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Journal of Ophthalmic & Vision Research 2018To report the mouse-like configuration of detached endothelial keratoplasty graft observed on optical coherence tomographic imaging after pre-Descemet's endothelial...
PURPOSE
To report the mouse-like configuration of detached endothelial keratoplasty graft observed on optical coherence tomographic imaging after pre-Descemet's endothelial keratoplasty (PDEK).
CASE REPORT
Three eyes of 3 patients who underwent PDEK and had graft detachment in the initial postoperative period of <2 weeks were examined. Fourier domain optical coherence tomography was performed in all eyes. All 3 patients had partial graft detachment with the detached region involving the central and inferior cornea. One end of the graft formed a thick convex scroll detaching outward, downward, and upward, and the other end was attached to the edematous cornea forming the 'mouse' configuration. The graft was inverted, and rebubbling failed in all 3 eyes. Graft exchange was required.
CONCLUSION
Mouse sign in OCT imaging indicates the possibility of an inverted graft and predicts unsuccessful rebubbling. Graft exchange is required in such eyes.
PubMed: 30090192
DOI: 10.4103/jovr.jovr_1_17 -
Radiology Case Reports Aug 2024Choroidal detachment (CD) is a rare and potentially vision-threatening complication of glaucoma surgery. Inflammation and prolonged ocular hypotony can promote fluid...
Choroidal detachment (CD) is a rare and potentially vision-threatening complication of glaucoma surgery. Inflammation and prolonged ocular hypotony can promote fluid accumulation between the choroid and sclera. Risk factors include trauma, advanced age, use of anticoagulant medications, systemic hypertension, atherosclerosis, and diabetes. CD ultrasound findings will show 2 layers, detaching as far anteriorly as the ciliary bodies, that protrude convexly into the vitreous without extending to the optic disc, often described as the appositional or In contrast, retinal detachments will show a distinct "V" shape due to the retina's fixation to the optic nerve head posteriorly. In the case of hemorrhagic CD, therapy should be targeted at reducing intraocular pressure. In this case, the patient was started on atropine and prednisolone drops and discontinued on all glaucoma medications in the left eye. While serous choroidal detachments are usually benign, persistent choroidal effusions may cause significant morbidity with hemorrhagic CD having a worse prognosis. Point of care ultrasound can help emergency physicians quickly distinguish between choroidal and retinal detachments and thus guide management in a safe and timely manner.
PubMed: 38737180
DOI: 10.1016/j.radcr.2024.04.017 -
Science (New York, N.Y.) Feb 2021Kinesin motors are essential for the transport of cellular cargo along microtubules. How the motors step, detach, and cooperate with each other is still unclear. To...
Kinesin motors are essential for the transport of cellular cargo along microtubules. How the motors step, detach, and cooperate with each other is still unclear. To dissect the molecular motion of kinesin-1, we developed germanium nanospheres as ultraresolution optical trapping probes. We found that single motors took 4-nanometer center-of-mass steps. Furthermore, kinesin-1 never detached from microtubules under hindering load conditions. Instead, it slipped on microtubules in microsecond-long, 8-nanometer steps and remained in this slip state before detaching or reengaging in directed motion. Unexpectedly, reengagement and thus rescue of directed motion was more frequent. Our observations broaden our knowledge on the mechanochemical cycle and slip state of kinesin. This state and rescue need to be accounted for to understand long-range transport by teams of motors.
Topics: Adenosine Triphosphate; Biological Transport; Germanium; Kinesins; Kinetics; Lipid Bilayers; Microtubules; Models, Biological; Nanospheres; Optical Tweezers; Single Molecule Imaging
PubMed: 33574186
DOI: 10.1126/science.abd9944 -
Experimental Eye Research Nov 1992The bleaching and regeneration of rhodopsin in the skate retina was studied by means of fundus reflectometry, both in the normal eyecup preparation and after the retina...
The bleaching and regeneration of rhodopsin in the skate retina was studied by means of fundus reflectometry, both in the normal eyecup preparation and after the retina had been detached and then replaced on the surface of the pigment epithelium (RPE). After bleaching virtually all the rhodopsin in the retinal test area of the normal eyecup, more than 90% of the photopigment was reformed after about 2 hr in darkness; over most of this time course, rhodopsin density rose linearly at a rate of 0.875% min-1 with a half-time of 55 min. Detaching the retina from its pigment epithelium resulted in a number of abnormalities, both structural and functional. Histological examination of the detached/replaced (D/R) retina showed striking alterations in the structural integrity of the RPE cells at their interface with the neural retina. The cells appeared vacuolated and misshapen, and the apical processes of the RPE, which normally ensheath the receptor outer segments, were shredded and free of their association with the visual cells. These morphological changes, as well as dilution of the IRBP content of the subretinal space caused by separation of the tissues, appear to be the main factors contributing to the functional abnormalities in rhodopsin kinetics. But despite these abnormalities and the persistent detachment, the rate of regeneration and the amount of rhodopsin reformed after bleaching were reduced by less than 50% of their normal values. The fact that a significant fraction of the bleached rhodopsin was regenerated under these conditions indicates that 11-cis retinal formed in the RPE was able to traverse a much greater than normal subretinal space to reach the opsin-bearing photoreceptor membranes.
