Apoptotic death of beta cells after optic nerve transection in adult cats

We have revealed previously that the survival rate of beta cells of cat retinal ganglion cells (RGCs) rapidly decreased to 29% on day 7 after optic nerve transection, whereas that of alpha cells slowly decreased to 64% on day 14 (Watanabe et al., 2001). The reason that beta cells die more rapidly than alpha cells was not clear. In the present study, we tested the possibility that the rapid death of beta cells is attributable to apoptosis, as shown for some axotomized RGCs in rats. The following results were obtained. First, the proportion of pyknotic cells in Nissl-stained cat retinas started to increase sharply starting on day 4 and reached a peak on day 6 after optic nerve transection. The time course of occurrence of pyknotic cells corresponded well with that of the rapid death of axotomized beta cells. Secondly, the proportion of pyknotic cells was the highest in the area centralis (AC), in which beta cells are densely distributed. The preferential death of axotomized RGCs in the AC was also confirmed by terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling staining in cross sections. Thirdly, after the intravitreal injection of caspase 3 inhibitor (z-DEVD-cmk) the survival of axotomized beta cells on day 7 was significantly enhanced, whereas no such survival-promoting effect was obtained in axotomized alpha cells. Taken together, these results suggest that the rapid death of axotomized beta cells is attributable mainly to apoptosis, which is mediated by caspase 3.

Connecting the eye to the brain: the molecular basis of ganglion cell axon guidance

In the past several years, a great deal has been learnt about the molecular basis through which specific neural pathways in the visual system are established during embryonic development. This review provides a framework for understanding the principles of retinal ganglion cell axon guidance, and introduces some of the families of axon guidance molecules involved. In addition, the potential relevance of retinal axon guidance to human visual developmental disorders, and to retinal axon regeneration, is discussed.

[Age factor in eye regeneration of the gastropod mollusk Achatina fulica]

The dependence of the ability to regenerate the eye on the age of experimental animals was studied in the snail Achatina fulica. The degree of regeneration was estimated by light-microscopic and electrophysiological methods and by analyzing the motor response to visual stimuli. In older age groups, the number of regenerated eye-bearing tentacles decreased, whereas the period of regeneration increased. The regenerated eyes of the snails operated at the age of more than two months remained smaller than normal eyes even after six months. Regeneration of the distal part of the optic nerve was observed, and the regenerated eyes recovered the ability to respond to stimulation by light. In the electroretinogram, the responses of the regenerated eye, compared to the control, were characterised by a lower amplitude and longer repolarization and refractory periods. Manifestations of the motor response to visual stimuli in the young snails with regenerating eyes could be regarded as evidence for the recovery of connection between the organ of sight and the central ganglia.

Activation of protein kinase C inhibits retrograde transport of neurotrophins in mice

Retrograde axonal transport of neurotrophins from nerve terminal to cell body requires a number of key processes, including internalization of the receptor-neurotrophin complex into vesicles and formation of multivesicular bodies and their transport along the axon. Previous studies have shown that each of these processes can be regulated by kinases. In this study, we looked at the role of protein kinase C (PKC) in retrograde transport by injecting labeled neurotrophins together with relevant pharmacological agents into the eye and measuring the accumulation of radioactivity in the trigeminal and superior cervical ganglia. Inhibitors of PKC, Ro-31-8220 and rottlerin, did not affect the retrograde transport of nerve growth factor (NGF); however, phorbol ester activation of classical and novel PKCs blocked retrograde transport. The effect of phorbol esters was partially reversed by rottlerin and Ro-31-8220. Activation of PKC has been shown to be involved in the disorganization of actin filaments. In this study, we show that Ro-31-8220 reverses growth cone collapse by phorbol 12-myristate 13-acetate and suggest that one of the effects of activating PKC on retrograde transport is to disrupt the actin filaments.

[Traumatic injuries to the oculomotor nerve]

PURPOSE OF THE STUDY

A collective summary of the pathogenesis, character and clinical significance of damage to the oculomuscular innervation, arising from closed head trauma, based on our own clinical observations, together with a review of literature on the topic.

