Hand-Held OCT Clinical & Research Applications

The Leicester University Ulverscroft Eye Unit (UK) is a world-renowned pediatric ophthalmology center of excellence, with more than 275 scientific publications to date. The team has been working with hand-held OCT for over 10 years. It treats around 800 children each year and is involved in 13 OCT projects.

In a recent online symposium, Dr. Frank Proudlock, Dr. Mervyn Thomas and Dr. Zhanhan Tu shared their experience with hand-held OCT and how it enables them to diagnose and treat earlier.

Hand-held OCT makes it easier to examine children and infants. However, Dr. Frank Proudlock, Associate Professor of Ophthalmology and Ulverscroft Eye Unit team manager, points out: “Hand-held OCT has more applicability than just using it on children”.

Both conventional OCT and hand-held OCT are spectral-domain OCT, with very high sampling rates. They both have microscopic resolution, in the range of research imaging technology. However, while it provides high-quality scans, hand-held OCT does have some limitations: there is no fixation target, no eye tracking allowing averaging and no automatic segmentation. As such, the Ulverscroft Eye Unit essentially relies on caliper measurements with comparisons based on published data.

One of the big advantages of hand-held OCT is that it is portable. It can be used everywhere, including in the operating theater. This makes it very easy to perform a scan, on both adults and children. Hand-held OCT can be used with lenses to acquire images of the anterior and posterior segment.

Performing retinal imaging in a baby can be difficult with classical table-mounted OCT. Solutions such as RetCam allow ultra-widefield (UWF) retinal imaging but do not provide ultrastructural data. The launch of the Leica Envisu C2300 system helped address this unmet clinical need, revolutionizing pediatric ophthalmology. Hand-held OCT delivers retinal architecture data at unprecedented levels.

According to Dr. Mervyn Thomas, NIHR Academic Clinical Lecturer, hand-held OCT has numerous clinical benefits. It makes pediatric imaging more accessible and enables non-invasive monitoring. It can be used as a diagnostic and prognostic tool, with the ability to assess the development of the pediatric eye. It can also be used for imaging in adult patients with poor posture or spinal deformities.

Hand-held OCT has had a significant impact on the Ulverscroft Eye Unit clinical practice. It has become central to clinical workflow, helping to establish an earlier diagnosis and accelerating treatment initiation. It also eliminates the need for more invasive tests such as MRIs, ERGs (electroretinography) and genetic testing in a large number of cases. Hand-held OCT can be used as a front-line diagnostic tool.

Hand-held OCT has several clinical applications. First, it supports the diagnosis of foveal development disorders. Each development event can be observed with hand-held OCT, for example the foveal pit and extrusion of inner retinal layers. The Ulverscroft Eye Unit has developed a foveal hypoplasia grading system as well as diagnostic algorithms. The use of hand-held OCT is often pivotal to making the diagnosis and managing these conditions. Dr. Thomas shared three clinical cases during the symposium.

Hand-held OCT also aids the diagnosis and monitoring of optic nerve diseases. In addition, it can be used as a reassurance scan, with the images shown to parents during the consultation. Furthermore, it is a prognostic tool, which can help predict future visual acuity, as well as a tool for surgical planning.

Hand-held OCT is currently being used in several Leicester University studies as shared by Dr. Zhanhan Tu, Researcher. This includes a study on foveal and optic nerve head (ONH) development, where images have been collected using hand-held OCT from more than 1,500 healthy children since 2012. The aim of the study is to characterize the time course of normal foveal and ONH development. Some data has already been published. The availability of hand-held OCT made this project possible.

The team is also using hand-held OCT to further investigate the course of nystagmus. Hand-held OCT helps easily detect foveal hypoplasia, supporting the diagnosis of nystagmus and often predicting future vision in children affected by the disease.

Other research applications include retinopathy of prematurity and childhood glaucoma as well as cerebral malaria for which the team has set up a specific project in Malawi. Studies have shown that the severity of retinal changes in cerebral malaria strongly predict the clinical course of disease, including brain swelling, duration of coma and death. Hand-held OCT allows to examine retinal changes in patients in coma.

Dr. Tu shared some tips on working with children of different ages, and how to provide a target for children to fixate their eyes for scanning in the absence of a built-in fixation target. The team has found that infants under 6 months of age usually prefer a funny noise. Children under 18 months prefer songs while older children under 3 can be provided with content on a tablet, such as a cartoon with animated characters. Children over 4 years old are generally easier to work with and tend to better follow instructions.

In the future, working together with Leica Microsystems, the Ulverscroft Eye Unit aims to improve diagnostics testing leveraging artificial intelligence, in particular in conditions such as retinopathy of prematurity, optic nerve oedema, infantile glaucoma, foveal hypoplasia, retinoblastoma and cerebral malaria.

The team demonstrated how to take an image using the probe. The hand-held OCT is connected to a screen. Once set-up is completed, the first step is to adjust the device to the refractive error of the child, using the dial to adjust the refraction and the appropriate lens. The image can be captured using the foot pedal or with the help of a second operator. The instrument is brought close to the eye to obtain the image, with no contact.

Disclaimer: The statements and explanations of the healthcare professionals in this video reflect only their opinion and personal experiences. Their statements do not necessarily reflect the opinion of any institution with whom they are affiliated.