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Current Eye Research Oct 2023Neodymium yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered as safe and effective method in the treatment of posterior capsule opacification....
PURPOSE
Neodymium yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered as safe and effective method in the treatment of posterior capsule opacification. Nevertheless, side effects are described. The incorrectly adjusted focus of the laser beam during the procedure can lead to so-called YAG-pits or YAG-shots. In this experimental study, we measured spectral transmission to evaluate the image contrast and analyze the impact of YAG-pits in intraocular lenses (IOL).
METHODS
Acrylic, foldable, one-piece IOLs with 6.0 mm optic and different material properties were studied. These included: monofocal IOLs and enhanced monofocal IOLs with water content of 0.3%, 26.0%, and 4.0% and a refractive index of 1.49, 1.46, and 1.54, respectively. All measurements were done with new, unaltered IOLs and IOLs with YAG-pits. Damage was intentionally created, performing YAG-pits ( = 7) in the central zone (3.5 mm) using a photodisruption laser (2.0mJ). All laboratory measurements were repeated: These included surface topography characterization, United States Air Force (USAF) resolution test chart analysis, spectral transmittance measurements and through focus contrast measurement.
RESULTS
Significant differences were found between the unaltered lenses and lenses with defects. The YAG-pits within the optic of the IOLs decreased the image contrast and spectral transmission and changed results of USAF test images at the focal position by 62%, 57% and 54%, respectively. In all IOLs a reduction of the relative intensity of total transmitted light was observed between 450 and 700 nm wavelength.
CONCLUSION
This experimental study confirmed that the IOL image performance deteriorates with YAG-pits. The total intensity of transmitted light or transmittance (without scattering) was reduced in the wavelength between 450 and 700 nm. The contrast was significantly reduced and USAF test targets showed much worse results compared to unmodified counterparts. There was no systematic difference between monofocal and enhanced monofocal lenses. Further experiments should investigate the effect of YAG-pits on diffractive IOLs.
Topics: Humans; Lens Implantation, Intraocular; Lenses, Intraocular; Capsule Opacification; Lens Capsule, Crystalline; Lens, Crystalline; Laser Therapy; Prosthesis Design; Postoperative Complications
PubMed: 37382106
DOI: 10.1080/02713683.2023.2229540 -
Investigative Ophthalmology & Visual... Nov 2023The purpose of this study was to evaluate the relationship between peripheral defocus and pupil size on axial growth in children randomly assigned to wear either single...
PURPOSE
The purpose of this study was to evaluate the relationship between peripheral defocus and pupil size on axial growth in children randomly assigned to wear either single vision contact lenses, +1.50 diopter (D), or +2.50 D addition multifocal contact lenses (MFCLs).
METHODS
Children 7 to 11 years old with myopia (-0.75 to -5.00 D; spherical component) and ≤1.00 D astigmatism were enrolled. Autorefraction (horizontal meridian; right eye) was measured annually wearing contact lenses centrally and ±20 degrees, ±30 degrees, and ±40 degrees from the line of sight at near and distance. Photopic and mesopic pupil size were measured. The effects of peripheral defocus, treatment group, and pupil size on the 3-year change in axial length were modeled using multiple variables that evaluated defocus across the retina.
RESULTS
Although several peripheral defocus variables were associated with slower axial growth with MFCLs, they were either no longer significant or not meaningfully associated with eye growth after the treatment group was included in the model. The treatment group assignment better explained the slower eye growth with +2.50 MFCLs than peripheral defocus. Photopic and mesopic pupil size did not modify eye growth with the +2.50 MFCL (all P ≥ 0.37).
CONCLUSIONS
The optical signal causing slower axial elongation with +2.50 MFCLs is better explained by the lens type worn than by peripheral defocus. The signal might be something other than peripheral defocus, or there is not a linear dose-response relationship within treatment groups. We found no evidence to support pupil size as a criterion when deciding which myopic children to treat with MFCLs.
