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IEEE Transactions on Bio-medical... Jun 2024This paper aims at quantifying biomarkers from the segmentation of retinal arteries in adaptive optics ophthalmoscopy images (AOO).
OBJECTIVE
This paper aims at quantifying biomarkers from the segmentation of retinal arteries in adaptive optics ophthalmoscopy images (AOO).
METHODS
The segmentation is based on the combination of deep learning and knowledge-driven deformable models to achieve a precise segmentation of the vessel walls, with a specific attention to bifurcations. Biomarkers (junction coefficient, branching coefficient, wall to lumen ratio (wlr) are derived from the resulting segmentation.
RESULTS
reliable and accurate segmentations (mse = 1.75 ± 1.24 pixel) and measurements are obtained, with high reproducibility with respect to images acquisition and users, and without bias.
SIGNIFICANCE
In a preliminary clinical study of patients with a genetic small vessel disease, some of them with vascular risk factors, an increased wlr was found in comparison to a control population.
CONCLUSION
The wlr estimated in AOO images with our method (AOV, Adaptive Optics Vessel analysis) seems to be a very robust biomarker as long as the wall is well contrasted.
PubMed: 38829761
DOI: 10.1109/TBME.2024.3408232 -
BMJ Open May 2024To determine the prevalence, causes and risk factors associated with visual impairment (VI) in the Nirmal district of Telangana, India, using extended Rapid Assessment...
OBJECTIVE
To determine the prevalence, causes and risk factors associated with visual impairment (VI) in the Nirmal district of Telangana, India, using extended Rapid Assessment of Visual Impairment (RAVI) methodology.
DESIGN
Cross-sectional study.
SETTING
Community setting.
PARTICIPANTS
Participants aged ≥16 years were enumerated from 90 randomly selected clusters and 4629/5400 (85.7%) participants were examined. Presenting visual acuity (VA) was assessed using a Snellen chart with E optotypes at a 6 m distance. Near vision was assessed binocularly using an N notation chart with tumbling E optotypes at a 40 cm distance. An anterior segment examination done followed by distance direct ophthalmoscopy at 50 cm. Non-mydriatic fundus images were obtained. VI was defined as presenting VA worse than 6/12 in the better eye. The prevalence of VI in the current study was compared with a RAVI study conducted in 2014 to assess the trends in VI among those aged ≥40 years.
PRIMARY OUTCOME
Prevalence, causes and risk factors for VI.
RESULTS
Among those examined, 55% were women, 53% had at least school-level education, 2.3% self-reported diabetes and 8.7% self-reported hypertension. The prevalence of VI was 8.81% (95% CI 8.01% to 9.67%). Overall, uncorrected refractive errors (49.5%) were the leading cause of VI, followed by cataracts (40.2%) and posterior segment diseases (4.9%). Among those aged ≥40 years, the prevalence of VI declined by 19.3% compared with the 2014 baseline study (from 20.2% to 16.3%; p<0.01).
CONCLUSION
The extended RAVI study conducted in the Nirmal district showed a considerable decline in the prevalence of VI. Targeted interventions are needed to provide adequate eye care for the high-risk groups in this district.
Topics: Humans; Cross-Sectional Studies; India; Female; Male; Middle Aged; Adult; Prevalence; Risk Factors; Aged; Young Adult; Adolescent; Visual Acuity; Vision Disorders; Cataract
PubMed: 38816051
DOI: 10.1136/bmjopen-2023-083199 -
BMC Ophthalmology May 2024Macular retinoschisis (MRS) and myopic macular neovascularization (mMNV) are both potentially blinding complications of high myopia. In this case report, we highlight... (Review)
Review
BACKGROUND
Macular retinoschisis (MRS) and myopic macular neovascularization (mMNV) are both potentially blinding complications of high myopia. In this case report, we highlight the progression of MRS after intravitreal anti-vascular endothelial growth factor (anti-VEGF) treatment for mMNV, as well as an extensive review of the literature on this topic.
