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Veterinary Ophthalmology Nov 2023To investigate bacterial contamination of indirect ophthalmoscopes and condensing lenses used in three UK veterinary referral centers, and the impact of an implemented...
PURPOSE
To investigate bacterial contamination of indirect ophthalmoscopes and condensing lenses used in three UK veterinary referral centers, and the impact of an implemented cleaning protocol.
METHODS
Bacteriology samples from 10 indirect ophthalmoscopes and 10 condensing lenses were taken at each center (n = 30 T0), before initiating one of three cleaning frequencies (every 2 weeks/once weekly/daily) for 28 days. The most contaminated indirect ophthalmoscope and condensing lens from each center were re-sampled 30 min prior to (T1; n = 9) and 30 min after (T2; n = 9) the final clean. Sensitivity testing was completed using MIC.
RESULTS
Seventy-three isolates representing 15 different bacterial populations (genus/species) were cultured from 36 of 48 (75%) swabs tested. The most frequently cultured isolates were Staphylococcus spp. 30%, Micrococcus 22%, and Bacillus 14%. Pseudomonas aeruginosa, Pantoea, and Staphylococcus pseudintermedius demonstrated resistance to >50% of antibiotics against which they were tested. Eighty-three percent of T0 samples (54 isolates across 11 species, median 2 isolates/swab), all T1 samples (15 isolates across 8 species, median 2 isolates/swab), and 22% of T2 samples (4 isolates across 4 species, median 0 isolates/swab) were contaminated. Head contact points were most contaminated irrespective of time point. A T1 sample was 57 times more likely (95% CI: 2.4-1376) to have a positive culture than a T2 sample (p = .01).
CONCLUSIONS
Baseline contamination was high, representing a potential source of nosocomial infection in ophthalmic patients and handlers of diagnostic equipment. No center implemented a cleaning protocol prior to this study. Routine cleaning reduces bacterial contamination.
PubMed: 37985395
DOI: 10.1111/vop.13162 -
Translational Vision Science &... Nov 2023Adaptive optics scanning light ophthalmoscope (AOSLO) imaging offers a microscopic view of the living retina, holding promise for diagnosing and researching eye diseases...
PURPOSE
Adaptive optics scanning light ophthalmoscope (AOSLO) imaging offers a microscopic view of the living retina, holding promise for diagnosing and researching eye diseases like retinitis pigmentosa and Stargardt's disease. The technology's clinical impact of AOSLO hinges on early detection through automated analysis tools.
METHODS
We introduce Cone Density Estimation (CoDE) and CoDE for Diagnosis (CoDED). CoDE is a deep density estimation model for cone counting that estimates a density function whose integral is equal to the number of cones. CoDED is an integration of CoDE with deep image classifiers for diagnosis. We use two AOSLO image datasets to train and evaluate the performance of cone density estimation and classification models for retinitis pigmentosa and Stargardt's disease.
RESULTS
Bland-Altman plots show that CoDE outperforms state-of-the-art models for cone density estimation. CoDED reported an F1 score of 0.770 ± 0.04 for disease classification, outperforming traditional convolutional networks.
CONCLUSIONS
CoDE shows promise in classifying the retinitis pigmentosa and Stargardt's disease cases from a single AOSLO image. Our preliminary results suggest the potential role of analyzing patterns in the retinal cellular mosaic to aid in the diagnosis of genetic eye diseases.
TRANSLATIONAL RELEVANCE
Our study explores the potential of deep density estimation models to aid in the analysis of AOSLO images. Although the initial results are encouraging, more research is needed to fully realize the potential of such methods in the treatment and study of genetic retinal pathologies.
Topics: Humans; Ophthalmoscopy; Retinal Cone Photoreceptor Cells; Retina; Ophthalmoscopes; Retinitis Pigmentosa
PubMed: 37982767
DOI: 10.1167/tvst.12.11.25 -
Measuring macular pigment optical density using reflective images of confocal scanning laser system.Japanese Journal of Ophthalmology Jan 2024To develop a method to measure the macular pigment optical density (MPOD) using scanning laser ophthalmoscopic images in young adults and children.
