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Eye (London, England) Mar 2022To analyse structural characteristics and perifoveal/peripapillary vasculature by OCT in children with peripapillary hyperreflective ovoid mass-like structures (PHOMS)...
BACKGROUND
To analyse structural characteristics and perifoveal/peripapillary vasculature by OCT in children with peripapillary hyperreflective ovoid mass-like structures (PHOMS) and compare the results with those of normal subjects.
METHODS
Forty-five patients (84 eyes) under 18 years old with blurry disc margin were evaluated with spectral domain-OCT and swept course-OCT. Patients were divided into four groups, according to presence of PHOMS and then the size of the existing PHOMS. Eyes with visible optic disc drusen (ODD) were not included. Foveal avascular zone (FAZ) and vessel densities from macula and optic disc area were assessed and potential associations between vessel density and structural parameters, such as peripapillary retinal nerve fibre layer (pRNFL), and macular ganglion cell and inner plexiform layer (mGCIPL) thickness, were analysed.
RESULTS
Among 45 patients (eighty-four eyes), coexisting buried ODD were found only in eyes with PHOMS. The scleral canal diameter was significantly smaller in PHOMS positive eyes compared to control eyes. Vessel density measurements from the papillary, peripapillary and optic nerve head (ONH) regions in the large PHOMS group were significantly lower compared to the control group (papillary; P = 0.014, peripapillary; P = 0.001, ONH; P = 0.046). FAZ area and macular vessel densities showed no difference compared to normal eyes in all three PHOMS groups. pRNFL and mGCIPL thickness did not differ among four groups and correlations were also not significant.
CONCLUSIONS
Children with PHOMS have smaller scleral canal and can entail buried ODD. Vessel densities of optic disc area in large PHOMS eyes are significantly lower than in normal eyes.
Topics: Adolescent; Child; Humans; Macula Lutea; Optic Disk; Optic Disk Drusen; Sclera; Tomography, Optical Coherence
PubMed: 33731891
DOI: 10.1038/s41433-021-01461-w -
Eye (London, England) Jul 2021Studying the biomechanical properties of biological tissue is crucial to improve our understanding of disease pathogenesis. The biomechanical characteristics of the... (Review)
Review
Studying the biomechanical properties of biological tissue is crucial to improve our understanding of disease pathogenesis. The biomechanical characteristics of the cornea, sclera and the optic nerve head have been well addressed with an extensive literature and an in-depth understanding of their significance whilst, in comparison, knowledge of the retina and choroid is relatively limited. Knowledge of these tissues is important not only to clarify the underlying pathogenesis of a wide variety of retinal and vitreoretinal diseases, including age-related macular degeneration, hereditary retinal dystrophies and vitreoretinal interface diseases but also to optimise the surgical handling of retinal tissues and, potentially, the design and properties of implantable retinal prostheses and subretinal therapies. Our aim with this article is to comprehensively review existing knowledge of the biomechanical properties of retina, internal limiting membrane (ILM) and the Bruch's membrane-choroidal complex (BMCC), highlighting the potential implications for clinical and surgical practice. Prior to this we review the testing methodologies that have been used both in vitro, and those starting to be used in vivo to aid understanding of their results and significance.
Topics: Bruch Membrane; Choroid; Humans; Macular Degeneration; Optic Disk; Retina
PubMed: 33649576
DOI: 10.1038/s41433-021-01437-w -
Scientific Reports Jun 2022We present a compact multi-modal and multi-scale retinal imaging instrument with an angiographic functional extension for clinical use. The system integrates scanning...
We present a compact multi-modal and multi-scale retinal imaging instrument with an angiographic functional extension for clinical use. The system integrates scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT) and OCT angiography (OCTA) imaging modalities and provides multi-scale fields of view. For high resolution, and high lateral resolution in particular, cellular imaging correction of aberrations by adaptive optics (AO) is employed. The entire instrument has a compact design and the scanning head is mounted on motorized translation stages that enable 3D self-alignment with respect to the subject's eye by tracking the pupil position. Retinal tracking, based on the information provided by SLO, is incorporated in the instrument to compensate for retinal motion during OCT imaging. The imaging capabilities of the multi-modal and multi-scale instrument were tested by imaging healthy volunteers and patients.
