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Progress in Retinal and Eye Research Mar 2024There are many unanswered questions on the relation of intraocular pressure to glaucoma development and progression. IOP itself cannot be distilled to a single, unifying... (Review)
Review
There are many unanswered questions on the relation of intraocular pressure to glaucoma development and progression. IOP itself cannot be distilled to a single, unifying value, because IOP level varies over time, differs depending on ocular location, and can be affected by method of measurement. Ultimately, IOP level creates mechanical strain that affects axonal function at the optic nerve head which causes local extracellular matrix remodeling and retinal ganglion cell death - hallmarks of glaucoma and the cause of glaucomatous vision loss. Extracellular tissue strain at the ONH and lamina cribrosa is regionally variable and differs in magnitude and location between healthy and glaucomatous eyes. The ultimate targets of IOP-induced tissue strain in glaucoma are retinal ganglion cell axons at the optic nerve head and the cells that support axonal function (astrocytes, the neurovascular unit, microglia, and fibroblasts). These cells sense tissue strain through a series of signals that originate at the cell membrane and alter cytoskeletal organization, migration, differentiation, gene transcription, and proliferation. The proteins that translate mechanical stimuli into molecular signals act as band-pass filters - sensing some stimuli while ignoring others - and cellular responses to stimuli can differ based on cell type and differentiation state. Therefore, to fully understand the IOP signals that are relevant to glaucoma, it is necessary to understand the ultimate cellular targets of IOP-induced mechanical stimuli and their ability to sense, ignore, and translate these signals into cellular actions.
Topics: Humans; Optic Disk; Glaucoma; Intraocular Pressure; Axons; Retinal Ganglion Cells
PubMed: 38110030
DOI: 10.1016/j.preteyeres.2023.101232 -
Indian Journal of Ophthalmology Mar 2024To analyze primary congenital glaucoma (PCG) anterior chamber and angle anomalies over 360° as possible biomarkers of severity and prognosis. (Observational Study)
Observational Study
PURPOSE
To analyze primary congenital glaucoma (PCG) anterior chamber and angle anomalies over 360° as possible biomarkers of severity and prognosis.
METHODS
A cross-sectional observational study was conducted analyzing anterior segment anomalies of PCG patients over 4 years of age who underwent trabeculectomy combined with trabeculotomy and age-matched controls using anterior segment optical coherence tomography (ASOCT), CASIA-2. Anterior iridotrabecular adhesions or anterior iris insertion was identified and quantified from the scleral spur using the iridotrabecular contact (ITC) index parameter as a surrogate.
RESULTS
There was a variable but significantly increased anterior iridotrabecular adhesion on ITC index, ITC area, corneal volume, anterior chamber volume, iris volume, anterior chamber depth, and small/absent trabecular meshwork in PCG eyes compared to control eyes. In PCG eyes, anterior iridotrabecular adhesion had a positive correlation with pre-operative central corneal thickness (CCT) (r = 0.53, P = 0.02), review iris thickness (r = 0.4, P = 0.04), and ITC area (r = 0.85, P < 0.001). Review iris thickness had a negative correlation with pre-operative vertical cup-disc ratio (r = -0.51, P = 0.008). Iris hypoplasia with fewer or absent folds, collarette, pupillary ruff, and pupillary ruff to collarette distance was significantly different from controls.
CONCLUSION
ASOCT in PCG eyes has shown that they have variable anterior iridotrabecular tissue adhesions, anomalous tissue/membranes in the angle, and iris hypoplasia correlating with pre-operative cup-disc ratio. These features could be used as gonioscopic and clinical biomarkers to assess the severity and prognosis of the disease. The presence of abnormal iris morphology and iridotrabecular tissue anomalies in PCG suggests that it is more than just isolated trabeculodysgenesis and is probably best considered as part of the anterior segment dysgenesis spectrum.
