Optical Coherence Tomography Results Research Articles

POSSIBLE ERRORS IN THE DIAGNOSIS OF INTRAOCULAR TUMORS

Rationale: The article discusses difficulties in the differential diagnosis of intraocular tumors (IOT), particularly in cases of small choroidal melanoma. Despite a substantial number of publications dedicated to the diagnosis of intraocular tumors, difficulties in interpreting imaging methods, such as optical coherence tomography (OCT), persist.Objective: to analyze the OCT patterns that have led to diagnostic errors.Methods: We analyzed the OCT results of 15 patients whose diagnosis of «choroidal hemangioma» was revised to «choroidal melanoma» in 11 cases or «progressive nevus» in 4 cases. The mean age at the time of IOT detection was 50.20±13.08 years (range: 35–79 years); the average tumor prominence was 2.22±0.82 mm (range: 1-3.6 mm), and the average diameter was 8.01±2.72 mm (range: 3.11–11.5 mm). A detailed analysis of the specific OCT patterns that led to diagnostic errors was conducted.Results and discussion: The characteristics of the identified OCT patterns that frequently caused diagnostic difficulties were thoroughly examined, such as cystic changes and the «subretinal cleft» phenomenon. Cases in which complex OCT patterns overlapped with both melanoma and hemangioma were also analyzed, reinforcing the need for a multimodal approach to the interpretation of imaging data. Conclusion: for accurate diagnosis and to avoid erroneous planning of treatment strategies, OCT should be evaluated within the context of the clinical picture and patient history.

Retinal and Corneal OCT Results of Patients Hospitalized and Treated in the Acute Phase of COVID-19.

Objective: This study aimed to assess changes in the morphology of the retina and cornea in patients treated and hospitalized during the acute active phase of SARS-CoV-2 infection. Methods: A total of 24 patients with symptomatic early COVID-19 disease and 38 healthy participants from a control group were enrolled in our study. Among them, 20 received oxygen therapy at flow rates ranging from 1-10 L, while four received high-flow intranasal oxygen therapy (HFNOT). Some patients were treated with other types of therapy, such as Remdesivir, COVID-19 convalescent plasma therapy, or Tocilizumab. In the study, we focused on the analysis of optical coherence tomography (OCT) images of the cornea and retina including corneal thickness, central retinal thickness, retinal nerve fiber layer (RNFL), and optic disc parameters. The measurements were acquired using Spectral-domain OCT REVO FC 130. Results: The analysis did not show significant changes between the examined ophthalmological parameters before and after therapy. Furthermore, there were no detected significant differences between the tested parameters of the retina and cornea in COVID-19-positive patients compared to the control group. Conclusions: No ophthalmological manifestations of COVID-19 disease were observed during the study. Taking into account the results of other publications, the lack of an unambiguous position on this topic requires further research.

Prevalence of Normal-Tension Glaucoma in Patients With Primary Aldosteronism

PurposeTo investigate patients with primary aldosteronism (PA) and the prevalence of normal-tension glaucoma (NTG). DesignCross-sectional study. MethodsNewly diagnosed PA patients were evaluated in this cross-sectional study, with ophthalmic examinations such as intraocular pressure (IOP) measurements by a Goldmann applanation tonometer, central corneal thickness (CCT), slit-lamp biomicroscopic examination, gonioscopy, ophthalmoscopy, fundus photography, visual field test with a Humphrey Field Analyzer 24-2 SITA Standard program, and optical coherence tomography (OCT) of the peripapillary retinal nerve fiber layer (RNFL), performed in each of the subjects. Optic disc appearance, perimetric results, OCT results, and other ocular findings were all used for determining the glaucoma diagnosis. The primary outcome was shown the prevalence of NTG in patients with PA. ResultsNTG prevalence in the 212 PA patients was 11.8% (95% confidence interval [CI], 4.7%-20.7%). As compared to the hypertensive patients without PA, the hypertensive patients with PA exhibited a significantly increased NTG prevalence (odds ratio; 4.019, 95% CI, 1.223-13.205; P = .022). Increased NTG prevalence was associated with age, ranging from 8.8% (95% CI, 2.1%-15.6%) for those aged 40 to 49 years, to 37.5% (95% CI, 13.8%-61.2%) for those aged 70 years and older. In 72 hypertensive patients without PA, who were used as the controls, NTG prevalence was 5.2%, with a 95% CI ranging from 0.5% to 14.4%. ConclusionsThere was an 11.8% prevalence of NTG in PA patients, with these patients at an elevated risk of NTG, which was not mediated by blood pressure.

