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 Table of Contents  
Year : 2020  |  Volume : 32  |  Issue : 1  |  Page : 83-86

Custom-made three-dimensional-printed adapter for smartphone slit-lamp photography

1 Department of Ophthalmology, Mansoura Ophthalmic Hospital, Mansoura, Egypt
2 Department of Ophthalmology, Little Flower Hospital, Angamaly, Kerala, India
3 Department of Retina, Aravind Eye Hospital, Chennai, Tamil Nadu, India

Date of Submission09-Feb-2020
Date of Acceptance09-Feb-2020
Date of Web Publication17-Apr-2020

Correspondence Address:
Dr. John Davis Akkara
Department of Ophthalmology, Little Flower Hospital, Angamaly, Kerala
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/kjo.kjo_12_20

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In this article, we introduce a custom-made smartphone slit-lamp adapter that is designed by one of the authors and made using three-dimensional (3D) printing technology. It is built upon a commercially available part used in selfie sticks and tripods which is used to hold the phone. The rest of the adapter is designed and 3D printed to enable attaching the mobile with that holder to the selected eyepiece. The design depends on each slit-lamp or microscope eyepiece dimensions, and the idea is about making a complementary design that automatically fits the eyepiece which slides in the adapter and then the mobile weight and gravity do the rest to hold the adapter in place. Within few seconds of sliding the phone into the adapter, place the camera against the eyepiece then you are ready to go. It is named blink to allude to its ease of use and quick adjustment like in a blink of an eye.

Keywords: Adapter, imaging, photography, slit lamp, smartphone, three-dimensional printing

How to cite this article:
Ateya A, Akkara JD, Kuriakose A. Custom-made three-dimensional-printed adapter for smartphone slit-lamp photography. Kerala J Ophthalmol 2020;32:83-6

How to cite this URL:
Ateya A, Akkara JD, Kuriakose A. Custom-made three-dimensional-printed adapter for smartphone slit-lamp photography. Kerala J Ophthalmol [serial online] 2020 [cited 2023 Feb 2];32:83-6. Available from: http://www.kjophthal.com/text.asp?2020/32/1/83/282648

  Introduction Top

Photography is becoming a cornerstone in ophthalmology practice. Smartphones are easily available to everyone, and they help in low-cost innovation.[1] Smartphone photography in ophthalmology has a wide variety of uses including examination with or without other examination tools such as slit lamp or condensing lenses. Smartphones can be used for fundus photography,[2],[3],[4] slit-lamp photography,[5] microscope-free anterior segment photography,[6] gonioscopy,[7] and more.[5]

In addition, it is useful in the documentation for medicolegal reasons, counseling, follow-up, and even teaching purposes. The authors have previously written a guide to smartphone slit-lamp photography.[5]

Besides using manual technique for smartphone slit-lamp photography, the use of a variety of adapters to make the job easier is becoming popular.

There are two main categories of smartphone photography adapters. Universal adapters that can be adjusted to many eyepieces with different designs and dimensions and custom design that can fit only one design of smartphone and slit lamp for each adapter.

The ideal adapter is one that proves to be quick, easy, and efficient to use.

Being universal is an advantage, but universal adapters almost always take some time and effort to adjust for every single use.

The authors decided that it is best to combine the advantages of both approaches. Three-dimensional (3D) printing is a technology, which is very useful in rapid design prototyping and has several uses in ophthalmology. The author has also previously designed a 3D-printed smartphone fundus camera.[8]

  Methods Top

Once the target slit-lamp microscope was selected, the eyepiece measurements were taken using Vernier calipers [Figure 1]. 3D computer-aided design (CAD) modeling was done on Tinkercad[9] website to make a virtual model of the adapter according to the measured dimensions. SketchUp[10] Free software was used to further refine the models. Repetier-Host,[11] which includes the toolpathing slic3r (RepRap Ltd, Bath, England) was used for slicing to prepare for 3D printing. From the 3D CAD virtual model, the slicer software generates a g-code file which gives specific commands to the 3D printer on how to make the physical adapter.
Figure 1: Measurements of slit-lamp eyepiece being taken using digital Vernier calipers

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Rostock MAX v2 3D printer[12](SeeMeCNC, Indiana, USA) was used with Acrylonitrile Butadiene Styrene material to make the adapter. The 3D-printed part was fixed to the universal smartphone holder[13] part to complete the device. The fitting was tested and refined to account for manufacturing tolerances [Figure 2].
Figure 2: Three-dimensional-printed adapter fixed on eyepiece to refine the sizing

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More units can be easily made by printing the same CAD file and fixing it to the universal smartphone holding bracket[13] [Figure 3].
Figure 3: Two copies of the blink three-dimensional-printed slit-lamp adapter (in gray and black acrylonitrile butadiene styrene material) fixed to universal smartphone holders

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After inserting a smartphone into the holder, the device was fixed to the eyepiece of the slit lamp. Smartphone slit-lamp photos could be easily taken with this setup [Figure 4].
Figure 4: Smartphone fixed on the Blink adapter and placed on slit-lamp eyepiece

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  Results Top

The blink 3D-printed smartphone slit-lamp adapter was successfully designed, modeled, 3D-printed, and tested. Each type of slit-lamp eyepiece required a small modification in the 3D design based on measurements. Good-quality images could be captured in diffuse, slit, retro, and cobalt-blue illumination [Figure 5], [Figure 6], [Figure 7], [Figure 8].
Figure 5: Diffuse illumination, high magnification slit-lamp cropped photo showing iris nodules

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Figure 6: Slit illumination image of nuclear sclerosis cataract. Black circle represents the uncropped view through eyepiece

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Figure 7: Retroillumination image showing a partial lamellar cataract

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Figure 8: Cobalt-blue illumination image showing dendritic ulcer on cornea stained by fluorescein sodium dye

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Fundus could also be imaged using 90D lens [Figure 9] and [Figure 10].
Figure 9: 90D image showing retinal hemorrhages of a macular branch retinal vein occlusion

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Figure 10: 90D image showing myelinated nerve fibers and a disc hemorrhage

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Fixing and removing the device on slit lamp hardly took a few seconds, making it a useful tool for slit-lamp photography.