Topics: Humans; Ophthalmoscopy; Optics and Photonics; Pupil; Retina; Tomography, Optical Coherence
PubMed: 35688890
DOI: 10.1038/s41598-022-13631-1 -
Wavefront aberrations and retinal image quality in different lenticular opacity types and densities.Scientific Reports Nov 2017To investigate wavefront aberrations in the entire eye and in the internal optics (lens) and retinal image qualities according to different lenticular opacity types and... (Clinical Trial)
Clinical Trial
To investigate wavefront aberrations in the entire eye and in the internal optics (lens) and retinal image qualities according to different lenticular opacity types and densities. Forty-one eyes with nuclear cataract, 33 eyes with cortical cataract, and 29 eyes with posterior subcapsular cataract were examined. In each group, wavefront aberrations in the entire eye and in the internal optics and retinal image quality were measured using a raytracing aberrometer. Eyes with cortical cataracts showed significantly higher coma-like aberrations compared to the other two groups in both entire eye and internal optic aberrations (P = 0.012 and P = 0.007, respectively). Eyes with nuclear cataract had lower spherical-like aberrations than the other two groups in both entire eye and internal optics aberrations (P < 0.001 and P < 0.001, respectively). In the nuclear cataract group, nuclear lens density was negatively correlated with internal spherical aberrations (r = -0.527, P = 0.005). Wavefront technology is useful for objective and quantitative analysis of retinal image quality deterioration in eyes with different early lenticular opacity types and densities. Understanding the wavefront optical properties of different crystalline lens opacities may help ophthalmic surgeons determine the optimal time to perform cataract surgery.
Topics: Aged; Cataract; Corneal Topography; Female; Humans; Lens, Crystalline; Male; Middle Aged; Retina
PubMed: 29127310
DOI: 10.1038/s41598-017-15245-4 -
Investigative Ophthalmology & Visual... Jun 2022To investigate the characteristics of the optic nerve head (ONH) in myopia using swept-source optical coherence tomography (SS-OCT).
PURPOSE
To investigate the characteristics of the optic nerve head (ONH) in myopia using swept-source optical coherence tomography (SS-OCT).
METHODS
Participants were divided into three groups according to the axial length (AL). The optic disc morphology, retinal nerve fiber layer (RNFL) thickness, and radial peripapillary capillary (RPC) vessel density (VD), optic disc tilt, rotation, Bruch's membrane opening distance (BMOD), border length (BL), border tissue angle, focal lamina cribrosa (LC) defects, β- and γ-zone peripapillary atrophy (PPA), microvasculature dropout (MvD), choroidal thickness (CT), and the choroidal vascularity index (CVI) were compared. Linear regression analysis evaluated relationships between spherical equivalent, AL, and ONH parameters.
RESULTS
One hundred five, 98, and 118 eyes were included in groups 1, 2, and 3, respectively. With AL increasing, the mean, superior and temporal CT, central mean and temporal, pericentral mean, inferior and nasal RPC VD, and temporal CVI decreased, whereas the mean and temporal RNFL thickness, optic disc, RIM and β-PPA area, presence and area of γ-PPA, BMOD and BL increased. Compared to other groups, group 3 depicted a larger cup area, more focal LC defect and total and juxtapapillary MvD; a lower central superior, inferior and nasal, pericentral superior, and temporal RPC VD. Group 1 demonstrated more tilted disc, larger inferior and nasal CT, mean, superior, inferior, and nasal CVI.
CONCLUSIONS
Myopia eyes have larger ONH changes, PPAs, regional RNFL, and MvD, but smaller regional CTs, RPC VD, and CVIs. SS-OCT may be useful in detecting ONH variations during myopia.
Topics: Bruch Membrane; Humans; Myopia; Optic Disk; Retinal Ganglion Cells; Tomography, Optical Coherence
PubMed: 35731511
DOI: 10.1167/iovs.63.6.20 -
Current Topics in Developmental Biology 2010Organogenesis of the eye is a multistep process that starts with the formation of optic vesicles followed by invagination of the distal domain of the vesicles and the... (Review)
Review
Organogenesis of the eye is a multistep process that starts with the formation of optic vesicles followed by invagination of the distal domain of the vesicles and the overlying lens placode resulting in morphogenesis of the optic cup. The late optic vesicle becomes patterned into distinct ocular tissues: the neural retina, retinal pigment epithelium (RPE), and optic stalk. Multiple congenital eye disorders, including anophthalmia or microphthalmia, aniridia, coloboma, and retinal dysplasia, stem from disruptions in embryonic eye development. Thus, it is critical to understand the mechanisms that lead to initial specification and differentiation of ocular tissues. An accumulating number of studies demonstrate that a complex interplay between inductive signals provided by tissue-tissue interactions and cell-intrinsic factors is critical to ensuring proper specification of ocular tissues as well as maintenance of RPE cell fate. While several of the extrinsic and intrinsic determinants have been identified, we are just at the beginning in understanding how these signals are integrated. In addition, we know very little about the actual output of these interactions. In this chapter, we provide an update of the mechanisms controlling the early steps of eye development in vertebrates, with emphasis on optic vesicle evagination, specification of neural retina and RPE at the optic vesicle stage, the process of invagination during morphogenesis of the optic cup, and maintenance of the RPE cell fate.
