Lithium-induced downbeat nystagmus

Common systemic medications that every optometrist should know

Healthcare in the twenty-first century has witnessed an increased use of prescription drugs. As a member of a patient's health care team, optometrists should be aware of the pharmaceuticals taken by patients and their potential ocular complications. This paper will discuss the most prescribed medications in Australia today and their effects on the visual system. The paper will review the agents used to treat six common systemic conditions, their frequency of use, mechanism of action, clinical indications, and potential ocular manifestations. Literature has documented both positive and negative associations of systemic medications on the eye's health. Many associations documented here have shown conflicting evidence, thus warranting further investigation. Based on the frequency and severity of the ocular manifestations in the literature, recommendations for clinical care are given. Being familiar with the most common ocular side effects associated with common systemic medications aids in the correct and timely diagnosis of ocular complications to prevent permanent sequelae.

Ophthalmic adverse effects of lithium

Lithium is the current mainstay treatment for both acute and maintenance management of bipolar disorders. However, its narrow therapeutic index and array of side effects, although well-documented, can be challenging to manage. Comparatively, the side effects of lithium that involve the ophthalmic structures are not as well established in the literature and only partially appreciated, which can potentially lead to noncompliance. In this article, an extensive literature review of lithium and its ophthalmic adverse effects were performed and comprehensively summarized. Based on the search, documented ophthalmic adverse effects of lithium include: exophthalmos; abnormal eye movements; ocular myasthenia gravis; papilledema; photophobia; and abnormal tear film, contributing to dry eye disease. Additional studies are anticipated to be helpful in expanding the current understanding of lithium and its adverse ophthalmic side effects and certainly warranted to fill the knowledge gap. Close interprofessional management between psychiatrists and ophthalmologists is expected to be beneficial in patient care.

Eye-head coordination abnormalities in schizophrenia

BACKGROUND

Eye-movement abnormalities in schizophrenia are a well-established phenomenon that has been observed in many studies. In such studies, visual targets are usually presented in the center of the visual field, and the subject's head remains fixed. However, in every-day life, targets may also appear in the periphery. This study is among the first to investigate eye and head movements in schizophrenia by presenting targets in the periphery of the visual field.

METHODOLOGY/PRINCIPAL FINDINGS

Two different visual recognition tasks, color recognition and Landolt orientation tasks, were presented at the periphery (at a visual angle of 55° from the center of the field of view). Each subject viewed 96 trials, and all eye and head movements were simultaneously recorded using video-based oculography and magnetic motion tracking of the head. Data from 14 patients with schizophrenia and 14 controls were considered. The patients had similar saccadic latencies in both tasks, whereas controls had shorter saccadic latencies in the Landolt task. Patients performed more head movements, and had increased eye-head offsets during combined eye-head shifts than controls.

CONCLUSIONS/SIGNIFICANCE

Patients with schizophrenia may not be able to adapt to the two different tasks to the same extent as controls, as seen by the former's task-specific saccadic latency pattern. This can be interpreted as a specific oculomotoric attentional dysfunction and may support the hypothesis that schizophrenia patients have difficulties determining the relevance of stimuli. Patients may also show an uneconomic over-performance of head-movements, which is possibly caused by alterations in frontal executive function that impair the inhibition of head shifts. In addition, a model was created explaining 93% of the variance of the response times as a function of eye and head amplitude, which was only observed in the controls, indicating abnormal eye-head coordination in patients with schizophrenia.

Ocular adverse effects of common psychotropic agents: a review

All psychotropic medications have the potential to induce numerous and diverse unwanted ocular effects. Visual adverse effects can be divided into seven major categories: eyelid and keratoconjunctival disorders; uveal tract disorders; accommodation interference; angle-closure glaucoma; cataract/pigmentary deposits in the lens and cornea; retinopathy; and other disorders. The disorders of the eyelid and of the keratoconjunctiva are mainly related to phenothiazines and lithium. Chlorpromazine, at high dosages, can commonly cause abnormal pigmentation of the eyelids, interpalpebral conjunctiva and cornea. It can also cause a more worrisome but rarer visual impairment, namely corneal oedema. Lithium can rarely lead to a bothersome eye irritation by affecting sodium transport. Uveal tract problems are mainly associated with tricyclic antidepressants (TCAs), typical antipsychotics, topiramate and selective serotonin reuptake inhibitors (SSRIs). TCAs, typical antipsychotics and SSRIs can all cause mydriasis that is often transient and with no major consequences, but that can promote closure of angles in susceptible patients. Topiramate has been frequently associated with a number of significant ocular symptoms including acquired myopia and angle-closure glaucoma. Problems with accommodation are related to TCAs and to low-potency antipsychotics. TCAs cause transient blurred vision in up to one-third of patients. Angle-closure glaucoma is a serious condition that has been mainly associated with TCAs, low-potency antipsychotics, topiramate and, to a lesser extent, SSRIs. When patients with narrow angles are given TCAs, they all appear to experience induction of glaucomatous attacks. Antipsychotics and SSRIs may lead to an added risk of developing angle-closure glaucoma, but only in predisposed eyes. Topiramate can lead to an allergic-type reaction whereby structures of the lens and ciliary body are displaced, which results in angle-closure glaucoma. Cataractous changes can result from antipsychotics, mainly from high dosages of chlorpromazine or thioridazine. These two drugs, when used at high dosages and for prolonged periods, frequently cause lenticular opacifications. Retinopathy has been shown to be related to high dosages of typical antipsychotics, mainly chlorpromazine and thioridazine. The frequency of occurrence of retinal effects seems to be proportional to the total amount of drug used over a long period of time. Other visual problems of special concern are the ocular dystonias, other eye movement disorders, and decreased ability to perceive colours and to discriminate contrast. Ocular dystonias can occur with antipsychotics (especially high-potency ones), carbamazepine (especially in polytherapy), topiramate and, rarely, with SSRIs. Disturbance in various eye movements is frequently seen with benzodiazepines, antiepileptic drugs and lithium. Impairment in the perception of colours and the discrimination of contrasts has been shown to occur not uncommonly with carbamazepine and lorazepam. Thus, typical antipsychotics, TCAs, lithium, benzodiazepines, carbamazepine, topiramate and SSRIs appear to produce most of the currently recognized ocular problems. Psychiatrists, ophthalmologists and patients need to be aware of and prepared for any medication-induced adverse effect. Early prevention and intervention can avoid most of the serious and potentially irreversible ocular toxicities.

