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 Table of Contents  
Year : 2021  |  Volume : 33  |  Issue : 2  |  Page : 217-221

Smartphone microscope in eye clinic to visualize fungus and Demodex

1 Department of Ophthalmology, Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, Amritsar Eye Hospital, Amritsar, P]unjab, India
2 Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, Punjab, India
3 Department of Ophthalmology, Amritsar Eye Hospital, Kochi, Kerala, India
4 Department of Ophthalmology, Sri Ramachandra Medical College, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India

Date of Submission25-May-2021
Date of Decision26-May-2021
Date of Acceptance26-May-2021
Date of Web Publication21-Aug-2021

Correspondence Address:
Dr. John Davis Akkara
Department of Ophthalmology, Sri Ramachandra Medical College, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/kjo.kjo_125_21

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Purpose: Ophthalmologists often need to use a compound microscope to see slides of corneal scrapings, Demodex blepharitis, histopathology, or tear ferning test for diagnostic purposes. While such a microscope may be available in tertiary care centers, most eye clinics do not have it due to cost, space required, and infrequent use. These tests are often not done or delayed till a tertiary referral is possible. We demonstrate an alternative method using smartphone and an inexpensive attachment. Materials and Methods: Using the smartphone microscope attachment, the authors were able to capture excellent photographs and videos of corneal scrapings, histopathology, and Demodex. Photographs of the same slides were taken with a standard compound microscope as well. Trypan blue dye was used for staining the corneal scraping specimens to make the fungal hyphae in it clearly visible. Results: Photographs and videos captured by the smartphone microscope were compared with those from a compound microscope and found to be of adequate quality. They were determined to be good enough for diagnostic use. Conclusions: We determined that smartphone microscope attachment can be a useful adjunctive diagnostic tool for eye clinics corneal scrapings, histopathology, and Demodex, perhaps even for more applications.

Keywords: Corneal scraping, Demodex blepharitis, fungal hyphae, histopathology, smartphone microscopy

How to cite this article:
Prasher P, Singh B, Vig VK, Akkara JD. Smartphone microscope in eye clinic to visualize fungus and Demodex. Kerala J Ophthalmol 2021;33:217-21

How to cite this URL:
Prasher P, Singh B, Vig VK, Akkara JD. Smartphone microscope in eye clinic to visualize fungus and Demodex. Kerala J Ophthalmol [serial online] 2021 [cited 2022 Jan 29];33:217-21. Available from: http://www.kjophthal.com/text.asp?2021/33/2/217/324211

  Introduction Top

Microscopes are very important and indispensable tools in ophthalmology.[1] Common uses include slit lamp biomicroscope in eye clinics, surgical microscope in operating rooms, and compound microscope for microbial/histopathological specimens.

With ubiquitous availability of smartphones, several innovations[2] have been described incorporating them for ophthalmic devices for slit lamp and fundus photography.[3],[4] A smartphone is easy to handle, can be carried in a pocket or purse, and is a portable alternative to conventional expensive diagnostic devices. In ophthalmology, slit lamp adapters have even been three-dimensional printed[5],[6] for smartphone slit lamp photography and fundus photography.[7] Magnifiers attached to smartphones have been described as a method to identify microorganisms.[8],[9],[10] It is reported that a smartphone with a simple attachment allows 1.5-μm resolution with satisfactory image quality.[11] Various magnifying attachments and miniature lenses[12] have been attached to cameras of smartphone without any alteration in hardware.[13] Medical Hackathons[14] have greatly helped in the development of low-cost innovations, and smartphones have greatly helped in affordable access to the technology needed.[15] Thus, smartphones help in biological imaging, other points of care diagnostics, monitoring, progression, and assessing treatment. Some of this diagnostic capability has been enhanced by artificial intelligence[16] to identify, for example, malarial parasite in blood smear.[17] Herein, we demonstrate utility of a commercially available smartphone microscope attachment Nurugo Micro (Nurugo, Seoul, South Korea) in various clinical situations in routine eye clinics. This device can be used to diagnose Demodex blepharitis, demonstrate the presence of hyphae in fungus keratitis, tear ferning test,[18] and for examination of histopathological slides of ocular specimens.

