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Retinal Cases & Brief Reports Jan 2024To report a case of peripapillary subretinal fluid associated with a ridge-shaped morphology surrounding the optic disk, which we termed ridge-shaped peripapilla.
PURPOSE
To report a case of peripapillary subretinal fluid associated with a ridge-shaped morphology surrounding the optic disk, which we termed ridge-shaped peripapilla.
METHODS
Case report.
RESULTS
A 6-year-old girl with mild-to-moderate myopia was referred for an abnormal fundus appearance of the left eye. Fundus examination of the left eye showed a vertical whitish elevation just temporal to the disk with pigment clumping. Spectral domain optical coherence tomography of the left eye showed an elevation of the fundus at the temporal edge of the disk with thinning of the choroid overlying the thickened scleral protrusion and a serous subretinal fluid. Fluorescein angiography of the left eye showed a hyperfluorescent area without leakage at the temporal edge of the disk, indicative of retinal pigment epithelium atrophy. There was no sign of choroidal neovascularization. Based on the fluorescein angiography and optical coherence tomography findings, the protrusion of the sclera seemed to result in overlying choroidal thinning with choroidal blood flow disturbances, and consequent retinal pigment epithelium atrophy, leading to the subretinal fluid.
CONCLUSION
This case highlights an unusual presentation of ridge-shaped peripapilla, characterized by inward convexity of the peripapillary area with a ridge-shaped morphology and localized thickening of the peripapillary sclera, in eyes with myopia.
Topics: Female; Humans; Child; Choroid; Fundus Oculi; Optic Disk; Tomography, Optical Coherence; Atrophy; Myopia; Fluorescein Angiography
PubMed: 36007179
DOI: 10.1097/ICB.0000000000001308 -
Survey of Ophthalmology 2022Superior segmental optic nerve hypoplasia (SSONH) is a congenital condition characterized by developmental abnormalities of the superior optic disc and an... (Review)
Review
Superior segmental optic nerve hypoplasia (SSONH) is a congenital condition characterized by developmental abnormalities of the superior optic disc and an underappreciated differential diagnosis for glaucoma. The reported prevalence is less than 1%, although likely underestimated due to the difficulties with diagnosis. The exact pathophysiology of SSONH remains elusive, but a mechanism involving developmental attrition of retinal ganglion cells has been proposed, and maternal diabetes is recognized as a major risk factor. SSONH often is observed incidentally, and the patients typically are then evaluated for an acquired optic atrophy, often glaucoma because of the presence of inferior visual field defects. There are 4 characteristic signs of SSONH: superior entrance of the central retinal artery, superior disc pallor, superior peripapillary halo, and thinning of the superior peripapillary nerve fiber layer; however, the presence of these signs is variable. Optical coherence tomography can be helpful in distinguishing SSONH by demonstrating superonasal retinal nerve fiber layer thinning, as compared to the inferotemporal thinning seen in glaucoma, and an aberrant extension of retinal pigment epithelium over Bruch membrane. Overall, the prognosis of SSONH is favorable, with a non-progressive course. It is essential that ophthalmologists recognize and differentiate SSONH from glaucoma to avoid misdiagnosis and unnecessary treatment.
Topics: Glaucoma; Humans; Optic Disk; Optic Nerve Hypoplasia; Retinal Ganglion Cells; Tomography, Optical Coherence; Visual Field Tests
PubMed: 35189184
DOI: 10.1016/j.survophthal.2022.02.008 -
Bioelectromagnetics Feb 2022Vitreous "floaters" are a common entoptic phenomenon that can result in significant reduction in quality of life in a proportion of sufferers. The authors use a...
