Smartphone fundus photography: a narrative review

Abstract Background The idea to use smartphone for fundus photography was put forward in 2010. Over the last decade, there has been a dramatic development in this field. This narrative review focuses on the principle of smartphone fundus photography, how to master this technique, problems encountered by the beginners, camera applications/devices designed for this purpose and the safety profile of smartphone flashlights for retinal photoreceptors. Discussion Smartphone fundus photography using a condensing lens is based on the same principle as indirect ophthalmoscopy. Smartphone flashlight serves the purpose of light source or illuminating system. Real and inverted image of the retina is focused by the smartphone camera after adjustment of the filming distance. Beginners can face difficulties like adjustment of the filming distance, glare from condensing lens and reflection from the ceiling lights. Mobile camera applications and holding devices designed for this purpose can help the beginners to address these difficulties. There have been safety concerns about photo-biological risk for retinal photoreceptors by flashlight. Although the spectral irradiance on the retina, while using smartphone for fundus imaging is within the safety limits set by ISO 15004-2.2. The safety profile of latest model flashlights which deliver more power compared to older flashlights, need to be assessed. Conclusion Smartphone fundus photography is a cheap, cost effective, portable and a convenient method for retinal imaging. With practice and use of smartphone camera applications designed for this purpose, the beginners can master this technique. By training young ophthalmology residents and ophthalmic primary caretakers, this retinal imaging technique can be utilized for artificial intelligence, patient diagnostic and educational purposes.

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Wide-field Imaging of Retinal Diseases

US Ophthalmic Review ◽

10.17925/usor.2015.08.02.125 ◽

2015 ◽

Vol 08 (02) ◽

pp. 125 ◽

Cited By ~ 1

Author(s):

Esther Lee Kim ◽

Andrew A Moshfeghi ◽

◽

Keyword(s):

Retinal Imaging ◽

Vascular Diseases ◽

Posterior Uveitis ◽

Fundus Photography ◽

Wide Field ◽

Advantages And Disadvantages ◽

Fundus Imaging ◽

Multiple Imaging ◽

Field Imaging ◽

Wide Field Imaging

Retinal imaging serves as a critical adjunct to the diagnosis, monitoring, and treatment of numerous ocular diseases. In particular, wide-field retinal imaging is quickly moving to the forefront in imaging the posterior segment. While conventional fundus imaging captures 30 to 50° field of view in a single capture, significant advances have been made in the past 2 decades to increase the viewing angle, speed, and accuracy of fundus photography, such that a single-field capture is now up to 200°. Moreover, multiple imaging modalities, including color fundus photography, fluorescein angiography, and autofluorescence, are now available a single wide-field imaging platform. This breadth of functionality makes wide-field imaging especially useful in peripheral retinal vascular diseases, such as diabetic retinopathy, posterior uveitis, and retinopathy of prematurity. This review aims to provide a historical perspective on wide-field retinal imaging, highlight the imaging platforms currently available, discuss the advantages and disadvantages of wide-field versus conventional fundus imaging, summarize the current clinical applications of wide-field retinal imaging, and provide an outlook for its future implications.

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Cost effective DIY Smartphone based Retinal Imaging

2021 2nd International Conference on Intelligent Engineering and Management (ICIEM) ◽

10.1109/iciem51511.2021.9445288 ◽

2021 ◽

Author(s):

Shubhi Gupta ◽

Akhilesh Kumar ◽

Sanjeev Thakur ◽

Ashutosh Gupta ◽

Swati Vashisht ◽

...

