Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “OPTICS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources
PubMed2001

Endoscopic optic nerve decompression for the treatment of traumatic optic neuropathy.

Optic nerve decompression has been accomplished by a variety of procedures. Since 1995, endoscopic optic nerve decompression (EOND) has been used to treat traumatic optic neuropathy (TON) patients in our hospital after medical treatment failed. To date, 17 TON patients have received EOND in our hospital and have been followed up for more than half a year. After decompression, vision improved in 9 patients, remained the same in 6, and became worse in 2. The dura was incidentally exposed during the operation in 1 patient. We conclude that it is easier and more precise to perform optic nerve decompression by EOND than by other optic nerve decompression procedures. However, its efficacy still needs further investigation.

Adolescent↗
PubMed2002

[A case of orbital myositis complicated with optic neuropathy--analysis of the pathological mechanism of optic neuropathy from magnetic resonance imaging findings].

BACKGROUND: We observed a rare case of orbital myositis involving the optic nerve. CASE: A 52-year-old woman complained of visual disturbance, lid swelling, ocular pain, and conjunctival injection in her right eye. Her corrected vision was 0.15 in the right eye and 1.2 in the left eye. Relative afferent pupillary defect(RAPD) and central scotoma in visual field test were noted in the right eye. Ocular movement of her right eye was moderately disturbed in all directions. Although laboratory data showed elevation of erythrocyte sedimentation rate, other hematological data such as thyroid function, autoimmune antibodies, and viral infection antibodies were normal. Magnetic resonance imaging(MRI) findings showed compression of the optic nerve at the orbital apex by marked thickening of the right lateral rectus muscle and superior rectus muscle, and inflammation directly invading the optic nerve. Based on the above findings, we diagnosed the case as orbital myositis complicated with optic neuropathy, and started corticosteroid therapy. Her right corrected vision improved dramatically, and the RAPD, central scotoma, and lid swelling disappeared shortly after administration. Enlargement of the extraocular muscles was still present one month after corticosteroid therapy. CONCLUSION: MRI findings suggested that optic neuropathy in this case was induced not only by mechanical compression by the enlarged extraocular muscles at the orbital apex but also by direct inflammatory infiltration from the extraocular muscles.

Female↗
PubMed2003

[Arterial microcirculation in the optic chiasm, optic tracts and lateral geniculate bodies].

OBJECTIVES: The purpose of this study was to point out the microscopic vessels in the optic chiasm, optic tracts and lateral geniculate bodies. MATERIAL AND METHODS: This study was carried out on 20 brains, fixed in formaldehyde 10% and dissected under the surgical microscope. The material was summated to histological techniques on paraffin and performed on routine coloration. RESULTS: The lateral borders of the optic chiasm have more perforant branches as the median zone. The anterior and posterior segments of the optic tracts are rich in capillary vessels. The arteriolar branches penetrate into the lateral geniculate body on his inferior surface and borders. CONCLUSIONS: The knowledge of the arteriolar distribution in this segments of the optic pathways can explain the visual defects in some neuroophthalmologic syndromes.

Arterioles↗
PubMed2005

[Transnasal optic nerve decompression for optic nerve injury].

OBJECTIVE: To investigate the feasibility, techniques and advantages of the treatment of optic nerve injury by intranasal endoscopic surgery. METHOD: This retrospective study presents the results of 39 cases (40 optic nerves) of indirect optic neuropathy where surgical decompression represented the primary mode of treatment within 2-18 days after trauma. The surgery is performed using the transethmoidal or trans-sphenoid technique. The optic nerve canal and fracture line are located in Onodi cells or lateral wall of sphenoid sinus. The optic nerve and its sheath are exposed, and the nose is packed by gelfoam; The medication and Hyperbaric oxygen are used after surgical. RESULT: The following up period is at least 3 months. The total effective rate of visual improvement was 60%, and the effective rate operating within 2-7 days or 8-18 days after trauma turned out to be 66.7% and 30%. CONCLUSION: The endoscopic technique offers several advantages over other surgical approaches. It provides excellent visualization of the surgical site, avoids the morbidity associated with intracranial and external exeracranial approaches and offers the best option for recovery of useful vision. With the development of this technique, the indication should be extended. The prognosis had correlated with the degree of trauma, days until surgery and surgical technique.

