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Translational Vision Science &... Jun 2024Both hypertension and diabetes are known to increase the wall-to-lumen ratio (WLR) of retinal arterioles, but the differential effects are unknown. Here, we study the...
PURPOSE
Both hypertension and diabetes are known to increase the wall-to-lumen ratio (WLR) of retinal arterioles, but the differential effects are unknown. Here, we study the timing and relative impact of hypertension versus diabetes on the WLR in diabetic retinopathy (DR) to address this unresolved question.
METHODS
This prospective cross-sectional study compared the retinal arteriolar WLR in 17 healthy eyes, 15 with diabetes but no apparent DR (DM no DR), and 8 with diabetic macular edema (DME) and either nonproliferative or proliferative DR. We imaged each arteriole using adaptive optics scanning laser ophthalmoscopy and measured the WLR using ImageJ. Multiple linear regression (MLR) was performed to estimate the effects of hypertension, diabetes, and age on the WLR.
RESULTS
Both subjects with DM no DR and subjects with DME had significantly higher WLR than healthy subjects (0.36 ± 0.08 and 0.42 ± 0.08 vs. 0.29 ± 0.07, 1-way ANOVA P = 0.0009). MLR in healthy subjects and subjects with DM no DR showed hypertension had the strongest effect (regression coefficient = 0.08, P = 0.009), whereas age and diabetes were not significantly correlated with WLR. MLR in all three groups together (healthy, DM no DR, and DME) showed diabetes had the strongest effect (regression coefficient = 0.05, P = 0.02), whereas age and hypertension were not significantly correlated with WLR.
CONCLUSIONS
Hypertension may be an early driver of retinal arteriolar wall thickening in preclinical DR, independent of age or diabetes, whereas changes specific to DR may drive wall thickening in DME and later DR stages.
TRANSLATIONAL RELEVANCE
We offer a framework for understanding the relative contributions of hypertension and diabetes on the vascular wall, and emphasize the importance of hypertension control early in diabetes even before DR onset.
Topics: Humans; Cross-Sectional Studies; Male; Diabetic Retinopathy; Female; Middle Aged; Prospective Studies; Arterioles; Hypertension; Ophthalmoscopy; Aged; Adult; Retinal Artery; Macular Edema
PubMed: 38874974
DOI: 10.1167/tvst.13.6.8 -
BMC Ophthalmology Jun 2024Refractive errors, amblyopia, strabismus, and low vision are more common among children with hearing impairments in comparison with their hearing peers. Neglecting...
BACKGROUND AND AIM
Refractive errors, amblyopia, strabismus, and low vision are more common among children with hearing impairments in comparison with their hearing peers. Neglecting visual disorders can pose educational and social problems for these children. The present study aimed to assess the prevalence of refractive errors, amblyopia, strabismus, and low vision among hearing-impaired and deaf students in Kermanshah.
MATERIALS AND METHODS
A total of 79 deaf and hearing impaired students within the age range of 7-20 years (mean age of 15.01 ± 2.72) underwent optometric examinations, including autorefractometry, retinoscopy, ophthalmoscopy, slit lamp, visual acuity measurement, and cover-uncover test. Those who needed further evaluation were referred to the Ophthalmology Clinic of Imam Khomeini Hospital.
RESULTS
Regarding the prevalence of refractive errors, 32 (40.5%) subjects had one or a combination of refractive errors, the most common of which was astigmatism (36.7%), followed by amblyopia (15.1%). The most common type of strabismus was latent strabismus (heterophoria) (88.6%), followed by exophoria (81%). Moreover, 3 (3.7%) cases had nystagmus. A significant difference was observed between the prevalence of amblyopia and the degree of hearing loss (P = 0.026), and no significant difference was detected in other cases.
CONCLUSION
As evidenced by the obtained results, refractive errors, amblyopia, strabismus, and low vision are more prevalent among deaf and hearing-impaired children compared to normal children because deaf and hearing-impaired children are not able to convey their vision problems and need to compensate for their poor hearing with an enhanced sense of sight, inattention to these disorders can present these children with serious educational and social problems. Therefore, eye screening examinations are of paramount importance in deaf and hearing-impaired children.
Topics: Humans; Strabismus; Child; Adolescent; Male; Female; Refractive Errors; Vision, Low; Amblyopia; Prevalence; Young Adult; Visual Acuity; Iran; Cross-Sectional Studies; Persons With Hearing Impairments; Deafness; Students
PubMed: 38867144
DOI: 10.1186/s12886-024-03515-5 -
Scientific Reports Jun 2024This study tested if a high-resolution, multi-modal, multi-scale retinal imaging instrument can provide novel information about structural abnormalities in vivo. The...
