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ELife Oct 2020Our recent work characterized the movement of single blood cells within the retinal vasculature (Joseph et al. 2019) using adaptive optics ophthalmoscopy. Here, we apply...
Our recent work characterized the movement of single blood cells within the retinal vasculature (Joseph et al. 2019) using adaptive optics ophthalmoscopy. Here, we apply this technique to the context of acute inflammation and discover both infiltrating and tissue-resident immune cells to be visible without any labeling in the living mouse retina using near-infrared light alone. Intravital imaging of immune cells can be negatively impacted by surgical manipulation, exogenous dyes, transgenic manipulation and phototoxicity. These confounds are now overcome, using phase contrast and time-lapse videography to reveal the dynamic behavior of myeloid cells as they interact, extravasate and survey the mouse retina. Cellular motility and differential vascular responses were measured noninvasively and in vivo across hours to months at the same retinal location, from initiation to the resolution of inflammation. As comparable systems are already available for clinical research, this approach could be readily translated to human application.
Topics: Animals; Diagnostic Imaging; Eye Diseases; Male; Mice; Mice, Inbred C57BL; Ophthalmoscopes; Ophthalmoscopy; Optics and Photonics; Retinal Vessels
PubMed: 33052099
DOI: 10.7554/eLife.60547 -
Medical Education Online Dec 2023To evaluate the effectiveness of smartphone ophthalmoscope (SO) in teaching ophthalmoscopy, compared with direct ophthalmoscope (DO). In this cross-over study, 45... (Randomized Controlled Trial)
Randomized Controlled Trial
To evaluate the effectiveness of smartphone ophthalmoscope (SO) in teaching ophthalmoscopy, compared with direct ophthalmoscope (DO). In this cross-over study, 45 final-year medical students attending sessions at a single institution were randomly allocated to two groups (A and B). Both groups attended two training sessions. In the first session, Group A students were taught ophthalmoscopy using DO and Group B students using SO. In the second session, the training sessions were crossed over. A series of eye models with 10 letters placed on the inner surface were designed to assess the students' skill on ophthalmoscopy. Students performed ophthalmoscopy on the eye models, recorded their findings, and completed a questionnaire of feedback on DO and SO. The main outcome measure was the score of ophthalmoscopy, assessed by the student correctly recording each letter (score 1 for each letter). For Group A, the mean score of ophthalmoscopy on the eye model using DO and SO was 3.9±2.4 and 8.2±2.2, respectively. For Group B, the mean score of ophthalmoscopy on the eye model using SO and DO 8.7±1.8 and 5.7±3.5 . Students scored significantly higher in ophthalmoscopy when using SO than DO (<0.001). They expressed better visualization of the fundus using SO than DO (4.49±0.65 vs 4.13±0.81, =0.004). Students' performance of ophthalmoscopy was better when SO was used compared with DO. The use of SO as an adjunctive tool is recommended to improve the effectiveness of teaching ophthalmoscopy.
Topics: Humans; Smartphone; Cross-Over Studies; Ophthalmology; Ophthalmoscopy; Ophthalmoscopes; Students, Medical; Teaching
PubMed: 36762913
DOI: 10.1080/10872981.2023.2176201 -
Indian Journal of Ophthalmology Apr 2022The emergence of smartphone-based imaging devices has been a boon in the field of ophthalmology, especially in obtaining high-quality ocular images. They can be...
The emergence of smartphone-based imaging devices has been a boon in the field of ophthalmology, especially in obtaining high-quality ocular images. They can be specialized and utilized for imaging-specific regions of the eye. Among the multitude of applications of smartphone-based imaging, one of the upcoming major use is to image the microbiological world. Previous few reports have described attaching magnifying lenses of various types to the smartphone camera and transforming it into a microscope for imaging fungal hyphae and ocular surface parasites. We describe a novel technique of attaching the smartphone-based intraocular lens microscope (IOLSCOPE) to the slit lamp, thereby utilizing the slit lamp joystick for moving the smartphone over the concerned slide specimen to make it steady and obtain images of high resolution. This innovative do-it-yourself novel modification is especially useful in peripheral centers, vision centers, and local clinics for immediate screening and identification of microbial pathogens such as fungi and ocular surface parasites.
Topics: Humans; Lenses, Intraocular; Microscopy; Slit Lamp; Slit Lamp Microscopy; Smartphone
PubMed: 35326059
DOI: 10.4103/ijo.IJO_2389_21 -
Clinical & Experimental Optometry Nov 2017The aim was to determine the prevalence of convergence insufficiency and its relationship with age, gender and refractive error in a population-based study.
PURPOSE
The aim was to determine the prevalence of convergence insufficiency and its relationship with age, gender and refractive error in a population-based study.
METHODS
In this cross-sectional study, all residents over one year old in Mashhad city, in the north east of Iran, were sampled through random stratified cluster sampling. After selecting samples and their participation in the study, they all had eye examinations including the measurement of visual acuity, refraction, binocular vision assessment, including cover test, measurement of near point of convergence and fusional vergences and finally, slitlamp biomicroscopy.