Topics: Animals; Eye; Gene Expression Regulation, Developmental; Lens, Crystalline; Morphogenesis; Retina; Retinal Pigment Epithelium; Signal Transduction
PubMed: 20959163
DOI: 10.1016/B978-0-12-385044-7.00003-5 -
Eye (London, England) Oct 2021To evaluate the distribution of macula and circumpapillary retina nerve fiber layer (cpRNFL) thickness and other associated factors among grade-1 primary school children...
OBJECTIVE
To evaluate the distribution of macula and circumpapillary retina nerve fiber layer (cpRNFL) thickness and other associated factors among grade-1 primary school children in Lhasa using spectral-domain optical coherence tomography (SD-OCT).
METHODOLOGY
OCT assessment was conducted on 1856 grade-1 students from 7 primary schools in Lhasa, Tibet following a successful random stratified sampling of the students. Each child underwent comprehensive general and ocular examinations as well as an SD-OCT detection (12 × 9 mm, 3D wide scan mode, Topcon 3D OCT-1) to assess the thickness of the macula, ganglion cell-inner plexiform layer (GCIPL), ganglion cell complex (GCC), and cpRNFL. Multivariate and correlation analyses were performed to evaluate the association of the demographic and ocular variables.
RESULTS
The average age of the 1762 (94.43%) students who underwent OCT assessment was 6.83 ± 0.46 years. Among them, 984 (53.02%) were boys. The number of students who had macular, cpRNFL, and optic disc scans completed and with adequate image quality were 1412 (82.2%), 1277 (74.4%), and 1243 (72.4%), respectively. The average macula full retinal thickness (FRT), GCIPL, GCC, and cpRNFL thickness of the students was 279.19 ± 10.61 μm, 76.41 ± 4.70 μm, 108.15 ± 6.15 μm, and 112.33 ± 13.5 μm, respectively. Multivariate regression and correlation analysis further revealed that boys and girls had significant differences in their average cpRNFL thickness. Moreover, GCC and GCIPL thickness was negatively correlated with IOP but positively correlated with the body mass index. The thickness of all the layers of the macula and cpRNFL were positively correlated with spherical equivalent. Further to this, the average macular FRT, GCIPL, and GCC thicknesses were positively correlated with cpRNFL global thickness.
CONCLUSION
This study describes the normal distribution of macular retina, cpRNFL, and optic disc parameters in grade-1 Tibetan children in Lhasa. It contributes to the establishment of a normative ophthalmology database of Tibetan children, and advances the ability of OCT in ophthalmic disorder diagnosis during long-term monitoring in plateau.
Topics: Child; Cross-Sectional Studies; Female; Humans; Macula Lutea; Male; Nerve Fibers; Optic Disk; Retina; Retinal Ganglion Cells; Tomography, Optical Coherence
PubMed: 33239762
DOI: 10.1038/s41433-020-01313-z -
Investigative Ophthalmology & Visual... May 2022To investigate the potential glaucomatous changes caused by scleral cross-linking (CXL) in a guinea pig form-deprivation (FD) myopia model.
PURPOSE
To investigate the potential glaucomatous changes caused by scleral cross-linking (CXL) in a guinea pig form-deprivation (FD) myopia model.
METHODS
Eighty 4-week-old tricolor guinea pigs were divided into four groups: FD only, genipin CXL only, FD plus CXL, and control. Refractive error, axial length (AL), intraocular pressure (IOP), and structural and vasculature optic disc changes in optical coherence tomography (OCT) and OCT angiography (OCTA) were measured at baseline and day 21. CXL efficacy was evaluated by scleral rigidity Young's modulus values. Histological and molecular changes in the anterior chamber angle, retina, and sclera were assessed.