CASE DESCRIPTION
A 49-year-old woman presented with two weeks of recent onset blurring and metamorphopsia in her right eye. She had high myopia in both eyes (right eye - 20/60 with - 16D, left eye - 20/20 with - 13D). Slit-lamp ophthalmoscopy found a normal anterior segment in both eyes. On fundus examination, features of pathological myopia with posterior staphyloma and peripapillary atrophy were observed in both eyes. An active mMNV, as well as intraretinal fluid, minimal perifoveal inner and outer MRS, and focal posterior vitreous traction along the inferotemporal retinal arcade, were detected on optical coherence tomography (OCT) of the right eye. The patient received an intravitreal injection of Aflibercept (2 mg/0.05 ml).
RESULTS
OCT scans at two- and four-month follow-up visits revealed regressed mMNV with a taut epiretinal membrane, progressive worsening of outer MRS, and the development of multiple perifoveal retinal detachment inferior to the fovea. Pars plana vitrectomy surgery was performed for the progressive MRS with good anatomical (resolved MRS) and functional outcome (maintained visual acuity at 20/60) at the last one-month post-surgery visit.
CONCLUSION
Intravitreal anti-VEGF injections for mMNV can cause vitreoretinal interface changes, exacerbating MRS and causing visual deterioration. Vitrectomy for MRS could be one of several treatment options.
Topics: Humans; Receptors, Vascular Endothelial Growth Factor; Female; Intravitreal Injections; Middle Aged; Retinoschisis; Recombinant Fusion Proteins; Myopia, Degenerative; Tomography, Optical Coherence; Visual Acuity; Angiogenesis Inhibitors; Disease Progression; Retinal Neovascularization; Fluorescein Angiography
PubMed: 38807066
DOI: 10.1186/s12886-024-03497-4 -
The British Journal of Ophthalmology May 2024To evaluate the capabilities and incapabilities of a GPT-4V(ision)-based chatbot in interpreting ocular multimodal images.
PURPOSE
To evaluate the capabilities and incapabilities of a GPT-4V(ision)-based chatbot in interpreting ocular multimodal images.
METHODS
We developed a digital ophthalmologist app using GPT-4V and evaluated its performance with a dataset (60 images, 60 ophthalmic conditions, 6 modalities) that included slit-lamp, scanning laser ophthalmoscopy, fundus photography of the posterior pole (FPP), optical coherence tomography, fundus fluorescein angiography and ocular ultrasound images. The chatbot was tested with ten open-ended questions per image, covering examination identification, lesion detection, diagnosis and decision support. The responses were manually assessed for accuracy, usability, safety and diagnosis repeatability. Auto-evaluation was performed using sentence similarity and GPT-4-based auto-evaluation.
RESULTS
Out of 600 responses, 30.6% were accurate, 21.5% were highly usable and 55.6% were deemed as no harm. GPT-4V performed best with slit-lamp images, with 42.0%, 38.5% and 68.5% of the responses being accurate, highly usable and no harm, respectively. However, its performance was weaker in FPP images, with only 13.7%, 3.7% and 38.5% in the same categories. GPT-4V correctly identified 95.6% of the imaging modalities and showed varying accuracies in lesion identification (25.6%), diagnosis (16.1%) and decision support (24.0%). The overall repeatability of GPT-4V in diagnosing ocular images was 63.3% (38/60). The overall sentence similarity between responses generated by GPT-4V and human answers is 55.5%, with Spearman correlations of 0.569 for accuracy and 0.576 for usability.
CONCLUSION
GPT-4V currently is not yet suitable for clinical decision-making in ophthalmology. Our study serves as a benchmark for enhancing ophthalmic multimodal models.