RESULTS
Of the 4,453 selected people, 3,132 participated in the study and finally, analyses were done with data from 2,219 individuals. The mean age of the participants was 30.5 ± 14.0 years (range: 10 to 69). The prevalence of convergence insufficiency in this study was 5.51 per cent (range: 4.51 to 6.52): 4.78 per cent (range: 3.11 to 6.45) in males and 5.86 per cent (range: 4.60 to 7.11) in females (p = 0.276). Convergence insufficiency prevalence in different age groups showed no significant linear trend; however, a significant increase was observed after the age of 60 years. The prevalence of myopia, emmetropia and hyperopia was respectively 12.1, 56.9 and 31 per cent in participants with convergence insufficiency and 15.9, 54.4 and 29.6 per cent in those without convergence insufficiency (p = 0.537). Multiple logistic regression models revealed no significant relationship between the prevalence of convergence insufficiency and age, gender or refractive errors.
CONCLUSION
This study showed that the overall prevalence of convergence insufficiency in the Iranian population was 5.46 per cent, which is lower than that in the majority of previous studies. Convergence insufficiency prevalence had no significant change with age up to the age of 60 years but increased significantly after 60 years.
Topics: Adolescent; Adult; Age Distribution; Aged; Aged, 80 and over; Child; Cross-Sectional Studies; Female; Humans; Iran; Male; Middle Aged; Ocular Motility Disorders; Prevalence; Refractive Errors; Sex Distribution; Slit Lamp; Young Adult
PubMed: 28222490
DOI: 10.1111/cxo.12522 -
American Journal of Ophthalmology Oct 2011To correlate macular structural changes by spectral-domain optical coherence tomography (SD-OCT) with functional changes by scanning laser ophthalmoscope (SLO)... (Comparative Study)
Comparative Study
PURPOSE
To correlate macular structural changes by spectral-domain optical coherence tomography (SD-OCT) with functional changes by scanning laser ophthalmoscope (SLO) microperimetry testing in patients with sickle cell hemoglobinopathies.
DESIGN
Prospective, investigational study.
METHODS
Patients with electrophoretic confirmation of sickle cell hemoglobinopathies and normal subjects underwent SD-OCT and microperimetry testing with the OPKO Spectral OCT/SLO instrument. Based on SD-OCT findings, patients were grouped into those with focal macular thinning (Group A) and those without (Group B). Main outcome measure were mean retinal sensitivities measured by microperimetry and mean macular thicknesses in the 9 Early Treatment Diabetic Retinopathy Study (ETDRS)-like subfields.
RESULTS
Thirty-seven eyes of 19 patients with sickle cell hemoglobinopathies (SS, SC, and S-thalassemia) and 34 eyes of 34 age-similar normal controls were included. Mean age and mean logMAR best-corrected visual acuity between Groups A and B were not statistically different (39.7 years vs 36.5 years, P = .64 and 0.015 vs 0.016, P = .93, respectively). Group A had significantly thinner retinas compared to Group B in the parafoveal superior (P = .019), parafoveal temporal (P < .004), parafoveal inferior (P = .003), perifoveal superior (P = .04), perifoveal temporal (P = .0005), and perifoveal inferior (P = .045) subfields. The overall mean microperimetry retinal sensitivities of Group A were significantly less than those of Group B (14.2 dB vs 16.5 dB, P = .00005). However, there was no statistical difference between Group B and controls (16.5 dB vs 16.7 dB, P = .63).
CONCLUSION
Sickle cell patients with focal macular thinning present on SD-OCT have significantly decreased retinal sensitivities compared to those without focal thinning or normal controls based on mean microperimetry sensitivities, despite similar age and visual acuity. Microperimetry is a sensitive measurement of macular function in patients with sickle cell hemoglobinopathies.
Topics: Adult; Aged; Anemia, Sickle Cell; Humans; Lasers; Middle Aged; Ophthalmoscopes; Prospective Studies; Retina; Retinal Diseases; Tomography, Optical Coherence; Visual Acuity; Visual Field Tests; Visual Fields; Young Adult
PubMed: 21726848
DOI: 10.1016/j.ajo.2011.03.035 -
The Journal of Clinical Investigation Jan 2022BackgroundNoninvasive assessment of metabolic processes that sustain regeneration of human retinal visual pigments (visual cycle) is essential to improve ophthalmic...