Keyword(s):

Retinal Imaging ◽

Cost Effective

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Iron-Containing Contraceptives and Their Effect on Hemoglobin and Biomarkers of Iron Status: A Narrative Review

Nutrients ◽

10.3390/nu13072340 ◽

2021 ◽

Vol 13 (7) ◽

pp. 2340

Author(s):

Jordie A. J. Fischer ◽

Carolina S. Sasai ◽

Crystal D. Karakochuk

Keyword(s):

Oral Contraceptive ◽

Iron Deficiency ◽

Contraceptive Use ◽

Iron Status ◽

Cost Effective ◽

Narrative Review ◽

Deficiency Anemia ◽

Oral Contraceptive Use ◽

Contraception Use ◽

Hb Concentration

Oral contraceptive use has been associated with decreased menstrual blood losses; thus, can independently reduce the risk of anemia and iron deficiency in women. Manufacturers have recently started to include supplemental iron in the non-hormonal placebo tablets of some contraceptives. The aims of this narrative review are: (i) to describe the relationship between oral contraceptive use and both anemia and iron status in women; (ii) to describe the current formulations of iron-containing oral contraceptives (ICOC) available on the market; and (iii) to systematically review the existing literature on the effect of ICOC on biomarkers of anemia and iron status in women. We discovered 21 brands of ICOC, most commonly including 25 mg elemental iron as ferrous fumarate, for seven days, per monthly tablet package. Our search identified one randomized trial evaluating the effectiveness of ICOC use compared to two non-ICOC on increasing hemoglobin (Hb) and iron status biomarker concentrations in women; whereafter 12 months of contraception use, there were no significant differences in Hb concentration nor markers of iron status between the groups. ICOC has the potential to be a cost-effective solution to address both family planning needs and iron deficiency anemia. Yet, more rigorous trials evaluating the effectiveness of ICOC on improving markers of anemia and iron deficiency, as well as investigating the safety of its consumption among iron-replete populations, are warranted.

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Structural evaluation in inherited retinal diseases

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2021-319228 ◽

2021 ◽

pp. bjophthalmol-2021-319228

Author(s):

Malena Daich Varela ◽

Burak Esener ◽

Shaima A Hashem ◽

Thales Antonio Cabral de Guimaraes ◽

Michalis Georgiou ◽

...

Keyword(s):

Adaptive Optics ◽

Fundus Autofluorescence ◽

Standard Of Care ◽

Laser Speckle ◽

Fundus Photography ◽

Laser Speckle Flowgraphy ◽

Retinal Diseases ◽

Autofluorescence Imaging ◽

Structural Evaluation ◽

Fundus Imaging

Ophthalmic genetics is a field that has been rapidly evolving over the last decade, mainly due to the flourishing of translational medicine for inherited retinal diseases (IRD). In this review, we will address the different methods by which retinal structure can be objectively and accurately assessed in IRD. We review standard-of-care imaging for these patients: colour fundus photography, fundus autofluorescence imaging and optical coherence tomography (OCT), as well as higher-resolution and/or newer technologies including OCT angiography, adaptive optics imaging, fundus imaging using a range of wavelengths, magnetic resonance imaging, laser speckle flowgraphy and retinal oximetry, illustrating their utility using paradigm genotypes with on-going therapeutic efforts/trials.

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Cost-Effectiveness Analysis of Non-Mydriatic Ultrawide- Field Fundus Photography versus Pharmacological Pupil Dilatation in Diabetic Retinopathy Screening Program

Journal of the Medical Association of Thailand ◽

10.35755/jmedassocthai.2021.05.12238 ◽

2021 ◽

Vol 104 (5) ◽

pp. 818-824

Keyword(s):