Automatic retinal image analysis methods using colour fundus images for screening glaucomatous optic neuropathy

ObjectivesTrain an automatic retinal image analysis (ARIA) method to screen glaucomatous optic neuropathy (GON) on non-mydriatic retinal images labelled with the additional results of optical coherence tomography (OCT) and assess...

Abstract P130: Predictive value of the MCG-based Nomogram model for the anatomical and functional evaluation of coronary artery lesions

Objective: Optical coherence tomography (OCT) is an intravascular imaging technology that can provide cross-sectional images of coronary arteries, which can more accurately assess the condition of coronary artery lesions and the degree of vascular stenosis. It is an important method for the anatomical evaluation of coronary artery lesions. Radionuclide myocardial perfusion imaging (MPI) is a commonly used non-invasive method for functional evaluation of myocardial ischemia in clinical practice. The clinical application of these two methods is greatly limited due to operational risk and high cost. This study aimed to explore the potential predictive value of the MCG-based Nomogram model for the anatomical and functional evaluation of coronary artery lesions. Methods: We reviewed the patients who were hospitalized in the cardiovascular department of our hospital from October 2021 to July 2023 for MCG test. A total of 137 patients were included in the OCT subgroup, including 48 patients in the severe coronary artery stenosis group (inclusion criteria: OCT showed coronary artery area stenosis ≥70.0%) and 89 patients in the control group (inclusion criteria: OCT showed coronary artery area stenosis <50.0% or CCTA showed no coronary artery stenosis). A total of 46 patients were included in the MPI subgroup, including 10 patients in the severe myocardial ischemia group (inclusion criteria: MPI showed abnormal perfusion scores of at least one ventricular segment ≥3 points) and 36 patients in the control group (inclusion criteria: MPI showed abnormal perfusion scores of all ventricular segments ≤2 points). The Nomogram model was used to predict the results of patients in the two subgroups, and the results were compared with the OCT and MPI results. The sensitivity, specificity and Youden index were calculated. Results: The Nomogram model based on MCG had a sensitivity of 70.8%, a specificity of 85.4%, and a Youden index of 0.562 for predicting OCT results. The sensitivity, specificity and Youden index of Nomogram model for predicting MPI results were 70.0%, 72.2% and 0.422, respectively. Conclusions: The MCG-based Nomogram model has good prediction accuracy for the anatomical and functional evaluation of coronary artery lesions, which has potential application value.

Intra-operative Intravitreal Bevacizumab For Patients With Diabetic Macular Edema Undergoing Phacoemulsification with Foldable IOL Implantation

