Optical coherence tomography (OCT) in unconscious and systemically unwell patients using a mobile OCT device: a pilot study

Abstract

ObjectiveThis study aims to evaluate the feasibility of retinal imaging in critical care using a novel mobile optical coherence tomography (OCT) device. The Heidelberg SPECTRALIS FLEX module (Heidelberg Engineering, Heidelberg, Germany) is an OCT unit with a boom arm, enabling ocular OCT assessment in less mobile patients.DesignWe undertook an evaluation of the feasibility of using the SPECTRALIS FLEX for undertaking ocular OCT images in unconscious and critically ill patients.SettingThis study was conducted in the critical care unit of a large tertiary referral unit in the United Kingdom.Participants13 systemically unwell patients admitted to the critical care unit were purposively sampled to enable evaluation in patients with a range of clinical states.Outcome measuresThe primary outcome was the feasibility of acquiring clinically interpretable OCT scans on a consecutive series of patients. The standardised scanning protocol included macula-focused OCT, OCT optic nerve head (ONH), OCT angiography (OCTA) of the macula and ONH OCTA.ResultsOCT images from 13 patients were attempted. The success rates of each scan type are 84% for OCT macula, 76% for OCT ONH, 56% for OCTA macula and 36% for OCTA ONH. The overall mean success rate of scans per patient was 64% (95% CI 46% to 81%). Clinicians reported clinical value in 100% scans which were successfully obtained, including both ruling in and ruling out relevant ocular complications such as corneal thinning, macular oedema and optic disc swelling. The most common causes of failure to achieve clinically interpretable scans were inadequately sustained OCT alignment in delirious patients and a compromised ocular surface due to corneal exposure.ConclusionsThis prospective evaluation indicates the feasibility and potential clinical value of the SPECTRALIS FLEX OCT system on the critical care unit. Portable OCT systems have the potential to bring instrument-based ophthalmic assessment to critically ill patients, enabling detection and micron-level monitoring of ocular complications.

Stability of OCT and OCTA in the Intensive Therapy Unit Setting

“…As critical illness often requires treatment in the intensive therapy unit (ITU) [16], and intra-hospital transport of ITU patients is associated with morbidity [17], patient movement into clinic to allow OCT and OCTA images to be taken on a standard table-top device is usually not possible. New portable OCT systems allow assessment of patients in the ITU [18], but the effect of imaging in these more challenging clinical locations has not been reported. We therefore conducted a pilot study aiming to investigate the stability of OCT and OCTA assessment in the ITU setting in patients with planned non-neurological ITU stays following oesophagectomy, through comparison of measurements taken from pre-and post-operative retinal imaging, in order to assess the potential clinical utility of portable OCT and OCTA measures as a monitoring tool in the ITU environment.…”

The Future Is Now: Incorporating Telemedicine into Glaucoma Care

“…Optic nerve assessment involves both optic disc photography for qualitative evaluation of the nerve and quantitative structural analysis with OCT. Standard equipment for acquiring optic nerve photos and OCTs are bulky and require in-person visits for images to be obtained. Portable fundus cameras and OCT machines are under evaluation for clinical use and show promise for the tele-evaluation of glaucoma patients [ 51 , 52 ]. There is certainly a trend toward portable diagnostic tools, several of which interface with smart phones that will likely enhance the future use of teleglaucoma both for patient monitoring and for expanding the scope of tele-screening in glaucoma but this is still an area that needs improvement [ 53 , 54 ].…”

Optical coherence tomography in the 2020s—outside the eye clinic

“…A third device, the Heidelberg Spectralis Flex Module (Heidelberg Engineering, Heidelberg, Germany) incorporates a flexible 'boom' arm, which houses the acquisition lens and can be adjusted up to 100 cm from the main device body (Fig. 1) [5]. The portability of all these devices has allowed for imaging of patients in different positions and beyond the outpatient clinic, from intensive care to the surgical environment [6].…”