PURPOSE
To develop a method to measure the macular pigment optical density (MPOD) using scanning laser ophthalmoscopic images in young adults and children.
STUDY DESIGN
Cross-sectional study.
METHODS
Blue light reflectance fundus images of 32 healthy subjects were used. A profile of the linear reflectance changes across the center of the fovea on a grayscale fundus image was generated. The ratio of the macula-to-periphery reflection was designated as the peak value of the MPOD (MPOD) based on established fundamentals. In the MPOD profile, the basal width of the pixels at MPOD < 0 (wMP) and width at one-half value of the MPOD (wMP) were determined. The MOPD at eccentricity of 0.5° was measured by heterochromatic flicker photometry (MPOD), and the correlation between the MPOD and MPOD was evaluated.
RESULTS
The MPOD ranged from 0.17 to 0.73 with a mean of 0.40 ± 0.13. The wMP ranged from 88 to 173 pixels with a mean of 121.7 ± 24.2 pixels, and the wMP ranged from 38 to 83 pixels with a mean of 54.1 ± 10.3 pixels. A significant correlation was found between the MPOD and MPOD (r = 0.41, P = 0.02).
CONCLUSIONS
This simplified method can provide accurate and reliable values of the MPOD comparable to heterochromatic flicker photometry. Obtaining the fundus images in this fast and easy way should be suitable for children thus enabling clinicians to determine the MPODs for children.
Topics: Young Adult; Child; Humans; Macular Pigment; Cross-Sectional Studies; Macula Lutea; Photometry; Lasers
PubMed: 37966565
DOI: 10.1007/s10384-023-01031-5 -
Experimental Eye Research Jan 2024This study aimed to examine the intraocular tolerability of the epidermal growth factor receptor antibody cetuximab, when applied intravitreally, and its effect on axial...
This study aimed to examine the intraocular tolerability of the epidermal growth factor receptor antibody cetuximab, when applied intravitreally, and its effect on axial elongation. Guinea pigs aged 2-3 weeks were subjected to bilateral plano glasses and bilateral lens-induced myopization (LIM) as a single procedure for group I (n = 8) and group II (n = 8), respectively. In the animals of group III (n = 8), group IV (n = 8), and group V (n = 8), the right eyes of the animals, in addition to LIM, received four weekly intravitreal injections of cetuximab (Erbitux®) in doses of 6.25 μg, 12.5 μg, and 25 μg, respectively. As controls, the left eyes, in addition to LIM, received corresponding intraocular injections of phosphate-buffered saline. The animals underwent regular ophthalmoscopic examinations and biometry for axial length measurements. With increasing doses of cetuximab, the inter-eye difference in axial elongation (at study end, left eyes minus right eyes) were significantly the smallest in group I (0.00 ± 0.02 mm) and group II (-0.01 ± 0.02 mm), they were larger in group III (0.04 ± 0.04 mm) and group IV (0.10 ± 0.03 mm), and they were the largest in group V (0.11 ± 0.01 mm). The inter-eye difference in axial elongation enlarged (P < 0.001) with the number of injections applied. Retinal thickness at the posterior pole (right eyes) was significantly thicker in group V than in group II (P < 0.01). The density of apoptotic cells (visualized by TUNEL-staining) did not vary significantly between any of the groups (all P > 0.05). The results suggest that intravitreal injections of cetuximab in young guinea pigs with LIM resulted in a reduction in axial elongation in a dose-dependent and number of treatment-dependent manner. Intraocular toxic effects, such as intraocular inflammation, retinal thinning, or an increased density of apoptotic cells in the retina, were not observed in association with the intravitreally applied cetuximab.
Topics: Guinea Pigs; Animals; Myopia; Cetuximab; Retina; Lens, Crystalline; Injections, Intraocular; Disease Models, Animal
PubMed: 37951338
DOI: 10.1016/j.exer.2023.109715 -
Health Science Reports Nov 2023To report the scope of optometry practice in Trinidad and Tobago to identify areas that need improvement.
BACKGROUND AND AIM
To report the scope of optometry practice in Trinidad and Tobago to identify areas that need improvement.
