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Journal of Vision Mar 2021When the scotoma is binocular in macular degeneration (MD), it often obscures objects of interest, causing individuals to miss information. To map the binocular scotoma...
When the scotoma is binocular in macular degeneration (MD), it often obscures objects of interest, causing individuals to miss information. To map the binocular scotoma as precisely as current methods that map the monocular scotoma, we propose an iterative eye-tracker method. Study participants included nine individuals with MD and four age-matched controls. We measured the extent of the monocular scotomata using a scanning laser ophthalmoscope/optical coherence tomography (SLO/OCT). Then, we precisely mapped monocular and binocular scotomata with an eye tracker, while fixation was monitored. Participants responded whenever they detected briefly flashed dots, which were first presented on a coarse grid, and then at manually selected points to refine the shape and edges of the scotoma. Monocular scotomata measured in the SLO and eye tracker are highly similar, validating the eye-tracking method for scotoma mapping. Moreover, all participants used clustered fixation loci corresponding to their dominant preferred fixation locus. Critically, for individuals with binocular scotomata, the binocular map from the eye tracker was consistent with the overlap of the monocular scotoma profiles from the SLO. Thus, eye-tracker-based perimetry offers a reliable and sensitive tool for measuring both monocular and binocular scotomata, unlike the SLO/OCT that is limited to monocular viewing.
Topics: Aged; Case-Control Studies; Female; Humans; Macular Degeneration; Male; Middle Aged; Ophthalmoscopes; Scotoma; Tomography, Optical Coherence; Vision, Binocular; Visual Field Tests
PubMed: 33666643
DOI: 10.1167/jov.21.3.9 -
Frontiers in Cellular and Infection... 2021Slit lamps are routinely used to examine large numbers of patients every day due to high throughput. Previous, cultivation-based results suggested slit lamps to be...
Slit lamps are routinely used to examine large numbers of patients every day due to high throughput. Previous, cultivation-based results suggested slit lamps to be contaminated with bacteria, mostly coagulase-negative staphylococci, followed by micrococci, bacilli, but also . Our study aimed at obtaining a much more comprehensive, cultivation-independent view of the slit lamp bacteriota and its hygienic relevance, as regularly touched surfaces usually represent fomites, particularly if used by different persons. We performed extensive 16S rRNA gene sequencing to analyse the bacteriota, of 46 slit lamps from two tertiary care centers at two sampling sites, respectively. 82 samples yielded enough sequences for downstream analyses and revealed contamination with bacteria of mostly human skin, mucosa and probably eye origin, predominantly cutibacteria, staphylococci and corynebacteria. The taxonomic assignment of 3369 ASVs (amplicon sequence variants) revealed 19 bacterial phyla and 468 genera across all samples. As antibiotic resistances are of major concern, we screened all samples for methicillin-resistant (MRSA) using qPCR, however, no signals above the detection limit were detected. Our study provides first comprehensive insight into the slit lamp microbiota. It underlines that slit lamps carry a highly diverse, skin-like bacterial microbiota and that thorough cleaning and disinfection after use is highly recommendable to prevent eye and skin infections.
Topics: Humans; Methicillin-Resistant Staphylococcus aureus; RNA, Ribosomal, 16S; Slit Lamp; Staphylococcal Infections; Staphylococcus aureus
PubMed: 34869057
DOI: 10.3389/fcimb.2021.745653 -
The British Journal of Ophthalmology Apr 1948
Topics: Microscopy; Physical Examination; Slit Lamp
PubMed: 18170442
DOI: 10.1136/bjo.32.4.232 -
Transactions of the American... 1965
Topics: Ophthalmoscopes; Ophthalmoscopy
PubMed: 5859789
DOI: No ID Found -
Optics Express Jun 2020Poor access to eye care is a major global challenge that could be ameliorated by low-cost, portable, and easy-to-use diagnostic technologies. Diffuser-based imaging has...
Poor access to eye care is a major global challenge that could be ameliorated by low-cost, portable, and easy-to-use diagnostic technologies. Diffuser-based imaging has the potential to enable inexpensive, compact optical systems that can reconstruct a focused image of an object over a range of defocus errors. Here, we present a diffuser-based computational funduscope that reconstructs important clinical features of a model eye. Compared to existing diffuser-imager architectures, our system features an infinite-conjugate design by relaying the ocular lens onto the diffuser. This offers shift-invariance across a wide field-of-view (FOV) and an invariant magnification across an extended depth range. Experimentally, we demonstrate fundus image reconstruction over a 33 FOV and robustness to ±4D refractive error using a constant point-spread-function. Combined with diffuser-based wavefront sensing, this technology could enable combined ocular aberrometry and funduscopic screening through a single diffuser sensor.
