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Axonal transport of RNA during regeneration of the optic nerves of goldfish.

The distribution of radioactive RNA and RNA precursors in the goldfish optic tecta following intraocular injection of 3H-uridine has been studied during various stages of optic nerve regeneration. 3H-uridine was injected into the posterior chamber of the right eye 17, 30, or 60 days after both optic nerves were crushed. Five were sacrificed at time intervals ranging from 0.5 to 21 days after injection. One day prior to sacrificing, 14C-proline was also injected into the right eye as a marked of fast axonal protein transport. Seventeen to 23 days after crushing, the approximate time of nerve reconnection, the amount of radioactive RNA appearing in the left optic tectum was increased by more than ten times control values. Approximately 30 days after crushing the nerve, when the reconnected nerve is maturing, RNA values were still elevated, but significantly decreased from the earlier stage. By 60 days after crushing the optic nerve, the amounts of RNA in the left tectum was close to normal. Evidence suggesting that, at least, some of the radioactive RNA in the tectum originated from RNA transported along optic axons rather than from RNA synthesized locally in the tectum was provided by autoradiographic experiments. Autoradiograms of paraffin sections taken from the goldfish optic tecta after the intraocular injection of 3H-uridine showed a distribution of grains in a linear pattern, suggesting a distribution over the incoming fibers during the reconnection stage of regeneration. Electron microsocpic autoradiography of glutaraldehyde fixed epoxy sections confirmed that a significant number of grains (shown to be 3H-RNA) were, in fact, over regenerating optic axons. Intracranial injection of 3H-uridine, during the same stage of regeneration, on the other hand, resulted in a distribution of grains, specifically over cell perikaprya. These experiments suggest that during the reconnection phase of nerve regeneration, large amounts of RNA may be carried within regenerating optic axons as they enter the optic tectum.

Animals↗

Synthesis of elastic microfibrillar components fibrillin-1 and fibrillin-2 by human optic nerve head astrocytes in situ and in vitro.

The purpose of this study was to identify elastic microfibrillar components fibrillin-1 and fibrillin-2 in optic nerve heads of adult normal and glaucomatous subjects, in cultured optic nerve head astrocytes (type 1B astrocytes), as well as fibrillin-1 in fetal optic nerve heads. To characterize synthesis and gene expression of microfibrillar proteins in human optic nerve heads and cultured type 1B astrocytes, light microscopy immunohistochemistry, in situ hybridization, and RT-PCR or Northern blots were performed. Our results demonstrated that fibrillin-1 was associated with blood vessels, astrocytes in the glial columns and cribriform plates, and with astrocyte processes in the nerve bundles in all samples. In glaucomatous optic nerves there was enhanced fibrillin-1 immunoreactivity, especially surrounding blood vessels. Fibrillin-2 was localized primarily to blood vessels in all samples, without qualitative differences between normal and glaucomatous samples. In fetal optic nerve heads fibrillin-1 mRNA was localized to glial cells and to the blood vessel walls. In adult optic nerve heads, there was little fibrillin-1 mRNA as detectable by in situ hybridization and RT-PCR. There was no detectable upregulation of fibrillin-1 mRNA in glaucoma. In cultured type 1B astrocytes, fibrillin-1 staining was mostly pericellular. There was little fibrillin-2 immunoreactivity. In conclusion, astrocytes from the optic nerve head deposit elastic microfibrillar components in situ and in vitro, with a predominance of fibrillin-1. Upregulation of fibrillin-1 mRNA was not observed in glaucoma, suggesting that increased transcription may occur early in the disease process. Cultures of type 1B astrocytes from the optic nerve head provides a useful model to study mechanisms regulating the interactions of elastin and the microfibrils in optic nerve head astrocytes.

Aged↗

Visual rehabilitation of patients with advanced stages of glaucoma, optic atrophy, myopia or retinitis pigmentosa.