Diabetic Retinopathy ◽

Cost Effectiveness ◽

Screening Program ◽

Cost Effective ◽

Cost Effectiveness Analysis ◽

Fundus Photography ◽

Diabetic Retinopathy Screening ◽

Effectiveness Analysis ◽

The Cost ◽

Retinopathy Screening

Background: Diabetic retinopathy (DR) causes blindness of the population in many countries worldwide. Early detection and treatment of this disease via a DR screening program is the best way to secure the vision. An annual screening program using pharmacological pupil dilatation becomes the standard method. Recently, non-mydriatic ultrawide-field fundus photography (UWF) has been proposed as a choice for DR screening. However, there was no cost-effectiveness study between the standard DR screening and this UWF approach. Objective: To compare the cost-effectiveness between UWF and pharmacological pupil dilatation in terms of hospital and societal perspectives. Materials and Methods: Patients with type 2 diabetes mellitus that visited the ophthalmology clinic at Chulabhorn Hospital for DR screening were randomized using simple randomization method. The patients were interviewed by a trained interviewer for general and economic information. The clinical characteristics of DR and staging were recorded. Direct medical costs, direct non-medical costs, and informal care costs due to DR screening were recorded. Cost analyses were calculated for the hospital and societal perspectives. Results: The present study presented the cost-effectiveness analyses of UWF versus pharmacological pupil dilatation. Cost-effectiveness analysis from the hospital perspective showed the incremental cost-effectiveness ratio (ICER) of UWF to be –13.87. UWF was a cost-effective mean in DR screening in the societal perspective when compared with pharmacologically pupil dilatation with the ICER of 76.46, under the threshold of willingness to pay. Conclusion: The UWF was a cost-effective mean in DR screening. It can reduce screening duration and bypass post-screening blurred vision. The results suggested that UWF could be a viable option for DR screening. Keywords: Diabetic retinopathy, Diabetic retinopathy screening, Non-mydriatic ultrawide-field fundus photography, Cost-effectiveness analysis

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Non-contact smartphone-based fundus imaging compared to conventional fundus imaging: a low-cost alternative for retinopathy of prematurity screening and documentation

Scientific Reports ◽

10.1038/s41598-019-56155-x ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Maximilian W. M. Wintergerst ◽

Michael Petrak ◽

Jeany Q. Li ◽

Petra P. Larsen ◽

Moritz Berger ◽

...

Keyword(s):

Retinopathy Of Prematurity ◽

Low Cost ◽

Cost Effective ◽

Field Of View ◽

Fundus Examination ◽

Fundus Imaging ◽

Examination Time ◽

Sensitivity Specificity ◽

Rop Screening ◽

Good Agreement

AbstractRetinopathy of prematurity (ROP) is a frequent cause of treatable childhood blindness. The current dependency of telemedicine-based ROP screening on cost-intensive equipment does not meet the needs in economically disadvantaged regions. Smartphone-based fundus imaging (SBFI) allows for affordable and mobile fundus examination and, therefore, could facilitate cost-effective telemedicine-based ROP screening in low-resources settings. We compared non-contact SBFI and conventional contact fundus imaging (CFI) in terms of feasibility for ROP screening and documentation. Twenty-six eyes were imaged with both SBFI and CFI. Field-of-view was smaller (ratio of diameters, 1:2.5), level of detail was equal, and examination time was longer for SBFI as compared to CFI (109.0 ± 57.8 vs. 75.9 ± 36.3 seconds, p < 0.01). Good agreement with clinical evaluation by indirect funduscopy was achieved for assessment of plus disease and ROP stage for both SBFI (squared Cohen’s kappa, 0.88 and 0.81, respectively) and CFI (0.86 and 0.93). Likewise, sensitivity/specificity for detection of plus disease and ROP was high for both SBFI (90%/100% and 88%/93%, respectively) and CFI (80%/100% and 100%/96%). SBFI is a non-contact and low-cost alternative to CFI for ROP screening and documentation that has the potential to considerably improve ROP care in middle- and low-resources settings.

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Cost-effective studies in spine surgeries: a narrative review

The Spine Journal ◽

10.1016/j.spinee.2014.04.026 ◽

2014 ◽

Vol 14 (11) ◽

pp. 2748-2762 ◽

Cited By ~ 12

Author(s):

Young Lu ◽

Sheeraz A. Qureshi

Keyword(s):

Cost Effective ◽

Narrative Review

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Deep Ensemble Learning Based Objective Grading of Macular Edema by Extracting Clinically Significant Findings from Fused Retinal Imaging Modalities

Sensors ◽

10.3390/s19132970 ◽

2019 ◽

Vol 19 (13) ◽

pp. 2970 ◽

Cited By ~ 4

Author(s):