METHODS
A cross-sectional study of optometrists in Trinidad and Tobago was conducted using a validated self-structured questionnaire. Data obtained was exported to the Statistical Package for Social Sciences. Descriptive analysis and Pearson were used to summarize the demographic data and determine associations, respectively.
RESULT
A total of 63 optometrists participated in the study. Majority of them were females (69.8%, = 44), Christians (65.1%), East Indians (47.6%), and 30 years and below (66.7%). Most (87%) of them utilized routine optometric equipment in their clinical practice including autorefractors, retinoscopes, direct ophthalmoscopes, lensometers, phoropters, slit lamp biomicroscopes, trial lens boxes, and visual acuity chart projectors. A few of them have noncontact tonometer (4.8%), Volk lenses (1.6%), and perform color vision tests (1.6%). Fewer (12.7%, = 8) practitioners provided low-vision services. The use of pharmaceutical agents was prevalent among the participants (55.6%). Additionally, the provision of contact lenses was the most frequently practiced service among the participants (85.7%, = 54). A significant association was observed between the provision of low-vision services and sex ( = 0.03).
CONCLUSION
The scope of optometry practice in Trinidad and Tobago is in accordance with the basic guidelines set out by the World Council of Optometry but there is need to get more involved in the provision of low vision and other specialty services.
PubMed: 37920658
DOI: 10.1002/hsr2.1667 -
The Journal of International Medical... Oct 2023We report a case of human herpes virus 6 (HHV-6)- and human herpes virus 7 (HHV-7)-associated choroiditis in an immunocompromised woman. A 42-year-old Chinese woman with...
We report a case of human herpes virus 6 (HHV-6)- and human herpes virus 7 (HHV-7)-associated choroiditis in an immunocompromised woman. A 42-year-old Chinese woman with a history of acute myelogenous leukemia presented with blurred vision and black floaters in her right eye. Anterior segment examination findings were normal. Ophthalmoscopic examination revealed a subretinal lesion in the superonasal peripapillary region with several punctate hemorrhages. Optical coherence tomography showed a crater-like choroidal protuberance, associated with retinal pigment epithelium rupture and full-thickness retinal edema in the involved area. Indocyanine green angiography demonstrated a broad hypofluorescent lesion in the choroid. The patient was diagnosed with choroiditis. Subsequently, metagenomic next-generation sequencing revealed HHV-6B and HHV-7 DNA in the aqueous humor. Therefore, antiviral therapy was initiated. The patient experienced resolution of all symptoms and signs after treatment with intravenous foscarnet and oral acyclovir. The findings in this case indicate that HHV-6 and HHV-7 can cause ocular infection, particularly in immunocompromised patients.
Topics: Humans; Female; Adult; Herpesvirus 6, Human; Herpesvirus 7, Human; Choroiditis; Choroid; Leukemia, Myeloid, Acute; Tomography, Optical Coherence
PubMed: 37873767
DOI: 10.1177/03000605231204479 -
Experimental Eye Research Dec 2023Heimler syndrome (HS) is a rare autosomal recessive hereditary disease that is caused by biallelic variants in peroxisomal biogenic factor 1 gene (PEX1), peroxisomal...
Heimler syndrome (HS) is a rare autosomal recessive hereditary disease that is caused by biallelic variants in peroxisomal biogenic factor 1 gene (PEX1), peroxisomal biogenic factor 6 gene (PEX6) or peroxisomal biogenic factor 26 gene (PEX26), resulting in intracellular peroxisomal dysfunction (PBDs). We report a patient with HS with a new compound heterozygous PEX1 variant. Exon sequencing was used to screen pathologic variants in the patient. Retinal characteristics and serum metabolome alterations were evaluated. Scanning laser ophthalmoscope showed a large area of retinal choroidal atrophy at the posterior pole of the retina, with scattered patchy subretinal pigmentation. Optical coherence tomography showed fovea atrophy accompanied by retinal retinoschisis in the right eye and macular retinoschisis and edema in the left eye. The electroretinogram showed obviously reduced amplitudes of a-waves and b-waves under photopic and scotopic conditions in both eyes. Visual field tests showed a reduced central visual field in both eyes. Exon sequencing identified the compound heterozygous variant including c.2966T > C and c.1670+1G > T of the PEX1 gene, with the latter being novel. Nontargeted determination of total lipid metabolites and targeted determination of medium- and long-chain fatty acids in the serum of the patient and his healthy sibling were tested. This study identified a new compound heterozygous PEX1 variant, expanding our understanding of phenotypes in HS.
