Cost-Effectiveness of Preoperative OCT in Cataract Evaluation for Multifocal Intraocular Lens.

PURPOSE: To determine the cost effectiveness of an adjunctive screening OCT during the preoperative evaluation of a patient considering cataract surgery with a multifocal intraocular lens (IOL) implantation. DESIGN: Cost-effectiveness analysis. PARTICIPANTS: A 67-year-old man with 20/60 vision undergoing evaluation for first-eye cataract surgery. METHODS: The cost-effectiveness analysis of the reference patient undergoing a preoperative cataract examination with and without a screening OCT was performed, evaluating for vitreoretinal diseases including an epiretinal membrane, age-related macular degeneration, vitreomacular traction, and cystoid macular edema. It was assumed that patients with macular pathologies detected before surgery would receive a monofocal IOL and be referred to a retina specialist for evaluation and management. The Medicare reimbursable cost of an OCT was $41.81. All costs and benefits were adjusted for inflation to 2019 United States dollars and discounted 3% per annum over a 16-year time horizon. Probability sensitivity analyses and 1-way deterministic sensitivity analyses were performed to assess for uncertainty. MAIN OUTCOME MEASURES: Incremental cost-effectiveness ratio and incremental cost-utility ratio (ICUR) measured in quality-adjusted life years (QALYs). RESULTS: Approximately 20.5% of patients undergoing cataract surgery may have macular pathologies, of which 11% may not be detected on the initial clinical examination. In the base case, an adjunctive preoperative OCT was cost effective from a third-party payer and societal perspective in the United States. In the probability sensitivity analyses, the ICURs were within the societal willingness-to-pay threshold of $50 000/QALY in approximately 64.4% of the clinical scenarios. CONCLUSIONS: A preoperative screening OCT during the evaluation of a patient considering a multifocal IOL added to the costs of the cataract surgery, but the OCT increased the detection of macular pathologies and improved the QALYs over time. An adjunctive screening OCT can be cost effective from a third-party payer and societal perspective.

Intravascular ultrasound, optical coherence tomography, and fractional flow reserve use in acute myocardial infarction.

BACKGROUND: There are limited data on the use of intravascular ultrasound (IVUS), optical coherence tomography (OCT), and fractional flow reserve (FFR) during acute myocardial infarction (AMI). OBJECTIVES: To assess the temporal trends of IVUS, OCT, and FFR use in AMI. METHODS: A retrospective cohort study from the National Inpatient Sample (2004-2014) was designed to include AMI admissions that received coronary angiography. Administrative codes were used to identify percutaneous coronary intervention (PCI), IVUS, OCT, and FFR. Outcomes included temporal trends, inhospital mortality and resource utilization stratified by IVUS, OCT, or FFR use. RESULTS: In 4,419,973 AMI admissions, IVUS, OCT, and FFR were used in 2.6%, 0.1%, and 0.6%, respectively. There was a 22-fold, 118-fold, and 33-fold adjusted increase in IVUS, OCT, and FFR use, respectively, in 2014 compared to the first year of use. Non-ST-elevation AMI presentation, male sex, private insurance coverage, admission to a large urban hospital, and absence of cardiac arrest and cardiogenic shock were associated with higher IVUS, OCT, or FFR use. PCI was performed in 83.2% of the IVUS, OCT, or FFR cohort compared to 64.2% of the control group (p < .001). The cohort with IVUS/OCT/FFR use had lower inhospital mortality (adjusted odds ratio 0.53 [95% confidence interval 0.50-0.56]), more frequent discharges to home (83.7% vs. 76.8%), shorter hospital stays (4.3 ± 4.4 vs. 5.0 ± 5.5 days) and higher hospitalization costs ($90,683 ± 74,093 vs. $74,671 ± 75,841). CONCLUSIONS: In AMI, the use of IVUS, OCT, and FFR has increased during 2004-2014. Significant patient and hospital-level disparities exist in the use of these technologies.

Simple approach for aberration-corrected OCT imaging of the human retina.