Bilal Hassan ◽

Taimur Hassan ◽

Bo Li ◽

Ramsha Ahmed ◽

Omar Hassan

Keyword(s):

Macular Edema ◽

Ensemble Learning ◽

Retinal Imaging ◽

Imaging Modalities ◽

Fundus Photography ◽

Support Vector ◽

Hard Exudates ◽

Retinal Examination ◽

Clinically Significant ◽

Retinal Fundus

Macular edema (ME) is a retinal condition in which central vision of a patient is affected. ME leads to accumulation of fluid in the surrounding macular region resulting in a swollen macula. Optical coherence tomography (OCT) and the fundus photography are the two widely used retinal examination techniques that can effectively detect ME. Many researchers have utilized retinal fundus and OCT imaging for detecting ME. However, to the best of our knowledge, no work is found in the literature that fuses the findings from both retinal imaging modalities for the effective and more reliable diagnosis of ME. In this paper, we proposed an automated framework for the classification of ME and healthy eyes using retinal fundus and OCT scans. The proposed framework is based on deep ensemble learning where the input fundus and OCT scans are recognized through the deep convolutional neural network (CNN) and are processed accordingly. The processed scans are further passed to the second layer of the deep CNN model, which extracts the required feature descriptors from both images. The extracted descriptors are then concatenated together and are passed to the supervised hybrid classifier made through the ensemble of the artificial neural networks, support vector machines and naïve Bayes. The proposed framework has been trained on 73,791 retinal scans and is validated on 5100 scans of publicly available Zhang dataset and Rabbani dataset. The proposed framework achieved the accuracy of 94.33% for diagnosing ME and healthy subjects and achieved the mean dice coefficient of 0.9019 ± 0.04 for accurately extracting the retinal fluids, 0.7069 ± 0.11 for accurately extracting hard exudates and 0.8203 ± 0.03 for accurately extracting retinal blood vessels against the clinical markings.

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Scope and costs of autorefraction and photoscreening for childhood amblyopia—a systematic narrative review in relation to the EUSCREEN project data

Eye ◽

10.1038/s41433-020-01261-8 ◽

2020 ◽

Author(s):

Anna M. Horwood ◽

◽

Helen J. Griffiths ◽

Jill Carlton ◽

Paolo Mazzone ◽

...

Keyword(s):

Cost Effectiveness ◽

Large Scale ◽

English Language ◽

Cost Effective ◽

Original Data ◽

Community Services ◽

Narrative Review ◽

Effective Option ◽

Automated Screening ◽

Project Data

Abstract Background Amblyopia screening can target reduced visual acuity (VA), its refractive risk factors, or both. VA testing is imprecise under 4 years of age, so automated risk-factor photoscreening appears an attractive option. This review considers photoscreening used in community services, focusing on costs, cost-effectiveness and scope of use, compared with EUSCREEN project Country Reports describing how photo- and automated screening is used internationally. Methods A systematic narrative review was carried out of all English language photoscreening literature to September 10th 2018, using publicly available search terms. Where costs were considered, a CASP economic evaluation checklist was used to assess data quality. Results Of 370 abstracts reviewed, 55 reported large-scale community photoscreening projects. Five addressed cost-effectiveness specifically, without original data. Photoscreening was a stand-alone, single, test event in 71% of projects. In contrast, 25 of 45 EUSCREEN Country Reports showed that if adopted, photoscreening often supplements other tests in established programmes and is rarely used as a stand-alone test. Reported costs varied widely and evidence of cost-effectiveness was sparse in the literature, or in international practice. Only eight (13%) papers compared the diagnostic accuracy or cost-effectiveness of photoscreening and VA testing, and when they did, cost-effectiveness of photoscreening compared unfavourably. Discussion Evidence that photoscreening reduces amblyopia or strabismus prevalence or improves overall outcomes is weak, as is evidence of cost-effectiveness, compared to later VA screening. Currently, the most cost-effective option seems to be a later, expert VA screening with the opportunity for a re-test before referral.

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