To determine the efficacy of a colorimetric pupil light reflex (PLR) device (Melan-100(®), U.S.A.) in dogs of sudden acquired retinal degeneration syndrome (SARDS; 16 cases), progressive retinal atrophy (PRA; 10 cases) and optic pathway disease (6 cases). The colorimetric device detected PLR abnormality in 32, 16, and 9 eyes with SARDS, PRA and optic pathway disease, respectively, whereas white light detected PLR abnormality in 18, 11 and 9 eyes with SARDS, PRA and optic pathway disease, respectively. SARDS dogs displayed miosis, while optic pathway disease dogs displayed mydriasis by blue light examination. Thus, colorimetric PLR may be a useful method for determining whether electroretinography (ERG) or magnetic resonance imaging (MRI) should be performed for dogs with acute blindness.

We present a case of Horner's syndrome occurring as a complication of thyroidectomy. A 42-year-old female patient presented with eyelid drop which developed immediately after thyroidectomy for goitre. Ophthalmic examination revealed eyelid ptosis, miosis and anhidrosis. Preoperative ultrasonography showed multiple isohyperechogenic solid nodules in each lobe, consistent with multinodular goitre. Therefore, the patient underwent subtotal thyroidectomy. The ophthalmic findings did not improve at the end of 6 months follow-up. Similar cases have been reported related to neck tumours or their surgery, mediastinum-located goitre and retropharyngeal abscess surgeries, but not after benign nodular goitre surgery. Several possible mechanisms have been proposed to explain this phenomenon; anatomical variations making the patient susceptible to damage to the sympathetic chain seem to be most likely in our patient.

BACKGROUND:

Tramadol is an atypical analgesic with monoamine and modest mu opioid agonist activity. The purpose of this study was to evaluate: (1) the efficacy of extended-release (ER) tramadol in treating prescription opioid withdrawal and (2) whether cessation of ER tramadol produces opioid withdrawal.

METHODS:

Prescription opioid users with current opioid dependence and observed withdrawal participated in this inpatient, two-phase double blind, randomized placebo-controlled trial. In Phase 1 (days 1-7), participants were randomly assigned to matched oral placebo or ER tramadol (200 or 600mg daily). In Phase 2 (days 8-13), all participants underwent double blind crossover to placebo. Breakthrough withdrawal medications were available for all subjects. Enrollment continued until 12 completers/group was achieved.

RESULTS:

Use of breakthrough withdrawal medication differed significantly (p<0.05) among groups in both phases; the 200mg group received the least amount in Phase 1, and the 600mg group received the most in both phases. In Phase 1, tramadol 200mg produced significantly lower peak ratings than placebo on ratings of insomnia, lacrimation, muscular tension, and sneezing. Only tramadol 600mg produced miosis in Phase 1. In Phase 2, tramadol 600mg produced higher peak ratings of rhinorrhea, irritable, depressed, heavy/sluggish, and hot/cold flashes than placebo. There were no serious adverse events and no signal of abuse liability for tramadol.

CONCLUSIONS:

ER tramadol 200mg modestly attenuated opioid withdrawal. Mild opioid withdrawal occurred after cessation of treatment with 600mg tramadol. These data support the continued investigation of tramadol as a treatment for opioid withdrawal.

Recently, Rousselet et al. reported a 1 ms/year delay in visual processing speed in a sample of healthy aged 62 subjects (Frontiers in Psychology 2010, 1:19). Here, we replicate this finding in an independent sample of 59 subjects and investigate the contribution of optical factors (pupil size and luminance) to the age-related slowdown and to individual differences in visual processing speed. We conducted two experiments. In experiment 1 we recorded EEG from subjects aged 18-79. Subjects viewed images of faces and phase scrambled noise textures under nine luminance conditions, ranging from 0.59 to 60.8 cd/m(2). We manipulated luminance using neutral density filters. In experiment 2, 10 young subjects (age < 35) viewed similar stimuli through pinholes ranging from 1 to 5 mm. In both experiments, subjects were tested twice. We found a 1 ms/year slowdown in visual processing that was independent of luminance. Aging effects became visible around 125 ms post-stimulus and did not affect the onsets of the face-texture ERP differences. Furthermore, luminance modulated the entire ERP time-course from 60 to 500 ms. Luminance effects peaked in the N170 time window and were independent of age. Importantly, senile miosis and individual differences in pupil size did not account for aging differences and inter-subject variability in processing speed. The pinhole manipulation also failed to match the ERPs of old subjects to those of young subjects. Overall, our results strongly suggest that early ERPs to faces (<200 ms) are delayed by aging and that these delays are of cortical, rather than optical origin. Our results also demonstrate that even late ERPs to faces are modulated by low-level factors.

