This work is supported in part by an educational found FRS 445960. &#160;We would like to thank Anh Tran, Juan Ortiz, and Ali Nazari for their help in preparing figure 2.

Ensure that fundus photography in the protocol follows the guidelines of your institutes&#160;human research ethics committee.
Note: Smartphone retinal imaging, like conventional indirect ophthalmoscopy, should be performed through a dilated pupil. A strong smartphone camera flash light is crucial to obtain a clear fundus picture, especially with mild to moderate media opacity. Make sure to practice the method on a model eye or on peers before attempting to examine the patient. Patient cooperation is a key for good smartphone fundus photography.
1. Smartphone Retinal Imaging
<ol>
	<li>Explain the procedure to the patient and obtain permission. Explain that the process may take 1 - 2 min and involves shining a bright light into the eye.</li>
	<li>Dilate the patient&#39;s pupil using a combination of mydriatic drops such as 2.5% Phenylephrine and 1% Tropicamide ophthalmic drops (one drop from each, 2 - 3 min apart, in the eye to be examined). Wait 15 - 20 min for pupils to dilate.</li>
	<li>Sit in front of the patient on a comfortable chair and be positioned 30 - 60 cm from the patient and at about the same level (Figure 2).</li>
	<li>Ask the patient to look at a far target with the other eye.</li>
	<li>Set the smartphone camera on video mode.</li>
	<li>Turn on the camera&#39;s flashlight.</li>
	<li>After darkening the room, press the camera record button on the smartphone to record a continuous video.</li>
	<li>Hold the +20 diopter (D) or any other indirect ophthalmoscopy lens in front of the patient&#8217;s eye with your thumb and index finger. Use the middle and ring fingers to stabilize the hand and lens and to help keep eyelids open.</li>
	<li>Hold the camera 10 - 35 cm from the lens. Direct the camera along the patient&#39;s pupillary axis. Aim the light to the pupil and find the retina glow. Direct the light through the lens onto the retina and continue video recording.</li>
	<li>While recording, move the camera and the lens to find a good focus and an image free of light reflections. Adjust the handheld lens to and from the patient&#8217;s eye to see a clear retina image filling the entire lens area. 
	NOTE: In our experience, the lens should be held 3 - 5 cm from the eye (this is slightly further away from the cornea surface compared to what is appropriate for an indirect ophthalmoscopy exam).</li>
	<li>Try to eliminate unnecessary light reflections by adjusting the camera and lens positions. Losing the image while searching the retina means that the camera and its flash light are not aligned with the handheld lens and pupil. It takes practice to keep the camera, handheld lens, and patient pupil aligned.</li>
	<li>Continue to record video until a good view of the area of interest without significant light reflections and aberrations is captured.</li>
	<li>Stop the recording and ask the patient to sit back and be comfortable.</li>
	<li>Re-play the recorded movie until there is a good retina view within the handheld lens area. Stop the movie and take a screen shot of the view (Figure 3).</li>
	<li>Magnify the screen shot and take another screen shot for a larger retina image (Figure 3). Like an indirect ophthalmoscope view, this image is inverted.</li>
</ol>