Topics: Humans; ATPases Associated with Diverse Cellular Activities; Retinoschisis; Retina; Atrophy; Membrane Proteins
PubMed: 37871882
DOI: 10.1016/j.exer.2023.109688 -
BMC Ophthalmology Oct 2023To investigate the diagnostic sensitivity of Optos imaging for vision degrading myodesopsia (VDM).
BACKGROUND
To investigate the diagnostic sensitivity of Optos imaging for vision degrading myodesopsia (VDM).
METHODS
A total of 420 eyes from 345 patients with VDM were collected in this cross-sectional study. All eyes were classified as having posterior vitreous detachment (PVD) or not having PVD. The sensitivity of Optos imaging for the visibility of vitreous floaters was evaluated. The associated factors with the visibility of vitreous floaters on Optos images were analyzed in univariate and multivariate logistic regression analyses.
RESULTS
The mean age of all patients was 56.19 ± 13.89 years old, and 66.67% of patients were female. The vitreous floaters were visible on the ultrasound B scan in all eyes, but only in 47.62% of Optos images (55.29% in eyes with PVD and 15% in eyes without PVD). In the multiple binary logistic regression analysis, age (OR = 1.094, 95%CI = 1.063-1.125, P < 0.001), spherical equivalent (OR = 0.869, 95%CI = 0.791-0.955, P = 0.004) and the distance of the floaters from the retina (OR = 1.191, 95%CI = 1.059-1.339, P = 0.003) were significantly correlated with the visibility of vitreous floaters on Optos images. On Optos images, 25.71% of VDM eyes presented additional retinal abnormalities.
CONCLUSIONS
Optos imaging has a low sensitivity for vitreous floaters, particularly in eyes without PVD. On Optos imaging, floaters were more visible in older patients, eyes with greater myopia, and floaters that were further from the retina.
Topics: Humans; Female; Aged; Adult; Middle Aged; Male; Cross-Sectional Studies; Vitreous Body; Eye Diseases; Vitreous Detachment; Ophthalmoscopes; Lasers
PubMed: 37864149
DOI: 10.1186/s12886-023-03166-y -
Hybrid spiral scanning in a double-clad fiber-based handheld confocal scanning light ophthalmoscope.Biomedical Optics Express Oct 2023High-speed, accessible, and robust imaging of the human retina is critical for screening of retinal pathologies, such as diabetic retinopathy, age-related macular...
High-speed, accessible, and robust imaging of the human retina is critical for screening of retinal pathologies, such as diabetic retinopathy, age-related macular degeneration, and others. Scanning light ophthalmoscopy (SLO) is a retinal imaging modality that produces digital, images of the human retina with superior image gradability rates when compared to the current standard of care in screening for these diseases, namely the flood-illumination handheld fundus camera (HFC). However, current-generation commercial SLO systems are mostly tabletop devices, limiting their accessibility and utility in screening applications. Moreover, most existing SLO systems use raster scan patterns, which are both inefficient and lead to undesired subject gaze drift when used with visible or pseudo-visible illumination. Non-raster scan patterns, especially spiral scanning as described herein, promise advantages in both scan efficiency and reduced subject eye motion. In this work, we introduce a novel "hybrid spiral" scan pattern and the associated hardware design and real-time image reconstruction techniques necessary for its implementation in an SLO system. Building upon this core hybrid spiral scanning SLO (HSS-SLO) technology, we go on to present a complete handheld HSS-SLO system, featuring a fiber-coupled portable patient interface which leverages a dual-clad fiber (DCF) to form a single-path optical topology, thus ensuring mechanically robust co-alignment of illumination and collection apertures, a necessity for a handheld system. The feasibility of HSS-SLO for handheld, imaging is demonstrated by imaging eight human volunteers.
PubMed: 37854550
DOI: 10.1364/BOE.500608