Journal of Clinical Ophthalmology and Research

LETTER TO EDITOR
Year
: 2019  |  Volume : 7  |  Issue : 1  |  Page : 30-

Smartphone-based monochromatic green filter fundus imaging


Ashish A Ahuja1, Olukorede O Adenuga2,  
1 Department of Retina, Sadhu Kamal Eye Hospital, Mumbai, Maharashtra, India
2 Department of Ophthalmology, Jos University Teaching Hospital, Jos, Plateau State, Nigeria

Correspondence Address:
Ashish A Ahuja
Sadhu Kamal Eye Hospital, Navjivan Society, Bldg. No. 2, First Floor, Lamington Road, Mumbai Central, Mumbai - 400 008, Maharashtra
India




How to cite this article:
Ahuja AA, Adenuga OO. Smartphone-based monochromatic green filter fundus imaging.J Clin Ophthalmol Res 2019;7:30-30


How to cite this URL:
Ahuja AA, Adenuga OO. Smartphone-based monochromatic green filter fundus imaging. J Clin Ophthalmol Res [serial online] 2019 [cited 2020 Nov 29 ];7:30-30
Available from: https://www.jcor.in/text.asp?2019/7/1/30/253990


Full Text



Sir,

Smartphone fundus photography is becoming increasingly popular. It is indispensable when picture documentation of optic nerve, retina, and retinal vessels is necessary, but a fundus camera is not available.[1] There are, however, limited reports on its use with a green filter for taking retinal pictures. Greenlight provides excellent contrast and the best overall view of the fundus. It enhances the visibility of the retinal vasculature, and common findings such as hemorrhages, drusen, and exudates.[2] For this reason, green filter “red-free” photos are routinely taken as baseline images in conjunction with fluorescein angiography.[2] The fluorescein exciter filter, with a peak wavelength of 490 nm, can be used as a blue-green monochromatic filter.

We hereby describe a novel technique of smartphone-based green filter imaging of the fundus. We obtained a green filter from an unused Zeiss slit-lamp in our clinic and attached it in front of the smartphone's camera and flash. An Aurolab slit-lamp adapter (manufactured by Aurolab, Madurai, India) for fundus imaging with an external light emitting diode (LED) illumination was then attached. A 20 diopter (D) lens was used along with the smartphone to capture the fundus images using indirect ophthalmoscopy technique.

Suto et al. had previously used the excitation and barrier filters along with a smartphone with an external LED illumination to perform fundus fluorescein angiography.[3] Similarly, we have used a green filter with a smartphone to document fundus lesions [Figure 1]. We believe that our simple technique of smartphone-based green filter imaging is promising and will help in the documentation of certain retinal pathologies as well as in the early detection of glaucoma when a fundus camera is not available.{Figure 1}

Acknowledgment

We would like to thank Dr. Naresh Babu for the inspiration and guidance.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Khanamiri HN, Naatuska A, El-Annan J. Smartphone fundus photography. J Vis Exp 2017;125:55958.
2Bennett TJ. Ophthalmic imaging – An overview and current state of the art: Part l. JBC 2006;32:19-26.
3Suto S, Hiraoka T, Oshika T. Fluorescein fundus angiography with smartphone. Retina 2014;34:203-5.