<ol>
	<li>Lord, R. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+uses+of+smartphones+in+ophthalmology.">Novel uses of smartphones in ophthalmology.</a> Ophthalmology. 117 (6), 1274-1274 (2010).</li><li>Chhablani, J., Kaja, S., Shah, V. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Smartphones+in+ophthalmology.">Smartphones in ophthalmology.</a> Indian J Ophthalmol. 60 (2), 127-131 (2012).</li><li>Bolster, N. M., Giardini, M. E., Bastawrous, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Diabetic+Retinopathy+Screening+Workflow:+Potential+for+Smartphone+Imaging.">The Diabetic Retinopathy Screening Workflow: Potential for Smartphone Imaging.</a> J Diabetes Sci Technol. 10 (2), 318-324 (2015).</li><li>Haddock, L. J., Kim, D. Y., Mukai, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simple,+Inexpensive+Technique+for+High-Quality+Smartphone+Fundus+Photography+in+Human+and+Animal+Eyes.">Simple, Inexpensive Technique for High-Quality Smartphone Fundus Photography in Human and Animal Eyes.</a> J Ophthalmol. , (2013).</li><li>Maamari, R. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+mobile+phone-based+retinal+camera+for+portable+wide+field+imaging.">A mobile phone-based retinal camera for portable wide field imaging.</a> Br J Ophthalmol. 98 (4), 438-441 (2014).</li><li>Raju, B., Raju, N. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regarding+fundus+imaging+with+a+mobile+phone:+a+review+of+techniques.">Regarding fundus imaging with a mobile phone: a review of techniques.</a> Indian J Ophthalmol. 63 (2), 170-171 (2015).</li><li>Shanmugam, M. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fundus+imaging+with+a+mobile+phone:+a+review+of+techniques.">Fundus imaging with a mobile phone: a review of techniques.</a> Indian J Ophthalmol. 62 (9), 960-962 (2014).</li><li>Adam, M. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quality+and+Diagnostic+Utility+of+Mydriatic+Smartphone+Photography:+The+Smartphone+Ophthalmoscopy+Reliability+Trial.">Quality and Diagnostic Utility of Mydriatic Smartphone Photography: The Smartphone Ophthalmoscopy Reliability Trial.</a> Ophthalmic Surg Lasers Imaging Retina. 46 (6), 631-637 (2015).</li><li>Snead, M. P., Rubinstein, M. P., Jacobs, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+optics+of+fundus+examination.">The optics of fundus examination.</a> Surv Ophthalmol. 36 (6), 439-445 (1992).</li><li>Russo, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+smartphone+ophthalmoscopy+with+slit-lamp+biomicroscopy+for+grading+diabetic+retinopathy.">Comparison of smartphone ophthalmoscopy with slit-lamp biomicroscopy for grading diabetic retinopathy.</a> Am J Ophthalmol. 159 (2), 360-364 (2015).</li><li>Kim, D. Y., Delori, F., Mukai, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Smartphone+photography+safety.">Smartphone photography safety.</a> Ophthalmology. 119 (10), 2200-2201 (2012).</li></ol>

No proprietary interest to declare.

The quality of fundus images taken by smartphone could be comparable to that of fundus cameras. In one comparison study of fundus images taken by smartphones and fundus cameras, masked reviewers did not find a significant difference.8,10 In the same study, the quality of fundus images was higher when images were captured by more experienced examiners compared to junior examiners.8
Smartphone fundus photography may appear a challenging technique in the beginning. However, like any other examination technique, mastering the technique needs practice and the process of smartphone imaging of the retina becomes routine with time. A particular challenge is related to the location of smartphone cameras and their screen. Most smartphone cameras are located at the corner of the phone while the screen to view and focus the image is at the center. A beginner should focus on mastering coordination between filming and lens hands and proper alignment of the phone, handheld lens, and the pupil axis.
Flashlight intensity cannot be adjusted within most smartphone camera settings. However, one may dim the light intensity by applying a semitransparent adhesive tape over the light source. Alternatively, filming interface apps may help adjusting the camera light intensity. Multiple smartphone apps are available that allow adjusting exposure, focus control, and flashlight intensity.4 While not an absolute requirement for smartphone fundus photography, examiners may find these filming/image taking interfaces helpful in improving the quality of their images.
The field of view varies with the diopter strength of the handheld indirect ophthalmoscopy lens. Lower power lenses (such as +15 D or +20 D lenses) provide a smaller field of view with higher magnification.
The confidentiality of personal data in accordance with Health Insurance Portability and Accountability Act 1996 (HIPAA), the Data Protection Act 1998, and Access to Health Records Act 1990 is a critical issue when using personal cameras to record health information. We take still retina pictures within our institute&#39;s electronic medical record (EMR) app that allows recording and transferring confidential patient images. Using dedicated cameras, encrypted phones, and HIPAA compatible email services are mandatory in many institutes for protecting patient privacy.
Smartphone fundus photography is a safe technique. Kim et al. showed that iPhone 4 camera flashlight is 10 times less luminous than a conventional indirect ophthalmoscope light.11 While this may offer more comfort for patients during imaging, it limits image clarity in the presence of moderate to significant media opacity. In the same study, the light levels of the smartphone light source were 150 times below the limit set by the International Organization for Standardization (ISO 15004-2.2) for ocular thermal hazard and 240 times below those limits for the photochemical hazard. Although light intensity and energy have not been measured for other smartphone models, it is suggested that they can be well below hazard limits.11
Although retinal images obtained with smartphone could be comparable to images taken by a fundus camera,8,10 recording a high-resolution smartphone retinal image requires an experienced examiner, a well-dilated pupil, clear ocular media, and a cooperative patient. Also, the field of view is usually limited in smartphone fundus images and creating widefield montage images may be time consuming. Nevertheless, smartphone fundus photography is a unique simple and affordable technique that allows picture documentation of retinal changes in many clinical settings where retinal imaging was not previously possible.