Objective: To assess the efficacy of Intra-operative Intravitreal Bevacizumab in treating Diabetic Macular Edema in patients undergoing Phacoemulsification with Foldable intraocular lens (IOL) Implantation, in comparison to a control group.Methodology: This experimental study was performed in department of Ophthalmology, Madinah Teaching Hospital, Faisalabad from 5th October to 2022 – 5th March 2023. Sixty patients (30 in each group) were enrolled in the study. Patients in group “A” received Intravitreal Bevacizumab immediately after phacoemulsification with foldable IOL implantation.Whereas Intravitreal Bevacizumab was not given to patients in group B (control group). Best Corrected Visual Acuity (BCVA) and macular thickness using optical coherence tomography (OCT) were recorded within a timeframe of 7-30 days prior to surgery, as well as at 1 and 3 months after the surgery for comparison between the two study groups. Results: The study comprised 60 patients, with a mean age of 56.43 ± 5.90 years, representing both genders. Among the participants, males were predominant, accounting for 32 (53.3%) individuals, while females constituted 28 (46.7%) of the sample. The baseline best-corrected visual acuity (BCVA) measurements between group A and group B were 0.22 ± 0.68 and 0.21 ± 0.07, respectively. There was no statistically significant difference observed between the two groups (P = 0.677). However, significant disparities in BCVA were observed after one- and three-months post-surgery, favoring group A.Similarly, mean optical coherence tomography (OCT) at baseline was 271.09 ± 26.87 in group A and 307.57 ± 32.81 in group B, with no significant difference (P = 0.771). Nonetheless, significant differences in OCT were noted after one- and three-months post-surgery, with group A demonstrating superior results. These findings underscore the beneficial impact of intra-operative Bevacizumab in improving both BCVA and OCT outcomes post-surgery. Conclusion: The administration of intravitreal bevacizumab during phacoemulsification has been shown to yield notable improvements in Best Corrected Visual Acuity (BVCA) and Optical Coherence Tomography (OCT) among those with diabetes with macular edema who are undergoing cataract surgery.

Optical coherence tomography analysis of lesion characteristics and thrombus types in non ST-segment elevation myocardial infarction patients

The precise features of lesions in non-ST-segment elevation myocardial infarction (NSTEMI) patients with total occlusion (TO) of the infarct-related artery (IRA) are still unclear. This study employs optical coherence tomography (OCT) to investigate pathological features in NSTEMI patients with or without IRA TO and explores the relationship between thrombus types and IRA occlusive status. This was a single-center retrospective study. A total of 202 patients diagnosed with NSTEMI were divided into two groups: those with Thrombolysis In Myocardial Infarction (TIMI) flow grade 0 before percutaneous coronary intervention (PCI) (referred to as the TO group, n = 100) and those TIMI flow grade 1–3 (referred to as the Non-TO group, n = 102). Baseline characteristics, coronary angiography findings, and OCT results were collected. Multivariate logistic analysis identified factors influencing TO in NSTEMI. The category of NSTEMI was further subdivided based on the type of electrocardiogram (ECG) into two subgroups: ST segment unoffset myocardial infarction (STUMI) and ST segment depression myocardial infarction (STDMI). This division allows for a more specific classification of NSTEMI cases. The TO group had a younger age, higher male representation, more smokers, lower hypertension and cerebrovascular disease incidence, lower left ventricular ejection fraction (LVEF), and higher creatine kinase myocardial band (CKMB) and creatine kinase (CK) peak levels. In the TO group, LCX served as the main IRA (52.0%), whereas in the Non-TO group, LAD was the predominant IRA (45.1%). Compared to the Non-TO group, OCT findings demonstrated that red thrombus/mixed thrombus was more common in the TO group, along with a lower occurrence of white thrombus (p < 0.001). The TO group exhibited a higher prevalence of STUMI (p = 0.001), whereas STDMI was more commonly observed in the Non-TO group (p = 0.001). NSTEMI presents as STUMI and STDMI distinct entities. Red thrombus/mixed thrombus in IRA often indicates occlusive lesions with STUMI on ECG. White thrombus suggests non-occlusive lesions with STDMI on ECG.

Prediction of vitreomacular traction syndrome outcomes with deep learning: A pilot study.

To investigate the potential of an Optical Coherence Tomography (OCT) based Deep-Learning (DL) model in the prediction of Vitreomacular Traction (VMT) syndrome outcomes. A single-centre retrospective review. Records of consecutive adult patients attending the Royal Adelaide Hospital vitreoretinal clinic with evidence of spontaneous VMT were reviewed from January 2019 until May 2022. All patients with evidence of causes of cystoid macular oedema or secondary causes of VMT were excluded. OCT scans and outcome data obtained from patient records was used to train, test and then validate the models. For the deep learning model, ninety-five patient files were identified from the OCT (SPECTRALIS system; Heidelberg Engineering, Heidelberg, Germany) records. 25% of the patients spontaneously improved, 48% remained stable and 27% had progression of their disease, approximately. The final longitudinal model was able to predict 'improved' or 'stable' disease with a positive predictive value of 0.72 and 0.79, respectively. The accuracy of the model was greater than 50%. Deep-learning models may be utilised in real-world settings to predict outcomes of VMT. This approach requires further investigation as it may improve patient outcomes by aiding ophthalmologists in cross-checking management decisions and reduce the need for unnecessary interventions or delays.