Topics: Humans; Cross-Sectional Studies; Intraocular Pressure; Glaucoma, Angle-Closure; Iris; Iris Diseases; Tomography, Optical Coherence; Gonioscopy; Biomarkers; Anterior Eye Segment; Eye Abnormalities
PubMed: 38099353
DOI: 10.4103/IJO.IJO_370_23 -
Scientific Reports Nov 2023The purpose of this study was to investigate and compare the optical performance of five trifocal intraocular lenses (IOLs) following the ISO 11979-2 standards,...
The purpose of this study was to investigate and compare the optical performance of five trifocal intraocular lenses (IOLs) following the ISO 11979-2 standards, analysing the impact of tilt and decentration. Five different diffractive trifocal IOLs were evaluated in this experimental study: Acriva Trinova (VSY-Biotechnology) (AT), FineVision HP (PhysIOL) (FVHP), AT LISA tri 839 MP (Zeiss) (ATLT), PanOptix TFNT00 IOL (Alcon) (PO), and Tecnis Synergy (J&J Vision) (TS). In-vitro optical quality analysis of them was performed with the Lambda PMTF system that has an aberration neutral cornea model (Lambda-X Ophthalmics). Measurements were performed on-axis, with 5º of IOL tilt and with 0.5 mm of IOL decentration using 543-nm monochromatic light. Finally, IOL dimensions and diffractive disk profile inspection was performed using the VisIOLA system (Rotlex). On-axis measurements showed a far through-focus MTF > 0.3 at 3 mm aperture, except for TS. FVHP and PO showed better far MTFs for larger apertures (3.75 mm and 4.5 mm) while AT showed good intermediate and near vision for such apertures. With 5º of IOL tilt, the better optical performance at all distances was found with AT for medium-sized pupils (3 mm) and an important reduction of MTF was found for ATLT and PO, especially in the intermediate focus. The induction of 0.5 mm of IOL decentration especially affected the intermediate focus of ATLT and TS and the far focus of FVHP and PO. IOL dimensions and diffractive profile were consistent with those described by the manufacturer. In conclusion, there are differences in the optical performance according to the pupil aperture of the five trifocal IOLs evaluated and this should be considered in clinical practice when selecting the most appropriate implant in each specific case. IOL tilt and decentration can affect significantly in most of the designs evaluated the performance of the IOL at intermediate vision range. It should be noted that measurements were made with an aberration-free cornea, being necessary future studies analysing the impact of different levels of corneal aberrations.
Topics: Prosthesis Design; Optics and Photonics; Lenses, Intraocular; Multifocal Intraocular Lenses; Pupil
PubMed: 37950090
DOI: 10.1038/s41598-023-47102-y -
Medical Science Monitor : International... Dec 2023Visualization of the retinal structure is crucial for understanding the pathophysiology of ophthalmic diseases, as well as for monitoring their course and treatment... (Review)
Review
Visualization of the retinal structure is crucial for understanding the pathophysiology of ophthalmic diseases, as well as for monitoring their course and treatment effects. Until recently, evaluation of the retina at the cellular level was only possible using histological methods, because the available retinal imaging technology had insufficient resolution due to aberrations caused by the optics of the eye. Adaptive optics (AO) technology improved the resolution of optical systems to 2 µm by correcting optical wave-front aberrations, thereby revolutionizing methods for studying eye structures in vivo. Within 25 years of its first application in ophthalmology, AO has been integrated into almost all existing retinal imaging devices, such as the fundus camera (FC), scanning laser ophthalmoscopy (SLO), and optical coherence tomography (OCT). Numerous studies have evaluated individual retinal structures, such as photoreceptors, blood vessels, nerve fibers, ganglion cells, lamina cribrosa, and trabeculum. AO technology has been applied in imaging structures in healthy eyes and in various ocular diseases. This article aims to review the roles of AO imaging in the diagnosis, management, and monitoring of age-related macular degeneration (AMD), diabetic retinopathy (DR), glaucoma, hypertensive retinopathy (HR), central serous chorioretinopathy (CSCR), and inherited retinal diseases (IRDs).