Vitreous "floaters" are a common entoptic phenomenon that can result in significant reduction in quality of life in a proportion of sufferers. The authors use a computational mathematical model based on Fourier optics and reflection and transmission coefficients calculated for a planar type II collagen opacity suspended in aqueous to show that floaters are perceived by the patient through interference effects that result in significant variations in intensity on the retina when viewing a constant brightness surface. The model also predicts that backscattered intensity from floaters is ten thousand to one million times lower than the variations in intensity produced on the retina, which demonstrates that the visible effects of floaters for the patient can be highly significant, whereas clinical observation of the vitreous may be entirely unremarkable. Importantly, the results also demonstrate that floaters do not need to be opaque to cause symptoms, with only small differences in refractive index between the floater material and the surrounding vitreous needed to produce significant optical effects. The model predicts that pupil size is an important factor in determining the severity of symptoms from floaters, with constricted pupils giving much greater effect than dilated pupils. Finally, the authors' model predicts that floaters degrade contrast sensitivity function, with greatest degradation occurring in the 5-40 cycles per degree spatial frequency range and that the effects of shadowing caused by floaters are very strongly correlated to the predicted degradation of contrast sensitivity function. Bioelectromagnetics. 43:90-105, 2022. © 2021 The Authors. Bioelectromagnetics published by Wiley Periodicals LLC on behalf of Bioelectromagnetics Society.
Topics: Eye Diseases; Humans; Quality of Life; Retina; Vitreous Body
PubMed: 34969150
DOI: 10.1002/bem.22386 -
Progress in Biophysics and Molecular... Sep 2018In the vertebrate embryo, the eyes develop from optic vesicles that grow laterally outward from the brain tube and contact the overlying surface ectoderm. Within the... (Review)
Review
In the vertebrate embryo, the eyes develop from optic vesicles that grow laterally outward from the brain tube and contact the overlying surface ectoderm. Within the region of contact, each optic vesicle and the surface ectoderm thicken to form placodes, which then invaginate to create the optic cup and lens pit, respectively. Eventually, the optic cup becomes the retina, while the lens pit closes to form the lens vesicle. Here, we review current hypotheses for the physical mechanisms that create these structures and present novel three-dimensional computer (finite-element) models to illustrate the plausibility and limitations of these hypotheses. Taken together, experimental and numerical results suggest that the driving forces for early eye morphogenesis are generated mainly by differential growth, actomyosin contraction, and regional apoptosis, with morphology mediated by physical constraints provided by adjacent tissues and extracellular matrix. While these studies offer new insight into the mechanics of eye development, future work is needed to better understand how these mechanisms are regulated to precisely control the shape of the eye.
Topics: Animals; Biomechanical Phenomena; Eye; Humans; Lens, Crystalline; Mechanical Phenomena
PubMed: 29432780
DOI: 10.1016/j.pbiomolbio.2018.01.004 -
Ophthalmologica. Journal International... 2016To assess the clinical application of multicolor imaging by confocal scanning laser ophthalmoscopy (cSLO). (Review)
Review
PURPOSE
To assess the clinical application of multicolor imaging by confocal scanning laser ophthalmoscopy (cSLO).
METHODS
Retinal imaging was performed in 76 patients including cSLO multicolor imaging (SPECTRALIS SD-OCT, Heidelberg Engineering, Heidelberg, Germany) and color fundus photography (CFP).
RESULTS
The use of confocal optics, reduced light scatter and automated eye tracking enable high-resolution cSLO reflectance images. Compared to CFP, the appearance of pigment alterations and hemorrhages were some of the differences observed. Various artifacts including those derived from optical media alterations need to be considered when interpreting images. Specific pathological findings including epiretinal membranes, fibrovascular proliferations, and reticular pseudodrusen may be better visualized on multicolor images.
CONCLUSIONS
When using multicolor imaging, ophthalmologists need to be mindful about differences in the appearance of pathological changes and artifacts. Multicolor imaging may offer information over and above conventional CFP; it can be performed through undilated pupils and is less affected by media opacities.
Topics: Diagnostic Imaging; Fluorescein Angiography; Fundus Oculi; Humans; Ophthalmoscopy; Optics and Photonics; Photography; Retina; Retinal Drusen; Retinal Pigment Epithelium; Tomography, Optical Coherence
PubMed: 27404384
DOI: 10.1159/000446857 -
Journal of Visualized Experiments : JoVE Apr 2023The ocular micro-dissection of the rodent eye involves the segmentation of the enucleated eyeball with the attached nictitating membrane, or third eyelid, to obtain the...