BackgroundNoninvasive assessment of metabolic processes that sustain regeneration of human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and to accelerate development of new treatments to counter retinal diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates of these processes, are highly sensitive to UV light; thus, safe analyses of these processes in humans are currently beyond the reach of even the most modern ocular imaging modalities.MethodsWe present a compact, 2-photon-excited fluorescence scanning laser ophthalmoscope and spectrally resolved images of the human retina based on 2-photon excitation (TPE) with near-infrared light. A custom Er:fiber laser with integrated pulse selection, along with intelligent postprocessing of data, enables excitation with low laser power and precise measurement of weak signals.ResultsWe demonstrate spectrally resolved TPE fundus images of human subjects. Comparison of TPE data between human and mouse models of retinal diseases revealed similarity with mouse models that rapidly accumulate bisretinoid condensation products. Thus, visual cycle intermediates and toxic byproducts of this metabolic pathway can be measured and quantified by TPE imaging.ConclusionOur work establishes a TPE instrument and measurement method for noninvasive metabolic assessment of the human retina. This approach opens the possibility for monitoring eye diseases in the earliest stages before structural damage to the retina occurs.FundingNIH, Research to Prevent Blindness, Foundation for Polish Science, European Regional Development Fund, Polish National Agency for Academic Exchange, and Polish Ministry of Science and Higher Education.
Topics: Animals; Disease Models, Animal; Female; Humans; Male; Mice; Mice, Knockout; Middle Aged; Ophthalmoscopes; Optical Imaging; Retina; Retinal Diseases
PubMed: 34847075
DOI: 10.1172/JCI154218 -
Scientific Reports Jan 2016Mutations in collagen, type IV, alpha 1 (COL4A1), a major component of basement membranes, cause multisystem disorders in humans and mice. In the eye, these include...
Mutations in collagen, type IV, alpha 1 (COL4A1), a major component of basement membranes, cause multisystem disorders in humans and mice. In the eye, these include anterior segment dysgenesis, optic nerve hypoplasia and retinal vascular tortuosity. Here we investigate the retinal pathology in mice carrying dominant-negative Col4a1 mutations. To this end, we examined retinas longitudinally in vivo using fluorescein angiography, funduscopy and optical coherence tomography. We assessed retinal function by electroretinography and studied the retinal ultrastructural pathology. Retinal examinations revealed serous chorioretinopathy, retinal hemorrhages, fibrosis or signs of pathogenic angiogenesis with chorioretinal anastomosis in up to approximately 90% of Col4a1 mutant eyes depending on age and the specific mutation. To identify the cell-type responsible for pathogenesis we generated a conditional Col4a1 mutation and determined that primary vascular defects underlie Col4a1-associated retinopathy. We also found focal activation of Müller cells and increased expression of pro-angiogenic factors in retinas from Col4a1(+/Δex41)mice. Together, our findings suggest that patients with COL4A1 and COL4A2 mutations may be at elevated risk of retinal hemorrhages and that retinal examinations may be useful for identifying patients with COL4A1 and COL4A2 mutations who are also at elevated risk of hemorrhagic strokes.
Topics: Animals; Collagen Type IV; Disease Models, Animal; Disease Progression; Mice; Mice, Knockout; Mutation; Ophthalmoscopes; Phenotype; Retina; Retinal Diseases; Tomography, Optical Coherence
PubMed: 26813606
DOI: 10.1038/srep18602 -
Optics Express Jun 2009We have developed a compact retinal imager that integrates adaptive optics (AO) into a line scanning ophthalmoscope (LSO). The bench-top AO-LSO instrument significantly...
We have developed a compact retinal imager that integrates adaptive optics (AO) into a line scanning ophthalmoscope (LSO). The bench-top AO-LSO instrument significantly reduces the size, complexity, and cost of research AO scanning laser ophthalmoscopes (AOSLOs), for the purpose of moving adaptive optics imaging more rapidly into routine clinical use. The AO-LSO produces high resolution retinal images with only one moving part and a significantly reduced instrument footprint and number of optical components. The AO-LSO has a moderate field of view (5.5 deg), which allows montages of the macula or other targets to be obtained more quickly and efficiently. In a preliminary human subjects investigation, photoreceptors could be resolved and counted within approximately 0.5 mm of the fovea. Photoreceptor counts matched closely to previously reported histology. The capillaries surrounding the foveal avascular zone could be resolved, as well as cells flowing within them. Individual nerve fiber bundles could be resolved, especially near the optic nerve head, as well as other structures such as the lamina cribrosa. In addition to instrument design, fabrication, and testing, software algorithms were developed for automated image registration and cone counting.
Topics: Computer-Aided Design; Equipment Design; Equipment Failure Analysis; Lenses; Microscopy, Confocal; Miniaturization; Ophthalmoscopes; Pilot Projects; Reproducibility of Results; Sensitivity and Specificity
PubMed: 19506678
DOI: 10.1364/oe.17.010242 -
Clinical & Experimental Optometry Mar 2010
Topics: Female; Fovea Centralis; Humans; Ophthalmoscopes; Optic Disk; Retinitis Pigmentosa; Severity of Illness Index; Visual Fields; Young Adult
PubMed: 20406260
DOI: 10.1111/j.1444-0938.2009.00435.x -
The British Journal of Ophthalmology Oct 1954
Topics: Contact Lenses; Humans; Lenses; Ophthalmoscopes; Ophthalmoscopy
PubMed: 13199234
DOI: 10.1136/bjo.38.10.626