography (OCT) is an intravascular imaging modality which allows the differentiation of coronary tissue morphological characteristics including the identification of thin cap fibroatheroma and the differentiation between plaque rupture or erosion, due to its high resolution. In this narrative review we will discuss the role of OCT in patients presenting with MINOCA. In this group of patients OCT has been shown to reveal abnormal findings in almost half of the cases. Moreover, combining OCT with cardiac magnetic resonance (CMR) was shown to allow the identification of most of the underlying mechanisms of MINOCA. Hence, it is recommended that both OCT and CMR can be used in patients with a working diagnosis of MINOCA. Well-designed prospective studies are needed in order to gain a better understanding of this condition and to provide optimal management while reducing morbidity and mortality in that subset patients.