The ocular micro-dissection of the rodent eye involves the segmentation of the enucleated eyeball with the attached nictitating membrane, or third eyelid, to obtain the anterior and posterior eyecups. With this technique, the sub-parts of the eye, including the corneal tissue, neural tissue, retinal pigment epithelial (RPE) tissue, and lens, can be obtained for wholemounts, cryo-sectioning, and/or single-cell suspensions of a specific ocular tissue. The presence of the third eyelid presents unique and significant advantages, as it benefits the maintenance of the orientation of the eye, which is important for understanding eye physiology following any localized intervention or in studies involving ocular analysis relating to the eye's spatial topography. In this method, we enucleated the eyeball at the socket along with the third eyelid by carefully and slowly cutting through the extraocular muscles and severing the optic nerve. The eyeball was pierced through the corneal limbus using a microblade. The incision was used as the point of entry, allowing for cutting along the corneal-scleral junction by inserting micro-scissors through the incision point. Small and continuous cuts along the circumference were made until the cups separated. These could be further dissected by gently peeling the translucent layer of the neural retina using Colibri suturing forceps to obtain the neural retina and RPE layers. Further, three/four equidistant cuts were made from the periphery perpendicularly to the optic center until the optic nerve was reached. This opened the hemispherical cups into a floret shape so that they fell flat and could be easily mounted. This technique has been used in our lab for corneal wholemounts and retinal sections. The presence of the third eyelid delineates the nasal-temporal orientation, which allows for the study of various cell therapy interventions post-transplantation and, thus, the targeted physiological validation vital for visualization and accurate representation in such studies.
Topics: Animals; Microdissection; Eye; Retina; Retinal Pigment Epithelium; Lens, Crystalline; Cornea
PubMed: 37154568
DOI: 10.3791/64414 -
Eye (London, England) Oct 2015Glaucoma is one of the leading causes of blindness worldwide and will affect 79.6 million people worldwide by 2020. It is caused by the progressive loss of retinal... (Review)
Review
Glaucoma is one of the leading causes of blindness worldwide and will affect 79.6 million people worldwide by 2020. It is caused by the progressive loss of retinal ganglion cells (RGCs), predominantly via apoptosis, within the retinal nerve fibre layer and the corresponding loss of axons of the optic nerve head. One of its most devastating features is its late diagnosis and the resulting irreversible visual loss that is often predictable. Current diagnostic tools require significant RGC or functional visual field loss before the threshold for detection of glaucoma may be reached. To propel the efficacy of therapeutics in glaucoma, an earlier diagnostic tool is required. Recent advances in retinal imaging, including optical coherence tomography, confocal scanning laser ophthalmoscopy, and adaptive optics, have propelled both glaucoma research and clinical diagnostics and therapeutics. However, an ideal imaging technique to diagnose and monitor glaucoma would image RGCs non-invasively with high specificity and sensitivity in vivo. It may confirm the presence of healthy RGCs, such as in transgenic models or retrograde labelling, or detect subtle changes in the number of unhealthy or apoptotic RGCs, such as detection of apoptosing retinal cells (DARC). Although many of these advances have not yet been introduced to the clinical arena, their successes in animal studies are enthralling. This review will illustrate the challenges of imaging RGCs, the main retinal imaging modalities, the in vivo techniques to augment these as specific RGC-imaging tools and their potential for translation to the glaucoma clinic.
Topics: Apoptosis; Axons; Diagnostic Imaging; Diagnostic Techniques, Ophthalmological; Glaucoma; Humans; Optic Disk; Optic Nerve Diseases; Retinal Ganglion Cells
PubMed: 26293138
DOI: 10.1038/eye.2015.154 -
Romanian Journal of Ophthalmology 2017For many years, amblyopia was regarded as a disorder of the visual system in which an organic cause could not be identified. Optical Coherence Tomography opens new... (Review)
Review
For many years, amblyopia was regarded as a disorder of the visual system in which an organic cause could not be identified. Optical Coherence Tomography opens new horizons in understanding the etiopathology of amblyopia and seems to highlight morphologic anomalies in the retina of the amblyopic eye. The objective of this paper is to analyze the macular thickness, optic nerve changes, and choroidal thickness found in patients diagnosed with amblyopia based on trials reported in the literature. This study analyzes 30 clinical trials regarding amblyopia evaluation with Optical Coherence Tomography. The research articles analyzed were published between 2006 - 2016 and were identified on PubMed database. 19 research studies focused on macular and nerve optic changes, 7 on choroidal changes and 6 on retinal changes after occlusion. The results were discussed according to the type of amblyopia, alteration of macular thickness, optic nerve changes, ganglion cell layer changes, and alteration of choroidal thickness. The results are of great variability, and it seems that macula and choroid involvement is more frequently suggested compared with optic nerve involvement. OCT = Optical Coherence Tomography, RNFL = Retinal Nerve Fiber Layer, GCC = Ganglion Cell Complex, ACD = Anterior Chamber Depth, BCVA = Best Corrected Visual Acuity.