Fundus photography is the standard method for documenting ocular fundus findings. Fundus photography is traditionally performed in a clinic setting using a fundus camera. However, fundus cameras are not available in many situations including in emergency rooms or on hospital floors where documentation of the retinal changes may be necessary. Indirect ophthalmoscope-mounted and handheld contact and non-contact fundus cameras are alternative ways to document retinal images, but availability and high cost limit their day-to-day use in most ophthalmology practices. Smartphones equipped with high-resolution cameras are increasingly being used for anterior segment and retinal imaging in ophthalmology.1,2
In smartphone retinal imaging, the smartphone camera&#39;s coaxial flashlight and a handheld high plus power lens create an indirect ophthalmoscopy-like optical system that is able to record high resolution digital retinal images (Figure 1).3,4,5,6,7 Smartphone adaptors for such retinal photography are commercially available from multiple companies3 and educational videos are publicly available to teach how to obtain retinal images using smartphones and these products. However, smartphone retinal photography does not necessarily need such adaptors. Here, we intend to teach how to record a good quality retinal image with a smartphone and tools readily available in an ophthalmology practice.
With increasing availability of smartphones and the expansion of telemedicine, this method can be adapted by ophthalmologists and optometrists to document retinal pathologies in emergency room settings and telemedicine consultations. In addition, health care providers may find this method useful&#160;in developing countries and in medical aid camps during a disaster rescue operation. Like any new technique, mastering smartphone retinal photography needs practice.8 The following protocol will explain detailed steps for smartphone photography. Optical basis of the technique will be discussed in the next section. Technical and operational constraints such as image resolution, field of view, and patient privacy and confidentiality will be discussed in the end.

<table><tbody><tr><td>smartphone</td><td></td><td></td><td></td></tr><tr><td>high plus handheld lens (+20 D)</td><td></td><td></td><td></td></tr><tr><td>Tropicamide 1%</td><td></td><td></td><td></td></tr><tr><td>Phenyl ephrine 2.5%</td><td></td><td></td><td></td></tr></tbody></table>

smartphone fundus photography

Smartphone fundus photography is a simple technique to obtain ocular fundus pictures using a smartphone camera and a conventional handheld indirect ophthalmoscopy lens. This technique is indispensable when picture documentation of optic nerve, retina, and retinal vessels is necessary but a fundus camera is not available. The main advantage of this technique is the widespread&#160;availability of smartphones that allows documentation of macula and optic nerve changes in many settings that was not previously possible. Following the well-defined steps detailed here, such as proper alignment of the phone camera, handheld lens, and the patient&#39;s pupil, is the key for obtaining a clear retina picture with no interfering light reflections and aberrations. In this paper, the optical principles of indirect ophthalmoscopy and fundus photography will be reviewed first. Then, the step-by-step method to record a good quality retinal image using a smartphone will be explained.