Aberration-corrected imaging of human photoreceptor cells, whether hardware or software based, presently requires a complex and expensive setup. Here we use a simple and inexpensive off-axis full-field time-domain optical coherence tomography (OCT) approach to acquire volumetric data of an in vivo human retina. Full volumetric data are recorded in 1.3 s. After computationally correcting for aberrations, single photoreceptor cells were visualized. In addition, the numerical correction of ametropia is demonstrated. Our implementation of full-field optical coherence tomography combines a low technical complexity with the possibility for computational image correction.

Volumetric laser endomicroscopy in the management of Barrett's esophagus.

PURPOSE OF REVIEW: The incidence of esophageal adenocarcinoma is on the rise despite widespread appreciation that the precursor lesion is Barrett's esophagus. Studies have shown that some patients known to have Barrett's esophagus develop cancer despite their enrollment in conventional endoscopic surveillance programs. This highlights the need for advanced endoscopic imaging to help identify early neoplasia and prevent its progression to esophageal cancer. Recently, a wide-field, second-generation optical coherence tomography endoscopic platform called volumetric laser endomicroscopy (VLE) was cleared by the Food and Drug Administration and made commercially available for advanced imaging in Barrett's esophagus. RECENT FINDINGS: The current review discusses current literature on VLE imaging in Barrett's esophagus. Based on ex-vivo studies, criteria have been established for identifying Barrett's esophagus-associated neoplasia. In addition, recent studies, case series, and case reports have demonstrated that VLE is well tolerated, efficacious, and can target neoplasia. SUMMARY: VLE is a new advanced imaging platform for Barrett's esophagus with considerable promise to target Barrett's esophagus-associated neoplasia. The following are needed to establish VLE's clinical role: studies showing incremental yield of dysplasia detection using VLE, studies to determine VLE's in-vivo diagnostic accuracy for identifying and classifying Barrett's esophagus-associated neoplasia, and studies on the cost-efficacy of VLE.

Hybrid averaging offers high-flow contrast by cost apportionment among imaging time, axial, and lateral resolution in optical coherence tomography angiography.

The current temporal, wavelength, angular, and spatial averaging approaches trade imaging time and resolution for multiple independent measurements that improve the flow contrast in optical coherence tomography angiography (OCTA). We find that these averaging approaches are equivalent in principle, offering almost the same flow contrast enhancement as the number of averages increases. Based on this finding, we propose a hybrid averaging strategy for contrast enhancement by cost apportionment. We demonstrate that, compared with any individual approach, the hybrid averaging is able to offer a desired flow contrast without severe degradation of imaging time and resolution. Making use of the extended range of a VCSEL-based swept-source OCT, an angular averaging approach by path length encoding is also demonstrated for flow contrast enhancement.

AIMING FOR THE BULL'S EYE: The Cost-Utility of Screening for Hydroxychloroquine Retinopathy.

BACKGROUND: Throughout medicine, the cost of various treatments has been increasingly studied with the result that certain management guidelines might be reevaluated in their context. Cost-utility is a term referring to the expense of preventing the loss of quality of life, quantified in dollars per quality-adjusted life year. In 2002, the American Academy of Ophthalmology published hydroxychloroquine screening recommendations which were revised in 2011. The purpose of this report is to estimate the cost-utility of these recommendations. METHODS: A hypothetical care model of screening for hydroxychloroquine retinopathy was formulated. The costs of screening components were calculated using 2016 Medicare fee schedules from the Centers for Medicare and Medicaid Services. RESULTS: The cost-utility of screening for hydroxychloroquine retinopathy with the 2011 American Academy of Ophthalmology guidelines was found to vary from 33,155 to 344,172 dollars per quality-adjusted life year depending on the type and number of objective screening tests chosen, practice setting, and the duration of hydroxychloroquine use. Screening had a more favorable cost-utility when the more sensitive and specific diagnostics were used, and for patients with an increased risk of toxicity. CONCLUSION: American Academy of Ophthalmology guidelines have a wide-ranging cost-utility. Prudent clinical judgment of risk stratification and tests chosen is necessary to optimize cost-utility without compromising the efficacy of screening.