Presence of subfoveal hyperreflective dots as an anatomic and functional prognostic biomarker in macular holes

ObjectiveTo evaluate the presence of subfoveal hyperreflective dots (SfHD) using optical coherence tomography (OCT) in macular holes (MH) and establish whether there is a relationship with postoperative anatomical and functional outcomes. MethodsAn observational cross-sectional study was conducted at the Dr. Elías Santana Hospital. Sixty-eight eyes of 67 patients with a tomographic diagnosis of full-thickness MH who underwent pars plana vitrectomy (PPV) and internal limiting membrane (ILM) peeling were included. Preoperative and postoperative measurements were obtained using radial macular scans and HD raster scans with Optovue and Cirrus 5000 (Zeiss) OCT machines. The main outcome measures were anatomical closure by OCT and functional outcome through best-corrected visual acuity (BCVA). ResultsThe anatomical closure rate in our study was 63%. MHs that failed to achieve anatomical closure exhibited a higher number of hyperreflective dots and worse postoperative BCVA. A statistically significant association was found between exposed retinal pigment epithelium (RPE) in microns and the number of SfHD (P = .001). ConclusionSfHD is a common tomographic finding in MH, and the presence of a higher number of these points is associated with poorer anatomical and functional outcomes. This imaging finding is a potential prognostic biomarker in this pathology.

Presencia de puntos hiperreflectivos subfoveales como biomarcador pronóstico anatómico y funcional en agujero macular

ObjectiveTo evaluate the presence of subfoveal hyperreflective dots (SfHD) using optical coherence tomography (OCT) in macular holes (MH) and establish whether there is a relationship with postoperative anatomical and functional outcomes. MethodsAn observational cross-sectional study was conducted at the Dr. Elías Santana Hospital. Sixty-eight eyes of 67 patients with a tomographic diagnosis of full-thickness MH who underwent pars plana vitrectomy (PPV) and internal limiting membrane (ILM) peeling were included. Preoperative and postoperative measurements were obtained using radial macular scans and HD raster scans with Optovue and Cirrus 5000 (Zeiss) OCT machines. The main outcome measures were anatomical closure by OCT and functional outcome through best-corrected visual acuity (BCVA). ResultsThe anatomical closure rate in our study was 63%. MHs that failed to achieve anatomical closure exhibited a higher number of hyperreflective dots and worse postoperative BCVA. A statistically significant association was found between exposed retinal pigment epithelium (RPE) in microns and the number of SfHD (p=0.001). ConclusionSfHD is a common tomographic finding in MH, and the presence of a higher number of these points is associated with poorer anatomical and functional outcomes. This imaging finding is a potential prognostic biomarker in this pathology.

Potential ocular indicators to distinguish posterior cortical atrophy and typical Alzheimer’s disease: a cross-section study using optical coherence tomography angiography