Ninety-six patients with advanced stages of glaucoma, optic atrophy, myopia or retinitis pigmentosa (RP) who could not manage with ordinary spectacles or simple magnifying aids were taken care of at the Low Vision Clinic for rehabilitation and followed for an average of 3.6 years (the glaucoma group) up to an average of 6.0 years (the optic atrophy group). They were given high power optical aids and subjected to educational training in the proper use of these aids for best utilization of residual vision. Many of them (for optic atrophy as high a percentage as 40.7) were taught to use extra macular retina by means of eccentric viewing technique. The mean age of the oldest group, the glaucoma patients, was 69.3 years. The three other groups were about 20 to 25 years younger, on an average. (Another 35 patients were seen for the first series of visits but could not be followed up, the main reasons being death (13 patients) and moving out of the area (9 patients). The mean power of the aids (mainly telescopes) used for distance vision was 2.1 x (RP)-5.3 x (optic atrophy). Increased near addition and hyperocular lenses were the main aids for reading and near vision, the mean power being 17.0 dioptres (glaucoma)-23.5 dioptres (RP)(4.3 x -5.9 x). Aids were also provided for intermediate distance and for "spot use". The mean number of series of visits was 3.1 (myopia)-3.5 (glaucoma) and the average number of 1 h training sessions 2.2 (glaucoma)-2.5 (optic atrophy, RP) per series of visits. With aids and educational training, the mean visual acuity improved on the first series of visits from 0.31 to 0.60 for the glaucoma group, from 0.19 to 0.70 for the optic atrophy group, from 0.12 to 0.68 for the myopes and from 0.35 to 0.52 for the RP group. After the last series of visits acuity was still as good as 0.51, 0.61, 0.73 and 0.45, respectively. The number of individuals able to read newspaper text increased from 16.1% to 100.0% for the glaucoma patients, from 14.8% to 100.0% for the optic atrophy patients, from 75.0% to 100.0% for the myopes, and from 50.0% to 95.5% for the RP patients. The results show clearly that the methods used for rehabilitation of patients with glaucoma, optic atrophy, myopia or RP through optical aids and sessions of educational training are very successful, with substantial improvement of life quality.

Adolescent↗

Optic neuropathy in systemic lupus erythematosus and antiphospholipid syndrome (APS): clinical features, pathogenesis, review of the literature and proposed ophthalmological criteria for APS diagnosis.

Optic neuropathy is a well-known ocular manifestation occurring in patients with systemic lupus erythematosus (SLE), and it remains one of the major causes of blindness in these patients. We report data from six SLE patients with optic neuropathy, one of whom was considered to have antiphospholipid syndrome (APS). This patient had monolateral optic neuropathy, whereas the other five SLE patients had bilateral optic nerve disease. We believe that the monolateral occurrence of optic neuropathy in our patient can be considered as a 'focal' neurological disease due to a thrombotic event involving the ciliary vasculature. Conversely, bilateral optic nerve damage in SLE could be considered to be a 'general' neurological disease due to different immunological mechanisms, such as vasculitis. Additionally, the literature on SLE patients affected by optic neuropathy is reviewed to evaluate the major clinical features, particularly neurological features. In reviewing the literature, it appears that bilateral optic neuropathy in SLE occurs more frequently than monolateral optic neuropathy, and the main neurological manifestation seen in these patients is transverse myelitis, particularly in SLE patients with bilateral optic nerve disease. Finally, we propose a clinico-ophthalmological spectrum of APS and outline the ocular clinical manifestations that can be considered as diagnostic for the syndrome.

Adult↗

A quantitative study of developing axons and glia following altered gliogenesis in rat optic nerve.