Topics: Humans; Retina; Ophthalmoscopy; Tomography, Optical Coherence; Diabetic Retinopathy; Central Serous Chorioretinopathy
PubMed: 38044597
DOI: 10.12659/MSM.941926 -
Investigative Ophthalmology & Visual... Sep 2023Progress toward treatment and prevention of age-related macular degeneration (AMD) requires imaging end points that relate to vision. We investigated choriocapillaris...
PURPOSE
Progress toward treatment and prevention of age-related macular degeneration (AMD) requires imaging end points that relate to vision. We investigated choriocapillaris flow signal deficits (FD%) and visual function in eyes of individuals aged ≥60 years, with and without AMD.
METHODS
One eye of each participant in the baseline visit of the Alabama Study on Early Age-Related Macular Degeneration 2 (ALSTAR2; NCT04112667) was studied. AMD presence and severity was determined using the Age-Related Eye Disease Study (AREDS) grading system. FD% was quantified using macular spectral domain optical coherence tomography angiography (OCTA) scans. Vision tests included rod-mediated dark adaptation (RMDA), best-corrected visual acuity, and contrast sensitivity (photopic and mesopic), and microperimetric light sensitivity (scotopic, mesopic, and photopic). Presence of subretinal drusenoid deposits (SDD) was determined using multimodal imaging.
RESULTS
In 410 study eyes of 410 participants (mean [SD] age = 71.7 years [5.9]), FD% was higher in early AMD (mean [SD] = 54.0% [5.5], N = 122) and intermediate AMD (59.8% [7.4], N = 92), compared to normal (52.1% [5.3], N = 196) eyes. Among visual functions evaluated, RMDA showed the strongest association with FD% (r = 0.35, P < 0.0001), followed by contrast sensitivity (r = -0.22, P < 0.0001). Eyes with SDD had worse FD% (58.3% [7.4], N = 87), compared to eyes without SDD (53.4% [6.0], N = 323, P = < 0.0001).
CONCLUSIONS
Choriocapillaris FD% were associated with AMD severity and with impaired vision, especially RMDA. Reduced metabolic transport and exchange across the choriocapillaris-Bruch's membrane retinal pigment epithelium (RPE) complex, a causal factor for high-risk soft drusen formation, also may impair photoreceptor sustenance from the circulation. This includes retinoid resupply, essential to dynamic rod function.
Topics: Humans; Dark Adaptation; Macular Degeneration; Retina; Retinal Drusen; Tomography, Optical Coherence; Choroid
PubMed: 37768273
DOI: 10.1167/iovs.64.12.41 -
International Journal of Molecular... Jan 2024Glaucoma is a complex and multifactorial disease defined as the loss of retinal ganglion cells (RGCs) and their axons. Besides an elevated intraocular pressure (IOP),... (Review)
Review
Glaucoma is a complex and multifactorial disease defined as the loss of retinal ganglion cells (RGCs) and their axons. Besides an elevated intraocular pressure (IOP), other mechanisms play a pivotal role in glaucoma onset and progression. For example, it is known that excitotoxicity, immunological alterations, ischemia, and oxidative stress contribute to the neurodegeneration in glaucoma disease. To study these effects and to discover novel therapeutic approaches, appropriate animal models are needed. In this review, we focus on various glaucoma animal models beyond an elevated IOP. We introduce genetically modified mice, e.g., the optineurin E50K knock-in or the glutamate aspartate transporter (GLAST)-deficient mouse. Excitotoxicity can be mimicked by injecting the glutamate analogue N-methyl-D-aspartate intravitreally, which leads to rapid RGC degeneration. To explore the contribution of the immune system, the experimental autoimmune glaucoma model can serve as a useful tool. Here, immunization with antigens led to glaucoma-like damage. The ischemic mechanism can be mimicked by inducing a high IOP for a certain amount of time in rodents, followed by reperfusion. Thereby, damage to the retina and the optic nerve occurs rapidly after ischemia/reperfusion. Lastly, we discuss the importance of optic nerve crush models as model systems for normal-tension glaucoma. In summary, various glaucoma models beyond IOP increase can be utilized.
