Toxic effects of phenothiazines on the eye

Macular Findings of Patients on Pentosan Polysulfate Sodium

INTRODUCTION

In 2018, a unique maculopathy associated with chronic pentosan polysulfate sodium (PPS) use for the treatment of interstitial cystitis (IC) was described, where the authors detailed macular retinal pigment epithelial abnormalities in six patients. In this paper, a retrospective study of a larger patient pool at one large tertiary retina practice was undertaken to evaluate patients taking PPS and their macular findings.

MATERIALS AND METHODS

A retrospective chart review was performed on all patients presenting to a single large retina practice between 2011 and 2019. Patient's macular diagnosis, findings, optical coherence tomography scans, and macular auto-fluorescent scans were assessed. This project was Institutional Review Board (IRB) approved by the St Luke's Hospital IRB board (St Louis, MO, USA).

RESULTS

Fifty-five patients were identified as taking PPS for IC. Fifty-three patients were found to have a diagnosis consistent with changes attributable to known macular diseases to include macular degeneration and pattern dystrophies. Two (4%) of fifty-five patients had macular findings suggestive of PPS toxicity. The first was a 58-year-old female with subtle retinal pigment epithelium (RPE) deposits on optical coherence tomography that exhibited hyper-autofluorescence. The second was a 72-year-old female with 14 years of PPS use who exhibited RPE excrescences and parafoveal areas of atrophy.

CONCLUSIONS

Pentosan polysulfate sodium may be the cause of macular findings in a small percentage of patients referred to a tertiary retina practice. Although causation of macular changes with PPS use has yet to be elucidated, clinicians should be aware of this possibility when assessing patients with atypical macular findings. Future longitudinal studies are necessary to evaluate a definitive relationship. This paper should remind all clinicians of the importance of a throughout review of the patient's medication list as novel toxicities may become apparent years after initial FDA trials. The strength of this study is the larger patient population compared to earlier studies, and the main weaknesses include the retrospective nature of the study, lack of family and genetic testing, and lack of multimodal imaging for all patients.

Scleral Discoloration Because of Minocycline Use: A Case Report and Review of the Literature

In this case report, we highlight minocycline-induced scleral hyperpigmentation, combined with ear and fingernail discoloration that developed after over 15 years of use for rosacea in a 78-year-old male with multiple medical comorbidities. Minocycline, a tetracycline antibiotic, is used to treat rosacea and acne as well as some orthopedic infections. It is typically used for extended periods of time; long-term use of minocycline is associated with hyperpigmentation of the sclera, conjunctiva, retina, teeth, skin, subcutaneous fat, oral mucosa, tympanic membrane, and gingiva. This case highlights that hyperpigmentation is more likely to occur in older patients than in younger patients. Scleral hyperpigmentation is not associated with vision loss; however, cosmetic concerns can prompt discontinuation of minocycline. Nonetheless, after cessation, the lesions persist in some patients. Monitoring for hyperpigmentation in patients using minocycline is important, as the hyperpigmentation is more likely to be permanent with long-term use.

Oxidative Stress Plays an Important Role in the Pathogenesis of Drug-Induced Retinopathy

Several pharmaceutical agents have been associated with rare but serious retinopathies, some resulting in blindness. Little is known of the mechanism(s) that produce these injuries. Mechanisms proposed thus far have not been embraced by the medical and scientific communities. However, preclinical and clinical data indicate that oxidative stress may contribute substantially to iatrogenic retinal disease. Retinal oxidative stress may be precipitated by the interaction of putative retinal toxins with the ocular redox system. The retina, replete with cytochromes P450 and myeloperoxidase, may serve to activate xenobiotics to oxidants, resulting in ocular injury. These activated agents may directly form retinal adducts or may diminish ocular reduced glutathione concentrations. Data are reviewed that suggest that indomethacin, tamoxifen, thioridazine, and chloroquine all produce retinopathies via a common mechanism—they produce ocular oxidative stress.

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.

Ocular abnormalities in chronic schizophrenia: clinical implications

OBJECTIVE

As part of a randomised double-blind study of a new atypical antipsychotic we sought to determine both the levels of visual acuity and the occurrence of toxic side-effects in a group of patients treated for many years on a variety of antipsychotics.

METHODS

Twenty-three inpatients with a DSM-III-R diagnosis of chronic schizophrenia from two separate hospital locations who met the criteria for the double-blind trial were examined for ocular abnormalities at both baseline and at trial completion.

RESULTS

At baseline a high prevalence of abnormalities was identified: 19 patients (82.6%) were found to have one or more ocular abnormalities, including lens opacities/cataracts and corneal pigmentation; three patients, with delusions related to the sun, were noted to have solar burns; a high proportion (almost 70%) of patients had untreated visual acuity problems. No further changes were observed at the follow-up examinations.

CONCLUSIONS

The possible causes of ocular disturbance in schizophrenia and the reasons for the relatively high ocular morbidity in this group are thought to result from both illness-related factors and the effects of antipsychotic medication. Causality is confounded by a number of issues such as the high prevalence of smoking, poor general health and the variety of antipsychotic medications used in the treatment of psychosis as well as substance abuse. The clinical implications are considered in this paper in relation to the move towards community-based psychiatric services.

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.

Toxicology of sensory systems: a perspective

This brief review is the result of a recent meeting of the British Toxicology Society (Toxicology of Sensory Systems, University of York, April 2-3, 1992). The meeting provided the opportunity to discuss the anatomy, physiology and function of the eye, ear, nasal epithelium and peripheral sensation and the methods that are available to detect injury or dysfunction both in the preclinical and clinical situation. In addition, the mechanism whereby certain chemicals can perturb some of these organs was discussed. The aim of this short article is to highlight some of the recent advances in understanding in these areas with regard to their relevance or impact on toxicology. For convenience the areas will be discussed under separate headings.

Electro-ophthalmology and side-effects of drugs

Diagnostic procedures have to be directed towards the prevention of irreversible changes. In this respect, patients using chloroquine have to be examined at least once a year. The most sensitive methods for detecting early reversible changes are the electro-oculogram and static perimetry. The latter is probably more specific. Concerning ethambutol, the patients themselves are aware of the onset because a decrease in visual acuity and a central scotoma are early and reversible symptoms. In these cases electro-ophthalmology is of help when the diagnosis is doubtful. Iatrogenic effects of other drugs are not seen regularly in our electro-ophthalmological departments.