Adolescent↗
PubMedDate not supplied

The optic neurogram: evaluation of CSF "block" caused by compressive lesions at the optic canal.

Patients with progressive blindness resulting from bony proliferative diseases such as osteopetrosis may benefit from optic canal decompression. A radiologic technique is described whereby the practicality of surgical optic canal widening is evaluated preoperatively using the intrathecal water-soluble contrast agent lopamidol. Conceptually, if a patient who is losing vision demonstrates a block on the optic neurogram, then likely there is still sufficient neural tissue within the optic canal and sheath to cause obstruction, and therefore decompression may be indicated. However, if preoperatively there is no block to lopamidol, then surgical intervention is not indicated, as the nerve has already undergone severe atrophy to the point of "autodecompression." Cases of differing etiologies, with and without blocks, illustrate the utility of the method and point out the importance of early surgical management to prevent irreversible damage to the optic nerve.

Adolescent↗
PubMed1996

Septo-optic dysplasia associated with cerebral cortical dysplasia (cortico-septo-optic dysplasia).

It is generally accepted that there are two subsets of septo-optic dysplasia (deMorsier's syndrome), one with schizencephaly and the other without schizencephaly. A third form of the anomaly which is associated with callosal absence has also been described. Except for schizencephaly, the association of septo-optic dysplasia with another major type of disorder of neuronal migration and organization such as cortical dysplasia, has not yet been reported. We report the MR imaging examination of a 3-year-old patient with bilateral rolandic cortical dysplasia, and with apparent thinning of the optic nerves, and absent septum pellucidum (septo-optic dysplasia) as a new combination. This can be labelled as cortico-septo-optic dysplasia.

Agenesis of Corpus Callosum↗
PubMed1997

Increase in extracellular calcium in the optic tectum of fish after optic nerve transection.

In this study the extracellular distribution of cytochemically generated calcium reaction product in the denervated optic tectum of a cichild fish (Oreochromis mossambicus) was investigated. The left optic nerve had been transected and the fish (5 per experimental condition) maintained for 2, 10 and 21 days. The amount of the calcium-containing precipitates was estimated using energy-filtering transmission electron microscopy (EFTEM) and image analysis. A special degeneration type of the optic terminals (neurofibrillar hypertrophy) was found which seems to be rare in other teleosts and was therefore chosen for quantification of the calcium deposits. These terminals are surrounded by astroglial processes and the calcium reaction product in the extracellular spaces between these glial processes and the terminals was measured and compared to normal optic terminals in nonoperated controls. A distinct and significant increase in the amount of calcium deposits was found 2 and 10 days after surgery which decreased to control levels after 21 days. This rise of deposits around the degenerating terminals was very local as arbitrarily selected extracellular spaces near these terminals showed values which were at the level of the nonoperated controls. Therefore, a transient and local increase in extracellular calcium precipitates was found after optic nerve transection which affected only the degenerating synapses.

Animals↗
PubMedDate not supplied

[The prognostic significance of the electrophysiological indices of the retina and optic nerve in patients with opacities of the optical media of the eye].

Prognostic significance of the main electrophysiological parameters (electroretinogram, electrocoagulogram, visual evoked potentials), and electric sensitivity of the eye in diseases of the retina and optic nerve, and their informative value in patients with opaque optic media of the eye are discussed. The authors note that decrease of the total retinal biopotential and constant potential not always characterize the level of its viability (in retinitis pigmentosa, detachment, vitreous opacities, etc.). Insufficient informative value of visual evoked potentials in patients with opaque optic media is explained by impossibility of presenting pattern stimuli. Many-year clinical experience gained in study of electric sensitivity in more than 40,000 patients with diseases of the neuroreceptor system of the eye brought the authors to a conclusion that this method allows rapid assessment of the total area of visual field and optic nerve conductivity. Study of the threshold electric sensitivity in patients with opaque optic media is in fact the only method for assessing peripheral vision and viability of a detached retina.

