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RETINA, THE JOURNAL OF RETINAL AND VITREOUS DISEASES 2014 VOLUME 34 NUMBER 3
†Vitreo-Retinal Unit, VISSUM, Alicante Institute of Ophthalmology, Alicante, Spain ‡Ophthalmology Unit, Pío del Río Hortega University Hospital, Valladolid, Spain References 1. Ruiz-Moreno JM, Arias L, Araiz J, et al. Spectral-domain optical coherence tomography study of macular structure as prognostic and determining factor for macular hole surgery outcome. Retina 2013;33:1117–1122. 2. Spaide RF, Curcio CA. Anatomical correlates to the bands seen in the outer retina by optical coherence tomography: literature review and model. Retina 2011;31:1609–1619. 3. Ruiz-Moreno JM, Lugo F, Montero JA, et al. Restoration of macular structure as the determining factor for macular hole surgery outcome. Graefes Arch Clin Exp Ophthalmol 2012;250:1409–1414. 4. Wakabayashi T, Fujiwara M, Sakaguchi H, et al. Foveal microstructure and visual acuity in surgically closed macular holes: spectral-domain optical coherence tomographic analysis. Ophthalmology 2010;117:1815–1824.
To the Editor: We read the article by Suto et al1 on fluorescein fundus angiography using a smartphone with great interest. We have been able to image the fundus with a smartphone but without the need for a condensing
Fig. 1. A Composite image showing the modified smartphone direct ophthalmoscope and fundus images of disk edema, diabetic retinopathy, and macular edema obtained with it. LED, light emitting diode.
lens using the direct ophthalmoscopic technique, and herein, we share the same. We found that a smartphone can be used as a direct ophthalmoscope by affixing a light emitting diode of a direct ophthalmoscope powered by an external battery pack, close to the smartphone camera aperture (Figure 1). Autofocus capability of the smartphone camera allows viewing fundi of eyes with refractive errors. The direct ophthalmoscope directs a focused beam of light into the eye, the reflected light being captured by the observer’s eye. By placing the light source close to the camera, the smartphone can effectively be transformed into a direct ophthalmoscope. Using the smartphone to image the fundus without the aid of a condensing lens offers multiple advantages. The mobile phone is an integral part of one’s life, and most physicians do carry one with them and is thus readily available to be used as an ophthalmoscope. One of the drawbacks of direct ophthalmoscopy is the need to examine the patient in close proximity that often discomfits the patient and the examiner. Using the smartphone as a direct ophthalmoscope allows examining the patient from a distance and also screens a wider area of the fundus. Smartphone images allow magnification and documentation of images, features that are not available with the direct ophthalmoscope. The disadvantage would be the inability to measure elevated lesions, a capability afforded by the direct ophthalmoscope. As in direct ophthalmoscopy, smartphone imaging through significant cataract posed some difficulty.
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Correspondence
Fig. 1. A. iPhone 4s with darkening filter (Post-it; Sumitomo 3M Limited) on LED. B. Normal optic nerve head. C. Optic nerve papilledema.
The inbuilt light emitting diode flash light of the smartphone camera can be used in lieu of the external light if only it was placed close to the camera, and we hope that this article will prompt manufacturers to build such a phone with additional software, built specifically for direct ophthalmoscopy such as a rheostat. Such a smartphone, wherein the alignment of the camera and light source are precisely engineered, will also allow an undilated fundus examination, which was possible albeit with difficulty, with our crude hand-built device. To conclude, we show that direct ophthalmoscopy is possible with a minimally modified smartphone but with several advantages over the direct ophthalmoscope. P. Mahesh Shanmugam, DO, FRCSEd, PhD, FAICO Divyansh Mishra, DO, DNB Rajesh Ramanjulu, MD, DNB, FAICO Sankara Eye Hospital, Bangalore, India None of the authors have any financial/conflicting interests to disclose. References 1. Suto S, Hiraoka T, Oshika T. Fluorescein fundus angiography with smartphone. Retina 2013;0:1–3. 2. Haddock LJ, Kim DY, Mukai S. Simple, inexpensive technique for high-quality smartphone fundus photography in human and animal eyes. J Ophthalmol 2013;2013:518479.
Reply To the Editor: We appreciate the interest of Shanmugam et al in our article1 and their report of the wide-region direct ophthalmoscope images.2 Previously, we tried to obtain some images using iPhone 4s as a direct
ophthalmoscope images like their report. However, the built-in flashlight is so bright, and thus we are currently using the Post-it 686S (Sumitomo 3M Limited, Tokyo, Japan) as a darkening filter when recording direct ophthalmoscope images (Figure 1A). Without an external light-emitting diode (LED), the iPhone 4s is capable of obtaining direct ophthalmoscope images because the built-in LED is placed comparatively close to the camera. This is a strong point of our method, however, our image is localized to a small region. Therefore, we usually use this method only for judging whether there are some abnormalities of optic disk such as papilledema and chocked disk (Figure 1, B and C). In contrast, their method can acquire wider area images than our method. Hence, it will be more helpful in clinical practice. In addition, we agree with their comment that articles of these kinds will prompt manufacturers to build phones with additional software created specifically for ophthalmoscopy. Shin Suto, MD Takahiro Hiraoka, MD Tetsuro Oshika, MD Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan None of the authors have any financial/conflicting interests to disclose. References 1. Suto S, Hiraoka T, Oshika T. Fluorescein fundus angiography with smartphone. Retina 2014;34:203–205. 2. Shanmugam PM, Mishra D, Ramanjulu R. Smart phone as a direct ophthalmoscope.