The optics of fundus imaging using a smartphone camera is similar in principle to retina examination with indirect ophthalmoscope (Figure 1).9 In an indirect ophthalmoscope, a beam of light is directed toward the patient&#39;s retina and the reflected rays off the retina are condensed to a real aerial image using a handheld +15 - +30 D lens (Figure 1). The viewer sees the real, inverted aerial image that is located 2 - 4 cm from the handheld lens, depending on the power of the lens. With a smartphone, the camera&#39;s flashlight replaces the indirect ophthalmoscope light source and the smartphone camera recording the aerial image replaces the observer&#39;s eye. Conventional fundus cameras are also designed based on the same optical principles; the camera&#39;s film or digital sensor array is located where the aerial image is formed.
The portability of smartphones makes smartphone retinal imaging a promising technique for emergency rooms, telemedicine consulting, and retinal disease screening programs. Two representative images (Figure 4 and Figure 5) are recorded in emergency room and hospital floor consultation settings.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/55958/55958fig1.jpg" /> 
Figure 1: Optics of Indirect Ophthalmoscopy and Smartphone Fundus Photography. 
Schematic drawing shows the viewing system of an indirect ophthalmoscope (A) and fundus photography using a smartphone (B). <a href="http://cloudflare.jove.com/files/ftp_upload/55958/55958fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/55958/55958fig2.jpg" /> 
Figure 2: Examiner and Patient Positioning for Smartphone Fundus Photography. 
The examiner sits in front and slightly to the side of the patient and holds the smartphone in one hand and the handheld lens in another hand about an arm length distance from the phone. <a href="http://cloudflare.jove.com/files/ftp_upload/55958/55958fig2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/55958/55958fig3.jpg" /> 
Figure 3: A Normal Macula and Optic Nerve Imaged Using a Smartphone. <a href="http://cloudflare.jove.com/files/ftp_upload/55958/55958fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/55958/55958fig4.jpg" /> 
Figure 4: Nonproliferative Diabetic Retinopathy Imaged Using a Smartphone. 
Note flame-shaped and dot and blot retinal hemorrhages. <a href="http://cloudflare.jove.com/files/ftp_upload/55958/55958fig4large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/55958/55958fig5.jpg" /> 
Figure 5: Nonarteritic Anterior Ischemic Optic Neuropathy Imaged Using a Smartphone. 
Note the blurring of optic disc margins in this image. <a href="http://cloudflare.jove.com/files/ftp_upload/55958/55958fig5large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about Smartphone Fundus Photography at JoVE.com

Smartphone Fundus Photography

Fundus photography normally requires specialized fundus cameras that are not always available in all clinical settings.&#160;Here, a simple method to record ocular fundus images using a smartphone camera and a conventional high-plus handheld indirect ophthalmoscopy lens is described.

Smartphone fundus photography is a simple technique to obtain ocular fundus pictures using a smartphone camera and a conventional handheld indirect ...

Research

JoVE Journal

Medicine

38.8K Views.  University of Texas Medical Branch.  Fundus fotografie vereist normaal gesproken gespecialiseerde fundus camera's die niet altijd beschikbaar zijn in alle klinische instellingen. Hier wordt een eenvoudige methode beschreven om oculaire fundusbeelden op te nemen met behulp van een smartphone camera en een conventionele high-plus handheld indirecte oftalmocopie lens. 

Video: Smartphone Fundus Photography

Wide-field Fluorescent Microscopy and Fluorescent Imaging Flow Cytometry on a Cell-phone

Fluorescent microscopy and flow cytometry are widely used tools in biomedical research and clinical diagnosis. However these devices are in general relatively bulky and costly, making them less effective in the resource limited settings. To potentially address these limitations, we have recently demonstrated the integration of wide-field fluorescent microscopy and imaging flow cytometry tools on cell-phones using compact, light-weight, and cost-effective opto-fluidic attachments. In our flow cytometry design, fluorescently labeled cells are flushed through a microfluidic channel that is positioned above the existing cell-phone camera unit. Battery powered light-emitting diodes (LEDs) are butt-coupled to the side of this microfluidic chip, which effectively acts as a multi-mode slab waveguide, where the excitation light is guided to uniformly excite the fluorescent targets. The cell-phone camera records a time lapse movie of the fluorescent cells flowing through the microfluidic channel, where the digital frames of this movie are processed to count the number of the labeled cells within the target solution of interest. Using a similar opto-fluidic design, we can also image these fluorescently labeled cells in static mode by e.g. sandwiching the fluorescent particles between two glass slides and capturing their fluorescent images using the cell-phone camera, which can achieve a spatial resolution of e.g. ~ 10 &mu;m over a very large field-of-view of ~ 81 mm2. This cell-phone based fluorescent imaging flow cytometry and microscopy platform might be useful especially in resource limited settings, for e.g. counting of CD4+ T cells toward monitoring of HIV+ patients or for detection of water-borne parasites in drinking water.