Animals↗
PubMed2006

Assessment of retinal nerve fiber layer using optical coherence tomography and scanning laser polarimetry in progressive glaucomatous optic neuropathy.

PURPOSE: To describe a case of progressive glaucomatous optic neuropathy using scanning laser polarimetry with fixed (SLP-FCC) and variable corneal compensation (SLP-VCC) and optical coherence tomography (OCT). DESIGN: Observational case report. METHODS: A 21-year-old male with juvenile primary open-angle glaucoma developed progression because of noncompliance with therapy. The patient underwent dilated stereoscopic examination and photography of the optic disk, standard automated perimetry (SAP), OCT, and SLP imaging with FCC and VCC at the baseline examination and after four years of follow-up. RESULTS: Optic disk, retinal nerve fiber layer (RNFL) atrophy, and SAP progression was observed. Reduction in mean RNFL thickness (average, superior, inferior) was 18, 18, and 27 microns (OCT); 22, 40, and 17 microns (SLP-FCC); and 6, 12, and 12 microns (SLP-VCC), respectively. CONCLUSIONS: This case demonstrates that digital imaging of the peripapillary RNFL is capable of documentation and measurement of progressive glaucomatous RNFL atrophy.

Adult↗
PubMed1995

[Computer controlled analysis of the optic papilla in patients with anterior ischemic optic neuropathy].

BACKGROUND: In patients with non-arteritic anterior ischaemic optic neuropathy disc parameters have been measured with a largely objective method (Optic Nerve Head Analyzer). We wanted to find out, whether the measurements of different disc parameters allow an assertion of predisposition to AION. METHODS: Measurements have been done with the Optic Nerve Head Analyzer (ONHA). In 25 patients with AION disc area and neuroretinal rim area was measured in the nonaffected fellow eye. The results were compared to those of 19 healthy subjects. In 12 of the 25 patients the disc structure of the AION-eye was measured over time with an average of 4 measurements in 16 months. RESULTS: 1) Disc area and neuroretinal rim area of the AION-eyes do not differ significantly from those of the healthy subjects. 2) Disc area and neuroretinal rim area of the healthy fellow eyes of the AION patients were not significantly different from those of the healthy subjects. 3) Measurements of disc parameters over time did not show significant differences between the parameters of the beginning of AION and after 16 months. CONCLUSIONS: Measurements of disc area and neuroretinal rim area with the Optic Nerve Head Analyzer do not allow assertions of predisposition to AION.

Adult↗
PubMed2005

Comparing glaucomatous optic neuropathy in primary open angle and chronic primary angle closure glaucoma eyes by optical coherence tomography.