Axonal and glial cell development within rat optic nerve in which gliogenesis was altered by systemic injection of 5-azacytidine (5-AZ) was examined by quantitative electron microscopy. In neonatal (0-2 days) rat optic nerves, all fibers are premyelinated, and they exhibit a fairly uniform diameter (approximately 0.22 micron). These fibers occupy approximately 55% of the optic nerve volume. At this early age, glia within the optic nerve consist only of cells of astrocytic lineage and progenitor cells. These glia occupy approximately 28% of the optic nerve volume, and there are approximately 80 glial cells/optic nerve cross section. In 14-day-old normal optic nerves, myelinated and ensheathed fibers comprise approximately 17% and 9%, respectively, of the total number of axons. Mean axonal diameter of myelinated fibers is approximately 0.75 micron, while mean diameter for ensheathed axons is approximately 0.50 micron. By volume, these fibers occupy approximately 25% of the nerve, which is similar to the volume occupied by premyelinated axons in these nerves. At 14 days of age, there are approximately 300 glial cells/optic nerve transverse section, and these glia occupy approximately 37% of the volume in normal optic nerve. Oligodendroglia represent approximately 40% of total glial cells present, while astroglia and progenitor cell each comprise approximately 30% of the cells. In optic nerves from 14-day-old rats treated with 5-AZ, few myelinated fibers are present and the number of oligodendroglia is markedly reduced. Axonal diameter of premyelinated fibers is similar to that of age-matched controls. Myelinated and ensheathed fibers comprise approximately 2% of the total fibers present in 5-AZ-treated optic nerves, with the remaining fibers being premyelinated. The few myelinated and ensheathed fibers present in 5-AZ-treated optic nerves display similar axonal diameters to corresponding fibers from age-matched control tissue. Glial cells occupy approximately 40% of the nerve volume, and there are approximately 200 glia/nerve cross section in 5-AZ-treated rats. Astroglia comprise approximately 63% of the total glial cells, while approximately 12% of the cells are oligodendroglia. These results demonstrate that 5-AZ is a potent inhibitor of oligodendrogliogenesis, with a concomitant marked reduction in the number of myelinated fibers.

Age Factors↗

Glial hyaluronate-binding protein (GHAP) in optic nerve and retina.

The distribution of glial fibrillary acidic protein (GFAP) and of glial hyaluronate-binding protein (GHAP) was studied by indirect immunofluorescence with monoclonal and polyclonal antibodies in dog, rat and rabbit optic nerve. In dog and rabbit, myelination extends into the optic nerve head inside the eye, while in the rat myelination of the optic nerve ceases abruptly at its entry into the eye. Outside the eye the distribution of the two proteins was similar. Both antigens formed a delicate mesh surrounding myelinated optic nerve axons. In all 3 species GFAP immunoreactivity continued uninterrupted into the optic nerve head inside the eye. Conversely, in both dog and rat, GHAP immunoreactivity ceased abruptly in the region of the lamina cribrosa, a sieve-like structure continuous with the sclera through which bundles of optic nerve axons pass. No staining was observed in the myelinated optic nerve head of the dog nor in the non-myelinated optic nerve head of the rat. In the rabbit lacking a lamina cribrosa, GHAP immunoreactivity did not cease abruptly at the optic nerve entry into the eye, but the staining intensity was reduced in the optic nerve head.

Animals↗

Histological and morphometric evaluation of transient retinal and optic nerve ischemia in rat.

Non-arteritic anterior ischemic optic neuropathy is caused by a transient optic nerve ischemia and results in permanent vision loss. Currently, there is no effective treatment for this ischemic optic nerve injury. This study characterized the duration and extent of ischemia induced after a coagulopathy injury to the optic nerve of adult rats. Acute ischemia was induced in adult rats by intravenous injection of Rose Bengal dye, followed by argon green laser treatment of the vessels at the optic disc. Rats were assessed in the short-term for hypoxyprobe-1 binding and expression of hypoxia inducible factor-1alpha (HIF-1 alpha) and fractin, markers of neuronal injury. Five months after injury, optic axon number was quantified. The coagulopathy injury resulted in short-term hypoxia in the optic nerve and retina. Tissues were hypoxic within 15 min of the coagulopathy injury, but normoxic by 24 h as measured by hypoxyprobe-1 staining. Both HIF-1alpha and fractin were upregulated in ganglion cells variably across the retina. Five months after the ischemic injury, there was a 71% reduction in optic axon number compared to controls. It is critical to have a reproducible and relevant method for producing transient hypoxia in order to test therapeutic strategies for rescuing injured neurons. The coagulopathy induced in this study resulted in a reproducible and transient ischemic optic nerve injury and long-term axonal loss. This ischemia shows similar, although not identical, morphological and physiological changes to those seen in the human eye after optic nerve ischemia. We are currently testing therapeutic strategies to protect ganglion cells from degeneration after this ischemic injury.

Animals↗

Main pancreatic duct, common bile duct and sphincter of Oddi structure visualized by optical coherence tomography: An ex vivo study compared with histology.