  Discussion Top

Easy availability of 3D printing technology in recent years has led to many innovations in several aspects of modern life. Online tutorials are available for learning 3D modeling and designing, free CAD software[9] is available, and low-cost 3D-printers[14] are also available. There are now several applications of 3D-printing in the field of medicine,[15] with a good number of applications in ophthalmology.[8] Some uses of 3D printing in ophthalmology are prototyping surgical instruments, smartphone fundus cameras like oDocs fundus,[16] spectacles, lenses, innovative devices, teaching tools, surgical planning, Optical Coherence Tomography (OCT) models, toys, bioprinting cornea, and more.[8]

Our article describes the process of designing and building a smartphone slit-lamp adapter to solve the problem of slit-lamp photography.[5] The cost of 3D printing a small part such as the adapter described here is small and can be done at a 3D printing shop which is available in all major cities in India, Egypt, and many other countries. Most of the work involved is in designing the CAD model according to measurements and physical constraints.

We hope that the easy access to 3D printing technology leads to many more low-cost grassroot innovations[17] from people all over the world.

  Conclusion Top

Easy accessibility to 3D printing enables quick and inexpensive prototyping. Development of this type of innovation from idea to virtual design to hardware does not need much time or money - only an innovative mind and the drive to learn these new techniques. Resources to learn 3D designing and 3D printing are freely available online. Hope this inspires many innovators to design more such frugal innovations to share with the world.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Akkara JD. Commentary: Dawn of smartphones in frugal ophthalmic innovation. Indian J Ophthalmol 2018;66:1619.  Back to cited text no. 1
[PUBMED]  [Full text]  
Raju B, Raju NS, Akkara JD, Pathengay A. Do it yourself smartphone fundus camera – DIYretCAM. Indian J Ophthalmol 2016;64:663-7.  Back to cited text no. 2
[PUBMED]  [Full text]  
Chandrakanth P, Ravichandran R, Nischal NG, Subhashini M. Trash to treasure Retcam. Indian J Ophthalmol 2019;67:541-4.  Back to cited text no. 3
[PUBMED]  [Full text]  
Sharma A, Subramaniam SD, Ramachandran KI, Lakshmikanthan C, Krishna S, Sundaramoorthy SK. Smartphone-based fundus camera device (MII Ret Cam) and technique with ability to image peripheral retina. Eur J Ophthalmol 2016;26:142-4.  Back to cited text no. 4
Akkara J, Kuriakose A. How-to guide for smartphone slit-lamp imaging. Kerala J Ophthalmol 2019;31:64-71.  Back to cited text no. 5
  [Full text]  
Chandrakanth P, Nallamuthu P. Anterior segment photography with intraocular lens. Indian J Ophthalmol 2019;67:1690-1.  Back to cited text no. 6
[PUBMED]  [Full text]  
Kumar N, Francesco B, Sharma A. Smartphone-based gonio-imaging: A novel addition to glaucoma screening tools. J Glaucoma 2019;28:e149-50.  Back to cited text no. 7
Akkara J, Kuriakose A. The magic of three-dimensional printing in ophthalmology. Kerala J Ophthalmol 2018;30:209-15.  Back to cited text no. 8
  [Full text]  
Tinkercad. Create 3D digital designs with online CAD. Tinkercad. Available from: https://www.tinkercad.com. [Last accessed on 2020 Feb 08].  Back to cited text no. 9
3D Design Software. 3D Modeling on the Web. Available from: https://www.sketchup.com/page/homepage. [Last accessed on 2020 Feb 08].  Back to cited text no. 10
Repetier Software. Available from: https://www.repetier.com/. [Last accessed on 2020 Feb 08].  Back to cited text no. 11
Rostock MAX-RepRap. Available from: https://reprap.org/wiki/Rostock_MAX. [Last accessed on 2020 Feb 09].  Back to cited text no. 12
Universal Smartphone Holder Bracket for tripod. Available from: https://amzn.to/2S9 vupC. [Last accessed on 2020 Feb 09].  Back to cited text no. 13
3D Printer. Available from: https://amzn.to/2vgLKfA. [Last accessed on 2020 Feb 09].   Back to cited text no. 14
Liaw CY, Guvendiren M. Current and emerging applications of 3D printing in medicine. Biofabrication 2017;9:024102.  Back to cited text no. 15
OphthalmicdocsFollow. Smartphone Ophthalmoscope ODocs Fundus. Instructables. Available from: http://www.instructables.com/id/Retinal-Imaging-Device-OphthalmicDocs-Fundus/. [Last accessed on 2018 Jun 16].  Back to cited text no. 16
Akkara JD, Kuriakose A. Commentary: Tsunami of grassroot innovations from makers. Indian J Ophthalmol 2019;67:545-6.  Back to cited text no. 17
[PUBMED]  [Full text]  


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10]

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