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Portable meibography technology using a smartphone device

2020; Elsevier BV; Volume: 55; Issue: 6 Linguagem: Inglês

10.1016/j.jcjo.2020.04.019

1715-3360

Dan Ni Wang, Yogesh Patel, Micah Luong,

Glaucoma and retinal disorders

Meibomian gland dysfunction (MGD) is a major cause of evaporative dry eye disease that occurs when the meibomian glands, modified sebaceous glands located within the lower and upper tarsal plate of the eyelids, produce abnormal and excessive amount of lipids and result in obstruction of the glandular ducts. Dry eye is one of the most common concerns that patients present with to an ophthalmologist, and up to 80%–90% of patients with dry eye disease have signs of MGD.1Chhadva P. Goldhardt R. Galor A. Meibomian gland disease: the role of gland dysfunction in dry eye disease.Ophthalmology. 2017; 124: S20-S26Abstract Full Text Full Text PDF PubMed Scopus (158) Google Scholar With advances in ophthalmic imaging, growing knowledge of the role of the meibomian glands in dry eye disease has led to increased interest in visualizing these glands by both ophthalmic practitioners and patients. Meibography, or the technique of directly visualizing the meibomian glands, can be used to evaluate meibomian gland dropout, guide treatment decisions, and follow the course of disease. It is also a great patient educational tool to increase compliance in dry eye treatment. Meibography is rooted in infrared (IR) imaging, because the meibomian glands are more easily visualized and appear brighter in IR. The human eye is able to see wavelengths in the visible spectrum between 400 and 700 nm, but IR imaging allows for the visualization of light absorbed and reflected off objects in the near-IR spectrum between 700 and 900 nm. IR imaging typically uses a camera that is paired with a filter that transmits only IR light and an IR-emitting light-emitting diode (LED) to illuminate the target. The earliest method of meibography was described in 1985 by transilluminating the lids with a light probe inserted behind the everted lid using a slit lamp while an IR film camera was used to take a photograph.2Robin J.B. Jester J.V. Nobe J. et al.In vivo transillumination biomicroscopy and photography of meibomian gland dysfunction: a clinical study.Ophthalmology. 1985; 92: 1423-1426Abstract Full Text PDF PubMed Scopus (125) Google Scholar In 1994, video meibography was introduced, where instead of a film camera, an IR video camera or highly sensitive IR monochromatic charge-coupled device (CCD) was used to capture the glands in real-time.3Mathers W.D. Daley T. Verdick R. Video imaging of the meibomian gland.Arch Ophthalmol. 1994; 112: 448-449Crossref PubMed Scopus (64) Google Scholar In 2008, noncontact meibography eliminated the need for transillumination with a light probe by combining an IR-CCD camera with an IR-transmitting filter.4Arita R. Itoh K. Inoue K. Amano S. Noncontact infrared meibography to document age-related changes of the meibomian glands in a normal population.Ophthalmology. 2008; 115: 911-915Abstract Full Text Full Text PDF PubMed Scopus (515) Google Scholar In 2010, Pult et al. modified an IR CCD video camera to emit IR light, and the lids could immediately be captured by the video camera and sent to a computer.5Pult H. Riede-Pult B.H. Non-contact meibography: keep it simple but effective.Cont Lens Anterior Eye. 2012; 35: 77-80Abstract Full Text Full Text PDF PubMed Scopus (91) Google Scholar Some corneal topographers now have a built-in IR bulb and camera, and laser scanning in vivo confocal microscopy and ultra-high-resolution optical coherence tomography have been used for meibography but are not commonly used. However, because of the cost, meibomian gland imaging has not been readily available at many ophthalmology offices. Given the new digital age, smartphones are now very easily accessible and capable of producing high-quality images. We present a portable meibography technology that can be paired with any smartphone-enabled camera. We developed a novel approach to portable meibography that is similar to the one described by Pult et al.5Pult H. Riede-Pult B.H. Non-contact meibography: keep it simple but effective.Cont Lens Anterior Eye. 2012; 35: 77-80Abstract Full Text Full Text PDF PubMed Scopus (91) Google Scholar However, to make the device portable, we paired the IR-CCD device with a smartphone because nearly everyone has access to a smartphone. Imaging sensors with built-in LED arrays have been made easily available as security camera components available commercially online. We used a 2.0-megapixel IR USB camera module that includes a 850 nm 24-LED array (Aptina, San Jose, CA), although any camera module with an IR LED array can be used as long as it is USB-based and compatible with USB Video Class to be recognized by common operating systems like Windows OS and/or Android OS without any additional setup or drivers. These devices can then be adapted for Android-based smart phones or tablets with an USB-C On-The-Go adaptor, which can be readily purchased at most commercial electronics stores. This allows for the potential to create a very compact portable imaging device that can illuminate the meibomian gland structure with a paired imaging sensor that is capable of capturing IR light. We used CAD software to design a casing to house the camera sensor and USB, although this is not necessary to use the device Figure 1. This smartphone-enabled portable meibography device has been used successfully with patients at our clinic (Figure 2). The use of the USB-C On-The-Go adaptor allows for the meibomian glands to be directly visualized on the smartphone in real-time and the desired image taken. The images are able to provide a quick and accurate photograph of the meibomian glands Figure 3.Fig. 3Photographs taken using the portable meibography device with an Android smartphone of a patient with meibomian gland dysfunction showing (A) the lower lid and meibomian gland dropout, (B) dilation of the meibomian gland ductal tissues, and (C) meibomian glands in the upper eye lid.View Large Image Figure ViewerDownload Hi-res image Download (PPT) As dry eye treatment and technology evolves, so do the expectation of patients. Accurate assessment of the meibomian glands is important in order to evaluate MGD and guide treatment options for patients. We present a novel meibography method that can be easily connected at any time to an Android smartphone and is portable, affordable, and convenient to use. Patients can be skeptical that their symptom of eye discomfort and intermittent blurry vision can be just explained by dry eyes. Therefore, it can be difficult for them to be compliant on dry eye treatment, some of which can be time-consuming or costly. Having a device that can illustrate meibomian gland loss is a valuable patient education tool that will increase compliance to dry eye treatment. Currently, the devices in the market can be costly and space-consuming, making them usually only available to clinics with a dry eye interest. Thus having an affordable device that is also portable and easy to use like the one illustrated here would allow meibomian gland imaging to many more ophthalmologists. Acknowledgment: Yogesh Patel for years of research into assembling the portable meibography device. The authors have no proprietary or commercial interest in any materials discussed in this article.