BackgroundPosterior cortical atrophy (PCA) is a form of dementia that frequently displays significant visual dysfunction and relatively preserved cognitive and executive functions, thus hindering early diagnosis and treatment. This study aimed to investigate possible fundus markers in PCA patients and compare them with those of typical Alzheimer’s disease (AD) patients to seek potential diagnostic patterns.MethodsAge-matched PCA and AD patients and healthy controls (HC) completed optometry, intraocular pressure measurement, neuropsychologic assessments, optical coherence tomography (OCT), and optical coherence tomography angiography (OCTA) examination in one visit. Overall, six outcomes of thicknesses of various retinal layers and seven outcomes of the retinal microvascular network were calculated. After adjusting for age, sex, and years of education, the OCT and OCTA results were analyzed using analysis of covariance and generalized linear models. Correlation analyses were performed using Spearman correlation, and ROC curves were plotted.ResultsTwelve PCA patients, nineteen AD patients, and thirty HC, aged 45–80 years were included. Fifty HC, thirty AD, and twenty PCA eyes were available for foveal avascular zone (FAZ) area analysis; forty-nine HC, thirty-four AD, and eighteen PCA eyes were available for OCT and OCTA assessments. PCA patients had thinner retinal nerve fiber layer and ganglion cell layer + inner plexiform layer than HC in the 0–3 mm circle and 1–3 mm ring. Few structural differences were observed between the AD group and the other two groups. The flow area of the superficial capillary plexus and the intermediate capillary plexus was smaller in the PCA group than in the HC group in the 0–1 mm circle, 0–3 mm circle. MMSE performed better than any combination of optical parameters in identifying AD and PCA from HC (AUC = 1), while the combination of MoCA, retinal thickness and vascular density of ICP in the 1-3 mm ring, with flow area of ICP in the 0-1 mm circle showed the strongest ability to distinguish PCA from AD (AUC = 0.944).ConclusionsPCA patients exhibited similar impairment patterns to AD patients in the fundus structure and microvascular network. OCTA may aid in the non-invasive detection of AD and PCA, but still remains to be substantiated.

Post-fever Retinitis With a Positive Weil-Felix Test: A Study From a Tertiary Center in South India.

Background Post-fever retinitis (PFR) is reported two to six weeks after fever and affects one or both eyes. Rickettsial fever is one of the most common causes of PFR. This study aimed to report the clinical features and treatment outcomes of PFR cases with a positive Weil-Felix test. Methodology In this study, we collected demographic data, fever details, eye symptoms, ocular examination findings, optical coherence tomography (OCT) and fundus fluorescein angiography findings, laboratory findings, and length of follow-up of consecutive PFR cases with a positive Weil-Felix test. All cases were treated with oral doxycycline and prednisolone. Final best-corrected visual acuity (BCVA) and ocular examination findings were recorded. Visual field examination and follow-up OCT results were noted if available. Results A total of nine patients (eight males) with a mean age of 39.1 years with fever before ocular symptoms and positive Weil-Felix test were included.Six patients had bilateral disease. The mean initial and final BCVA in the affected eyes was 1.16 and 0.35 logMAR units, respectively (p < 0001). All 15 eyes had typical white retinitis patches and retinal hemorrhages which resolved after treatment. OCT showed hyperreflectivity and inner retinal disorganization over retinitis patches. White subretinal lines were noted in three patients and retinal nerve fiber bundle defect with corresponding visual field defect was seen in one eye. Conclusions In this study, PFR due to rickettsia infections has been reported from our region for the first time. Hence, eye specialists in the region should be aware of this entity.

Prognostic Value of Optical Flow Ratio among Patients with Coronary Artery Disease after Percutaneous Coronary Treatment: A Hospital-Based Retrospective Cohort Investigation

Objective: The goal of this study was to examine the prognostic performance of optical flow ratio (OFR) among patients with coronary artery disease (CAD) after percutaneous coronary intervention (PCI). Methods: We recruited patients with CAD undergoing optical coherence tomography (OCT)-directed PCI between January 2019 and June 2021 for our single-center, hospital-based, retrospective cohort investigation. We assessed the link between post-PCI OFR and major adverse cardiovascular events (MACE) via multivariate Cox regression analysis. Results: Receiver operating characteristic analysis revealed that the best post-PCI OFR threshold for MACE was 0.91, and introduction of OFR into the baseline profile and OCT results markedly enhanced MACE identification after PCI. On the basis of survival curves, patients with OFR ≤0.91 (P &lt; 0.001) and thin-cap fibroatheroma (TCFA) (P = 0.007) exhibited higher MACE incidence, and myocardial infarction (MI) incidence was considerably greater among patients with OFR ≤0.91 (P &lt; 0.001), compared with OFR &gt;0.91. Multivariate Cox regression analysis suggested that OFR ≤0.91 (hazard ratio [HR]: 3.60; 95% confidence interval [CI]: 1.24–10.44; P = 0.019), and TCFA (HR: 3.63; 95% CI: 1.42–9.20; P = 0.007) were independent risk factors for MACE, and OFR ≤0.91 was independently associated with MI (HR: 14.64; 95% CI: 3.27–65.54; P &lt; 0.001). Conclusion: OFR after PCI is an independent MACE bio-indicator among patients with CAD. Adding OFR to post-PCI OCT results may potentially enhance MACE prediction.