Topics: Amblyopia; Animals; Humans; Macula Lutea; Nerve Fibers; Retinal Ganglion Cells; Tomography, Optical Coherence
PubMed: 29450380
DOI: 10.22336/rjo.2017.18 -
Anatomia, Histologia, Embryologia May 2019The cellular structure and functional relevance of the bird fovea are still incompletely understood. This review gives an overview of the cellular composition of the... (Review)
Review
The cellular structure and functional relevance of the bird fovea are still incompletely understood. This review gives an overview of the cellular composition of the bird fovea, with special regard to Müller glial cells that provide the mechanical stability of the foveal tissue. A survey of previous data shows that the visual acuity of different bird groups (with the exception of owls) depends on the eye size, while the shape of the foveal pit does not correlate with the visual acuity. Among various bird groups, the foveal pit may have two depths, shallow (80-120 µm) or deep (190-240 µm). There is a long-lasting debate whether the bird fovea acts as a local image enlarger or as a focus indicator and movement detector. These functions are supported by the refraction of the incoming light at the tissue surface. However, it was shown that Müller cells form highly refractive layers in the centre and walls of the deep avian fovea (Nature, 1978, 275, 127). Analysis of the light path through the tissue may suggest that Müller cell layers serve at least two optical functions: magnification of the image in the foveal centre and light focusing into a point within and/or a ring around the foveal centre. It is suggested that Müller glial cells contribute to various optical functions of the bird fovea.
Topics: Animals; Birds; Eagles; Fovea Centralis; Neuroglia; Photoreceptor Cells, Vertebrate; Retina; Strigiformes
PubMed: 30734347
DOI: 10.1111/ahe.12432 -
Ophthalmic & Physiological Optics : the... Jan 2024To analyse ocular coherence tomography (OCT) images of the retinal shadows caused by defocus and diffusion optics spectacles.
PURPOSE
To analyse ocular coherence tomography (OCT) images of the retinal shadows caused by defocus and diffusion optics spectacles.
METHODS
One eye was fitted successively with the Hoya Defocus Incorporated Multiple Segments (DIMS) spectacle lens, two variations of the +3.50 D peripheral add spectacle (DEFOCUS) and the low-contrast dot lens (Diffusion Optics Multiple Segments, DOMS); each at a vertex distance of 12 mm. Simultaneously, a retinal image of the macular region with central fixation was obtained using infrared OCT. The corneal power and intraocular distances were determined using an optical biometer.
RESULTS
The retinal images for the DIMS and DOMS lenses showed patterns of obvious retinal shadows in the periphery, while the central 10-11° remained clear. The DEFOCUS lens produced a darkened peripheral area. Dividing the size of the retinal pattern, measured with the calliper of the OCT software, by the actual size on the spectacle lens gave a magnification of -0.57 times. This is consistent with the incoming OCT beam being imaged to a position approximately 31 mm beyond the front of the eye. [Correction added on 26 October 2023 after first online publication: The preceding paragraph was corrected.] CONCLUSION: With device-specific correction, retinal OCT images can help visualise the regions affected by the defocus or lowered contrast induced by myopia control spectacles. This is of potential value for improving myopia therapies.
Topics: Humans; Refraction, Ocular; Eyeglasses; Myopia; Retina; Lens, Crystalline
PubMed: 37642972
DOI: 10.1111/opo.13228