About 25 million agricultural workers in the developing world suffer from at least one episode of poisoning each year, mainly by anticholinesterase-like organophosphates (OPs). The objective of this cross-sectional study was to establish the OP toxicity in 187 occupationally exposed farmers in terms of neurocognitive impairment, mental health status, clinical symptoms, diabetes, and haematological factors. The exposed group was compared to 187 healthy age-, sex-, and education-matching controls. Neurocognitive impairment was measured using the Subjective Neurocognition Inventory (SNI) and mental health status using the General Health Questionnaire-28 (GHQ-28). The subjects were also tested for fasting blood glucose (FBG), blood urea nitrogen (BUN), cholesterol (CL), triglycerides (TG), creatinine, oral glucose tolerance test (GTT), high-density lipoprotein (HDL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). The exposed farmers showed higher FBG (p<0.001), BUN (p=0.007), CL (p<0.001), oral GTT (p<0.001), and lower AST (p<0.001), ALP (p<0.001), and creatinine (p=0.004) than controls. The rates of anxiety/ insomnia and severe depression were also significantly higher in the farmers than in controls (p=0.015 and p<0.001, respectively). Meanwhile, the rate of social dysfunction was significantly lower than in controls (p<0.001). Disorders affecting psychomotor speed, selective attention, divided attention, verbal memory, nonverbal memory, prospective memory, spatial functioning, and initiative/energy were all lower in the farmers (p<0.001). Farmers showed clinical symptoms eczema, saliva secretion, fatigue, headache, sweating, abdominal pain, nausea, superior distal muscle weakness, inferior distal muscle weakness, inferior proximal muscle weakness, breath muscle weakness, hand tingling, foot tingling, epiphoria, polyuria, miosis, dyspnoea, bradycardia, and rhinorrhoea, which all significantly correlated with the number of working years. These findings indicate that farmers who work with OPs are prone to neuropsychological disorders and diabetes.

The link between arousal and pupil dilation is well studied, but it is less known that other cognitive processes can trigger pupil responses. Here we present evidence that pupil responses can be induced by high-level scene processing, independent of changes in low-level features or arousal. In Experiment 1, we recorded changes in pupil diameter of observers while they viewed a variety of natural scenes with or without a sun that were presented either upright or inverted. Image inversion had the strongest effect on the pupil responses. The pupil constricted more to the onset of upright images as compared to inverted images. Furthermore, the amplitudes of pupil constrictions to viewing images containing a sun were larger relative to control images. In Experiment 2, we presented cartoon versions of upright and inverted pictures that included either a sun or a moon. The image backgrounds were kept identical across conditions. Similar to Experiment 1, upright images triggered pupil constrictions with larger amplitudes than inverted images and images of the sun evoked greater pupil contraction than images of the moon. We suggest that the modulations of pupil responses were due to higher-level interpretations of image content.

The iris is the most anterior portion of the uveal tract. The pupil is round opening near the center of the iris; it is displaced slightly downward and nasally with respect to the center of the cornea. The mammalian iris sphincter is considered to be innervated by cholinergic, and the dilator muscle by adrenergic excitatory nerve fibers, and both miosis and mydriasis are the result of contraction of the iris sphincter and the dilator muscles due to activation of these excitatory nerve fibers. Pharmacological and histological investigations also reveal that the sphincter muscle is innervated in part by inhibitory adrenergic nerve fibers, and that the dilator muscle is also innervated by inhibitory cholinergic nerve fibers. In addition to the release of acetylcholine and norepinephrine by these nerves, the peripheral nerves to the mammalian iris contain various neuropeptides, although the functional role of these pepetides is not clear. It has been known for more than 100 years that two types of photosensitive cells exist in man. However, some totally blind individuals maintain a normal circadian rhythm. Such a phenomenon cannot be explained by the rod and cone functions. Recently, a new photosensitive pigment, melanopsin, was found in the dermal melanophore cells of the frog. In 2002, melanopsin-containing retinal ganglion cells (mRGCs) were discovered and revealed that mRGCs would depolarize without input from the photoreceptors, meaning that these cells are photosensitive. In the human retina, mRGCs comprise only 0.2% of all ganglion cells. Electrophysiological studies show that light slowly depolarizes mRGCs but rapidly hyperpolarizes rods and cones. The mRGCs innervate the suprachiasmatic nucleus, which is the master circadian pacemaker in mammals, and the olivary pretectal nucleus of the midbrain. In addition to their role in circadian entrainment, the mRGCs mediate the pupillary light reflex. We investigated the mechanism of photoreception by retinal photoreceptor cells, and to evaluate the relative contribution of pupil light response using the control, instigated pharmacological blockade of neurotransmission (PB) model and a transgenic model of retinal degeneration (Tg) rabbit. Although rod and cone photoreceptors disappeared in the PB and Tg models, miosis was still induced during exposure to blue light (470 nm). The greater sustained constriction of pupils to blue light in eyes with outer retinal damage reflects mRGC activation. Our study also indicated that some histologically-identified RGCs were consistent with the characteristics and structures of mRGC. Clinically, in age-related macular degeneration patients, there was no reliable recordable pupil response to red light, even at the brightest intensity but a blue light evoked a sustained pupil constriction. However, in glaucoma patients, there was no reliable recordable pupil response to the brightest intensity of blue light. These preliminary recordings in human subjects demonstrate that changes in the pupil responses to chromatic stimuli are readily detectable and easily quantifiable with standard instruments of clinical testing. We hypothesize that changes in the transient pupil response to red light and low intensity blue light may be more sensitive to cone and rod disease, whereas changes in the sustained pupil response to bright blue light may be more sensitive to optic nerve disease. Ongoing studies of the pupil are aimed at optimizing stimulus conditions that elicit pupil responses that can better localize the site of damage to rods, cones, and RGCs, to quantify the extent of disease.