This study tested if a high-resolution, multi-modal, multi-scale retinal imaging instrument can provide novel information about structural abnormalities in vivo. The study examined 11 patients with very mild to moderate non-proliferative diabetic retinopathy (NPDR) and 10 healthy subjects using fundus photography, optical coherence tomography (OCT), OCT angiography (OCTA), adaptive optics scanning laser ophthalmoscopy (AO-SLO), adaptive optics OCT and OCTA (AO-OCT(A)). Of 21 eyes of 11 patients, 11 had very mild NPDR, 8 had mild NPDR, 2 had moderate NPDR, and 1 had no retinopathy. Using AO-SLO, capillary looping, inflections and dilations were detected in 8 patients with very mild or mild NPDR, and microaneurysms containing hyperreflective granular elements were visible in 9 patients with mild or moderate NPDR. Most of the abnormalities were seen to be perfused in the corresponding OCTA scans while a few capillary loops appeared to be occluded or perfused at a non-detectable flow rate, possibly because of hypoperfusion. In one patient with moderate NPDR, non-perfused capillaries, also called ghost vessels, were identified by alignment of corresponding en face AO-OCT and AO-OCTA images. The combination of multiple non-invasive imaging methods could identify prominent microscopic abnormalities in diabetic retinopathy earlier and more detailed than conventional fundus imaging devices.
Topics: Humans; Tomography, Optical Coherence; Diabetic Retinopathy; Female; Male; Ophthalmoscopy; Middle Aged; Capillaries; Adult; Retinal Vessels; Aged; Fluorescein Angiography
PubMed: 38862584
DOI: 10.1038/s41598-024-63749-7 -
Biomedical Optics Express May 2024The use of "quality" to describe the usefulness of an image is ubiquitous but is often subject to domain specific constraints. Despite its continued use as an imaging...
The use of "quality" to describe the usefulness of an image is ubiquitous but is often subject to domain specific constraints. Despite its continued use as an imaging modality, adaptive optics scanning light ophthalmoscopy (AOSLO) lacks a dedicated metric for quantifying the quality of an image of photoreceptors. Here, we present an approach to evaluating image quality that extracts an estimate of the signal to noise ratio. We evaluated its performance in 528 images of photoreceptors from two AOSLOs, two modalities, and healthy or diseased retinas. The algorithm was compared to expert graders' ratings of the images and previously published image quality metrics. We found no significant difference in the SNR and grades across all conditions. The SNR and the grades of the images were moderately correlated. Overall, this algorithm provides an objective measure of image quality that closely relates to expert assessments of quality in both confocal and split-detector AOSLO images of photoreceptors.
PubMed: 38855680
DOI: 10.1364/BOE.516477 -
BioRxiv : the Preprint Server For... May 2024In response to central nervous system (CNS) injury, tissue resident immune cells such as microglia and circulating systemic neutrophils are often first responders. The...
In response to central nervous system (CNS) injury, tissue resident immune cells such as microglia and circulating systemic neutrophils are often first responders. The degree to which these cells interact in response to CNS damage is poorly understood, and even less so, in the neural retina which poses a challenge for high resolution imaging in vivo. In this study, we deploy fluorescence adaptive optics scanning light ophthalmoscopy (AOSLO) to study fluorescent microglia and neutrophils in mice. We simultaneously track immune cell dynamics using label-free phase-contrast AOSLO at micron-level resolution. Retinal lesions were induced with 488 nm light focused onto photoreceptor (PR) outer segments. These lesions focally ablated PRs, with minimal collateral damage to cells above and below the plane of focus. We used in vivo (AOSLO, SLO and OCT) imaging to reveal the natural history of the microglial and neutrophil response from minutes-to-months after injury. While microglia showed dynamic and progressive immune response with cells migrating into the injury locus within 1-day after injury, neutrophils were not recruited despite close proximity to vessels carrying neutrophils only microns away. Post-mortem confocal microscopy confirmed in vivo findings. This work illustrates that microglial activation does not recruit neutrophils in response to acute, focal loss of photoreceptors, a condition encountered in many retinal diseases.
PubMed: 38854151
DOI: 10.1101/2024.05.25.595864 -
Veterinary Ophthalmology Jun 2024To determine normal ocular parameters of the MacQueen's bustard (Chlamydotis macqueenii) and describe ophthalmic lesions in a captive bred population.
OBJECTIVES
To determine normal ocular parameters of the MacQueen's bustard (Chlamydotis macqueenii) and describe ophthalmic lesions in a captive bred population.
ANIMALS STUDIED
Captive breeding population of 257 Macqueen's bustards.
METHODS
All birds were screened for ocular abnormalities using direct ophthalmoscopy. Abnormalities were photographed. Normative values for Schirmer tear test-1 (STT-1), applanation tonometry, aerobic and anaerobic bacterial culture, fungal culture, and transcorneal ocular ultrasonography were derived from multiple cohorts of clinically normal adult birds. Five birds with ocular pathology also underwent transcorneal ultrasonography. Statistical comparisons for normative values between OD and OS, and males and females were made using a paired t-test or Mann-Whitney U-test, with a significance level of p < .05.