A health economic pilot study comparing two diabetic retinopathy screening strategies.

To compare two screening strategies for diabetic retinopathy (DR), and to determine the health-economic impact of including optical coherence tomography (OCT) in a regular DR screening. This cross-sectional study included a cohort of patients (≥ 18 years) with type 1 or 2 diabetes mellitus (T1D or T2D) from a pilot DR screening program at Oslo University Hospital, Norway. A combined screening strategy where OCT was performed in addition to fundus photography for all patients, was conducted on this cohort and compared to our existing sequential screening strategy. In the sequential screening strategy, OCT was performed on a separate day only if fundus photography indicated diabetic macular edema (DME). The presence of diabetic maculopathy on fundus photography and DME on OCT was determined by two medical retina specialists. Based on the prevalence rate of diabetic maculopathy and DME from the pilot, we determined the health-economic impact of the two screening strategies. The study included 180 eyes of 90 patients. Twenty-seven eyes of 18 patients had diabetic maculopathy, and of these, 7 eyes of 6 patients revealed DME on OCT. When diabetic maculopathy was absent on fundus photographs, OCT could not reveal DME. Accordingly, 18 patients (20%) with diabetic maculopathy would have needed an additional examination with OCT in the sequential screening strategy, 6 (33%) of whom would have had DME on OCT. In an extended healthcare perspective analysis, the cost of the sequential screening strategy was higher than the cost of the combined screening strategy. There was a weak association between diabetic maculopathy on fundus photography and DME on OCT. The health economic analysis suggests that including OCT as a standard test in DR screening could potentially be cost-saving.

Direct electronic linearization for camera-based spectral domain optical coherence tomography.

An electronic method of k-space linearization for an analog camera for use in optical coherence tomography is demonstrated. The method applies a chirp to the data transfer clock signal of the camera in order to temporally compensate for diffraction that is nonlinear in wavenumber. The optimum parameters are obtained experimentally and theoretically and are shown to be in good accordance. Close to maximum measurable axial range, by applying this method, the FWHM of the point spread function is reduced by a factor of 5.6 and sensitivity is increased by 9.8 dB.

Fractional Flow Reserve or Optical Coherence Tomography to Guide Management of Angiographically Intermediate Coronary Stenosis: A Single-Center Trial.

OBJECTIVES: The aim of this study was to compare optical coherence tomographic (OCT) guidance and fractional flow reserve (FFR) guidance in patients with angiographically intermediate coronary lesions (AICLs) in a single-center, prospective, 1:1 randomized trial. BACKGROUND: FFR and OCT imaging may help both in the assessment of AICLs and in percutaneous coronary intervention optimization. METHODS: Patients with AICLs were randomized to FFR or OCT imaging. In the FFR arm, PCI was performed if FFR was ≤0.80. In the OCT imaging arm, PCI was performed if area stenosis was ≥75% or 50% to 75% with minimal luminal area <2.5 mm2 or plaque rupture. Angina (evaluated using the Seattle Angina Questionnaire), major adverse cardiac events, and cost were assessed at the end of follow-up. The pre-defined primary endpoint was the composite of major adverse cardiac events or significant angina (defined as Seattle Angina Questionnaire frequency scale score <90) at 13 months. RESULTS: A total of 350 patients (with 446 AICLs) were enrolled (176 randomized to FFR and 174 to OCT imaging). The primary endpoint of major adverse cardiac events or significant angina at 13 months occurred in 14.8% of patients in the FFR arm and in 8.0% in the OCT imaging arm (p = 0.048). This result was driven by a statistically nonsignificant lower occurrence of all primary endpoint components. Up to 13 months, the rate of medically managed patients was significantly higher (p < 0.001) and total cost significantly lower (p < 0.001) with FFR in comparison with OCT imaging. CONCLUSIONS: In patients with AICLs, OCT guidance is associated with lower occurrence of the composite of major adverse cardiac events or significant angina. FFR guidance is associated with a higher rate of medical management and lower costs. FFR or OCT Guidance to Revascularize Intermediate Coronary Stenosis Using Angioplasty [FORZA]; NCT01824030).