PURPOSE: To comparatively evaluate the optic nerve head (ONH) using Optical Coherence Tomography (OCT) in normal subjects, primary open angle glaucoma (POAG) and chronic primary angle closure glaucoma (CPACG) patients. METHODS: A total of 138 normal eyes (138 subjects) and 139 glaucomatous eyes (139 patients), were evaluated in this cross-sectional observational study. The ONH was imaged on OCT using the optic disc scan. Disc area, cup area, rim area, vertical integrated rim area (VIRA), rim volume (horizontal integrated rim volume), average cup/disc ratio, horizontal and vertical cup/disc ratios, and cup volume were evaluated. Additionally, cup depth and slope of the temporal ONH were also measured. These ONH parameters were compared between normal subjects and eyes with early POAG and CPACG. Correlation of mean deviation and corrected pattern standard deviation on full threshold 30-2 perimetry, with measured ONH parameters was carried out amongst the two groups. RESULTS: There was a significant difference in disc area (2.38 +/- 0.5, 2.77 +/- 0.4, 2.62 +/- 0.4 mm(2), p < 0.01), cup area (0.88 +/- 0.6, 1.99 +/- 0.7, 1.60 +/- 0.7 mm(2), p < 0.01), rim area (1.48 +/- 0.4, 0.86 +/- 0.4, 0.96 +/- 0.4 mm(2), p < 0.01), VIRA (1.64 +/- 0.3, 1.23 +/- 0.3, 1.22 +/- 0.4 mm(2), p < 0.01), rim volume (0.34 +/- 0.2, 0.1 +/- 0.1, 0.15 +/- 0.1 mm(3), p < 0.01) and cup/disc ratio (0.36 +/- 0.2, 0.69 +/- 0.1, 0.63 +/- 0.2, p < 0.01) in normal vs POAG vs CPACG eyes respectively. A comparison of ONH parameters between early POAG and early CPACG showed a significant difference in the disc area (2.85 +/- 0.3, 2.57 +/- 0.4 mm(2), p = 0.03), cup area (2 +/- 0.5, 1.34 +/- 0.5 mm(2), p < 0.01), rim area (0.96 +/- 0.4, 1.21 +/- 0.5 mm(2), p = 0.009), rim volume (0.12 +/- 0.1, 0.18 +/- 0.1 mm(3), p < 0.01) and cup/disc ratio (0.67 +/- 0.1, 0.53 +/- 0.2, p < 0.01). The parameters with the highest area under the receiver operator characteristic (AROC) curves for differentiating normal and early POAG eyes were rim volume, 0.89, VIRA, 0.84, and rim area, 0.76. The AROC values (normal vs early CPACG eyes) were 0.75 for rim volume, 0.72 for VIRA, and 0.66 for rim area. CONCLUSION: OCT may serve as a useful diagnostic modality in distinguishing a normal optic disc from a glaucomatous one, even in the early stages of glaucoma. Rim volume, VIRA and rim area can be used to differentiate normal from early glaucoma (both early POAG and CPACG), and most efficiently early POAG eyes. CPACG eyes have smaller discs, a smaller cup, smaller cup/disc ratio, and a larger rim area when compared with eyes with POAG.

Adult↗
PubMed1983

Posterior ischemic optic neuropathy. I. Blood supply of the optic nerve.

The blood supply of the posterior optic nerve was investigated in 10 monkeys after an injection of synthetic resin into the carotid arteries. The posterior intraorbital and intracanalicular optic nerves were supplied by a centripetal vascular system, formed by the pial vessels arising from the first branches of the ophthalmic artery. Superior and inferior vascular semicircles were detected in the intracanalicular optic nerve. The intracranial optic nerve was supplied by branches of the internal carotid artery, anterior cerebral artery and/or anterior communicating artery, and ophthalmic artery.

Animals↗
PubMedDate not supplied

Reproducibility of optic nerve head measurements obtained by optical coherence tomography.

PURPOSE: To evaluate reproducibility of optic nerve head (ONH) morphometry measurements obtained by optical coherence tomography (the fast optical disk protocol of the -Zeiss model 3000 OCT system) in normal and glaucomatous eyes. METHODS: Prospective instrument-evaluation study. ONH measurements for 20 eyes were obtained in eight scan sessions taken during two visits to an ophthalmology clinic (10 normal patients, 10 glaucoma patients, one eye per subject). At every one of the eight sessions for each eye, estimates of eight ONH morphometry variables (see Main outcome measures) were obtained. The first two sessions were performed by two operators, followed by a 30-minute break. The same operators then completed a third and fourth session. This sequence was duplicated on a second visit. Intrasession, intersession, intervisit, and interoperator reproducibility of the eight variables were calculated by the use of a components variance model. Intraclass correlation coefficients (ICC) were used to assess reliability. RESULTS: Vertical integrated rim area, horizontal integrated rim area, disk area, cup area, rim area, cup/disk area ratio, cup/disk horizontal ratio, cup/disk vertical ratio. With the exception of the horizontal integrated rim area and rim area in normal subjects, the factor subject was the most important source of variance for all variables. Reliability values as measured by ICC for normal eyes were above 81%, with the exception of measurements of the horizontal integrated rim area (23.1%), rim area (33.3%), and disk area (64.7%). For glaucomatous eyes all values were above 85%, with the exception of the disk area (68.1%). CONCLUSIONS: ONH measurements obtained using the fast optical disk protocol of the Zeiss 3000 OCT system show good reproducibility, for both normal and glaucomatous eyes.