Results of a survey of ophthalmologists on the special aspects in performing and interpreting optical coherence tomography examination of the macula

BACKGROUND: Optical coherence tomography (OCT) is the main method for in vivo examination of the morphology of ocular posterior segment structures, used in modern ophthalmological practice.&#x0D; AIM: Study of special aspects in performing and interpreting the results of OCT of the macula by ophthalmologists working in the healthcare system of the Russian Federation.&#x0D; MATERIALS AND METHODS: In the anonymous survey, conducted using an original online questionnaire of 12 questions 59 respondents took part. They confirmed being ophthalmologists with experience in performing OCT and gave their consent to took part in the survey.&#x0D; RESULTS: The majority of respondents (79.6%) reported that they face the need to perform OCT without obtaining the patients clinical data. 66.1% of respondents always evaluate the correct placement of segmentation boundaries. Only 56% of the respondents always or often perform frontal (en face) scans during OCT examination of the macula. At the same time, 16.9% of specialists indicated that they did not know what segmentation boundaries are, and 8.5% noted that they did not understand the term en face scan. The principle of layer-by-layer analysis is used by 94.9% of respondents when describing images. Significant discrepancies were also revealed in the interpretation by the respondents of some parameters on specific examples of OCT scans. 71.2% of respondents have experience in using templates when describing OCT images, and 13.6% use them constantly. The proportion of specialists who consider it expedient to develop and introduce into clinical practice a standard protocol (template) for describing macular OCT images was 84.7%.&#x0D; CONCLUSIONS: Insufficient awareness of some ophthalmologists about particular principles of interpreting the results of an OCT imaging and about certain practical aspects of its application was revealed. This indicates the need in improving the quality of informational support and training of specialists. A request was received from ophthalmologists about the need to develop a standard protocol (template) for describing OCT images of the macular area with the aim of subsequent implementation into the clinical practice of the healthcare system of the Russian Federation.

Use of Adjunctive Corticosteroid With Antivascular Endothelial Growth Factor Agents in the Treatment of Choroidal Neovascular Membrane Associated With Presumed Ocular Histoplasmosis.

Purpose: To evaluate the impact of combination treatment of antivascular endothelial growth factor (anti-VEGF) intravitreal injections and corticosteroids in patients with choroidal neovascularization (CNV) secondary to presumed ocular histoplasmosis syndrome (POHS). Methods: A retrospective multicenter study was conducted in a cohort from Illinois and Missouri. Patients were identified over an 8-year period, and data were evaluated over a 1-year study window commencing with treatment initiation. Group 1 included patients treated with intravitreal injections of anti-VEGF, and group 2 included those who received intravitreal injections of anti-VEGF and adjuvant corticosteroids. Optical coherence tomography (OCT) measurements and increases in Early Treatment Diabetic Retinopathy Study (ETDRS) letter score were compared between each group. Results: Using the method of last visit carried forward, the visual acuity (VA) in group 2 was 6.42 ETDRS letters better than the VA in group 1 at the final assessment. Patients in group 2 had a mean ETDRS letter gain of 21.50 (P = .06) from the initial baseline vision. The average amount of decrease in OCT central subfield thickness compared with baseline was lower in group 1 (80.9 ± 129.8 µm) vs group 2 (102.8 ± 90.40 µm) at the 1-year follow-up visit (P = .25). Conclusions: Approved treatment of CNV secondary to POHS is limited. Adjuvant corticosteroid treatment in patients with CNV secondary to POHS may provide better long-term vision and OCT outcomes than anti-VEGF alone and may offer an additional therapy option for these patients.