MATERIALS AND METHODS

The clinical and pathophysiological evaluation of injuries to the oculomotor (III) nerve based on a prospective study in our clinic, dating from 1994 onwards: the clinical material consisted of 600 patients admitted to our Department of Neurosurgery following head trauma, the subgroup consisted of 38 patients, who died following major head trauma.

RESULTS

Few authors focus on damage to the innervation of oculomotor muscles, the diagnosis of damage being difficult due to the usually poor clinical condition of such patients, the interdisciplinary nature of the resulting damage, and their delayed ophthalmological evaluation. The oculomotor (III) nerve is the nerve most frequently damaged amongst the cranial nerves, taking into account the innervation of the ocular system nerves (II-VII). Of clinical importance is differentiating between the mechanism of damage, paying particular attention to intracranial damage. The mechanisms of damage can be distinguished by: 1) partial tearing of the parasympathetic fibres contused against the petroclinoid ligament, 2) total tearing of the parasympathetic nerve root, 3) complete tear of one or both oculomotor nerves at the interpeduncular base, 4) nerve root tear, resulting from vessel perforation. The oculomotor nerve has the ability to regenerate. The regenerative process should occur within 3 to 5 months, that is without pathological synkinesis. If this process prolongs, this may lead to unpleasant consequences, such as the "misdirection phenomenon".

CONCLUSIONS

Primary damage to the oculomuscular innervation resulting from closed head trauma is an integral component of such conditions. Early diagnosis and neuroprotective therapy may prevent pathological regeneration.

Axonal regrowth of layer II-III visual-projecting cortical neurons in rats fails beyond eye opening

Fetal neurons (embryonic age E16) of occipital origin grafted in the visual cortex of albino rats at increasing postnatal stages (P0, P7, P15, P30, P60, P120) can be activated by photic stimulation. Inputs originate from five major areas of the brain ipsilateral to the graft, namely, the claustrum, the periallocortex/proisocortex, the isocortex, the visual thalamus, and some unspecific subthalamic and hypothalamic nuclei. All inputs decrease in number with the age at which grafting was performed. Isocortical afferents exhibit furthermore a progressive laminar shaping. In neonates, layer II-III and layer V-VI neurons contribute equally to the graft input. In adults, grafts receive prominent input (approximately 70-80%) from layer VI neurons whereas layer II-III neurons account for less than 10%. Proportions of layer IV (approximately 2-4%) and layer V (approximately 15-20%) neurons innervating the graft remain stable, irrespective of the age of the recipient. The adult pattern of connectivity between the host brain and the graft establishes in frontal and temporal areas 1 week earlier than in occipital areas. It is nearly completed in postnatal day 15 (P15) grafted recipients. Supragranular neurons would be thus unable to innervate and to make stable synapses at the graft level beyond P15, i.e., when eyes open. Some infragranular neurons (supposedly remnants of the earliest generated cortical cell population) still have this capacity in adults.

Ocular kinematics and eye-hand coordination

Eye-hand coordination is complicated by the fact that the eyes are constantly in motion relative to the head. This poses problems in interpreting the spatial information gathered from the retinas and using this to guide hand motion. In particular, eye-centered visual information must somehow be spatially updated across eye movements to be useful for future actions, and these representations must then be transformed into commands appropriate for arm motion. In this review, we present evidence that early visuomotor representations for arm movement are remapped relative to the gaze direction during each saccade. We find that this mechanism holds for targets in both far and near visual space. We then show how the brain incorporates the three-dimensional, rotary geometry of the eyes when interpreting retinal images and transforming these into commands for arm movement. Next, we explore the possibility that hand-eye alignment is optimized for the eye with the best field of view. Finally, we describe how head orientation influences the linkage between oculocentric visual frames and bodycentric motor frames. These findings are framed in terms of our 'conversion-on-demand' model, in which only those representations selected for action are put through the complex visuomotor transformations required for interaction with objects in personal space, thus providing a virtual on-line map of visuomotor space.