Eliminating Visual Acuity and Dilated Fundus Examinations Improves Cost Efficiency of Performing Optical Coherence Tomogrpahy-Guided Intravitreal Injections.

PURPOSE: The clinic efficiency and cost savings achieved by eliminating formal visual acuity (VA) and dilated fundus examinations (DFEs) were assessed for established patients receiving optical coherence tomography (OCT)-guided intravitreal injections. DESIGN: Comparative cost analysis. METHODS: Two different treatment models were evaluated. The first model included patients undergoing routine VA assessment, DFEs, OCT imaging, and intravitreal injections. The second model eliminated the routine VA assessment and DFE while using OCT imaging through an undilated pupil followed by the intravitreal injection. The 2 models incorporated both bevacizumab and aflibercept. The number of patients per clinic day, the cost per visit, and the daily revenues were compared between the 2 models. RESULTS: Optimized schedules with and without VA assessments and DFEs allowed for 48 and 96 patients to be injected per day, respectively. Excluding drug costs, the cost per encounter for the visits with and without a DFE were $39.33 and $22.63, respectively. Including the drug costs, the costs per encounter for the visits with and without a DFE were $85.55 and $68.85 for bevacizumab and $1787.58 and $17770.88 for aflibercept, respectively. Once the reimbursements for each visit type were included, the clinics that eliminated the VA and DFEs were more cost efficient. CONCLUSION: Eliminating both VA assessments and DFEs for patients undergoing OCT-guided retreatment with intravitreal injections resulted in decreased exposure times between patients and clinic staff, decreased cost per encounter, and increased patient volumes per clinic day, resulting in improved clinic efficiency and safety while seeing more patients in a clinic day.

Effectiveness of Multimodal imaging for the Evaluation of Retinal oedema And new vesseLs in Diabetic retinopathy (EMERALD).

INTRODUCTION: Diabetic macular oedema (DMO) and proliferative diabetic retinopathy (PDR) are the major causes of sight loss in people with diabetes. Due to the increased prevalence of diabetes, the workload related to these complications is increasing making it difficult for Hospital Eye Services (HSE) to meet demands. METHODS AND ANALYSIS: Effectiveness of Multimodal imaging for the Evaluation of Retinal oedema And new vesseLs in Diabetic retinopathy (EMERALD) is a prospective, case-referent, cross-sectional diagnostic study. It aims at determining the diagnostic performance, cost-effectiveness and acceptability of a new form of surveillance for people with stable DMO and/or PDR, which entails multimodal imaging and image review by an ophthalmic grader, using the current standard of care (evaluation of patients in clinic by an ophthalmologist) as the reference standard. If safe, cost-effective and acceptable, this pathway could help HES by freeing ophthalmologist time. The primary outcome of EMERALD is sensitivity of the new surveillance pathway in detecting active DMO/PDR. Secondary outcomes include specificity, agreement between new and the standard care pathway, positive and negative likelihood ratios, cost-effectiveness, acceptability, proportion of patients requiring subsequent full clinical assessment, unable to undergo imaging, with inadequate quality images or indeterminate findings. ETHICS AND DISSEMINATION: Ethical approval was obtained for this study from the Office for Research Ethics Committees Northern Ireland (reference 17/NI/0124). Study results will be published as a Health Technology Assessment monograph, in peer-reviewed national and international journals and presented at national/international conferences and to patient groups. TRIAL REGISTRATION NUMBER: NCT03490318 and ISRCTN:10856638.

Super-Resolution in Optical Coherence Tomography.