We review our recent results on the integration of fluorescent microscopy and imaging flow cytometry tools on a cell-phone using compact and cost-effective opto-fluidic attachments. These cell-phone based micro-analysis devices might be useful for cytometric analysis, such as performing various cell counting tasks as well as for high-throughput screening of e.g., water samples in resource limited settings.

Fluorescent microscopy and flow cytometry are widely used tools in biomedical research and clinical diagnosis. However these devices are in general ...

Bioengineering

Fundus Photography as a Convenient Tool to Study Microvascular Responses to Cardiovascular Disease Risk Factors in Epidemiological Studies

The microcirculation consists of blood vessels with diameters less than 150 &#181;m. It makes up a large part of the circulatory system and plays an important role in maintaining cardiovascular health. The retina is a tissue that lines the interior of the eye and it is the only tissue that allows for a non-invasive analysis of the microvasculature. Nowadays, high-quality fundus images can be acquired using digital cameras. Retinal images can be collected in 5 min or less, even without dilatation of the pupils. This unobtrusive and fast procedure for visualizing the microcirculation is attractive to apply in epidemiological studies and to monitor cardiovascular health from early age up to old age.
Systemic diseases that affect the circulation can result in progressive morphological changes in the retinal vasculature. For example, changes in the vessel calibers of retinal arteries and veins have been associated with hypertension, atherosclerosis, and increased risk of stroke and myocardial infarction. The vessel widths are derived using image analysis software and the width of the six largest arteries and veins are summarized in the Central Retinal Arteriolar Equivalent (CRAE) and the Central Retinal Venular Equivalent (CRVE). The latter features have been shown useful to study the impact of modifiable lifestyle and environmental cardiovascular disease risk factors.
The procedures to acquire fundus images and the analysis steps to obtain CRAE and CRVE are described. Coefficients of variation of repeated measures of CRAE and CRVE are less than 2% and within-rater reliability is very high. Using a panel study, the rapid response of the retinal vessel calibers to short-term changes in particulate air pollution, a known risk factor for cardiovascular mortality and morbidity, is reported. In conclusion, retinal imaging is proposed as a convenient and instrumental tool for epidemiological studies to study microvascular responses to cardiovascular disease risk factors.

Retinal image analysis is an unobtrusive procedure for visualizing the microcirculation. The impact of cardiovascular disease risk factors can result in changes of retinal vessel calibers. The procedures to acquire fundus images and the steps for calculating the vessel calibers are described.

The microcirculation consists of blood vessels with diameters less than 150 &#181;m. It makes up a large part of the circulatory system and plays an ...

Smartphone-Based Imaging for C. elegans Lawn Avoidance Assay

A Smartphone-Based Imaging Method for C. elegans Lawn Avoidance Assay

When exposed to toxic or pathogenic bacteria, the nematode Caenorhabditis elegans displays a learned lawn avoidance behavior, in which the worms gradually leave their food source and prefer to remain outside the bacterial lawn. The assay is an easy way to test the worms' ability to sense external or internal cues to properly respond to harmful conditions. Though a simple assay, counting is time consuming, particularly with multiple samples, and assay durations that span overnight are inconvenient for researchers. An imaging system that can image many plates over a long period is useful but costly. Here, we describe a smartphone-based imaging method to record lawn avoidance in C. elegans. The method requires only a smartphone and a light emitting diode (LED) light box, to serve as a transmitted light source. Using free time-lapse camera applications, each phone can image up to six plates, with sufficient sharpness and contrast to manually count worms outside the lawn. The resulting movies are processed into 10 s audio video interleave (AVI) files for every hourly time point, then cropped to show each single plate to make them more amenable for counting. This method is a cost-effective way for those looking to examine avoidance defects and can potentially be extended to other C. elegans assays.

Author Spotlight: A Smartphone-Based Imaging Method for C. elegans Lawn Avoidance Assay  

This article describes a simple, low-cost method of recording the lawn avoidance behavior of Caenorhabditis elegans, using readily available items such as a smartphone and a light emitting diode (LED) light box. We also provide a Python script to process the video file into a format more amenable for counting.