  Materials and Methods Top

Nurugo Micro (Nurugo, Seoul, South Korea) magnifying attachment is a small device (3.5 cm × 2.0 cm × 0.5 cm) which can be clipped onto the smartphone camera to act as a histopathology microscope. It utilizes smartphone flash for illumination which directs the light with a patent-pending light guide, and thus, it does not require a separate light or battery. It contains two polarizing filters, one in front of the flash and another placed in between the magnifying lens and camera lens. This arrangement of polarizing filters reduces glare from the visualized slide. The smartphone camera is used for capturing microscopic images with the help of an app, Nurugo Box, which has features for measurement as well.

We tested the device on various models of Android and iPhone smartphones (for example, Samsung Galaxy S8, S9, Note 9, iPhone 6, 7, SE, X, XS) which had single, dual, triple, and quadruple cameras and had no problems with illumination as the light guide works with the flash position up to 1.5 cm away from the camera. However, this would not work on smartphones which do not have a flash [Figure 1].
Figure 1: Smartphone and Microscope attachment. (a) Smartphone iPhone 7 and Nurugo microscope attachment. (b) Back view of attachment fixed on smartphone. (c) Side view of the attachment fixed on smartphone. (d) Demonstration of slide examination with Nurugo attachment

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  Results Top

We evaluated the utility of this pocket microscope device as an adjunctive diagnostic tool in our eye clinic. We were able to establish its diagnostic value in three clinical situations which routinely otherwise need a histopathology compound microscope or laboratory services. We compared the same to pictures taken with a histopathology compound microscope [Figure 2], [Figure 3], [Figure 4].
Figure 2: Demodex mites. (a) Seen through histopathology microscope. (b) Seen through Nurugo microscope attachment

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Figure 3: Fungal hyphae stained with trypan blue dye. (a) Seen through histopathology microscope. (b) Seen through Nurugo microscope attachment

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Figure 4: Histopathology view of spheroidal degeneration in a section of the cornea. (a) Seen through histopathology microscope. (b) Seen through Nurugo microscope attachment

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Demodex blepharitis

It is an entity characterized by infestation of eyelashes by mites[19] of genus Demodex and is more commonly seen in patients with blepharitis.[20] The diagnosis is usually established by examination of epilated eyelashes under the microscope. Briefly, the eyelashes with scaly deposits at their bases, especially cylindrical dandruff, are epilated with forceps under the slit lamp magnification. The eyelashes are placed on a glass slide and covered with a coverslip. After initial examination, few drops of normal saline are added with a pipette or a small syringe to the margins of coverslip to loosen the debris. This helps in freeing of mites from the debris and hence better visualization. This procedure is routinely done by corneal surgeons to establish the diagnosis of this otherwise often undiagnosed entity. We found that this pocket microscope can be useful in visualizing these mites on the slides and capturing their images, although the contrast and other details were less clear as compared to the histopathology microscope.[21] [Figure 2].

Fungal hyphae

Identification of fungal hyphae in corneal scrapings by use of 10% (potassium hydroxide [KOH]) is a routine procedure in establishing the diagnosis of fungal keratitis which can play a critical role in guiding the treatment of these patients. Corneal scrapings are taken with a blade or needle from the base and margins of the ulcer and then placed on a glass slide. A 10% KOH solution is added to the material, and the specimen is examined after 5–10 min under the microscope. Although this is a routine procedure, it requires histopathology microscope and laboratory backup, which may not be always available, especially in peripheral or rural centers. We were initially unsuccessful in imaging the hyphae with this pocket microscope probably because of a lack of contrast between the hyphae and background illumination. It was likely because of the difference in illumination system between the histopathology microscope and smartphone microscope. In the histopathology microscope, illumination is provided by the bulb at the base, and light passing through the slide is picked up by the examiner through the viewing lenses of the microscope. On the other hand, Nurugo device uses the smartphone light which is on the same side of viewing lens. Hence, the contrast here is insufficient to pick up hyaline fungal filaments on 10% KOH stain. However, we found that adding a drop of trypan blue dye, which is routinely used for capsular staining in cataract surgery, stains the walls of these filaments blue and allows easy visualization of the hyphae[22] [[Figure 3] and Video 1].