Multimodal OCT Control for Early Histological Signs of Vulvar Lichen Sclerosus Recurrence after Systemic PDT: Pilot Study.

Photodynamic therapy (PDT) is a modern treatment for severe or treatment-resistant vulvar lichen sclerosus (VLS). The chronic and recurrent nature of VLS requires control of recurrences at an early stage. In this paper, a non-invasive multimodal optical coherence tomography (OCT) method was used to control for early histological signs of VLS recurrence after systemic PDT using Photodithazine®. To interpret the OCT data, a histological examination was performed before PDT and 3 months after PDT. Two groups of patients were identified: with early histological signs of VLS recurrence (Group I, n = 5) and without histological signs of VLS recurrence (Group II, n = 6). We use structural OCT, OCT angiography, and OCT lymphangiography throughout 6 months after PDT to visually assess the skin components and to quantitatively assess the dermis by calculating the depth-resolved attenuation coefficient and the density of blood and lymphatic vessels. The OCT data assessment showed a statistically significant difference between the patient groups 3 months after PDT. In Group II, all the studied OCT parameters reached maximum values by the 3rd month after PDT, which indicated recovery of the skin structure. At the same time, in Group I, the values of OCT parameters did not approach the values those in Group II even after 6 months. The obtained results of multimodal OCT can be used for non-invasive control of early histological recurrence of VLS after systemic PDT and for adjusting treatment tactics in advance, without waiting for new clinical manifestations of the disease.

Relationship between Full-Thickness Macular Hole Onset and Posterior Vitreous Detachment: A Temporal Onset Theory

PurposeTo evaluate the relationship between full-thickness macular hole (FTMH) onset and perifoveal posterior vitreous detachment using optical coherence tomography (OCT) data.DesignRetrospective study.ParticipantsA total of 742 patients with FTMH or impending macular hole (MH) in at least one eye, as determined by ophthalmoscopy and OCT.MethodsMHs were staged using OCT results. Patients with the posterior vitreous membrane clearly detected in the OCT images and vitreoretinal adhesion size ≤ 1500 μm—eyes with MH stages 1–3—were included in the study. The contralateral eyes were also included in the analyses if they showed the focal type of vitreomacular adhesion (VMA) (i.e., vitreoretinal adhesion ≤ 1500 μm). The distance between the posterior vitreous membrane and the surface of the retina was defined as the posterior vitreous separation height (PVSH). Using the OCT images, PVSHs of each eye in four directions (nasal, temporal, superior, and inferior) at 1 mm from the center of the MH or fovea were calculated.Main Outcome MeasuresThe main outcome measures were PVSHs according to the MH stage and VMA, the relationship of the foveal inner tear with PVSH, and the likelihood of a foveal inner tear based on the direction.ResultsThe PVSH trends in each of the four directions were as follows: VMA < MH stage 1 = MH stage 2 < MH stage 3. Initial MH stage 2 (onset of FTMH) was defined as the presence of a gap in only one of the four directions from the center of the MH. With increased PVSH, the likelihood of a gap increased (P = 0.002), and a temporal gap was more likely to occur than a nasal gap (P = 0.002).ConclusionsAt FTMH onset, a foveal inner tear likely appears on the temporal side or the side showing a high PVSH value.