Vestibular nucleus projections to the Edinger-Westphal and anteromedian nuclei of rabbits

The Edinger-Westphal nucleus (EW), anteromedian nucleus (AM) and adjacent neurons in the ventral tegmental area (VTA) are sources of preganglionic parasympathetic innervation of intraocular smooth muscle, including blood vessels, pupillary muscle and the ciliary body in mammals. They also have central connections that are believed to affect parasympathetic outflow indirectly. This study utilized anterograde transport of biotinylated dextran amine and Phaseolus vulgaris leucoagglutinin to demonstrate direct projections from the vestibular nuclei to the Edinger-Westphal and anteromedian nuclei in rabbits. The rabbit AM and adjacent VTA contain moderate to intensely choline acetyltransferase (ChAT)-immunopositive neurons. The rabbit EW, by contrast, is nearly devoid of ChAT-immunopositive neurons. Vestibular nucleus projections to these regions originate from all levels of the superior, medial and lateral vestibular nuclei, but do show topographic organization. The densest terminations were observed in AM and the ventral and central aspects of EW. The projections to AM terminate in both ipsilaterally and in a narrow paramedian region. Predominantly ipsilateral terminations were observed in VTA. Terminations on ChAT-positive cells in AM and VTA were verified in three rabbits. It is suggested that projections to some intensely ChAT-positive AM and VTA neurons may be a substrate for vestibular influences on lens accommodation, pupillary constriction and regulation of intraocular circulation during changes in posture and gravitoinertial challenges. The projections to ChAT-negative (and weakly immunoreactive) cells in AM, VTA and EW, on the other hand, are likely to contribute vestibular signals to a variety of motor responses via descending pathways.

Visuomotor transformations for eye-hand coordination

In recent years the scientific community has come to appreciate that the early cortical representations for visually guided arm movements are probably coded in a visual frame, i.e. relative to retinal landmarks. While this scheme accounts for many behavioral and neurophysiological observations, it also poses certain problems for manual control. For example, how are these oculocentric representations updated across eye movements, and how are they then transformed into useful commands for accurate movements of the arm relative to the body? Also, since we have two eyes, which is used as the reference point in eye-hand alignment tasks like pointing? We show that patterns of errors in human pointing suggest that early oculocentric representations for arm movement are remapped relative to the gaze direction during each saccade. To then transform these oculocentric representations into useful commands for accurate movements of the arm relative to the body, the brain correctly incorporates the three-dimensional, rotary geometry of the eyes when interpreting retinal images. We also explore the possibility that the eye-hand coordination system uses a strategy like ocular dominance, but switches alignment between the left and right eye in order to maximize eye-hand coordination in the best field of view. Finally, we describe the influence of eye position on eye-hand alignment, and then consider how head orientation influences the linkage between oculocentric visual frames and bodycentric motor frames. These findings are framed in terms of our 'conversion-on-demand' model, which suggests a virtual representation of egocentric space, i.e. one in which only those representations selected for action are put through the complex visuomotor transformations required for interaction with actual objects in personal space.

Neuropsychological perspectives on eye-hand coordination in visually-guided reaching

Substantial progress has been made in understanding the neural control of movement in the past 30 years. Lower cost technology for tracking movements of the eyes and the hands has increased our understanding of these two systems and their interactions in both neurologically intact individuals and non-human primates. Nevertheless the neuropsychology of eye-hand coordination during visually-guided tasks such as reaching and grasping remains relatively understudied. This chapter reviews some of the relevant neurophysiology and neuropsychology of eye-hand coordination during visually-guided reaching. Current models emphasising coordinate transformations are discussed in light of new patient data showing a particular type of failure of eye-hand coordination during reaching.