Symptomatic and Disease-Modifying Therapy for the Progressive Ataxias

BACKGROUND

The progressive ataxias are a diverse group of neurologic diseases that share features of degeneration of the cerebellum and its inflow/outflow pathways but differ in etiology, course, and associated noncerebellar system involvement. Some will have treatable causes, but for most, the pathophysiology is incompletely known.

REVIEW SUMMARY

Treatment strategies will include (1) definitive therapy when available, (2) symptomatic treatment and prevention of complications, and (3) rehabilitation and support resources. The physician will have to decide whether to introduce or approve the use of therapies based on as yet-unproven mechanisms or the use of complementary medicine approaches.

CONCLUSIONS

There are as yet no drugs that have been approved by the Food and Drug Administration for the treatment of the progressive ataxias and relatively few disease-modifying therapies, but symptomatic and rehabilitation interventions can greatly improve the quality of life of individuals with these disabling neurodegenerative disorders.

Further studies on a male monozygotic triplet with schizophrenia: cytogenetical and neurobiological assessments in the patients and their parents

We previously described a Swedish set of male schizophrenic monozygotic triplets. In this study the patients as well as their parents were further characterized. By high-resolution chromosomal analysis an extra band at chromosome 15p was found in all the triplets and the father. Microdissection, degenerate oligonucleotide-primed PCR (DOP-PCR) amplification and reverse painting indicates that the extra band probably contains only repetitive DNA sequences with no known effect on the phenotype. Magnetic resonance imaging (MRI) showed similar borderline ventricular enlargement and widened subarachnoid spaces over frontoparietal and basal regions as well as around the pituitary gland (empty sella) in all the triplets. The father also had widened subarachnoid spaces over the frontal and basal regions. The mother had an empty sella indicating widened subarachnoid spaces. All the boys also had a right-sided conductive hearing defect, probably due to malformation and fixation of the ossicular chain. The parents did not present any otological abnormalities. Neuropsychological assessment demonstrated similar marked reductions of attentional, mnestic, and executive functions in all the triplets, but the mother showed a normal pattern. Possible joint etiological mechanisms for the psychological and somatic abnormalities recorded in the triplets are discussed.

Ocular adverse effects of neuropsychiatric agents. Incidence and management

Neuropsychiatric agents may adversely affect the eye in various ways. The more frequently encountered effects include corneal oedema and pigmentary changes in the lens and cornea which are induced by phenothiazine derivatives; thioridazine-induced retinopathy; tricyclic antidepressant-induced accommodation interference and glaucoma; and lithium carbonate-induced exophthalmos and papilloedema. Several adverse effects, such as corneal oedema, retinopathy and glaucoma, are vision-threatening, and patients often fail to describe their symptoms properly. A more precise understanding of these conditions is essential for prompt diagnosis and appropriate treatment.

Neuro-ophthalmology and psychiatry

Neuro-ophthalmology and psychiatry interact over several issues. The neuro-ophthalmologist can confirm the suspicion of nonorganic visual dysfunction by demonstrating the functional integrity of the visual system and the nonphysiologic nature of the visual complaints. He or she may recognize evidence of organic dysfunction in the patient with a presumed psychiatric diagnosis. In some cases, the pathology may be related to the use of certain psychiatric medications. Specialized examination techniques within the realm of neuro-ophthalmology may provide subtle information about the functional integrity of the central nervous system in patients with psychiatric disease. Clinical and investigational collaboration between the neuro-ophthalmologist and the psychiatrist will provide the most appropriate patient management and may further our understanding of the biological basis of psychiatry.