BACKGROUND: Optical coherence tomography has been proposed to obtain high-resolution imaging of tissue structure of GI tract. Up till now, the optical coherence tomography appearance of the common bile duct, main pancreatic duct and sphincter of Oddi wall structure has not yet been defined. AIMS: To compare, in a prospective study, optical coherence tomography images of pancreato-biliary ductal system with histology and identify the optical coherence tomography pattern of the normal wall structure of the ducts. METHODS: Multiple sections of non-neoplastic segments of five consecutive ex vivo human pancreatic specimens were investigated by optical coherence tomography scanning within 1h of resection. Sixty optical coherence tomography images were compared with the corresponding histological findings. RESULTS: Optical coherence tomography appearance of normal common bile duct, main pancreatic duct and sphincter of Oddi is characterized by a differentiated three-layer architecture with a regular surface and a homogeneous back-scattered signal, corresponding to the single layer of epithelial cells, the connective-muscular layer and the muscular or acinar structure, respectively. Optical coherence tomography and histology findings were concordant in all cases. CONCLUSIONS: Optical coherence tomography was able to provide in real-time images of wall structure of the normal common bile duct, main pancreatic duct and sphincter of Oddi that are similar to those obtained by histology. These results suggest that optical coherence tomography could enable high-resolution images to be obtained from the pancreato-biliary system during an ERCP procedure.

Aged↗

Optical coherence tomography compared with histology of the main pancreatic duct structure in normal and pathological conditions: an 'ex vivo study'.

BACKGROUND AND STUDY AIMS: Optical coherence tomography permits high-resolution imaging of tissue microstructures by a probe inserted into the main pancreatic duct through a standard ERCP catheter. The aim of this study was to compare optical coherence tomography images of the main pancreatic duct with histology and identify the optical coherence tomography pattern of the normal and pathological structure of the main pancreatic duct. PATIENTS AND METHODS: Multiple sections of neoplastic and non-neoplastic segments of 10 consecutive surgical pancreatic specimens obtained from patients with pancreatic head adenocarcinoma were investigated by optical coherence tomography scanning within 1h of resection. One hundred optical coherence tomography findings were then compared with the corresponding histopathological diagnoses. RESULTS: Main pancreatic duct wall architecture appeared at optical coherence tomography investigation as a three-layer structure with a different back-scattered signal from each layer. Optical coherence tomography imaging was concordant with histology in 81.8% and 18.75% of sections with normal tissue and chronic inflammatory changes. The K statistic between the two procedures was equal to 0.059 for non-neoplastic main pancreatic duct wall appearance. In all neoplastic sections optical coherence tomography showed a subverted layer architecture with heterogeneous back-scattering of the signal and was concordant with histology. CONCLUSIONS: Optical coherence tomography provided images of main pancreatic duct wall structure that were concordant with histology in 100% of cases in presence of neoplastic ductal changes and did not have false-positive or negative results. Optical coherence tomography images were also concordant with histology in about 80% of cases with normal main pancreatic duct structure; however, the differential diagnosis between normal tissue and chronic pancreatitis or dysplastic changes appeared very difficult.

Adenocarcinoma↗

Optical coherence tomography for the characterization of basal cell carcinoma in vivo: a pilot study.

BACKGROUND: Optical coherence tomography combines principles of ultrasonography and optical interferometry to provide real-time cross-sectional images of subsurface microstructure of tissue in vivo. OBJECTIVE: The purpose of this pilot study was to define and characterize basal cell carcinoma by using optical coherence tomography. METHODS: Twenty-three patients with 49 lesions clinically suggestive of superficial basal cell carcinoma were recruited. Optical coherence tomography was used to characterize the features of the pearly papules in real time and in vivo. Shave biopsy and light microscopic images were compared with images from optical coherence tomography. RESULTS: Basal cell carcinoma was identified in 27 patients; all 27 had optical coherence tomographic images for comparison. Seven images were uninterpretable, probably because of technical problems. Of the remainder, 20 sites matched the histologic features seen on light microscopy, with excellent correlation between optical coherence tomographic images and histopathologic features of superficial, nodular, micronodular and infiltrative basal cell carcinomas. LIMITATIONS: This study was limited by the small number of patients examined. Also, as this study was not designed as an intent-to-diagnose study, the actual predictive value of optical coherence tomography technology remains unproven. CONCLUSIONS: Optical coherence tomography technology has potential for the diagnosis and histopathologic characterization of basal cell cancer. Additional studies to determine any practical role for optical coherence tomography are indicated.