Adult↗
PubMed2005

Low-noise broadband light generation from optical fibers for use in high-resolution optical coherence tomography.

Broadband light generation from a single-mode optical fiber was developed for high-resolution optical coherence tomography (OCT). No noise amplification was observed for light broadened by self-phase modulation. The investigation showed that the intensity noise of light broadened by self-phase modulation in a single-mode optical fiber was much lower than that of continuum light from a microstructure fiber (MSF). The spectral width of a femtosecond input laser pulse was successfully broadened by a factor of 11, and a coherence length of 3.7 microm was achieved with this source. The application of light broadened by a single-mode optical fiber and MSF was compared for use in OCT imaging. The results showed that a single-mode fiber with a small core diameter is a useful way to generate low-noise, broadband light for high-resolution OCT imaging.

Algorithms↗
PubMed2003

Optical-fiber-based Mueller optical coherence tomography.

An optical-fiber-based multichannel polarization-sensitive Mueller optical coherence tomography (OCT) system was built to acquire the Jones or Mueller matrix of a scattering medium, such as biological tissue. For the first time to our knowledge, fiber-based polarization-sensitive OCT was dynamically calibrated to eliminate the polarization distortion caused by the single-mode optical fiber in the sample arm, thereby overcoming a key technical impediment to the application of optical fibers in this technology. The round-trip Jones matrix of the sampling fiber was acquired from the reflecting surface of the sample for each depth scan (A scan) with our OCT system. A new rigorous algorithm was then used to retrieve the calibrated polarization properties of the sample. This algorithm was validated with experimental data. The skin of a rat was imaged with this fiber-based system.

Animals↗
PubMed2004

Jones matrix analysis for a polarization-sensitive optical coherence tomography system using fiber-optic components.

We present an analysis for polarization-sensitive optical coherence tomography that facilitates the unrestricted use of fiber and fiber-optic components throughout an interferometer and yields sample birefringence, diattenuation, and relative optic axis orientation. We use a novel Jones matrix approach that compares the polarization states of light reflected from the sample surface with those reflected from within a biological sample for pairs of depth scans. The incident polarization alternated between two states that are perpendicular in a Poincaré sphere representation to ensure proper detection of tissue birefringence regardless of optical fiber contributions. The method was validated by comparing the calculated diattenuation of a polarizing sheet, chicken tendon, and muscle with that obtained by independent measurement. The relative importance of diattenuation versus birefringence to angular displacement of Stokes vectors on a Poincaré sphere was quantified.

Algorithms↗
PubMed1992

Distended optic nerve sheaths in Leber's hereditary optic neuropathy.

Distension of the optic nerve sheaths is a feature of Leber's hereditary optic neuropathy (LHON) that has attracted attention only recently. We followed a patient with LHON for 23 years and obtained his eyes for pathological examination after death. We report the first histologic description of distension of the optic nerve sheaths, together with typical histopathological findings of LHON. Distension of the optic nerve sheaths could not be accounted for by any etiology other than LHON, although the precise pathogenic mechanisms remain enigmatic.

Adult↗
PubMed1989

Bilateral optic disc colobomas with orbital cysts and hypoplastic optic nerves and chiasm.

A 3-month-old boy with bilateral optic disc colobomas and orbital cysts is presented. Both eyes appeared relatively normal in size. Ultrasonography on one side demonstrated a communication between the globe and cyst by way of the optic disc coloboma. On computed tomography and magnetic resonance imaging, the cysts' contents were similar to vitreous. The optic nerves and chiasm appeared markedly hypoplastic on neuroimaging tests. Fluorescein angiography, electroretinography, and visual evoked responses suggested that the visual deficit primarily was ascribable to optic nerve or anterior visual pathway dysfunction.

Coloboma↗