Cortical frames of reference for eye-hand coordination

To reach for an object the brain must transform visual input from the eye into motor output of the arm. Recent neurophysiological experiments have shown that this transformation maps onto a network of brain areas including the posterior parietal (PPC) and premotor (PMC) cortices. In this chapter, we review evidence from our own experiments which demonstrate that this network can only partially complete the transformation when the eye and limb movement amplitudes are dissociated. We also discuss the effects of disrupting either the PPC or PMC using transcranial magnetic stimulation (TMS) on the ability to carry out the transformation successfully.

[Individual variability of external structure and topography of human ciliary ganglion]

The goal of present investigation was to find the interrelation between the dimensions and shape of ciliary ganlion, its topographic characteristics and skull type. By a method macromicropreparation ciliary ganlion and ciliary plexus from 200 corpses of the adult people were studied. It is established that the ganglion occupies posterior-inferior, intermediate or anterior-superior position in respect to common tendinous ring (Zinn's ligament) and optic nerve, that is associated with certain peculiarities of external structure of ciliary ganlion and ciliary plexus. The posterior-inferior position of the ciliary ganlion and ciliary plexus was associated with a concentrated type of their structure of, while the anterior-superior position was found in the ganglion and plexus with diffuse type of structure. It was also found that posterior-inferior position of the ganlion was typical to brachycephals, while the anterior-superior position was found in dolichocephals. It is suggested that of the ciliary ganlion topography and its external structure type are defined by the peculiarities of localization of neuroblasts, which are the precursors of ciliary ganlion neurons. In their turn, the peculiarities of neuroblast localization, are dictated by the influence of those factors, that determine the development of dolichocephaly or brachycephaly. The absence of sympathetic root in human ciliary ganlion is reported, and in this connection, the description of cavernous nervous plexus is presented in comparison with the data of the literature.

The phylogenetic significance of crustacean optic neuropils and chiasmata: a re-examination

Recent molecular data challenge the traditional hypotheses of arthropod phylogeny founded on morphologic characters. In this discussion, the structure of the visual systems in Pterygota (Hexapoda) and Decapoda (Malacostraca, Crustacea) is an important argument. Although many components of their visual systems depict structural homology, differences exist between Pterygota/Decapoda on the one side and Branchiopoda (Entomostraca) on the other in that the latter do not have a third optic neuropil or optic chiasmata. Therefore, the goals of the current study were to explore whether the third optic neuropils in Pterygota and Decapoda are homologous, to examine the formation of the first two optic neuropils and the chiasmata in Crustacea, and to compare these processes with Pterygota. For this purpose, five species of entomostracan and malacostracan crustaceans were analyzed by examination of serial sections, fluorescence labeling with phallotoxins, and anti-histamine immunohistochemistry. We found that the chiasmata of Decapoda and Pterygota are characterized by striking similarities regarding both the level of individually identifiable classes of neurons and ontogenetic mechanisms, which are clearly different from those in Branchiopoda. Furthermore, the third optic neuropil of Decapoda and Pterygota, the lobula, shares an ontogenetic protocerebral origin and an innervation by corresponding sets of histamine-immunoreactive neurons, suggesting homology of the lobula in these two groups. In conclusion, the characteristics of the visual system are in conflict with the traditional classification of Arthropoda. Instead, they support a sister-group relationship of Hexapoda and Malacostraca, as suggested by some of the molecular studies.

Decoupling eye-specific segregation from lamination in the lateral geniculate nucleus

To determine whether there is a critical period for development of eye-specific layers in the lateral geniculate nucleus (LGN), we prevented the normal segregation of retinogeniculate afferents and then allowed an extended period of time for recovery. After recovery, both anatomy and physiology revealed strictly nonoverlapping territories of input from the two eyes. However, the normal stereotyped pattern of eye-specific afferent and cellular layers never developed. Instead, the eye-specific territories of afferent input emerged as variable and disorganized patches with no corresponding interlaminar spaces in the LGN. These findings reveal a critical period for coordinating the development of three processes in the LGN: the segregation of afferents from the two eyes, the spatial organization of those afferents into layers, and the alignment of postsynaptic cytoarchitecture with the afferent inputs. We also assessed the physiological consequences of preventing normal lamination and found normal single-cell responses and topographic representation of visual space in the LGN. Clusters of ON-center and OFF-center LGN cells were segregated from one another as in normal animals. However, the organization of ON and OFF sublaminas in the treated animals was disrupted.