When exposed to toxic or pathogenic bacteria, the nematode Caenorhabditis elegans displays a learned lawn avoidance behavior, in which the worms gradually ...

Behavior

Smartphone as an Analytical Device to Quantify Protein Using Bradford Assay

RGBradford: Protein Quantitation with a Smartphone Camera

Protein quantitation is an essential procedure in life sciences research. Amongst several other methods, the Bradford assay is one of the most used. Because of its widespread, the limitations and advantages of the Bradford assay have been exhaustively reported, including several modifications of the original method to improve its performance. One of the alterations of the original method is the use of a smartphone camera as an analytical instrument. Taking advantage of the three forms of the Coomassie Brilliant Blue dye that exist in the conditions of the Bradford assay, this paper describes how to accurately quantify protein in samples using color data extracted from a single picture of a microplate. After performing the assay in a microplate, a picture is taken using a smartphone camera, and RGB color data is extracted from the picture using a free and open-source image analysis software application. Then, the ratio of blue to green intensity (in the RGB scale) of samples with unknown concentrations of protein is used to calculate the protein content based on a standard curve. No significant difference is observed between values calculated using RGB color data and those calculated using conventional absorbance data.

Author Spotlight: An Alternative Approach to Protein Quantification by Bradford Assay Using a Smartphone 

This paper provides a protocol for protein quantification using the Bradford assay and a smartphone as an analytical device. Protein levels in samples can be quantified using color data extracted from a picture of a microplate taken with a smartphone.

Protein quantitation is an essential procedure in life sciences research. Amongst several other methods, the Bradford assay is one of the most used. ...

Biochemistry

Quantitative Fundus Autofluorescence for the Evaluation of Retinal Diseases

The retinal pigment epithelium (RPE) is juxtaposed to the overlying sensory retina, and supports the function of the visual system. Among the tasks performed by the RPE are phagocytosis and processing of outer photoreceptor segments through lysosome-derived organelles. These degradation products, stored and referred to as lipofuscin granules, are composed partially of bisretinoids, which have broad fluorescence absorption and emission spectra that can be detected clinically as fundus autofluorescence with confocal scanning laser ophthalmoscopy (cSLO). Lipofuscin accumulation is associated with increasing age, but is also found in various patterns in both acquired and inherited degenerative diseases of the retina. Thus, studying its pattern of accumulation and correlating such patterns with changes in the overlying sensory retina are essential to understanding the pathophysiology and progression of retinal disease. Here, we describe a technique employed by our lab and others that uses cSLO in order to quantify the level of RPE lipofuscin in both healthy and diseased eyes.

The retinal pigment epithelium (RPE) supports the sensory retina through recycling visual cycle byproducts, which accumulate as lipofuscin. These products are autofluorescent and can be qualitatively imaged in vivo. Here, we describe a method to quantitatively image RPE lipofuscin using confocal scanning laser ophthalmoscopy.

The retinal pigment epithelium (RPE) is juxtaposed to the overlying sensory retina, and supports the function of the visual system. Among the tasks ...

Video Movement Analysis Using Smartphones (ViMAS): A Pilot Study

The use of smartphones in clinical practice is steadily increasing with the availability of low cost/freely available &#34;apps&#34; that could be used to assess human gait. The primary aim of this manuscript is to test the concurrent validity of kinematic measures recorded by a smartphone application in comparison to a 3D motion capture system in the sagittal plane. The secondary aim was to develop a protocol for clinicians on the set up of the smartphone camera for video movement analysis.
The sagittal plane knee angle was measured during heel strike and toe off events using the smart phone app and a 3D motion-capture system in 32 healthy subjects. Three trials were performed at near (2-m) and far (4-m) smartphone camera distances. The order of the distances was randomized. Regression analysis was performed to estimate the height of the camera based on either the subject&#39;s height or leg length.
Absolute measurement errors were least during toe off (3.12 &#177; 5.44 degrees) compared to heel strike (5.81 &#177; 5.26 degrees). There were significant (p &#60; 0.05) but moderate agreements between the application and 3D motion capture measures of knee angles. There were also no significant (p &#62; 0.05) differences between the absolute measurement errors between the two camera positions. The measurement errors averaged between 3 - 5 degrees during toe off and heel strike events of the gait cycle.
The use of smartphone apps can be a useful tool in the clinic for performing gait or human movement analysis. Further studies are needed to establish the accuracy in measuring movements of the upper extremity and trunk.