Multimodal imaging of laser-induced choroidal neovascularization in pigmented rabbits

This study aimed to demonstrate longitudinal multimodal imaging of laser photocoagulation-induced choroidal neovascularization (CNV) in pigmented rabbits. Six Dutch Belted pigmented rabbits were treated with 12 laser lesions in each eye at a power of 300 mW with an aerial diameter spot size of 500 μm and pulse duration of 100 ms. CNV progression was monitored over a period of 4 months using different imaging techniques including color fundus photography, fluorescein angiography (FA), photoacoustic microscopy (PAM), and optical coherence tomography (OCT). All treated eyes developed CNV with a success rate of 100%. The margin and morphology of CNV were detected and rendered in three dimensions using PAM and OCT. The CNV was further distinguished from the surrounding melanin and choroidal vessels using FDA-approved indocyanine green dye-enhanced PAM imaging. By obtaining PAM at 700 nm, the location and density of CNV were identified, and the induced PA signal increased up to 59 times. Immunohistochemistry with smooth muscle alpha-actin (αSMA) antibody confirmed the development of CNV. Laser photocoagulation demonstrates a great method to create CNV in pigmented rabbits. The CNV was stable for up to 4 months, and the CNV area was measured from FA images similar to PAM and OCT results. In addition, this study demonstrates that contrast agent-enhanced PAM imaging allows for precise visualization and evaluation of the formation of new blood vessels in a clinically-relevant animal model of CNV. This laser-induced CNV model can provide a unique technique for longitudinal studies of CNV pathogenesis that can be imaged with multimodal imaging.

Finite-Element Modelling Based on Optical Coherence Tomography and Corresponding X-ray MicroCT Data for Three Human Middle Ears.

Optical coherence tomography (OCT) is an emerging imaging modality which is non-invasive, can be employed in vivo, and can record both anatomy and vibrations. The purpose here is to explore the application of finite-element (FE) modelling to OCT data. We recorded vibrations for three human cadaver middle ears using OCT. We also have X-ray microCT images from the same ears. Three FE models were built based on geometries obtained from the microCT images. The material properties and boundary conditions of the models were obtained from previously reported studies. Tympanic-membrane (TM) vibration patterns were computed for the three models and compared with the patterns measured using OCT. Frequency responses were also computed for all three models for several locations in the middle ear and compared with the OCT displacements and with the literature. The three models were compared with each other in terms of geometry and function. Parameter sensitivity analyses were done and the results were compared among the models and with the literature. The simulated TM displacement patterns are qualitatively similar to the OCT results. The simulated displacements are closer to the OCT results for 500Hz and 1kHz but the differences are greater at 2kHz. This study provides an initial look at the combined use of OCT measurements and FE modelling based on subject-specific anatomy. The geometries and parameters of the existing FE models could be modified for individual patients in the future to help identify abnormalities in the middle ear.

Optical Coherence Tomography Can Reduce Colposcopic Referral Rates in Patients With High-Risk Human Papillomavirus.

This study aimed to evaluate the feasibility of combined human papillomavirus (HPV) and optical coherence tomography (OCT) cervical cancer screening strategies. The OCT and cytology results were compared with the pathological results to calculate the sensitivity, specificity, positive predictive value, negative predictive value, and immediate cervical intraepithelial neoplasia grade 3 or worse (CIN3+) risk. The authors compared the efficiency of colposcopy by using different triage strategies. They discussed differentiation in OCT screening in different age groups. Eight hundred thirteen participants with high-risk HPV-positive and cervical cytology results underwent OCT before colposcopy between March 1 and October 1, 2021. The HPV16/18 genotyping with OCT triage has a specificity of CIN3+ lesions (61.1%; 95% CI = 57.6%-64.6%), intraepithelial neoplasia grade 2 or worse (CIN2+) (66.0%; 95% CI = 62.4%-69.6%). The HPV16/18 genotyping with cytology triage has a specificity of CIN3+ (44.0%; 95% CI = 40.4%-47.6%), CIN2+ (47.0%; 95% CI = 43.2%-50.8%). The OCT triage has a higher positive predictive value compared with the cytology, with a significant difference in CIN2+ lesions (45.0%; 95% CI = 38.8%-51.3% vs 29.2%; 95% CI = 24.7%-33.7%). The combination of OCT and high-risk HPV triage (both genotyping and nongenotyping) had a similar immediate CIN3+ risk stratification and reduced the number of colposcopies compared with the cytological triage strategy.