Betanodavirus as a novel transneuronal tracer for fish

In order to obtain a potential new tool to analyze networks of the central nervous system of teleost fishes, we tested a fish-pathogenic betanodavirus, sevenband grouper nervous necrosis virus (SGNNV), as a transneuronal tracer using the freshwater angelfish Pterophyllum scalare as a test animal. Intravitreous injections of SGNNV into the right eye resulted first in the labelings of neuronal cell bodies in the ganglion cell layers of the retina and then those in the inner and outer nuclear layers in sequence. For the first time, labeled neurons were found also in the stratum periventriculare of the contralateral optic tectum, the ventrolateral and ventromedial thalamic nuclei, and the periventricular nucleus of posterior tuberculum in the brain, then the periventricular pretectal nucleus pars dorsalis and pars ventralis. In contrast, by injections of biotinylated dextran amine into the eye no labeled cell bodies were observed in these brain areas, but axons and terminals were labeled anterogradely. These results suggest that the virus could be transported in both directions in axons of the first order neuron and transfected the second and third order neurons by passing across synaptic clefts, and that this technique is practically applicable to the study of neurobiology in teleost.

Early enucleation does not alter the gross morphology of identified projection neurons in the chicken optic tectum

During development of the nervous system, neurotrophic interactions are essential for the synchronization of substructures such as retina and visual midbrain. However, morphological studies of postsynaptic elements after ablation of afferents are sparse. We investigated the effect of uni- and bilateral eye anlagen removal on identified projection neurons in the chicken optic tectum. Without retinal input, neurons in the stratum griseum centrale express their specific cell adhesions molecules, retain large dendritic fields and form specialized dendritic endings; however, the latter are deformed and extend over a much larger area. Our results show that even monosynaptically innervated tectal neurons develop largely independently from trophic retinal inputs and only become dependent on these after synaptic contact with retinal afferents.

Endophilin is critically required for synapse formation and function in Drosophila melanogaster

Studies in cell-free systems and the lamprey giant synapse have implicated crucial roles for amphiphysin and endophilin in synaptic transmission. However, null mutants at the amphiphysin locus of Drosophila are viable and have no demonstrable synaptic vesicle-recycling defect. This has necessitated a re-examination of the role of Src homology 3 domain-containing proteins in synaptic vesicle recycling. In this report, we show that endophilin-deficient eye clones in Drosophila have an altered electroretinogram. A characteristic of this defect is its aggravation during heightened visual stimulation. It is shown that endophilin is primarily required in the nervous system. Decreased endophilin activity results in alterations in the neuromuscular junction structure and physiology. Immunofluorescence studies show colocalization of endophilin with dynamin consistent with a possible role in synaptic vesicle recycling.

Circadian efferent input to Limulus eyes: anatomy, circuitry, and impact

Much is known about the anatomy of Limulus retinal efferent neurons and the structural and functional consequences of their activation. Retinal efferent axons arise from cell bodies located in the cheliceral ganglia of the brain, and they project out all of the optic nerves. Their unique neurosecretory-like terminals contact all cell types in lateral eye ommatidia, the retinular cells of the median eye, and the internal rhabdom of ventral photoreceptors. Lateral and median rudimentary photoreceptors are also innervated. The activity of the efferents is circadian. They are active during the subjective night and inactive during the subjective day. Activation of the efferents drives dramatic and diverse changes in the structure and function of Limulus eyes and causes the sensitivity and responsiveness of the eyes to light to increase at night. Relatively little is known about the molecular mechanisms that produce these structural and functional changes, but one efferent-activated biochemical cascade has been identified. The biogenic amine octopamine is released from efferent terminals, and an octopamine-stimulated rise in cAMP in photoreceptors, with a subsequent activation of cAMP-dependent protein kinase, mediates many of the known effects of efferent input. A photoreceptor-specific protein, myosin III, is phosphorylated in response to efferent input; this protein may play a role in the efferent stimulated changes in photoreceptor structure and function. Anatomical, biophysical, biochemical, and molecular approaches are now being effectively combined in studies of Limulus eyes; thus, this preparation should be particularly useful for further detailed investigations of mechanisms underlying the modulation of primary sensory cells by efferent input.