RESULTS
Baseline parameters were similar among groups (P > 0.05). The FD plus CXL group at day 21 had the least increase of AL (0.14 ± 0.08 mm) and highest IOP elevation (31.5 ± 3.6 mmHg) compared with the FD-only group (AL: 0.68 ± 0.17 mm; IOP: 22.2 ± 2.6 mmHg) and the control group (AL: 0.24 ± 0.09 mm; IOP: 17.4 ± 1.8 mmHg) (all P < 0.001). OCT and OCTA parameters of the optic disc in the FD plus CXL group at day 21 showed glaucomatous changes and decreased blood flow signals. Sclera rigidity increased in the CXL and FD plus CXL groups. Advanced glycation end products deposited extensively in the retina, choroid, and sclera of FD plus CXL eyes.
CONCLUSIONS
CXL causes increased IOP and subsequent optic disc, anterior segment, and scleral changes while inhibiting myopic progression and axial elongation in FD guinea pig eyes. Therefore, applying CXL to control myopia raises safety concerns.
Topics: Animals; Choroid; Glaucoma; Guinea Pigs; Myopia; Optic Disk; Retina; Sclera
PubMed: 35594036
DOI: 10.1167/iovs.63.5.24 -
Developmental Dynamics : An Official... Oct 2014The vertebrate eye acquires its basic form during the process of optic cup morphogenesis, during which the optic vesicle emerges from the brain neuroepithelium and,... (Review)
Review
The vertebrate eye acquires its basic form during the process of optic cup morphogenesis, during which the optic vesicle emerges from the brain neuroepithelium and, through a series of cell and tissue movements, transforms itself into the multilayered optic cup, containing neural retina (comprised of retinal progenitors), retinal pigmented epithelium, and the lens, which is derived from the overlying ectoderm. While great strides have been made to understand the developmental signals controlling specification, patterning, and differentiation of the optic cup, only in recent years have the cellular and molecular bases of optic cup morphogenesis begun to be unraveled. One critical component of the morphogenetic process is the extracellular matrix: the complex, glycoprotein-rich layer that surrounds the optic vesicle and lens. Though the extracellular matrix has long been visualized by classical histological techniques and postulated to play various roles in optic cup development, its functional role was uncertain. This is now beginning to change, as live imaging techniques, quantitative image analyses, molecular genetics and in vitro models yield new insights into the process of optic cup morphogenesis and the specific influences of particular extracellular matrix components and their associated signaling pathways.
Topics: Animals; Extracellular Matrix; Eye; Humans; Lens, Crystalline; Morphogenesis; Retina; Retinal Pigment Epithelium; Vertebrates
PubMed: 25044784
DOI: 10.1002/dvdy.24162 -
Eye (London, England) Nov 2019We investigated the effects of topical phenylephrine 2.5% instillation on choroidal thickness (CT), peripapillary choroidal thickness (pCT) and retinal nerve fibre layer...
OBJECTIVES
We investigated the effects of topical phenylephrine 2.5% instillation on choroidal thickness (CT), peripapillary choroidal thickness (pCT) and retinal nerve fibre layer (RNFL).
METHODS
Healthy control patients underwent enhanced depth imaging (EDI) by spectral-domain optical coherence tomography (OCT) before and 30 min after phenylephrine instillation, using eye-tracking and follow-up software. Changes in 14 different locations of CT, 2 locations of pCT and RNFL were assessed.
RESULTS
The study included 119 eyes of 62 patients (19 males and 43 females), with a mean age of 59.8 ± 15.3 years (range: 26-88 years). Within 30 min after instillation, the mean subfoveal CT both in vertical and horizontal scan were significantly thinned (p = 0.005 and p = 0.018, respectively). In total, 1500, 1000 and 500 µm temporal CT measurements showed also a significant thinning (p = 0.021, p = 0.037 and p = 0.020, respectively), as well as 500 µm both superior (p = 0.045) and inferior (p = 0.009). 1500, 1000 and 500 µm nasal CT, and 1500 and 1000 µm CT superior and inferior measurements showed no significant thinning after phenylephrine instillation. pCT was significantly thinned after phenylephrine in both superior (p = 0.016) and inferior (p = 0.050) measurements. RNFL analysis did not significantly change after phenylephrine instillation (p = 0.209).
CONCLUSIONS
A significant thinning of CT and pCT occurred following phenylephrine instillation. Future studies analysing CT and pCT should detail if this mydriatic agent was used or not.
Topics: Administration, Ophthalmic; Adult; Aged; Aged, 80 and over; Choroid; Female; Healthy Volunteers; Humans; Macula Lutea; Male; Middle Aged; Mydriatics; Nerve Fibers; Ophthalmic Solutions; Optic Disk; Phenylephrine; Pupil; Retinal Ganglion Cells; Tomography, Optical Coherence
PubMed: 31164729
DOI: 10.1038/s41433-019-0478-z