Video Movement Analysis Using Smartphones ViMAS: A Pilot Study

This manuscript describes the method to test the concurrent validity of kinematic measures recorded by the smartphone application in comparison to a 3D motion capture system in the sagittal plane. This protocol will enable clinicians to set up smartphones for video capture of human movement.

The use of smartphones in clinical practice is steadily increasing with the availability of low cost/freely available &#34;apps&#34; that could be used to ...

Smartphone-Integrated Dengue NS1 Paper-Based Diagnostic Device

Portable Paper-Based Immunoassay Combined with Smartphone Application for Colorimetric and Quantitative Detection of Dengue NS1 Antigen

Dengue virus (DENV) infection, which is transmitted by Aedes mosquitoes, is a major public health concern in tropical and subtropical countries. With an annual incidence of approximately 10 million cases and 20,000-25,000 deaths, particularly among children, there is an urgent need for practical diagnostic tools. The presence of dengue non-structural protein 1 (NS1) during early infection has been linked to cytokine release, vascular leakage, and endothelial dysfunction, making it a potential marker for severe dengue. 
Paper-based immunoassays such as lateral flow assays (LFAs) and microfluidic paper-based analytical devices (PADs) have gained popularity as diagnostic tests due to their simplicity, rapidity, inexpensiveness, specificity, and ease of interpretation. However, conventional paper-based immunoassays for dengue NS1 detection typically rely on visual inspection, yielding only qualitative results. To address this limitation and enhance sensitivity, we proposed a highly portable NS1 dengue detection assay on a Paper-based Analytical Device (PAD), namely, DEN-NS1-PAD, that integrates a smartphone application as a colorimetric and quantitative reader. The development system enables direct quantification of NS1 concentrations in clinical samples. 
Serum and blood samples obtained from patients were utilized to demonstrate the system prototype performance. The results were obtained immediately and can be employed for clinical assessment, both in well-equipped healthcare facilities and resource-limited settings. This innovative combination of a paper-based immunoassay with a smartphone application offers a promising approach for enhanced detection and quantification of dengue NS1 antigen. By augmenting sensitivity beyond the capabilities of the naked eye, this system holds great potential for improving clinical decision-making in dengue management, particularly in remote or underserved areas.

Author Spotlight: Development of a Smartphone-Enhanced Paper-Based Device for Rapid Dengue NS1 Detection

Addressing urgent dengue diagnostic needs, here we introduce a smartphone app-integrated Dengue NS1 Paper-based Analytical Device (DEN-NS1-PAD) for quantifying Dengue NS1 antigen concentration in clinical serum/blood samples. This innovation enhances dengue management by aiding clinical decision-making in various healthcare settings, even resource-limited ones.

Dengue virus (DENV) infection, which is transmitted by Aedes mosquitoes, is a major public health concern in tropical and subtropical countries. With an ...

Immunology and Infection

Using an Automated Hirschberg Test App to Evaluate Ocular Alignment

A smartphone app has been developed to perform the automated photographic Hirschberg test for objective measurement of ocular misalignment. By computing the difference in corneal reflection generated by the phone camera flash relative to the iris center based on high resolution images, the app can measure misalignment with a much higher precision than the naked eye performing the Hirschberg test. It has been validated in a previous clinical evaluation study by comparing to the clinical gold standard-prism and alternate cover test. The goal of this article is to describe the testing techniques regarding how to use the app to measure ocular alignment for different fixation distances, without or with cover to break fusion, as well as angle kappa, so that users can use the app to perform equivalent tests typically done in clinic using prisms.

We present a protocol of using a smartphone app to perform Hirschberg test for measuring manifest and intermittent ocular misalignment (strabismus) under near and far fixation conditions.

A smartphone app has been developed to perform the automated photographic Hirschberg test for objective measurement of ocular misalignment. By computing ...