Topics: Humans; Child; Pupil; Contact Lenses, Hydrophilic; Astigmatism; Color Vision; Lens, Crystalline; Myopia
PubMed: 37910092
DOI: 10.1167/iovs.64.14.3 -
Journal of Glaucoma Oct 2023The thicknesses of the circumpapillary retinal nerve fiber layer (cpRNFL) and ganglion cell complex (GCC) did not change during 5 years in physiological large disc...
Longitudinal Assessment of Retinal Nerve Fiber Layer and Ganglion Cell Complex Thicknesses in Patients With Large Optic Disc Cups and Normal Intraocular Pressure and Visual Fields.
PRCIS
The thicknesses of the circumpapillary retinal nerve fiber layer (cpRNFL) and ganglion cell complex (GCC) did not change during 5 years in physiological large disc cupping.
PURPOSE
We evaluated longitudinal changes in the thicknesses of the cpRNFL and GCC in large disc cupping with a normal intraocular pressure (IOP) (<21 mm Hg) and visual field.
METHODS
This retrospective, consecutive case series study included 269 eyes of 269 patients with large disc cupping and normal IOP. We analyzed patient demographics, IOP, central corneal thickness, vertical cup-to-disc ratios using color fundus photography, the thicknesses of the cpRNFL and GCC using RTVue-100, and mean deviation using visual field examinations.
RESULTS
The differences in IOP, vertical cup-to-disc ratios, and mean deviation between the baseline and each follow-up visit were not statistically significant. The baseline average and mean average at 60 months follow-up of the cpRNFL thickness were 106.5±8.5 and 105.1±9.3 μm, respectively; differences between the baseline and each follow-up visit were not statistically significant. The baseline average and mean average at 60 months follow-up of the GCC thickness were 82.8±9. and 81.5±9.2 μm, respectively; differences between baseline and each follow-up visit were not statistically significant.
CONCLUSIONS
The thicknesses of the cpRNFL and GCC did not change in well-maintained optic nerve head findings with normal IOP and visual field during a 5-year follow-up period. Optical coherence tomography evaluations of the thicknesses of the cpRNFL and GCC help accurately diagnose physiological optic disc cupping.
Topics: Humans; Optic Disk; Visual Fields; Retinal Ganglion Cells; Intraocular Pressure; Retrospective Studies; Nerve Fibers; Tomography, Optical Coherence
PubMed: 37327476
DOI: 10.1097/IJG.0000000000002253 -
American Journal of Ophthalmology Oct 2023We used automated image analysis of scanning laser ophthalmoscopy (SLO) to investigate mechanical strains imposed on disc, and retinal and choroidal vessels during...
PURPOSE
We used automated image analysis of scanning laser ophthalmoscopy (SLO) to investigate mechanical strains imposed on disc, and retinal and choroidal vessels during horizontal duction in adults.
DESIGN
Deep learning analysis of optical images.
METHODS
The peripapillary region was imaged by SLO in central gaze, and 35° abduction and adduction, in younger and older healthy adults. Automated image registration was followed by deep learning-based optical flow analysis to track determine local tissue deformations quantified as horizontal, vertical, and shear strain maps relative to central gaze. Choroidal vessel displacements were observed when fundus pigment was light.
RESULTS
Strains in the retina and disc could be quantified in 22 younger (mean ± SEM, 26 ± 5 years) and 19 older (64 ± 10 years) healthy volunteers. Strains were predominantly horizontal and greater for adduction than for abduction. During adduction, maximum horizontal strain was tensile in the nasal hemi-disc, and declined progressively with distance from it. Strain in the temporal hemi-retina during adduction was minimal, except for compressive strain on the disc of older subjects. In abduction, horizontal strains were less and largely confined to the disc, greater in older subjects, and generally tensile. Vertical and shear strains were small. Nasal to the disc, choroidal vessels shifted nasally relative to overlying peripapillary retinal vessels.
CONCLUSIONS
Strain analysis during horizontal duction suggests that the optic nerve displaces the optic canal, choroid, and peripapillary sclera relative to the overlying disc and retina. This peripapillary shearing of the optic nerve relative to the choroid and sclera may be a driver of disc tilting and peripapillary atrophy.