RESULTS
Mean tear production based on Schirmer tear test 1 (STT-1) was 10.16 ± 4.61 mm/min (3-21 mm/min). Mean intraocular pressure (IOP) was 12.42 ± 4.94 mm Hg (5-26 mm Hg). Staphylococcus species were the most isolated bacteria from the conjunctival surfaces of normal birds (85%). Significant differences were found in transcorneal ultrasonographic measurements between males and females for axial globe length (p = .032), vitreous body depth (p = .049) and lens thickness (p = .0428). Corneal fibrosis was the most observed ocular abnormality amongst eyes with pathological changes (39%).
CONCLUSIONS
Schirmer tear testing, tonometry and transcorneal ultrasound can easily be utilized in MacQueen's bustards and provide reproducible results. Normal parameters for these tests were determined, and common pathological ocular changes were described in this species.
PubMed: 38849703
DOI: 10.1111/vop.13247 -
Journal of Vision Jun 2024The spectral locus of unique yellow was determined for flashes of different sizes (<11 arcmin) and durations (<500 ms) presented in and near the fovea. An adaptive...
The spectral locus of unique yellow was determined for flashes of different sizes (<11 arcmin) and durations (<500 ms) presented in and near the fovea. An adaptive optics scanning laser ophthalmoscope was used to minimize the effects of higher-order aberrations during simultaneous stimulus delivery and retinal imaging. In certain subjects, parafoveal cones were classified as L, M, or S, which permitted the comparison of unique yellow measurements with variations in local L/M ratios within and between observers. Unique yellow shifted to longer wavelengths as stimulus size or duration was reduced. This effect is most pronounced for changes in size and more apparent in the fovea than in the parafovea. The observed variations in unique yellow are not entirely predicted from variations in L/M ratio and therefore implicate neural processes beyond photoreception.
Topics: Humans; Photic Stimulation; Retinal Cone Photoreceptor Cells; Fovea Centralis; Color Perception; Retina; Adult; Ophthalmoscopy
PubMed: 38833255
DOI: 10.1167/jov.24.6.2 -
Ophthalmic Genetics Jun 2024Occult macular dystrophy (OMD) is a cause of visual loss in young adults with a grossly normal fundus appearance. It is considered an autosomal dominant disorder,...
PURPOSE
Occult macular dystrophy (OMD) is a cause of visual loss in young adults with a grossly normal fundus appearance. It is considered an autosomal dominant disorder, related to heterozygous pathogenic variants in the gene . The purpose of this study is to report a biallelic form of the disease.
RESULTS
A 29-year-old female had undergone neurological workup and ophthalmic examinations for transient visual loss in her left eye over the past two years but there was no definitive diagnosis. The best-corrected visual acuity was 20/30, 20/20. Indirect ophthalmoscopy with a 78D lens revealed subtle central retinal pigment epithelium mottling and optical coherence tomography confirmed subtle central thickening of the ellipsoid zone. Full-field electroretinography was normal, but pattern electroretinography showed decreased p50 responses. OMD was suspected. Retinal gene panel testing was significant only for a homozygous variant in (NM_178857.6: c.3571 G>T; p.Glu1191*). The parents and older brother were unavailable for segregation analysis. By history they did not have visual complaints other than a need for glasses.
CONCLUSIONS
This report presents the clinical and genetic findings of a biallelic form of OMD associated with a novel pathogenic variant in . It would be of interest to carefully assess macular function in heterozygotes with this variant.
PubMed: 38831741
DOI: 10.1080/13816810.2024.2352376 -
Current Diabetes Reviews May 2024Diabetic Retinopathy is a vascular microvascular disease also called diabetic eye disease caused by microangiopathy leading to progressive damage of the retina and...
Diabetic Retinopathy is a vascular microvascular disease also called diabetic eye disease caused by microangiopathy leading to progressive damage of the retina and blindness. The uncontrolled blood glycemic level or sugar level results in diabetic retinopathy. There are two stages of diabetic retinopathy: proliferative diabetic retinopathy and nonproliferative diabetic retinopathy. Symptoms of diabetic retinopathy often have no early warning signs, even muscular edema, which can cause rapid vision loss. Macular edema in which the blood vessels leak can also occur at any stage of diabetic retinopathy. Symptoms are darkened or distorted images and blurred vision that are not the same in both eyes. This review study primarily discusses the pathophysiology, genetics, and ALR, AGEs, VEGF, EPO, and eNOS involved in diabetic retinopathy. The longer a person has diabetes, the higher their risk of developing some ocular problems. During pregnancy, diabetic retinopathy may also be a problem for women with diabetes. NIH are recommends that all pregnant women with diabetes have an overall eye examination. Diagnosis of diabetic retinopathy is made during an eye examination that comprises ophthalmoscopy or fundus photography, and glow-in angiography for Fundus. Here, we present a review of the current insights into pathophysiology in diabetic retinopathy, as well as clinical treatments for diabetic retinopathy patients. Novel laboratory findings and related clinical trials are also analysed.
PubMed: 38831577
DOI: 10.2174/0115733998296228240521151050