PubMed: 38789133
DOI: 10.1136/bjo-2023-325054 -
Indian Journal of Ophthalmology Jul 2024To study ultra-widefield indocyanine green angiography (ICGA) patterns in central serous chorioretinopathy (CSC). (Observational Study)
Observational Study
PURPOSE
To study ultra-widefield indocyanine green angiography (ICGA) patterns in central serous chorioretinopathy (CSC).
METHODS
A cross-sectional observational study was undertaken on 30 patients aged 20 to 60 years with CSC at the retina clinic of a tertiary care center. Of them, 43 eyes were affected by CSC, whereas 17 eyes were unaffected as the bilateral disease was observed in 13 patients. All patients were evaluated for best-corrected visual acuity, intraocular pressure, detailed slit-lamp bio-microscopy, indirect ophthalmoscopy, ultra-widefield imaging for pseudo color photograph, fundus autofluorescence (FAF), fundus fluorescein angiography (FFA), and ICGA, and macular swept-source optical coherence tomography (SSOCT) characteristics.
RESULTS
The mean age of patients was 41.43 ± 8.81 years (range: 25-59 years). The median log MAR visual acuity in CSC eyes was 0.30 (range: 0.17-1.0), whereas it was 0 in non-CSC fellow eyes ( P < 0.001). Pachy-vessels and late hyperpermeability on ultra-widefield ICGA were observed in all eyes. Vortex vein anastomosis was present in 93% of the affected eyes versus 88.2% in unaffected fellow eyes ( P = 0.61). Disc and posterior poles were the sites of the maximum number of anastomoses in both affected and unaffected eyes ( P = 0.77). Asymmetry in vortex vein drainage of the macula was present in 88.4% of affected eyes and 88.2% of unaffected eyes.
CONCLUSION
Studying the ICGA findings in CSC patients emphasized the role of choroidal circulation in pathogenesis as Pachy vessels were observed in all eyes affected with CSC and even fellow eyes of patients. Vortex vein anastomosis around the disc or posterior pole and asymmetric drainage from the macula were noted and could be contributing to CSC pathology.
Topics: Humans; Central Serous Chorioretinopathy; Fluorescein Angiography; Adult; Middle Aged; Female; Male; Cross-Sectional Studies; Indocyanine Green; Coloring Agents; Tomography, Optical Coherence; Visual Acuity; Fundus Oculi; Young Adult; Choroid; Retinal Vessels
PubMed: 38770620
DOI: 10.4103/IJO.IJO_1852_23 -
The National Medical Journal of India 2023Background Fundus examination is an integral part of the clinical evaluation of patients with medical emergencies. It is done at the bedside using a portable direct...
Background Fundus examination is an integral part of the clinical evaluation of patients with medical emergencies. It is done at the bedside using a portable direct ophthalmoscope. Smartphone fundus photography (SFP) is a novel technique of retinal imaging. We evaluated the use of SFP by a physician in medical emergencies and compared it with direct ophthalmoscopy (DO) findings of the ophthalmologist. Methods We did a prospective study on patients admitted with medical emergencies with an indication for fundus examination. The SFP was done by the physician, and its findings were noted. These were compared with the DO findings of the ophthalmologist. Results Of the 182 patients studied, 111 (61%) had fundus findings by SFP and 95 (52.5%) by DO. Papilloedema (21.4%), haemorrhages (20%) and Roth spots (12.5%) were most common. DO missed early papilloedema and findings in the peripheral retina. Conclusions SFP is as effective as DO, in detecting retinal findings in patients with medical emergencies and can be performed at the bedside by the physician.