OCT-Based Multimodal Imaging of Human Donor Eyes for AMD Research

Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration

A progression sequence for age-related macular degeneration (AMD) learned from optical coherence tomography (OCT)-based multimodal (MMI) clinical imaging could add prognostic value to laboratory findings. In this work, ex vivo OCT and MMI were applied to human donor eyes prior to retinal tissue sectioning. The eyes were recovered from non-diabetic white donors aged &#8805;80 years old, with a death-to-preservation time (DtoP) of &#8804;6 h. The globes were recovered on-site, scored with an 18 mm trephine to facilitate cornea removal, and immersed in buffered 4% paraformaldehyde. Color fundus images were acquired after anterior segment removal with a dissecting scope and an SLR camera using trans-, epi-, and flash illumination at three magnifications. The globes were placed in a buffer within a custom-designed chamber with a 60 diopter lens. They were imaged with spectral domain OCT (30&#176; macula cube, 30 &#181;m spacing, averaging = 25), near-infrared reflectance, 488 nm autofluorescence, and 787 nm autofluorescence. The AMD eyes showed a change in the retinal pigment epithelium (RPE), with drusen or subretinal drusenoid deposits (SDDs), with or without neovascularization, and without evidence of other causes. Between June 2016 and September 2017, 94 right eyes and 90 left eyes were recovered (DtoP: 3.9 &plusmn; 1.0 h). Of the 184 eyes, 40.2% had AMD, including early intermediate (22.8%), atrophic (7.6%), and neovascular (9.8%) AMD, and 39.7% had unremarkable maculas. Drusen, SDDs, hyper-reflective foci, atrophy, and fibrovascular scars were identified using OCT. Artifacts included tissue opacification, detachments (bacillary, retinal, RPE, choroidal), foveal cystic change, an undulating RPE, and mechanical damage. To guide the cryo-sectioning, OCT volumes were used to find the fovea and optic nerve head landmarks and specific pathologies. The ex vivo volumes were registered with the in vivo volumes by selecting the reference function for eye tracking. The ex vivo visibility of the pathology seen in vivo depends on the preservation quality. Within 16 months, 75 rapid DtoP donor eyes at all stages of AMD were recovered and staged using clinical MMI methods.

Author Spotlight: Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration  

Laboratory assays can leverage prognostic value from the longitudinal optical coherence tomography (OCT)-based multimodal imaging of age-related macular degeneration (AMD). Human donor eyes with and without AMD are imaged using OCT, color, near-infrared reflectance scanning laser ophthalmoscopy, and autofluorescence at two excitation wavelengths prior to tissue sectioning.

A progression sequence for age-related macular degeneration (AMD) learned from optical coherence tomography (OCT)-based multimodal (MMI) clinical imaging ...

Neuroscience

A Standardized Approach to Extra-Oral and Intra-Oral Digital Photography

Contemporary dentistry mandates a more comprehensive and personalized analysis of each patient. Technological advances in digital photography have played vital roles in diagnostic accuracy, treatment planning, execution of therapies, and outcome evaluations, including esthetic enhancement. Digital photography also provides an excellent platform for patient education, communication, and co-management of cases with other healthcare providers. However, intra-oral photography often faces challenges such as inaccessibility of areas to be captured, different moveable vs. fixed tissues involved, contamination with saliva or blood, and differing illumination needs on various locations. Thus, a more standardized and systematic approach is proposed for intra- and extra-oral documentation via digital photography to overcome the existing technical challenges. The current work will outline the appropriate equipment specifications (camera bodies, macro lens, and flashes), positions and postures of the operator and patients, proper techniques of tissue retraction, the use of appropriate intra-oral mirrors, and the essential elements such as aperture settings (F-stop), ISO, shutter speed, and white balance. This article aims to provide all dental professionals with an approachable linear array of guidelines to produce simplified and standardized visual tools for more efficient and effective documentation.

The present protocol describes a method to capture intra- and extra-oral photographs for digital documentation in the clinical practice of dentistry. The protocol highlights all the critical components involved and the commonly utilized settings to capture dental photographs for clinical documentation.

Contemporary dentistry mandates a more comprehensive and personalized analysis of each patient. Technological advances in digital photography have played ...

Smartphone Fundus Photography

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