Topics: Adult; Humans; Aged; Optic Disk; Rotation; Retina; Ophthalmoscopy; Lasers; Tomography, Optical Coherence
PubMed: 37343739
DOI: 10.1016/j.ajo.2023.06.008 -
Experimental Eye Research Feb 2024Transient receptor potential vanilloid (TRPV) channels are members of the TRP channel superfamily, which are ion channels that sense mechanical and osmotic stimuli and... (Review)
Review
Transient receptor potential vanilloid (TRPV) channels are members of the TRP channel superfamily, which are ion channels that sense mechanical and osmotic stimuli and participate in Ca signalling across the cell membrane. TRPV channels play important roles in maintaining the normal functions of an organism, and defects or abnormalities in TRPV channel function cause a range of diseases, including cardiovascular, neurological and urological disorders. Glaucoma is a group of chronic progressive optic nerve diseases with pathological changes that can occur in the tissues of the anterior and posterior segments of the eye, including the ciliary body, trabecular meshwork, Schlemm's canal, and retina. TRPV channels are expressed in these tissues and play various roles in glaucoma. In this article, we review various aspects of the pathogenesis of glaucoma, the structure and function of TRPV channels, the relationship between TRPV channels and systemic diseases, and the relationship between TRPV channels and ocular diseases, especially glaucoma, and we suggest future research directions. This information will help to further our understanding of TRPV channels and provide new ideas and targets for the treatment of glaucoma and optic nerve damage.
Topics: Humans; Glaucoma; Sclera; Retina; Trabecular Meshwork; Optic Nerve Injuries; Optic Nerve
PubMed: 38199261
DOI: 10.1016/j.exer.2024.109784 -
BMJ Open Ophthalmology Nov 2023To explore the current research about the role of optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) in dysthyroid optic neuropathy... (Meta-Analysis)
Meta-Analysis
PURPOSE
To explore the current research about the role of optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) in dysthyroid optic neuropathy (DON).
METHODS
Studies in the literature that focused on OCT, OCTA and DON were retrieved by searching PubMed, EMBASE, Cochrane databases and Clinical Trial before 20 June 2023. The methodological quality was assessed using the Newcastle-Ottawa scale. The quantitative calculation was performed using Review Manager V.5.3.
RESULTS
Twelve studies met the eligibility criteria and were included. DON group presented lower macular ganglion cell complex in the overall, superior and inferior hemifields compared with the non-DON group. Furthermore, the ganglion cell layer and inner plexiform layer in DON group was thinner in contrast to the non-DON group. The optic nerve head vessel density was lower in the DON group than that in the non-DON group. A reduction of radial peripapillary capillary vessel density could be seen in the DON group than the non-DON group in overall, inside disc, peripapillary, superior-hemifield, temporal and nasal. Besides, the macular superficial retinal capillary layer of non-DON and DON is lower than the healthy control group.
CONCLUSIONS
This study supported the potential value of OCT and OCTA metrics as novel biomarkers of DON. Ophthalmologists should comprehensively consider the retinal structure and microvasculature in dealing with DON.
ETHICS AND DISSEMINATION
This systematic review included data from published literature and was exempt from ethics approval. Results would be disseminated through peer-reviewed publication and presented at academic conferences engaging clinicians.
PROSPERO REGISTRATION NUMBER
CRD42023414907.
Topics: Humans; Tomography, Optical Coherence; Optic Disk; Angiography; Retinal Ganglion Cells; Optic Nerve Diseases
PubMed: 37996119
DOI: 10.1136/bmjophth-2023-001379 -
International Journal of Molecular... May 2024The ocular glymphatic system subserves the bidirectional polarized fluid transport in the optic nerve, whereby cerebrospinal fluid from the brain is directed along... (Review)
Review
The ocular glymphatic system subserves the bidirectional polarized fluid transport in the optic nerve, whereby cerebrospinal fluid from the brain is directed along periarterial spaces towards the eye, and fluid from the retina is directed along perivenous spaces following upon its axonal transport across the glial lamina. Fluid homeostasis and waste removal are vital for retinal function, making the ocular glymphatic fluid pathway a potential route for targeted manipulation to combat blinding ocular diseases such as age-related macular degeneration, diabetic retinopathy, and glaucoma. Several lines of work investigating the bidirectional ocular glymphatic transport with varying methodologies have developed diverging mechanistic models, which has created some confusion about how ocular glymphatic transport should be defined. In this review, we provide a comprehensive summary of the current understanding of the ocular glymphatic system, aiming to address misconceptions and foster a cohesive understanding of the topic.