Topics: Humans; Smartphone; Photography; Cross-Sectional Studies; Male; Female; Prospective Studies; Adult; Emergencies; Ophthalmoscopy; Middle Aged; Fundus Oculi; Retinal Diseases; Aged; Young Adult; Adolescent; Papilledema
PubMed: 38759976
DOI: 10.25259/NMJI_208_21 -
Progress in Retinal and Eye Research Jul 2024The retina is an emerging CNS target for potential noninvasive diagnosis and tracking of Alzheimer's disease (AD). Studies have identified the pathological hallmarks of... (Review)
Review
The retina is an emerging CNS target for potential noninvasive diagnosis and tracking of Alzheimer's disease (AD). Studies have identified the pathological hallmarks of AD, including amyloid β-protein (Aβ) deposits and abnormal tau protein isoforms, in the retinas of AD patients and animal models. Moreover, structural and functional vascular abnormalities such as reduced blood flow, vascular Aβ deposition, and blood-retinal barrier damage, along with inflammation and neurodegeneration, have been described in retinas of patients with mild cognitive impairment and AD dementia. Histological, biochemical, and clinical studies have demonstrated that the nature and severity of AD pathologies in the retina and brain correspond. Proteomics analysis revealed a similar pattern of dysregulated proteins and biological pathways in the retina and brain of AD patients, with enhanced inflammatory and neurodegenerative processes, impaired oxidative-phosphorylation, and mitochondrial dysfunction. Notably, investigational imaging technologies can now detect AD-specific amyloid deposits, as well as vasculopathy and neurodegeneration in the retina of living AD patients, suggesting alterations at different disease stages and links to brain pathology. Current and exploratory ophthalmic imaging modalities, such as optical coherence tomography (OCT), OCT-angiography, confocal scanning laser ophthalmoscopy, and hyperspectral imaging, may offer promise in the clinical assessment of AD. However, further research is needed to deepen our understanding of AD's impact on the retina and its progression. To advance this field, future studies require replication in larger and diverse cohorts with confirmed AD biomarkers and standardized retinal imaging techniques. This will validate potential retinal biomarkers for AD, aiding in early screening and monitoring.
Topics: Alzheimer Disease; Humans; Retinal Diseases; Retina; Animals; Tomography, Optical Coherence; Amyloid beta-Peptides; Retinal Vessels
PubMed: 38759947
DOI: 10.1016/j.preteyeres.2024.101273 -
Investigative Ophthalmology & Visual... May 2024To demonstrate the first near-infrared adaptive optics fluorescence lifetime imaging ophthalmoscopy (NIR-AOFLIO) measurements in vivo of the human retinal pigment...
PURPOSE
To demonstrate the first near-infrared adaptive optics fluorescence lifetime imaging ophthalmoscopy (NIR-AOFLIO) measurements in vivo of the human retinal pigment epithelial (RPE) cellular mosaic and to visualize lifetime changes at different retinal eccentricities.
METHODS
NIR reflectance and autofluorescence were captured using a custom adaptive optics scanning light ophthalmoscope in 10 healthy subjects (23-64 years old) at seven eccentricities and in two eyes with retinal abnormalities. Repeatability was assessed across two visits up to 8 weeks apart. Endogenous retinal fluorophores and hydrophobic whole retinal extracts of Abca4-/- pigmented and albino mice were imaged to probe the fluorescence origin of NIR-AOFLIO.
RESULTS
The RPE mosaic was resolved at all locations in five of seven younger subjects (<35 years old). The mean lifetime across near-peripheral regions (8° and 12°) was longer compared to near-foveal regions (0° and 2°). Repeatability across two visits showed moderate to excellent correlation (intraclass correlation: 0.88 [τm], 0.75 [τ1], 0.65 [τ2], 0.98 [a1]). The mean lifetime across drusen-containing eyes was longer than in age-matched healthy eyes. Fluorescence was observed in only the extracts from pigmented Abca4-/- mouse.
CONCLUSIONS
NIR-AOFLIO was repeatable and allowed visualization of the RPE cellular mosaic. An observed signal in only the pigmented mouse extract infers the fluorescence signal originates predominantly from melanin. Variations observed across the retina with intermediate age-related macular degeneration suggest NIR-AOFLIO may act as a functional measure of a biomarker for in vivo monitoring of early alterations in retinal health.