RETINA, THE JOURNAL OF RETINAL AND VITREOUS DISEASES 2014 VOLUME 34 NUMBER 3
†Vitreo-Retinal Unit, VISSUM, Alicante Institute of Ophthalmology, Alicante, Spain ‡Ophthalmology Unit, Pío del Río Hortega University Hospital, Valladolid, Spain References 1. Ruiz-Moreno JM, Arias L, Araiz J, et al. Spectral-domain optical coherence tomography study of macular structure as prognostic and determining factor for macular hole surgery outcome. Retina 2013;33:1117–1122. 2. Spaide RF, Curcio CA. Anatomical correlates to the bands seen in the outer retina by optical coherence tomography: literature review and model. Retina 2011;31:1609–1619. 3. Ruiz-Moreno JM, Lugo F, Montero JA, et al. Restoration of macular structure as the determining factor for macular hole surgery outcome. Graefes Arch Clin Exp Ophthalmol 2012;250:1409–1414. 4. Wakabayashi T, Fujiwara M, Sakaguchi H, et al. Foveal microstructure and visual acuity in surgically closed macular holes: spectral-domain optical coherence tomographic analysis. Ophthalmology 2010;117:1815–1824.
To the Editor: We read the article by Suto et al1 on fluorescein fundus angiography using a smartphone with great interest. We have been able to image the fundus with a smartphone but without the need for a condensing
Fig. 1. A Composite image showing the modified smartphone direct ophthalmoscope and fundus images of disk edema, diabetic retinopathy, and macular edema obtained with it. LED, light emitting diode.
lens using the direct ophthalmoscopic technique, and herein, we share the same. We found that a smartphone can be used as a direct ophthalmoscope by affixing a light emitting diode of a direct ophthalmoscope powered by an external battery pack, close to the smartphone camera aperture (Figure 1). Autofocus capability of the smartphone camera allows viewing fundi of eyes with refractive errors. The direct ophthalmoscope directs a focused beam of light into the eye, the reflected light being captured by the observer’s eye. By placing the light source close to the camera, the smartphone can effectively be transformed into a direct ophthalmoscope. Using the smartphone to image the fundus without the aid of a condensing lens offers multiple advantages. The mobile phone is an integral part of one’s life, and most physicians do carry one with them and is thus readily available to be used as an ophthalmoscope. One of the drawbacks of direct ophthalmoscopy is the need to examine the patient in close proximity that often discomfits the patient and the examiner. Using the smartphone as a direct ophthalmoscope allows examining the patient from a distance and also screens a wider area of the fundus. Smartphone images allow magnification and documentation of images, features that are not available with the direct ophthalmoscope. The disadvantage would be the inability to measure elevated lesions, a capability afforded by the direct ophthalmoscope. As in direct ophthalmoscopy, smartphone imaging through significant cataract posed some difficulty.
e7
Correspondence
Fig. 1. A. iPhone 4s with darkening filter (Post-it; Sumitomo 3M Limited) on LED. B. Normal optic nerve head. C. Optic nerve papilledema.
The inbuilt light emitting diode flash light of the smartphone camera can be used in lieu of the external light if only it was placed close to the camera, and we hope that this article will prompt manufacturers to build such a phone with additional software, built specifically for direct ophthalmoscopy such as a rheostat. Such a smartphone, wherein the alignment of the camera and light source are precisely engineered, will also allow an undilated fundus examination, which was possible albeit with difficulty, with our crude hand-built device. To conclude, we show that direct ophthalmoscopy is possible with a minimally modified smartphone but with several advantages over the direct ophthalmoscope. P. Mahesh Shanmugam, DO, FRCSEd, PhD, FAICO Divyansh Mishra, DO, DNB Rajesh Ramanjulu, MD, DNB, FAICO Sankara Eye Hospital, Bangalore, India None of the authors have any financial/conflicting interests to disclose. References 1. Suto S, Hiraoka T, Oshika T. Fluorescein fundus angiography with smartphone. Retina 2013;0:1–3. 2. Haddock LJ, Kim DY, Mukai S. Simple, inexpensive technique for high-quality smartphone fundus photography in human and animal eyes. J Ophthalmol 2013;2013:518479.
Reply To the Editor: We appreciate the interest of Shanmugam et al in our article1 and their report of the wide-region direct ophthalmoscope images.2 Previously, we tried to obtain some images using iPhone 4s as a direct
ophthalmoscope images like their report. However, the built-in flashlight is so bright, and thus we are currently using the Post-it 686S (Sumitomo 3M Limited, Tokyo, Japan) as a darkening filter when recording direct ophthalmoscope images (Figure 1A). Without an external light-emitting diode (LED), the iPhone 4s is capable of obtaining direct ophthalmoscope images because the built-in LED is placed comparatively close to the camera. This is a strong point of our method, however, our image is localized to a small region. Therefore, we usually use this method only for judging whether there are some abnormalities of optic disk such as papilledema and chocked disk (Figure 1, B and C). In contrast, their method can acquire wider area images than our method. Hence, it will be more helpful in clinical practice. In addition, we agree with their comment that articles of these kinds will prompt manufacturers to build phones with additional software created specifically for ophthalmoscopy. Shin Suto, MD Takahiro Hiraoka, MD Tetsuro Oshika, MD Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan None of the authors have any financial/conflicting interests to disclose. References 1. Suto S, Hiraoka T, Oshika T. Fluorescein fundus angiography with smartphone. Retina 2014;34:203–205. 2. Shanmugam PM, Mishra D, Ramanjulu R. Smart phone as a direct ophthalmoscope.