Topics: Animals; Mice; Glaucoma; Eye; Glutamic Acid; Models, Animal; Ischemia
PubMed: 38255979
DOI: 10.3390/ijms25020906 -
The British Journal of Ophthalmology Oct 2023To investigate the factors associated with choroidal microvasculature drop-out (MvD) enlargement detected by optical coherence tomography angiography (OCT-A) in...
BACKGROUND/AIMS
To investigate the factors associated with choroidal microvasculature drop-out (MvD) enlargement detected by optical coherence tomography angiography (OCT-A) in glaucomatous eyes.
METHODS
Ninety-one eyes of 68 primary open-angle glaucoma patients were enrolled. Only eyes with a minimum of four good quality OCT-A and OCT scans of the optic nerve head acquired at least and with a minimum of 2 years follow-up were included. Area and angular circumference of MvD were analysed on en face images. Univariable and multivariable mixed effects models were constructed to identify the factors contributing to MvD area and angular circumference change over time.
RESULTS
Peripapillary MvD was detected in 53 (58.2%) eyes at baseline and in an additional 17 (18.6%) eyes during follow-up, whereas MvD was not detected in 21 (23.0 %) eyes during the entire follow-up period. In multivariable analysis, worse baseline visual field (VF) mean deviation (MD) (ß=0.27, 95% CI 0.10 to 0.44, p=0.002), greater intraocular pressure (IOP) fluctuations (ß=0.86, 95% CI 0.24 to 1.48, p=0.007), higher peak IOP (ß=0.17, 95% CI -0.01 to 0.35, p=0.067) and greater number of IOP lowering medications (ß=1.36, 95% CI 0.67 to 2.05, p<0.001) were associated with faster MvD area enlargement. Worse baseline VF MD and greater IOP fluctuation were also associated with significantly faster MvD circumferential enlargement in multivariable models.
CONCLUSION
Greater IOP fluctuation, higher peak IOP, worse baseline VF MD and greater number of glaucoma medications were significantly associated with MvD enlargement in glaucomatous eyes. The identification of factors associated with MvD enlargement may improve our understanding of the role of choroidal vasculature in glaucoma.
Topics: Humans; Glaucoma, Open-Angle; Choroid; Optic Disk; Visual Fields; Glaucoma; Intraocular Pressure; Tomography, Optical Coherence; Microvessels
PubMed: 35803672
DOI: 10.1136/bjo-2022-321157 -
Ceska a Slovenska Oftalmologie :... 2023Torpedo maculopathy is an incidental, congenital retinal lesion. The typical clinical finding is a unilateral, symmetric, oval, hypopigmented lesion in the...
AIM
Torpedo maculopathy is an incidental, congenital retinal lesion. The typical clinical finding is a unilateral, symmetric, oval, hypopigmented lesion in the inferotemporal macula. In most cases, the lesion is along the horizontal raphe, is torpedo-shaped, and the nasal edge is directed into the foveola. The diagnosis is determined on the basis of its characteristic shape, localization and findings on optical coherence tomography (OCT). The etiology and pathogenesis of torpedo maculopathy is unclear, but it is believed to be a congenital defect of the retinal pigment epithelium (RPE). The aim of this publication is highlight this diagnosis and to present an incidental finding of torpedo maculopathy in an adult patient.
CASE REPORT
A 30-year-old female patient reported for a routine eye examination. Fundus examination of the right eye revealed an oval hypopigmented lesion with a size of 1 disk diameter inferotemporally from the fovea, which was followed by a satellite lesion in the same axis directed into the foveola. Based on OCT, OCT angiography, fundus autofluorescence, and the typical shape and location of the lesion, the patient was diagnosed with torpedo maculopathy in the right eye.