Aged↗

Correlation between mean visual field loss and morphometric optic disk variables in the open-angle glaucomas.

PURPOSE: To correlate morphologic changes of the optic disk with mean visual field defect in glaucoma. METHODS: Color optic disk photographs of 302 patients with primary open-angle glaucoma, 53 patients with pseudoexfoliative glaucoma, and 55 patients with normal-pressure glaucoma were morphometrically evaluated. The data were correlated with mean visual field defect. RESULTS: The correlation between mean visual field defect and neuroretinal rim area was similar to a logarithmic function. The visual field deteriorated slightly in the early stage and markedly in the advanced stages of glaucoma. A discrepancy between normal visual field and abnormal optic disk occurred more often in young than in old patients. Neuroretinal rim shape, total rim area, and rim area in the temporal inferior and temporal superior disk sectors correlated best with mean visual field loss. Alpha and beta zones of peripapillary atrophy and diameter of retinal arterioles were less clearly correlated. Calculated rim variables that were corrected for optic disk area did not markedly improve the correlation coefficients. In eyes with normal visual fields, rim shape was the most important disk variable for detecting glaucomatous optic nerve damage. There were no patients with glaucomatous visual field loss and an unremarkable optic disk. CONCLUSIONS: In early glaucoma, changes are more marked in optic disk appearance than in the visual field, suggesting that at least for some patients, for early glaucoma diagnosis, optic disk appearance is more important than perimetry, whereas for follow-up examination, perimetry may be more useful than optic disk morphometry. The most useful planimetric optic disk parameters are neuroretinal rim shape and rim area.

Adult↗

Measurement of the subarachnoid pressure of the optic nerve in human subjects.

PURPOSE: We measured the subarachnoid pressure of the optic nerve in 16 patients scheduled for ocular enucleation or evisceration. METHODS: We measured the subarachnoid pressure of the optic nerve directly with an electronic digital manometer in 16 patients scheduled for enucleation or evisceration for various blinding conditions. The nerve was exposed via a medial orbitotomy, and the subarachnoid pressure of the optic nerve was measured 5 mm posterior to the optic nerve head. The subarachnoid pressure of the optic nerve was also measured in five patients who were placed in the Trendelenburg position (head declined at a 30-degree angle) for three minutes. RESULTS: The subarachnoid pressure of the optic nerve varied from 4 to 14 mm Hg in the 16 patients tested. The mean subarachnoid pressure of the optic nerve was 8.5 mm Hg in the 16 patients tested. An increase of 1 to 2 mm Hg in the subarachnoid pressure was observed in all five patients placed in the Trendelenburg position. CONCLUSIONS: Subarachnoid pressure of the optic nerve can be measured in vivo in humans. The values obtained are consistent with the known physiologic range of intracranial pressure. There was no statistically significant correlation between subarachnoid pressure of the optic nerve and age or cause of blindness. The subarachnoid pressure of the optic nerve varies over a wide range.

Adolescent↗

Age-related changes in the human optic nerve.

BACKGROUND: Recent morphologic research has demonstrated the presence of nerve fibres of different diameters in the human optic nerve. The purpose of this study was to investigate age-related changes in fibres of the human optic nerve. METHODS: We studied the left optic nerve of 50 male cadaveric donors, 16 aged 18 to 22 years (mean 20 [standard deviation 1.2] years) and 34 aged 68 to 76 years (mean 72 [standard deviation 1.6] years). The samples were carefully harvested during autopsy from the intracranial portion of the optic nerve. Each nerve was cut into four 4-mm segments. After morphologic, histochemical and immunohistochemical staining, the optic nerve fibres were counted and measured. Each segment was evaluated under light microscopy for microanatomic details, glial cells and glial fibrillary acidic protein (GFAP) staining. The protein content was determined under biochemical analysis. We performed morphometric analysis by examining the optic nerve images quantitatively. RESULTS: Compared with the younger group, in the older group there was an increase in mean diameter of the optic nerve (p < 0.001), due to an increase in the optic nerve:meningeal membrane ratio. There was also an increase in mean optic nerve area (p < 0.001) and in mean number of astrocytes and the related GFAP-immunoreactive area (p < 0.001). The mean number of nerve fibres of large diameter (greater than 4 pm) was decreased (p < 0.001). There was no difference in mean protein content of the fibres between the two groups. INTERPRETATION: The human optic nerve is sensitive to the aging process and may be considered as a model for studies on neuronal aging.