Topics: Humans; Glymphatic System; Animals; Optic Nerve; Retina; Eye; Glaucoma
PubMed: 38891923
DOI: 10.3390/ijms25115734 -
JAMA Ophthalmology Apr 2024
Topics: Humans; Retina; Retinal Diseases; Tomography, Optical Coherence; Fluorescein Angiography; Retinal Pigment Epithelium
PubMed: 38451506
DOI: 10.1001/jamaophthalmol.2024.0047 -
Pharmacological Research Jul 2024Melatonin, a versatile hormone produced by the pineal gland, has garnered considerable scientific interest due to its diverse functions. In the eye, melatonin regulates... (Review)
Review
Melatonin, a versatile hormone produced by the pineal gland, has garnered considerable scientific interest due to its diverse functions. In the eye, melatonin regulates a variety of key processes like inhibiting angiogenesis by reducing vascular endothelial growth factor levels and protecting the blood-retinal barrier (BRB) integrity by enhancing tight junction proteins and pericyte coverage. Melatonin also maintains cell health by modulating autophagy via the Sirt1/mTOR pathways, reduces inflammation, promotes antioxidant enzyme activity, and regulates intraocular pressure fluctuations. Additionally, melatonin protects retinal ganglion cells by modulating aging and inflammatory pathways. Understanding melatonin's multifaceted functions in ocular health could expand the knowledge of ocular pathogenesis, and shed new light on therapeutic approaches in ocular diseases. In this review, we summarize the current evidence of ocular functions and therapeutic potential of melatonin and describe its roles in angiogenesis, BRB integrity maintenance, and modulation of various eye diseases, which leads to a conclusion that melatonin holds promising treatment potential for a wide range of ocular health conditions.
Topics: Melatonin; Humans; Animals; Eye Diseases; Eye; Blood-Retinal Barrier
PubMed: 38862072
DOI: 10.1016/j.phrs.2024.107253 -
Proceedings of the National Academy of... Nov 2023Ongoing cell therapy trials have demonstrated the need for precision control of donor cell behavior within the recipient tissue. We present a methodology to guide stem...
Ongoing cell therapy trials have demonstrated the need for precision control of donor cell behavior within the recipient tissue. We present a methodology to guide stem cell-derived and endogenously regenerated neurons by engineering the microenvironment. Being an "approachable part of the brain," the eye provides a unique opportunity to study neuron fate and function within the central nervous system. Here, we focused on retinal ganglion cells (RGCs)-the neurons in the retina are irreversibly lost in glaucoma and other optic neuropathies but can potentially be replaced through transplantation or reprogramming. One of the significant barriers to successful RGC integration into the existing mature retinal circuitry is cell migration toward their natural position in the retina. Our in silico analysis of the single-cell transcriptome of the developing human retina identified six receptor-ligand candidates, which were tested in functional in vitro assays for their ability to guide human stem cell-derived RGCs. We used our lead molecule, SDF1, to engineer an artificial gradient in the retina, which led to a 2.7-fold increase in donor RGC migration into the ganglion cell layer (GCL) and a 3.3-fold increase in the displacement of newborn RGCs out of the inner nuclear layer. Only donor RGCs that migrated into the GCL were found to express mature RGC markers, indicating the importance of proper structure integration. Together, these results describe an "in silico-in vitro-in vivo" framework for identifying, selecting, and applying soluble ligands to control donor cell function after transplantation.
Topics: Infant, Newborn; Humans; Retina; Retinal Ganglion Cells; Stem Cells; Neurogenesis; Cell Movement
PubMed: 37931105
DOI: 10.1073/pnas.2302089120