CONCLUSION
In general, torpedo maculopathy is an asymptomatic, congenital, benign retinal lesion, which is mostly diagnosed accidentally during a routine fundus examination. TM is non-progressive retinal finding with a minimal risk of deterioration of visual functions, which does not require any treatment. Nevertheless, due to the rare risk of a choroidal neovascular membrane, it is recommended to examine patients once a year. It is necessary to consider this diagnosis when a unilateral hypopigmented lesion is found inferotemporally from the fovea, and to distinguish it from chorioretinal atrophy, scar, vitelliform dystrophy, or other RPE lesions as part of the differential diagnosis.
Topics: Adult; Female; Humans; Fluorescein Angiography; Retinal Diseases; Macular Degeneration; Retina; Retinal Pigment Epithelium; Tomography, Optical Coherence
PubMed: 37993275
DOI: 10.31348/2023/31 -
Translational Vision Science &... Oct 2023To evaluate the interocular differences of the peripapillary structural and vascular parameters and that of association with axial length (AL) in participants with...
PURPOSE
To evaluate the interocular differences of the peripapillary structural and vascular parameters and that of association with axial length (AL) in participants with myopic anisometropia using swept-source optical coherence tomography.
METHODS
This prospective cross-sectional study included 90 eyes of 45 participants. Each participant's eyes were divided into the more and less myopic eye respectively according to spherical equivalent. The β- and γ-parapapillary atrophy (PPA) areas, Bruch's membrane opening distance, border length, and border tissue angle were measured manually. Peripapillary choroidal vascularity index and choroidal thickness (CT) values in superior, nasal, inferior, and temporal were calculated using a custom-built algorithm based on MATLAB.
RESULTS
The interocular difference in AL and spherical equivalent was 0.62 ± 0.26 mm and -1.50 (-2.13, -1.25) diopters (D), respectively. The interocular difference in spherical equivalent was highly correlated with that of the AL. The β- and γ-PPA areas were significantly greater in more myopic eyes. The mean and inferior peripapillary choroidal vascularity index and all regions of peripapillary CT were significantly lower in the more myopic eyes. The interocular difference in AL was significantly positively correlated with the interocular differences in γ-PPA area and border length and negatively correlated with the interocular differences in temporal choroidal vascularity index and mean, inferior, and temporal peripapillary CT. There was an independent correlation between the interocular differences in AL and the interocular differences in γ-PPA area, inferior, and temporal peripapillary CT.
CONCLUSIONS
Significant differences between both groups were detected in most peripapillary parameters, especially in peripapillary CT. The γ-PPA area, border length, and peripapillary CT were significantly correlated with the elongation of AL.
TRANSLATIONAL RELEVANCE
The current study characterized and analyzed the peripapillary parameters in myopic anisometropia, which helped to monitor myopic progression.
Topics: Humans; Anisometropia; Optic Disk; Prospective Studies; Cross-Sectional Studies; Myopia
PubMed: 37850949
DOI: 10.1167/tvst.12.10.16 -
Current Biology : CB Nov 2023An animal's visual field is the three-dimensional space around its head from which it can extract visual information at any instant. Bird visual fields vary markedly...
An animal's visual field is the three-dimensional space around its head from which it can extract visual information at any instant. Bird visual fields vary markedly between species, and this variation is likely to be driven primarily by foraging ecology. The binocular visual field is the region in which the visual fields of the two eyes overlap; thus, objects in the binocular field are imaged by both eyes simultaneously. The binocular field plays a pivotal role in the detection of symmetrical optic flow-fields, providing almost instantaneous information on the direction of travel and the time to contact a target towards which the head or feet is travelling; thus, information from the binocular field is crucial in guiding key foraging behaviours. Here, we demonstrate an unusual visual field and binocular extent above the head in African Harrier-Hawks, also known as Gymnogenes (Polyboroides typus) compared to 18 other members of the Accipitridae. We argue that the observed visual field can be attributed to the unusual and specific foraging behaviour of African Harrier-Hawks.
Topics: Animals; Vision, Binocular; Hawks; Visual Fields; Eye; Eagles
PubMed: 37935124
DOI: 10.1016/j.cub.2023.09.016