Adolescent↗

Analog signal acquisition from computer optical disk drives for quantitative chemical sensing.

Optoelectronic consumer products that are widely employed in the office and home attract attention for optical sensor applications due to (1) their cost advantage over analytical instruments produced only in small quantities, (2) robustness in operation due to the detailed manufacturability improvements, and (3) ease of operation. We demonstrate here a new approach for quantitative chemical/biochemical sensing when analog signals are acquired from conventional optical disk drives, and these signals are used for quantitative detection of optical changes of sensor films deposited on conventional CD and DVD optical disks. Because we do not alter manufacturing process of optical disks, any disk can be employed for deposition and readout of sensor films. The optical disk drives also perform their original function of reading and writing digital content to optical media because no optical modifications are introduced to obtain the analog signal. Such a sensor platform is quite universal and can be applied for chemical and biological quantitative detection, as well as for monitoring of changes of physical properties of regions deposited onto a CD or DVD (e.g., during combinatorial screening of materials). As a model example, we demonstrate the concept using chemical detection of ionic species such as Ca2+ in liquids (e.g., blood, urine, or water). Colorimetric calcium-sensitive sensor films were deposited onto a DVD, exposed to water with different concentrations of Ca2+, and quantified in the optical disk drive. The developed lab-on-DVD system demonstrated a 5 ppm detection limit of Ca2+ determinations, similar or slightly better than that achieved using a conventional fiber-optic portable spectrometer. This detection limit corresponded to a 0.023 absorbance unit resolution, as determined by the measurement of the same colorimetric films with a portable spectrometer. Determinations of Ca2+ unknowns using the lab-on-DVD system demonstrated +/-5 ppm accuracy and 2-5% relative standard deviation precision in predicting 100 ppm Ca2+.

Biosensing Techniques↗

Major determinants of optic nerve head topographic characteristics in a normal Turkish population.

AIM: To determine the factors affecting the topographic characteristics of the optic nerve head in a normal Turkish population. METHODS: A cross-sectional study was performed on the optic nerve head of the right eyes of 613 healthy subjects of both sexes aged 11-77 years using a confocal scanning laser ophthalmoscope. The study population was divided into three groups (<20 years, 20-50 years, and>50 years) to evaluate age-related changes in the optic nerve head topography. A total of 15 variables were determined. Statistical analysis was performed using Student's t-test, anova, Tukey HSD test, linear regression analysis and Pearson's correlation coefficient. RESULTS: Four eyes were excluded from the study due to poor image quality. There were 307 female subjects and 302 male subjects. The mean age of the subjects was 42.1 +/- 15.1 years. The mean optic disc areas were 1.99 +/- 0.45 mm2 and 1.97 +/- 0.41 mm2 for male and female subjects, respectively. The disc area of the subjects ranged between 1.01 and 4.19 mm2. Disc area was found to be associated with all of the optic nerve head variables studied, and was also found to be significantly increased with advancing age (P < 0.05). The only variable that showed a sex-related difference was neuroretinal rim volume, which was found to be higher in female subjects in all cases. CONCLUSION: Optic disc area was found to be the main determinant of the optic nerve head topography in a normal population. Optic disc area was found to be significantly increased with ageing in a normal population. These acquired changes to the optic disc could suggest stretching of the scleral ring, which may highlight the role of advancing age on the pathogenesis of glaucomatous optic neuropathy.

Adolescent↗

[Prevalence of optic atrophy and associated ocular and systemic diseases in a department of paediatric ophthalmology].