Histopathology slides

Another useful feature of this device is its utility in examination and photography of the histopathology slides [[Figure 4] and Video 2]. Quite often, ophthalmologists would like to see and review the slides of surgical specimens generated and sent to the pathology laboratory and it may not always be possible to visit pathology laboratory for review of these slides. We found that with this Nurugo device, it is quite possible to decipher the relevant details of various ocular pathology slides. Furthermore, the zoom function incorporated in the accompanying app allows examination and photography or videography of the specimen in different magnifications. The pictures and videos can be saved and shared easily for teaching, research, or teleconsultation purposes.

  Discussion Top

Nowadays, smartphones have become an indispensable part in the life of any medical professional including ophthalmologists. With the innovative use of various commercially available attachments, smartphone technology can offer cost-effective solutions or alternatives in different areas. The smartphone has become an indispensable tool for ophthalmologists and has been found to be a useful adjunct in various diagnostic procedures, tool for personal and patient education, and as a tool or various office-based calculations.[23],[24] The device can be purchased online and costs around $40.[25] Hence, it offers a much cheaper alternative to histopathology microscope which would cost over $500. It is also very portable due to its very small size (3.5 cm × 2.0 cm × 0.5 cm) and can be carried in a small pocket along with the smartphone. It can also be set-up quickly and aligned due to the clip-on attachment.

The use of a smartphone with pocket magnifier has been previously reported by Agarwal et al. in this same journal to demonstrate stained fungal hyphae in scrapings of patients with fungal keratitis.[26] Although it was cheaper ($6 in 2015), the magnifier used in their study was a bigger battery-operated device with a light. It was 3.0 cm × 1.8 cm × 8.2 cm in size compared to 3.5 cm × 2.0 cm × 0.5 cm for the Nurugo device we used, making it 16 times bigger than our setup.

This is because the older device used much larger optics, lower dioptric power, and needed a battery and light, whereas the magnifier we used redirects camera flashlight to a diffuse glow with a patent-pending light guide and also uses high power aspheric optics. In addition, this device uses polarization filters to reduce glare and artifacts.

In their report, Agarwal et al. used lactophenol cotton blue (LPCB) and Gram staining to stain slides for fungal hyphae. LPCB and Gram stain are not easily available to an ophthalmologist whereas we can easily obtain trypan blue as leftover from cataract surgery. Therefore, in our study, we used trypan blue dye to stain the hyphae and capture it with the Nurugo device making the whole process easier. With this stain, we were able to stain the hyphae and capture good-quality pictures of the stained hyphae [Figure 3]. We also noted a new publication by Dr. Prithvi Chandrakanth et al. in the Indian Journal of Ophthalmology, where they describe a homemade smartphone microscope attachment made out of four intraocular lenses and a flashlight.[27] The device they made was about the same size as the device we used, not including the flashlight, which makes their setup much bigger than ours. The novel, patent-pending light guide eliminates the need for a separate source of illumination in our case.

We also report the novel use of this pocket microscope to detect Demodex mites in epilated eyelashes [Figure 2]. This should be helpful in establishing the diagnosis of Demodex blepharitis in situations where histopathology microscope is not available.

  Conclusions Top

In conclusion, we report the application of smartphone-based microscopic imaging in three key clinical entities which can be of great clinical significance in routine ophthalmic practice – Demodex blepharitis, fungal hyphae, and histopathology slides. Further studies may help in establishing the accuracy and cost-effectiveness of these innovative systems in these and other areas of ophthalmology.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

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