Efferent innervation of photoreceptors in spiders

The anterior median (AM) eye of the nocturnal spider Araneus ventricosus showed a marked circadian oscillation of sensitivity, but that of the diurnal spider Menemerus confusus showed no circadian oscillation. The AM eyes of the noct/diurnal spiders Argiope amoena and A. bruennichii have two types of photoreceptor cells with different sensitivities. The more sensitive cells showed a circadian oscillation of sensitivity, but the less sensitive cells did not. The circadian sensitivity change of the eyes was controlled by efferent neurosecretory fibers in the optic nerve. Illuminating the brain increased the frequency of efferent impulses in the optic nerve of Argiope, showing that certain photosensitive neurons are present in the brain. However, it seemed that the cerebral photosensitive neurons may be different from the efferent neurosecretory cells. The response of the cerebral photosensitive neurons increased transiently following diminution of the light intensity striking the eyes. The interaction between the cerebral photosensitive neurons and the eyes seemed to play a role in increasing this response.

Remifentanil and propofol sedation for retrobulbar nerve block

We studied remifentanil and propofol for analgesia and sedation during the placement of an ophthalmic block. Eighty ASA I or II patients undergoing elective cataract surgery under a retrobulbar block in a rural camp setting were included in the study. Patients were randomly divided into four groups and received different drug combinations as follows: Group I--remifentanil 1 microg/kg, Group II--remifentanil 0.5 microg/kg and propofol 0.5 mg/kg, Group III--remifentanil 1 microg/kg with propofol 0.5 mg/kg and Group IV--saline 0.1 ml/kg. Patients were observed for degree of movement, sedation, pain, recall and respiratory depression. No patient in the study groups reported pain or displayed movement whereas most of the patients in the control group had significant pain during the placement of the block. Also, seven (35%) patients in the control group showed significant movement which may have led to failure of block in two patients and retrobulbar haemorrhage in one patient. Incidence of significant respiratory depression was maximum in Group III patients (60%), followed by Group I (20%) and least in Group II (5%). All patients in the study groups remained cooperative and obeyed commands except four patients in group III (OAA/S-4). Postoperatively, other than the control group, recall was maximum in Group I (55%) and least in Group II (5%). Hence, a combination of remifentanil 0.5 microg/kg with propofol 0.5 mg/kg as a bolus was considered to provide excellent relief of pain and anxiety with least adverse effects for the placement of ophthalmic blocks.

Effect of addition of clonidine to local anaesthetic mixture for peribulbar block

Clonidine added to local anaesthetics prolongs the duration of anaesthesia and analgesia of peripheral, neuraxial and retrobulbar blocks. The present randomized blinded controlled study was conducted to evaluate the effect of the addition of clonidine to local anaesthetic mixture on the quality, onset time, duration of peribulbar block, perioperative analgesia and patients' comfort. The study comprised two groups of 12 patients each. Group A (control) patients received 7 ml of a mixture of 2% lignocaine and hyaluronidase with 1 ml normal saline, while group B (clonidine group) patients had clonidine 1 microg/kg added to the above mixture. Onset and duration of lid akinesia, globe anaesthesia and akinesia, time to first analgesic medication and total analgesic requirement were assessed. Patients were monitored for heart rate, blood pressure, sedation and respiratory depression. Addition of clonidine to local anaesthetic mixture resulted in a significant increase in duration of lid akinesia (85.4+/-25.6 vs 173.3+/-35.3 min, P<0.001), globe anaesthesia (63.2+/-6.9 vs 78.8+/-17.5 min, P=0.012) and globe akinesia (161.3+/-24.3 vs 201.2+/-45.7 min, P=0.016). The onset time and quality of block were similar in both the groups. No significant haemodynamic, respiratory or sedative effects were recorded. The perioperative pain scores and the analgesic requirements were significantly (P<0.01) lower in group B patients. We found that addition of clonidine 1 microg/kg to local anaesthetic mixture significantly increases the duration of anaesthesia and analgesia after peribulbar block.