Optical coherence tomography (OCT) is an essential medical imaging tool for retinal disease diagnosis. Nevertheless, as with all optical imaging techniques, image degradation is a very common phenomenon, affecting the quality of the images. In this paper, we address issues related to the resolution of OCT images and propose solutions based on solving inverse problems. A cost function for deconvolution and super-resolution is formulated and the alternating direction method of multiplier (ADMM) and forward-backward splitting (FBS) algorithms are then employed for its minimisation. On the one hand, the standard Ll norm regularisation with soft thresholding is compared with a total variation (TV) regularisation within an ADMM scheme. On the other hand, nonconvex regularisation is also considered via a multivariate generalisation of the minimax-concave scheme in FBS. In the latter case, the regularisation function is judiciously chosen in order to preserve the overall convexity of the cost function. To be able to evaluate our algorithms qualitatively, a number of standard images are initially used. Then, we also assess our algorithms subjectively by applying them to real OCT images of the human eye. Given that the point spread function (PSF) of OCT images is generally unknown, we also propose ways of estimating it in the deconvolution component of our methods. Our results show that the ADMM scheme with soft thresholding achieves the best performance in terms of enhancing the overall quality of OCT images.

Passively Driven Probe Based on Miniaturized Propeller for Intravascular Optical Coherence Tomography.

Optical coherent tomography (OCT) has enabled clinical applications ranging from ophthalmology to cardiology that revolutionized in vivo medical diagnostics in the last few decades, and a variety of endoscopic probes have been developed in order to meet the needs of various endoscopic OCT imaging. We propose a passive driven intravascular optical coherent tomography (IV-OCT) probe in this paper. Instead of using any electrically driven scanning device, the probe makes use of the kinetic energy of the fluid that flushes away the blood during the intravascular optical coherence tomography imaging. The probe converts it into the rotational kinetic energy of the propeller, and the rotation of the rectangular prism mounted on the propeller shaft enables the scanning of the beam. The probe is low cost, and enables unobstructed stable circumferential scanning over 360 deg. The experimental results show that the probe scanning speed can exceed 100 rotations per second (rps). Spectral-domain OCT imaging of a phantom and porcine cardiac artery are demonstrated with axial resolution of 13.6 µm, lateral resolution of 22 µm, and sensitivity of 101.7 dB. We present technically the passively driven IV-OCT probe in full detail and discuss how to optimize the probe in further.

Optical Coherence Tomography.

Optical coherence tomography (OCT) is a noninvasive diagnostic technique providing cross-sectional images of biologic structures based on the differences in tissue optical properties. OCT has been widely used in numerous clinical applications and is becoming popular as a promising technology in dentistry. Today, dental hard (tooth) and soft (hard palate mucosa and gingiva mucosa) tissues are visualized with OCT. With new developments in technology, the applications of OCT are being investigated in various fields in dentistry, such as to detect microleakage around restoration, tooth cracks/fractures, examination of periodontal tissues/pockets, early detection of oral cancerous tissues, and in endodontics for location of pulp canal.

Vitreopapillary traction: cost-effective diagnosis by optical coherence tomography.

CASE REPORTS: A prospective, noncomparative, observational case series. Three patients, aged 76 to 81, all referred to subspecialty services for evaluation of optic disc elevation, and all were found to have optic disc (vitreopapillary) traction as verified by optical coherence tomography. COMMENTS: Vitreopapillary traction is a recently recognized syndrome characterized by incomplete posterior vitreous detachment. The use of optical coherence tomography is helpful in the diagnosis of this syndrome, preventing many costly, unwarranted evaluations.

[Femtosecond laser-assisted cataract surgery]. / Chirurgie de la cataracte assistée par laser.

Femtosecond laser-assisted cataract surgery is a major technological innovation. The femtosecond laser, during a pretreatment step, helps to prepare the patient's eye for the surgery proper by creating corneal incisions, anterior capsulotomy and lens fragmentation in an automated fashion. Thus, these steps can be performed with precision and reproducibility, and lens fragmentation reduces the amount of ultrasound required during surgery. Drawbacks of this technology are a longer operating time, a more demanding surgical procedure and a much higher cost for patients and surgical centers. New models of organization in the operating room, patient flow, and financial systems have to be designed to adapt this procedure to our practice. The benefits of this technology should make it an essential tool in the future, provided that cataract surgery can be reconsidered logistically and economically.

