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.

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.

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.

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.

Fractional flow reserve or optical coherence tomography guidance to revascularize intermediate coronary stenosis using angioplasty (FORZA) trial: study protocol for a randomized controlled trial

BACKGROUND

The management of patients with angiographically intermediate coronary lesions is a major clinical issue. Fractional flow reserve provides validated functional insights while optical coherence tomography provides high resolution anatomic imaging. Both techniques may be applied to guide management in case of angiographically intermediate coronary lesions. Moreover, these techniques may be used to optimize the result of percutaneous coronary intervention. We aim to compare the clinical and economic impact of fractional flow reserve versus optical coherence tomography guidance in patients with angiographically intermediate coronary lesions.

METHODS/DESIGN

Patients with at least one angiographically intermediate coronary lesion will be randomized (ratio 1:1) to fractional flow reserve or optical coherence tomography guidance. In the fractional flow reserve arm, percutaneous coronary intervention will be performed if fractional flow reserve value is ≤0.80, and will be conducted with the aim of achieving a post-percutaneous coronary intervention fractional flow reserve target value of ≥0.90. In the optical coherence tomography arm, percutaneous coronary intervention will be performed if percentage of area stenosis (AS%) is ≥75% or 50 to 75% with minimal lumen area <2.5 mm2, or if a major plaque ulceration is detected. In case of percutaneous coronary intervention, optical coherence tomography will guide the procedure in order to minimize under-expansion, malapposition, and edge dissections.Cost load and clinical outcome will be prospectively assessed at one and thirteen months. The assessed clinical outcome measures will be: major cardiovascular events and occurrence of significant angina defined as a Seattle Angina Questionnaire score <90 in the angina frequency scale.

DISCUSSION

The FORZA trial will provide useful guidance for the management of patients with coronary artery disease by prospectively assessing the use of two techniques representing the gold standard for functional and anatomical definition of coronary plaques.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01824030.

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.

OCT technology development: where are we now? A commercial perspective

The field of optical coherence tomography (OCT) has grown enormously since its inception in 1991 at MIT, encompassing many areas of imaging research. Improvements in the optical technology used in OCT systems, and in the design of the OCT interferometers and probes, has resulted in steadily improving image quality and more practical probe designs. Successful commercial application of OCT occurred first in retina imaging, and many further applications now appear ripe for translation from the laboratory to the marketplace. In this paper, I review this translation process from a commercial perspective, and attempt to draw helpful conclusions.

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.