PURPOSE:

To report the ophthalmic findings in young patients with dopamine β-hydroxylase deficiency and to assess them in the context of other reports in an attempt to discern if ophthalmic criteria may assist in early detection of this debilitating, yet treatable, disorder.

DESIGN:

Prospective, observational case series.

METHODS:

An ophthalmic examination, including measuring intraocular and systemic blood pressures while supine, sitting, and standing, and eyelid function and pupillary function testing, was completed on 3 young patients with recently documented dopamine β-hydroxylase deficiency at a single institution.

RESULTS:

Mean arterial blood pressures were 90.1 ± 18.5 mm Hg supine, 79.1 ± 25.7 mm Hg sitting, and 45.8 ± 11.6 mm Hg standing (P = .021). Mean intraocular pressures in these patients were 15.8 ± 1.0 mm Hg supine, 15.0 ± 3.6 mm Hg sitting, and 7.7 ± 2.3 mm Hg standing (P = .03). Mean palpebral fissure, levator function, and margin reflex distance were 8.2 ± 1.0 mm, 16.0 ± 0 mm, and 2.8 ± 0.6 mm, respectively. Measurable miosis was present in only 1 patient, and pupillary supersensitivity to 2.5% phenylephrine was not observed.

CONCLUSIONS:

The ophthalmologic findings of the patients in this case series documented mild ptosis and striking orthostatic reductions in intraocular pressure and mean arterial blood pressure, as might be expected with a lack of intrinsic sympathetic function. Orthostatic intraocular pressure and mean arterial blood pressure may be a helpful early screening tool for autonomic dysfunction in children undergoing a ptosis evaluation.

Purpose:

  The purpose of this study was to assess the incidence of intraoperative floppy iris syndrome (IFIS) and the morphology of the corneal endothelium after cataract extraction in Caucasian male patients exposed to the α-1a adrenergic receptor antagonist tamsulosin.

Methods:

  In a clinical prospective study, 23 male patients (23 eyes) treated with tamsulosin due to benign prostatic hyperplasia and 25 male patients (25 eyes) with no tamsulosin treatment had cataract surgery. The divide-and-conquer technique was used with the Infinity OZil(®) machine. A combination of Healon and Healon5 was used in all patients, but the use of additional Vision Blue, iris retractors or intracameral phenylephrine in the tamsulosin group was at the discretion of the surgeon. The endothelial cell density, variation in endothelial cell size (CV), percentage of hexagonal cells and central corneal thickness (CCT) were recorded at baseline and at 3 months postoperatively.

Results:

  In the tamsulosin-treated group, 19 of 23 eyes (83%) developed IFIS, compared with no IFIS in the control group. Compared with the control group, the tamsulosin group showed significantly less dilatation at the start of the operation, significant miosis during surgery and significantly greater corneal endothelial cell loss 3 months postoperatively (12% versus 3%; p < 0.001).

Conclusion:

  Intraoperative floppy iris syndrome during cataract surgery is significantly associated with tamsulosin-treated male patients. Patients on tamsulosin showed less preoperative dilatation, significant miosis during surgery, and had significantly greater postoperative endothelial cell loss compared with nontreated patients despite recommended precautions.

Organophosphates are commonly used pesticides and cause about one million unintentional and 2 million suicidal exposures with up to 300,000 fatalities every year around the world. Toxicity of organophosphates is due to inhibition cholinesterase activity and prolonging the effects of acetylcholine in the receptor site. Clinical features of organophosphate poisoning are defecation, urination, miosis, bronchorrhea, emesis, lacrimation and salivation. Spontaneous abortion reported some when in pregnant patients. Intravenous administration of benzodiazepines, atropine and pralidoxime is the formal treatment of this toxicity. Atropine and pralidoxime have been assigned to pregnancy class C by the FDA and should be recommended for use in pregnant women clinically suffer organophosphate poisoning. Benzodiazepines have been assigned to pregnancy class D and should be avoided during pregnancy. Clinical experiments suggest transplacental transfer of organophosphates is possible, and fetal sensitivity is probable, but a single acute overdose most likely don't make any physical deformities, therefore termination of pregnancy is not imperative. Nonetheless, no definite strategy focused on maintaining pregnancy. Here we propose an idea that in any female case of acute organophosphate poisoning in childbearing range of age, maternal serum Beta-HCG should be tested for pregnancy and prophylactic progesterone should be used in pregnant cases of organophosphate poisoning.