Topics: Diagnostic Imaging; Equipment Design; Humans; Image Processing, Computer-Assisted; Light; Models, Theoretical; Ophthalmoscopes; Retina
PubMed: 32672237
DOI: 10.1364/OE.395112 -
BMC Ophthalmology Aug 2015Fungal keratitis is one of the major causes of infectious keratitis in tropical countries. Symptoms of fungal keratitis consist of blurred vision, redness, tearing,... (Review)
Review
BACKGROUND
Fungal keratitis is one of the major causes of infectious keratitis in tropical countries. Symptoms of fungal keratitis consist of blurred vision, redness, tearing, photophobia, pain and foreign body sensation. If not treated effectively, it could lead to blindness. Common causes include Candida spp., Fusarium spp. and Aspergillus spp.. With the limited choices of topical antifungal agents, we were faced with Cladosporium keratitis, a rare cause of fungal keratitis.
CASE PRESENTATION
A 62-year-old Asian male construction worker came to us with intense ocular pain, injection of the conjunctiva, blurred vision, and foreign body sensation in his left eye. His visual acuity was 20/40 OD and 20/400 OS. Slit-lamp exam revealed a corneal ulcer with feathery margin and Descemet's membrane folding. The culture yielded Cladosporium species.. The patient did not show improvements after applying topical natamycin (5 %), topical amphotericin B (1mg/ml), topical fluconazole (2mg/ml) and oral ketoconazole (200mg). After shifting the medical regimen to voriconazole via topical and systemic routes (1mg/ml and 200mg respectively), the keratitis was controlled.
CONCLUSIONS
Fungal keratitis remains a challenge for ophthalmologists as there is no evidence suggesting any particular drug or combination of drugs is more effective than another. A review of common topical antifungal agents was done. Voriconazole could be a good choice for treating corneal infection by Cladosporium species.
Topics: Administration, Topical; Antifungal Agents; Cladosporium; Corneal Ulcer; Eye Infections, Fungal; Humans; Male; Middle Aged; Mycoses; Slit Lamp; Visual Acuity; Voriconazole
PubMed: 26286482
DOI: 10.1186/s12886-015-0092-1 -
Arquivos de Neuro-psiquiatria May 2023The observation of the human retina began in 1851 after the invention of the first ophthalmoscope by the German physicist Hermann von Helmholtz. In the following...
The observation of the human retina began in 1851 after the invention of the first ophthalmoscope by the German physicist Hermann von Helmholtz. In the following decades, direct and indirect ophthalmoscopy, with the use of ophthalmoscopes and condensing lenses, respectively, became part of the clinical examination, especially in ophthalmology and neurology. Today, over 170 years later, many ophthalmoscopes and condensing lenses exist on the market. Nevertheless, ophthalmoscopy is still not widely adopted as part of the physical exam of general practitioners, and the teaching of ophthalmoscopy in medical school remains challenging. Studies have shown that students prefer using newer ophthalmoscope models or condensing lenses during training, but most do not feel confident in performing ophthalmoscopy afterwards, regardless of the models used. Also, few students acquire ophthalmoscopes for their future practice, and clinical trials have not clearly demonstrated superiority of newer ophthalmoscope models over the conventional ones in diagnostic accuracy. The technological improvement of smartphone cameras in recent years has made it feasible to photograph the fundus of the eye using ophthalmoscopes or condensing lenses, reducing the need for retinographs and similar equipment. Smartphone assisted indirect fundoscopy is becoming increasingly popular. This approach allows adequate identification of the structures of the fundus, is cost-efficient, easy to implement, and permits easy recording and sharing of the images obtained, which is useful for case discussions and medical teaching. However, controlled clinical trials validating this method in the evaluation of optic nerve pathologies are needed.
Topics: Humans; Smartphone; Ophthalmoscopy; Ophthalmoscopes; Fundus Oculi; Neurology
PubMed: 37257471
DOI: 10.1055/s-0043-1763489 -
International Journal of Computer... May 2022Intra-retinal delivery of novel sight-restoring therapies will require the precision of robotic systems accompanied by excellent visualisation of retinal layers....