Topics: Animals; Photic Stimulation; Pigment Epithelium of Eye; Retina; Rhodopsin; Skates, Fish
PubMed: 1478278
DOI: 10.1016/0014-4835(92)90173-p -
Investigative Ophthalmology & Visual... Jul 1988The local ERG (LERG) from detached retina within the intact rabbit eye has been recorded. Retinal detachments were made in Dutch rabbit eyes by injecting Hanks' balanced...
The local ERG (LERG) from detached retina within the intact rabbit eye has been recorded. Retinal detachments were made in Dutch rabbit eyes by injecting Hanks' balanced salt solution into the subretinal space through a glass micropipette. Electrical responses were recorded with a double-barrelled microelectrode that was advanced through the vitreous until the tip penetrated the retina to enter the subretinal space while the other tip remained in the vitreous. Recordings from detached retina showed an initial fast positive, fast negative and late slow positive wave. The waveform and stimulus response characteristics of these waves (inverted) corresponded to the a-, b-wave and slow PIII respectively. None of the LERG waves was affected by intravenous sodium iodate and only the slow positive wave was extinguished by intravitreal barium chloride. This system for recording the LERG may be useful in investigating physiological changes in detached retina in vivo.
Topics: Animals; Aspartic Acid; Electroretinography; Rabbits; Reaction Time; Retina; Retinal Detachment; Synaptic Transmission; Vitreous Body
PubMed: 2843478
DOI: No ID Found -
Radiology Feb 1991The sonographic criteria for diagnosis of retinal detachment and vitreous membranes are well established, and in most cases a diagnosis can be made. However, in...
The sonographic criteria for diagnosis of retinal detachment and vitreous membranes are well established, and in most cases a diagnosis can be made. However, in difficult cases, differentiation between the two may be difficult. In this study the use of high-resolution color flow Doppler was evaluated for differentiating between retinal detachments and vitreous membranes. Sonographic evaluation, including color flow Doppler, was performed in 25 symptomatic eyes. Seven eyes had areas of retinal detachment, all of which had detectable blood flow within at least a portion of the detached retina. Fifteen eyes had vitreous hemorrhages or membranes in which no flow was detected. Two diabetic patients with vitreous membranes and no retinal detachment did have flow detectable within the neovascular membranes. Another patient, who had a complete choroid detachment after surgery, demonstrated good flow within the area of detachment. It is concluded that in difficult cases high-resolution color flow Doppler can enable differentiation of an area of retinal detachment from a vitreous membrane in a patient without diabetes.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Diagnosis, Differential; Female; Humans; Male; Middle Aged; Regional Blood Flow; Retinal Detachment; Retinal Vessels; Ultrasonography; Vitreous Body; Vitreous Hemorrhage
PubMed: 1987604
DOI: 10.1148/radiology.178.2.1987604 -
The Journal of Comparative Neurology Feb 2001The lectin peanut agglutinin (PNA) and antibodies to short (S)- and medium to long wavelength (M/L)-sensitive cones were utilized in order to define the relative...
The lectin peanut agglutinin (PNA) and antibodies to short (S)- and medium to long wavelength (M/L)-sensitive cones were utilized in order to define the relative distributions of the two spectral types of cone across the domestic cat's retina. These values, in turn, were compared to those from retinas that had been experimentally detached from the retinal pigment epithelium. The pattern of cone distribution in the normal cat's retina is established by the preponderance of M-cones that constitute between 80% and 90% of all cones. Their peak density of over 26,000 cells/mm(2) resides at the area centralis. Though M-cone density decreases smoothly to the ora serrata where they have densities as low as 2,200 cells/mm(2), the density decrease along the nasotemporal axis is slower,creating a horizontal region of higher cone density. S-cones constitute between 10% and 20% of all cones, the number being quite variable even between individual animals of similar age. The highest S-cone densities are found in three distinct locations: at the superior far periphery near the ora serrata, immediately at the area centralis itself, and in a broad zone comprising the central and lower half of the inferior hemiretina. S-cones in the cat retina do not form a regular geometrical array at any eccentricity. As for the detached cat retina, the density of labeled S-cone outer segments (OS) decreases rapidly as early as 1 day postdetachment and continues decreasing to day 28 when the density of cones labeling with anti-S opsin has dropped to less than 10% of normal. This response points to a profound difference between rods and cones; essentially all rods, including those without OS, continue to express their opsin even in long-term detachments. The implications of these results for visual recovery after retinal reattachment are discussed.
