What is the VELscope and How Does the VELscope Work?
The VELscope is a device that is used as an adjunct to the Comprehensive Oral Examination (COE), aiding clinicians in visualizing oral mucosal abnormalities, including infections, trauma, oral cancer and pre-cancerous dysplasia. We often are asked about the technology behind the VELscope and the evidence for its efficacy as an adjunctive oral screening tool. In this article, we will take a look at the VELscope device, how the VELscope works via the principle of tissue fluorescence and what encompasses a typical VELscope examination.
The VELscope System
In order to understand how the VELscope works, let’s take a look at the device itself. The VELscope relies on two key components – an LED ring that emits a specific wavelength of blue light and an eyepiece with an integrated optical filter. The combination of shining light into the oral cavity and viewing the patient’s oral mucosa via an optical filter are what allows clinicians to observe cellular and structural tissue changes and, therefore, visualize areas that warrant further investigation. This brings us to the principle of tissue fluorescence.
Tissue Reflectance Versus Tissue Fluorescence
Traditional oral mucosal examination tools utilize the concept of tissue reflectance, where clinicians use standard white light to illuminate the oral cavity and conduct an oral examination. The VELscope, on the other hand, relies on the principle of tissue fluorescence rather than reflectance. Tissue fluorescence is caused by fluorophores, which are chemical compounds that react to light excitation. When exposed to the blue light of the VELscope, fluorophores respond by emitting their own light at a longer wavelength, which can be observed via the optical filter in the VELscope eyepiece. It’s the excitation of fluorophores, or lack thereof in some instances, that enables the VELscope to visualize cellular change in the oral mucosa.
When utilizing the VELscope, normal fluorescence patterns typically appear as a bright apple-green color, indicating that the fluorophores in the tissues of the oral mucosa are responding normally when exposed to blue light. Normal fluorescence patterns can also show a lack of fluorescence: lymphoid aggregates, the fungiform papillae on the tongue and the heavily vascularized anterior tonsillar pillars are good examples of this. Abnormal fluorescence patterns allow clinicians to observe unhealthy areas of the mucosa, which may be overlooked with the naked eye during a typical white-light reflectance examination.
Abnormal fluorescence patterns typically arise from:
- An increase in metabolic activity in the epithelium
- A breakdown of the fluorescent collagen cross-links in the connective tissue layer beneath the basement membrane
- An increase in tissue blood content, either from inflammation or angiogenesis (hemoglobin strongly absorbs fluorescence excitation [blue] and emission light [green])
- The presence of pigments (e.g., melanin or amalgam particles) which absorb light
The below illustration gives a great overview of tissue fluorescence in relation to a typical VELscope examination:
As you can see, the light emitted by the VELscope penetrates below the tissue surface, allowing fluorescence patterns to be visualized beyond the epithelium and into the basement membrane. Abnormal epithelial cells and disruption of stromal collagen will not produce a normal fluorescence response, which can be observed through the VELscope.
It is important to note that while the VELscope is often referred to as an oral cancer screening device, the concept of tissue fluorescence covers a wide variety of oral abnormalities, allowing the VELscope to aid in visualizing many oral health concerns:
- Viral, fungal and bacterial infections
- Inflammation from a variety of causes, including lichen planus and other lichenoid reactions
- Oral cancer, including squamous papillomas and salivary gland tumors
- Oral dysplasia
Clinicians should familiarize themselves with the typical fluorescence patterns that are presented by each of the above abnormalities. Our team has produced a series of training videos that cover a wide variety of topics, including fluorescence patterns, that can be viewed here.
A Typical VELscope Examination
A VELscope screening is painless, non-invasive and should take less than 2 minutes to complete. Typically, screenings are performed by a dentist or registered dental hygienist but is dependent upon health regulations in your state or province. We recommend discussing the VELscope examination with the patient so that they understand the importance of routine oral screenings and have the opportunity to ask any questions. The VELscope screening is then performed and may be documented via the VELscope photo system application and an Apple iPod touch*, which is connected to the device via a Vx Imaging Adapter. All findings are then recorded in the patient’s chart and the clinician will review to determine next steps, including determination if there is need for a referral to a specialist.
Studies on the Efficacy of the VELscope
There are many studies that have been performed to assess the effectiveness of tissue fluorescence visualization. We maintain a list of studies on our website that are available for in-depth education about the technology behind the VELscope device.
Other Tissue Fluorescence Technologies
While the VELscope is a widely known technology, there are other devices that employ tissue fluorescence as a method for visualizing oral abnormalities. While we believe the VELscope has a strong track record in the oral screening space, we do acknowledge that there are other options available. Dental practices interested in implementing adjunctive oral screening into their practice should research the options available to assess which device best fits the needs of their practice and patients.