Intraorbital anatomy of the koala (Phascolarctos cinereus)

This is the first documented study of the anatomical details of the contents of the normal koala orbit, excluding the bulbus oculi. Baseline data were established which are necessary for understanding and treating ocular disease in the koala (Phascolarctos cinereus). The anatomy of the orbital contents of the koala were examined and described from animals that presented dead or were euthanized for humane reasons. Dissections of the orbital cavity were performed under magnification. Polymethyl methacrylate (PMMA) casts of the nasolacrimal system and the vascular supply of the orbit were also made in order to study these systems. The superficial lymphatic drainage of the conjunctival tissues was studied by subcutaneous injection of Evan's Blue into the palpebral conjunctiva of a freshly deceased animal, and by Microfil casts of the efferent lymphatics. In general, the orbital contents of the koala are consistent with those of other carnivorous polyprotodont and herbivorous diprotodont marsupials.

[Orbital neuroma developing in the ciliary nerve]

Orbital neuroma is a rare disease accounting for a certain percentage of all orbital tumors. However, because of the anatomical features of the orbit, the origin of the tumor has been diagnosed in only a few cases. The authors report a case of orbital neuroma arising from a short ciliary nerve that was confirmed during surgery. The patient was a 72-year-old female. She visited our hospital with complaints of left visual disturbance, exophthalmus and diplopia. Neurological examination on admission also revealed Marcus gunn pupil sign. CT scan and MRI imaging showed a left orbital tumor located along the superior surface of the optic nerve and adjacent to the posterior pole of the eye ball. She underwent superior orbitotomy through a transcranial approach. The tumor was encapsulated and adhered tightly to the sclera, short ciliary nerve, and optic nerve. For this reason, it was removed without a part of the adhered capsule. Since histological examination revealed neuroma, the tumor was diagnosed as short ciliary nerve neuroma. Postoperatively no additional deficits occurred. The exophthalmus, diplopia and Marcus gunn pupil sign disappeared and visual acuity was improved after the surgery. In such a case of short ciliary nerve neuroma, it is possible to remove the tumor without any neurological deficit, if careful consideration of microsurgical anatomy is made.

Use of piritramide for analgesia and sedation during peribulbar nerve block for cataract surgery

PURPOSE

To investigate the effects of pre-block analgesia and sedation using piritramide on haemodynamic stability, endocrine stress response and patients' pain perception.

METHODS

In a randomized, single-blinded, placebo-controlled study, 60 patients having cataract surgery with peribulbar block were randomly assigned into two groups: group A (n = 30) received 0.05 mg/kg piritramide (Dipidolor) intravenously; group B received normal saline intravenously prior to peribulbar block. Mean arterial pressure, heart rate, respiratory rate and pulse oximetry were recorded perioperatively. Pain from peribulbar block was assessed using a verbal analogue scale. Urinary excretion of vanillylmandelic acid was measured to assess the endocrine stress response. Using a questionnaire, patients assessed their anxiety and back pain before and during surgery.

RESULTS

Mean arterial pressure remained near baseline in group A. In group B, a significant increase in mean arterial pressure after peribulbar block was found (p < 0.001). In addition, a significant increase in urinary excretion of vanillylmandelic acid was found in group B (p = 0.013). Pain scores (p < 0.001), anxiety before nerve block (p = 0.02) and during surgery (p < 0.001) and back pain (p = 0.003) were significantly lower in group A.

CONCLUSION

The presented study suggests that using piritramide for analgesia and sedation prior to peribulbar block produces haemodynamic stability and reduces pain perception and endocrine stress response.