Topics: Animals; Calbindins; Cats; Cell Count; Cell Death; Female; Immunohistochemistry; Nerve Regeneration; Peanut Agglutinin; Recovery of Function; Retinal Cone Photoreceptor Cells; Retinal Detachment; Rhodopsin; Rod Opsins; S100 Calcium Binding Protein G; Vision, Ocular
PubMed: 11169472
DOI: 10.1002/1096-9861(20010212)430:3<343::aid-cne1035>3.0.co;2-u -
Scientific Reports Apr 2018Continuous approaching and detaching displacement usually occurs in an adhesion test. Here, we found a transient adhesion force at the end of a non-fully detached...
Continuous approaching and detaching displacement usually occurs in an adhesion test. Here, we found a transient adhesion force at the end of a non-fully detached contact. This force occurred when the nominal detaching displacement was less than the traditional quasi-static theory predicted zero force point. The transient adhesion force was ascribed to interfacial adhesion hysteresis, which was caused by the cracking process of the contact and the deformation competition between the sphere and supporting spring. Results indicated that the testing of adhesion can be significantly affected by different combinations of stiffnesses of the contact objects and the supporting spring cantilever. This combination should be carefully designed in an adhesion test. All these results enabled increased understanding of the nature of adhesion and can guide the design of adhesive actuators.
PubMed: 29670291
DOI: 10.1038/s41598-018-24587-6 -
Retina (Philadelphia, Pa.) Jun 2008The presence of lipocalin-like prostaglandin D synthase (L-PGDS), a dominantly brain derived protein in the cerebrospinal fluid (CSF) with a low concentration in serum,...
BACKGROUND
The presence of lipocalin-like prostaglandin D synthase (L-PGDS), a dominantly brain derived protein in the cerebrospinal fluid (CSF) with a low concentration in serum, in the subretinal fluid (SRF) of detached retinas, has not been reported. L-PGDS has been demonstrated in the ciliary body and the retinal pigment epithelium in rats.
METHODS
SRF was sampled during surgery (scleral buckling) of rhegmatogenous retinal detachments in 20 eyes. Biochemical and nephelometric analysis for L-PGDS concentration were performed. Albumin concentrations were determined in the same samples.
RESULTS
L-PGDS concentrations in SRF (mean 18.9 mg/L +/- 14.8 mg/L) were markedly higher than the normal L-PGDS concentration in serum (<0.55 mg/L) and appears to decrease with the duration of the retinal detachment (P = 0.0064).
CONCLUSIONS
As the subretinal space is not accessible in attached retinas there are no data on normal levels of L-PGDS in the subretinal space. The L-PGDS concentrations measured in the SRF of detached retinas are on average 34 times higher than normal L-PGDS serum concentration and about in the range of normal L-PGDS CSF concentration (15.3 mg/L). As the concentrations of L-PGDS exceed normal serum levels, a choriocapillary transudation is highly improbable as the source of L-PGDS in SRF of detached retinas.
Topics: Aged; Aged, 80 and over; Body Fluids; Exudates and Transudates; Female; Humans; Intramolecular Oxidoreductases; Lipocalins; Male; Middle Aged; Nephelometry and Turbidimetry; Retinal Detachment; Scleral Buckling; Time Factors
PubMed: 18536603
DOI: 10.1097/IAE.0b013e3181631975 -
Graefe's Archive For Clinical and... Aug 2004Posterior vitreous detachment (PVD) is the consequence of changes in the macromolecular structure of gel vitreous that result in liquefaction, concurrent with... (Review)
Review
Posterior vitreous detachment (PVD) is the consequence of changes in the macromolecular structure of gel vitreous that result in liquefaction, concurrent with alterations in the extracellular matrix at the vitro-retinal interface that allow the posterior vitreous cortex to detach from the internal limiting lamina of the retina. Gel liquefaction that exceeds the degree of vitro-retinal dehiscence results in anomalous PVD (APVD). APVD varies in its clinical manifestations depending upon where in the fundus vitreo-retinal adhesion is strongest. At the periphery, APVD results in retinal tears and detachments. In the macula, APVD causes vitreo-macular traction syndrome, results in vitreoeschisis with macular pucker or macular holes, or contributes to some cases of diabetic macular edema. At the optic disc and retina, APVD causes vitreo-papillary traction and promotes retinal and optic disc neovascularization. Unifying the spectrum of vitreo-retinal diseases into the conceptual frame-work of APVD underscores that to more effectively treat, and ultimately prevent, these disorders it is necessary to replicate the two components of an innocuous PVD, i.e., gel liquefaction and vitreo-retinal dehiscence. Pharmacologic vitreolysis is designed to mitigate against APVD by chemically breaking down vitreous macromolecules and weakening vitro-retinal adhesion to safely detach the posterior vitreous cortex. This would not only facilitate surgery, but if performed early in the natural history of disease, it should prevent progressive disease.
Topics: Animals; Eye Diseases; Humans; Retinal Diseases; Vitreous Body; Vitreous Detachment
PubMed: 15309558
DOI: 10.1007/s00417-004-0980-1