BACKGROUND: Optic atrophy is one of the most common causes of severe visual impairment in children. So far an analysis of ocular and systemic findings comparing patients with and without optic atrophy has not performed. PATIENTS AND METHODS: Ocular and systemic findings of a total of 1042 patients (examination of all patients in May 1995 [N = 485] and May 2001 [N = 557]) of the department of paediatric ophthalmology in Homburg/Saar were retrospectively evaluated and diagnoses of patients with and without optic atrophy were compared. Optic atrophy was diagnosed ophthalmoscopically and in 1/3rd of the patients by VEP as well. RESULTS: 18 % of all patients (N = 188; 87.2 % [N = 164] were children) had optic atrophy. Nearly half of these children were prematurely born (46.7 %). 53.2 % of patients with optic atrophy (N = 88) showed nystagmus (without atrophy: 10.7 %), especially sensory defect nystagmus. Median of visual acuity level was 0.2 with optic atrophy and 0.8 without. Albinism and buphthalmia were common findings. 69.5 % of all patients with optic atrophy suffered from systemic diseases (without atrophy: 25.2 %), especially mental retardation, neurologic findings and oculocutaneous albinism. In 10.4 % more than two systemic diagnoses could be found. 55.3 % of all the patients with optic atrophy were disabled, 31.9 % multiply disabled. CONCLUSIONS: Sequelae of prematurity, peripartal asphyxia and congenital brain damages are the main findings in patients with optic nerve atrophy. Such children are worst-case patients of any paediatric ophthalmology department with a high prevalence of severe visual impairment, mental retardation and multiple disability. Treatment in a specialised center is therefore necessary for an efficient therapy. In addition, the statistical survey shows that in children who survived the critical phases of prematurity secondary damages can lead to persistent impairment and to alterations of visual and general development.

Adolescent↗

[Visual evoked potentials, contrast sensitivity and color perception in patients with optic nerve neuritis and multiple sclerosis].

Forty-nine patients with acute optic neuritis (in 21 cases associated with MS) and 26 patients known to have MS but with no history of optic nerve disease underwent visual evoked potential, contrast sensitivity and color vision tests. In patients with optic neuritis the contrast sensitivity was shown to detect optic nerve lesions better than the VEP an often permitted a distinction between acute and past optic neuritis. Combined testing with contrast sensitivity and VEP was superior to the single tests and detected 100% of the acute optic nerve lesions, although in many cases damage was selective and only involved some of the information channels. Desaturated color tests were abnormal in 3/4 of the patients, disturbances of blue-yellow discrimination being commoner than those of red-green. In cases with clinically unilateral optic neuritis the apparently normal partner eye was affected in 61% of the patients; complete recovery of optic nerve function without some residual deficit is rare. Approximately 3/4 of the eyes of patients known to have MS but with no history of past visual disturbances showed bilateral optic nerve involvement. The frequency of subclinical optic nerve lesions rose to 91% at a follow-up examination one year later. the literature is reviewed and our results are compared with the previously published data.

Adolescent↗

Preliminary morphometric study of tumor necrosis factor-alpha (TNF alpha)-induced rabbit optic neuropathy.

Intravitreal injections of tumor necrosis factor-alpha (TNF alpha) induce morphological changes in the optic nerve suggesting a primary TNF alpha-induced optic neuropathy. A preliminary morphometric analysis of axonal loss and degeneration in optic nerves of a TNF alpha rabbit eye model was conducted. Fifteen rabbits were injected in one eye only with TNF alpha (final doses: 2 U, 20 U and 200 U respectively), and optic nerve cross-sections were examined using a semi-automated image analysis system, at varying time intervals for up to 24 weeks post-injection. Control optic nerves (uninjected or injected with diluent only) were also assessed. Intact, degenerating and demyelinated axons were visible in TNF alpha-exposed optic nerves. Considerable variation was observed between TNF alpha-exposed optic nerves, however the intact axon density consistently decreased in the 200 U TNF alpha group, although not in the 2 U and 20 U groups. Overall, TNF alpha-exposed optic nerves had significantly more degenerating profiles compared to control optic nerves. These observations suggest a dose-dependent axonal loss and degeneration associated with the morphological changes induced in rabbit optic nerves following intravitreal injection of TNF alpha.

Animals↗