Topics: Humans; Retinal Pigment Epithelium; Ophthalmoscopy; Adult; Middle Aged; Animals; Female; Mice; Male; Young Adult; Optical Imaging; Reproducibility of Results; Infrared Rays; ATP-Binding Cassette Transporters; Fluorescein Angiography
PubMed: 38758638
DOI: 10.1167/iovs.65.5.27 -
Journal of Clinical Medicine Apr 2024This study aimed to compare keratometry and anterior chamber depth (ACD) changes after XEN implantation in primary open-angle glaucoma (POAG) cases over a 3-month...
This study aimed to compare keratometry and anterior chamber depth (ACD) changes after XEN implantation in primary open-angle glaucoma (POAG) cases over a 3-month follow-up period. Twenty patients with POAG who underwent XEN63 implantation, either standalone or combined with cataract surgery, were included. Preoperative data, including best-corrected visual acuity (BCVA), refraction, gonioscopy, ophthalmoscopy, intraocular pressure (IOP) evaluation, and axial length, were collected. Corneal topography and ACD measurements were assessed preoperatively and at postoperative days 1, 7, 15, 30, 60, and 90. Each patient's eye that underwent XEN surgery was included in the study group, with the fellow eye serving as a control. In the study group, there was a significant decrease in IOP after XEN stent implantation at all investigated time intervals ( < 0.05). However, changes in mean ACD did not show statistically significant differences at any follow-up examination in both the study and control groups. Additionally, keratometry readings revealed no significant changes in total astigmatism or steep keratometry values in either group. XEN implantation in POAG cases resulted in a significant decrease in IOP over the 3-month follow-up period. However, there were no significant changes observed in mean ACD or keratometry readings, indicating stability in these parameters post-XEN implantation. These findings suggest that XEN implantation may be an effective option for IOP reduction without affecting corneal curvature or ACD in POAG patients.
PubMed: 38731065
DOI: 10.3390/jcm13092537 -
Visual Neuroscience May 2024Animal models of retinal degeneration are critical for understanding disease and testing potential therapies. Inducing degeneration commonly involves the administration...
Animal models of retinal degeneration are critical for understanding disease and testing potential therapies. Inducing degeneration commonly involves the administration of chemicals that kill photoreceptors by disrupting metabolic pathways, signaling pathways, or protein synthesis. While chemically induced degeneration has been demonstrated in a variety of animals (mice, rats, rabbits, felines, 13-lined ground squirrels (13-LGS), pigs, chicks), few studies have used noninvasive high-resolution retinal imaging to monitor the cellular effects. Here, we used longitudinal scanning light ophthalmoscopy (SLO), optical coherence tomography, and adaptive optics SLO imaging in the euthermic, cone-dominant 13-LGS (46 animals, 52 eyes) to examine retinal structure following intravitreal injections of chemicals, which were previously shown to induce photoreceptor degeneration, throughout the active season of 2019 and 2020. We found that iodoacetic acid induced severe pan-retinal damage in all but one eye, which received the lowest concentration. While sodium nitroprusside successfully induced degeneration of the outer retinal layers, the results were variable, and damage was also observed in 50% of contralateral control eyes. Adenosine triphosphate and tunicamycin induced outer retinal specific damage with varying results, while eyes injected with thapsigargin did not show signs of degeneration. Given the variability of damage we observed, follow-up studies examining the possible physiological origins of this variability are critical. These additional studies should further advance the utility of chemically induced photoreceptor degeneration models in the cone-dominant 13-LGS.
Topics: Animals; Sciuridae; Retinal Degeneration; Retinal Cone Photoreceptor Cells; Tomography, Optical Coherence; Disease Models, Animal; Intravitreal Injections; Ophthalmoscopy; Nitroprusside; Female; Male
PubMed: 38725382
DOI: 10.1017/S0952523824000014