PURPOSE
Intra-retinal delivery of novel sight-restoring therapies will require the precision of robotic systems accompanied by excellent visualisation of retinal layers. Intra-operative Optical Coherence Tomography (iOCT) provides cross-sectional retinal images in real time but at the cost of image quality that is insufficient for intra-retinal therapy delivery.This paper proposes a super-resolution methodology that improves iOCT image quality leveraging spatiotemporal consistency of incoming iOCT video streams.
METHODS
To overcome the absence of ground truth high-resolution (HR) images, we first generate HR iOCT images by fusing spatially aligned iOCT video frames. Then, we automatically assess the quality of the HR images on key retinal layers using a deep semantic segmentation model. Finally, we use image-to-image translation models (Pix2Pix and CycleGAN) to enhance the quality of LR images via quality transfer from the estimated HR domain.
RESULTS
Our proposed methodology generates iOCT images of improved quality according to both full-reference and no-reference metrics. A qualitative study with expert clinicians also confirms the improvement in the delineation of pertinent layers and in the reduction of artefacts. Furthermore, our approach outperforms conventional denoising filters and the learning-based state-of-the-art.
CONCLUSIONS
The results indicate that the learning-based methods using the estimated, through our pipeline, HR domain can be used to enhance the iOCT image quality. Therefore, the proposed method can computationally augment the capabilities of iOCT imaging helping this modality support the vitreoretinal surgical interventions of the future.
Topics: Cross-Sectional Studies; Humans; Retina; Slit Lamp; Tomography, Optical Coherence
PubMed: 35364774
DOI: 10.1007/s11548-022-02603-5 -
Translational Vision Science &... Apr 2024To assess the agreement of retinoscope-based peripheral refraction techniques with the criterion standard open-field autorefractor.
PURPOSE
To assess the agreement of retinoscope-based peripheral refraction techniques with the criterion standard open-field autorefractor.
METHODS
Fifty young adults (mean age, 24 ± 3 years) participated in this study. Two masked, experienced senior examiners carried out central refraction and peripheral refraction at the temporal 22° (T22°) and nasal 22° (N22°) eccentricities. Peripheral refraction techniques were (a) peripheral refraction using ancillary retinoscope component (P-ARC), (b) retinoscopy with eye rotation, and (c) open-field autorefractor. Peripheral refraction with retinoscopy values was compared with an open-field autorefractor (Shinn Nippon NVision-K) to assess the agreement. All measurements were taken from the right eye under noncycloplegic conditions.
RESULTS
The mean difference ±95% limits of agreement of peripheral refraction values obtained using P-ARC from T22° (+0.11 diopters [D] ± 1.20 D; P = 0.20) or N22° (+0.13 D ± 1.16 D; P = 0.13) were comparable with open-field autorefractor. The eye rotation technique compared to autorefractor showed a significant difference for T22° (+0.30 D ± 1.26 D; P = 0.002); however, there was an agreement for N22° (+0.14 D ± 1.16 D; P = 0.10). With respect to the identification of peripheral refraction patterns, examiners were able to identify relative peripheral hyperopia in most of the participants (77%).
CONCLUSIONS
Peripheral refraction with P-ARC was comparable with open-field autorefractor at T22° and N22° eccentricities. Peripheral retinoscopy techniques can be another approache for estimating and identifying peripheral refraction and its patterns in a regular clinical setting.
TRANSLATIONAL RELEVANCE
Retinoscope with P-ARC has high potential to guide and enable eye care practitioners to perform peripheral refraction and identify peripheral refraction patterns for effective myopia management.
Topics: Young Adult; Humans; Adult; Retinoscopes; Refraction, Ocular; Vision Tests; Eye; Hyperopia
PubMed: 38568607
DOI: 10.1167/tvst.13.4.7 -
Indian Journal of Ophthalmology Aug 2022The authors describe a novel technique of performing retinoscopy assisted with a smartphone (gimbalscope). We found this technique of digital retinoscopy to be useful...
The authors describe a novel technique of performing retinoscopy assisted with a smartphone (gimbalscope). We found this technique of digital retinoscopy to be useful for demonstrating and documenting retinoscopic reflexes and in addition as an easy teaching tool. This technical report explains the assembly of our smartphone-assisted retinoscope and provides examples of the range of normal and abnormal reflexes that can be captured.
Topics: Humans; Refraction, Ocular; Retinoscopes; Retinoscopy; Smartphone
PubMed: 35918982
DOI: 10.4103/ijo.IJO_221_22