[Interest of optical coherence tomography performed immediately before intravitreal injection of anti-VEGF in exudative AMD]. / Intérêt de la tomographie à cohérence optique réalisée immédiatement avant injection intra-vitréenne d'anti-VEGF sur récidive exsudative dans la DMLA.

INTRODUCTION: Two or three systematic intravitreal injections (IVT) may be prescribed in a PRN approach to treat an exudative recurrence of neovascular age-related macular degeneration (AMD), according to the phenotype. Optical coherence tomography (OCT) may be performed immediately before the 2nd or the 3rd scheduled IVT, making it possible to cancel the procedure in the absence of exudation. The aim of the study was to evaluate the usefulness of this OCT examination and to assess the percentage of IVT cancelled, in order to evaluate a potential medico-economic benefit. METHODS: Monocentric retrospective study, in which were included 292 consecutive eyes with exudative recurrence of AMD, for which 2 or 3 IVT were scheduled between January 1st and April 30th, 2014. All patients received a first systematic IVT in the seven days following the diagnosis. Then, on the days of the 2nd and 3rd scheduled IVT, each patient had a visual acuity measurement and a Spectral domain-OCT (Spectralis, HRA Heidelberg Engineering). This measurement allowed for the IVT to be either performed as scheduled or cancelled. Both ranibizumab and aflibercept were used. A Chi(2) test was used to compare the qualitative variables and an adjusted Wilcoxon test for the quantitative values. RESULTS: Two hundred and ninety-two consecutive eyes were included; 172 in the "2 scheduled IVT" group (group A) and 120 in the "3 scheduled IVT" group (group B). At the first follow-up, 37.6% of scheduled IVT were cancelled after the OCT (44.1% in group A and 28.3% in group B). At the second follow-up, 33.3% of IVT were cancelled in group B. Overall, 150/412 (36.4%) IVT were avoided in this series. Presence of serous retinal detachment, retinal edema and increased central macular thickness were statistically correlated with confirmation of the scheduled IVT at the two follow-ups (P<0.001, P<0.001 and P=0.002, respectively). A savings of 429.80 € per patient was calculated during this short period of follow-up. CONCLUSION: An average non-injection rate of 36.4% of scheduled IVT was found in this protocol of management of recurrences with OCT performed the day of IVT. This protocol allowed to avoid unnecessary IVT one-third of the time and appeared highly cost-effective.

Improving the cost-effectiveness of photographic screening for diabetic macular oedema: a prospective, multi-centre, UK study.

BACKGROUND/AIMS: Retinal screening programmes in England and Scotland have similar photographic grading schemes for background (non-proliferative) and proliferative diabetic retinopathy, but diverge over maculopathy. We looked for the most cost-effective method of identifying diabetic macular oedema from retinal photographs including the role of automated grading and optical coherence tomography, a technology that directly visualises oedema. METHODS: Patients from seven UK centres were recruited. The following features in at least one eye were required for enrolment: microaneurysms/dot haemorrhages or blot haemorrhages within one disc diameter, or exudates within one or two disc diameters of the centre of the macula. Subjects had optical coherence tomography and digital photography. Manual and automated grading schemes were evaluated. Costs and QALYs were modelled using microsimulation techniques. RESULTS: 3540 patients were recruited, 3170 were analysed. For diabetic macular oedema, England's scheme had a sensitivity of 72.6% and specificity of 66.8%; Scotland's had a sensitivity of 59.5% and specificity of 79.0%. When applying a ceiling ratio of £30,000 per quality adjusted life years (QALY) gained, Scotland's scheme was preferred. Assuming automated grading could be implemented without increasing grading costs, automation produced a greater number of QALYS for a lower cost than England's scheme, but was not cost effective, at the study's operating point, compared with Scotland's. The addition of optical coherence tomography, to each scheme, resulted in cost savings without reducing health benefits. CONCLUSIONS: Retinal screening programmes in the UK should reconsider the screening pathway to make best use of existing and new technologies.