|LETTER TO EDITOR
|Year : 2015 | Volume
| Issue : 3 | Page : 160-162
Home made adapter for hands-free smart phone slit lamp photography
Nikhil Sharad Gokhale
Gokhale Eye Hospital, Dadar, Mumbai, Maharashtra, India
|Date of Web Publication||20-Aug-2015|
Nikhil Sharad Gokhale
Gokhale Eye Hospital, Anant Building, Dadar West, Mumbai - 400 028, Maharashtra
Source of Support: None, Conflict of Interest: None
Slit lamp photography has become more accessible and popular after the advent of digital cameras and smart phones. We describe a simple homemade adapter to provide hands-free smart phone slit lamp photography. The cost of the adapter is nominal and the image quality is very good and can be used for academics and patient education.
Keywords: Photography, slit lamp, slit lamp adapter, smart phones
|How to cite this article:|
Gokhale NS. Home made adapter for hands-free smart phone slit lamp photography. J Clin Ophthalmol Res 2015;3:160-2
Smart phones have a large number of applications in Ophthalmology.  Slit lamp photography has become more accessible and popular after the advent of digital cameras and smart phones. However, the picture quality can be variable with smart phone slit lamp photography due to several factors such as steadiness of the hand, camera settings, slit lamp optics and the cooperation of the patient.
We describe a simple adapter to provide hands-free smart phone slit lamp photography. It ensures that the camera is centered on the slit lamp ocular and is steady, which reduces any motion blur. The doctor can therefore concentrate on getting a better image by adjusting the zoom, illumination, camera settings and holding the patient's lids apart.
A smart phone camera with a large display is helpful for the purpose. We describe the use of this adapter for Samsung Note II phone coupled to a Topcon SL 1E slit lamp; however, our adapter can be modified for other makes of slit lamps and smart phones.
The basic requirements are the phone back case (preferably hard back case not soft), piece of PVC pipe and Araldite adhesive [Figure 1]. The diameter of the PVC pipe is selected so that it snugly fits on to the slit lamp ocular. The length of the pipe provides stability and should ensure that the camera is in close contact to the slit lamp eyepiece when the adapter is hooked up. The most important step is to align and stick the pipe with Araldite onto the casing so as to ensure perfect camera centration when the attachment is hooked on the slit lamp [Figure 2]. Araldite adhesive provides adequate strength to hold the phone on the adapter.
For taking pictures, the phone is inserted into the case and then the adapter is hooked onto the slit lamp [Figure 3]. The patient's eye can be seen uniocularly through the second eye piece and is brought into desired focus by adjusting the slit lamp joystick. The image visible on the phone is the same as what an observer will see uniocularly through the slit lamp ocular. Fine focus, exposure, centration and zoom level can then be adjusted prior to clicking an image. Focusing mono-ocularly requires some practice, patience and also cooperation of the patient to get good pictures.
To improve the image quality, manually changing the camera setting to low ISO speeds (200 or 400) is recommended. Due to lower illumination, the camera on auto mode often takes pictures at high ISO speeds (e. g., 2400) and this results in very grainy images. The use of free android apps such as the slit lamp pro can also help to change camera settings if this is not available on lower end phones.
To photograph good slit view images, due to low illumination (like in night photography) the camera selects a longer exposure resulting in a bright image with poor resolution. Longer exposure tends to increase motion blur in images. The slit lamp pro app also gives the added feature of locking the exposure which is analogous to half pressing the shoot button on a regular digital camera. To take sharp slit images sensing can be done with a wide slit beam (brighter illumination) to get shorter exposure setting, then lock exposure with the app setting and then narrow the beam and then click the image. This way despite the low illumination, we can get a sharp image due to lower exposure time.
The distance between the camera and slit lamp ocular can be adjusted by moving the adapter forward and backward. The area of exposure can be maximized by making small change in the camera to slit lamp ocular distance. For example, in the Samsung Note 2 the area of view is much more when the camera is about 1 centimeter from the slit lamp ocular [Figure 4]. Always set the camera to the highest available resolution to get best pictures.
|Figure 4: Field of view is widest when the camera is about 1 cm from the eyepiece|
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The image quality is very good and can be used for academics including publications [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9] and [Figure 10]. Images can be easily uploaded from the smart phone to internet discussion groups. It is useful for patient education and images can be quickly transferred to the patient's smart phones. The images saved on the mobile need to be transferred to the computer at regular intervals where they can be labeled and archived either in manually created folders or with the help of photo archiving software.
|Figure 7: Slit view post-collagen crosslinking showing posterior stromal haze and DM scarring suggestive of endothelial burns|
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The cost of the adapter is about 300 rupees and does not require changing the eyepiece or fitting a camera stand, etc. Several adapters internationally available such as the Tiger lens, Skylight, Keeler iPhone 4 adaptor, Eye Photo Doc, iExaminer, Zarf iPhone adapter and Magnifi cost anything from 70 to 520 US$.  Indian made adapters are also available for a lower cost but usually require replacing the slit lamp eyepiece with the adapter eyepiece fitted to a phone case. This is more cumbersome to use than the adapter described herein, which has to be hooked on and off without removing the eyepiece.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Chhablani J, Kaja S, Shah VA. Smartphones in ophthalmology. Indian J Ophthalmol 2012;60:127-31.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10]