Presumed topiramate-induced maculopathy

Efficacy and Tolerability of Erenumab and Topiramate for Prevention of Chronic Migraine: A Retrospective Cohort Study

Background and Objectives: Migraine is a chronic neurological disorder affecting approximately 14% of the global population. Beyond physical pain, migraines significantly impact individuals' quality of life, influencing education, employment, and income levels. Topiramate, a second-generation antiepileptic medication, has demonstrated notable efficacy in reducing the occurrence of chronic migraine. Over the past three decades, extensive research has implicated the neuropeptide calcitonin gene-related peptide (CGRP) in migraine pathogenesis. Erenumab, the first FDA-approved CGRP inhibitor, received approval in 2018. This study aims to compare the clinical efficacy of Erenumab and Topiramate for migraine prevention. Materials and Methods: We conducted a retrospective cohort study of adults with episodic or chronic migraine over a 12-month period, comparing Erenumab (n = 52) and Topiramate (n = 56). Outcomes assessed included changes in the Migraine Disability Assessment (MIDAS) scores from baseline over the last three months of treatment and the proportion of patients achieving a ≥50% reduction in MIDAS scores by the end of the study. Results: The Erenumab group showed significant improvement, with nearly 79% of patients achieving a 50% reduction in their MIDAS score, with a mean reduction of 3.76. Notably, only two patients (3.8.5) discontinued treatment due to adverse events. In contrast, the Topiramate group had over 15% of patients achieve a 50% reduction in MIDAS scores, with a mean reduction of 5.89, and a had discontinuation rate of 14.2% due to adverse events. Conclusions: Both Topiramate and Erenumab are effective for migraine prevention. However, Topiramate has lower tolerability and more side effects, while Erenumab offers better tolerability and safety at a higher cost. Treatment decisions should be individualized based on patient needs, efficacy, safety, and cost considerations.

Presumed topiramate-induced retinopathy in a 58-year-old woman

We present a case of presumed topiramate-induced retinopathy in a 58-year-old woman who presented with progressive, bilateral visual loss following a 3- to 4-year history of oral topiramate intake for migraine. She reported difficulty with light adaptation, hemeralopia, and color desaturation. Her best-corrected visual acuity was 1/60 (20/1200) in the right eye and 6/18 (20/60) in the left eye, and she performed poorly on Ishihara color plate testing. Anterior segment examination was normal; dilated funduscopy showed mild macular pigmentary changes. Optical coherence tomography revealed subtle thinning and reduced reflectivity of the subfoveal ellipsoid zone and interdigitation zone bilaterally, associated with increased foveal autofluorescence. Humphrey visual field 24-2 revealed central defects. Electrodiagnostic testing showed a reduced and delayed b-wave and a normal a-wave on photopic full-field electroretinogram (ERG), with normal scotopic responses; multifocal ERG revealed reduced responses in the inner 10° in both eyes. She underwent extensive investigations including whole-body computed tomography and positron emission tomography scan, magnetic resonance imaging of the brain, uveitis screening, retinal autoantibody testing, and genetic testing on the retinal dystrophy panel to rule-out other causes for her presentation, all of which were normal or negative.

Ocular dysfunctions and toxicities induced by antiepileptic medications: Types, pathogenic mechanisms, and treatment strategies

INTRODUCTION

Ocular dysfunctions and toxicities induced by antiepileptic drugs (AEDs) are rarely reviewed and not frequently received attention by treating physicians compared to other adverse effects (e.g. endocrinologic, cognitive and metabolic). However, some are frequent and progressive even in therapeutic concentrations or result in permanent blindness. Although some adverse effects are non-specific, others are related to the specific pharmacodynamics of the drug. Areas covered: This review was written after detailed search in PubMed, EMBASE, ISI web, SciELO, Scopus, and Cochrane Central Register databases (from 1970 to 2019). It summarized the reported ophthalmologic adverse effects of the currently available AEDs; their risks and possible pathogenic mechanisms. They include ocular motility dysfunctions, retinopathy, maculopathy, glaucoma, myopia, optic neuropathy, and impaired retinal vascular autoregulation. In general, ophthalmo-neuro- or retino-toxic adverse effects of AEDs are classified as type A (dose-dependent), type B (host-dependent or idiosyncratic) or type C which is due to the cumulative effect from long-term use. Expert opinion: Ocular adverse effects of AEDs are rarely reviewed although some are frequent or may result in permanent blindness. Increasing knowledge of their incidence and improving understanding of their risks and pathogenic mechanisms are crucial for monitoring, prevention, and management of patients' at risk.

Topiramate associated non-glaucomatous visual field defects

We report a 34-years-old woman who presented with bilateral incongruous inferior visual field defects after the commencement of topiramate for management of migraine. Investigations did not reveal any underlying angle closure glaucoma, reported in current literature to be associated commonly with topiramate associated visual field defects. The changes in the peripheral visual fields gradually improved over several months after the medication was withdrawn. There were only minor changes persistent on the left side on a background of pre-existing myopia and keratoconus. Visual field deficits secondary to topiramate are more commonly attributed to angle closure glaucoma due to ciliochoroidal effusion syndrome. In such instance, the visual field defects are associated with considerable pain due to raised intra-ocular pressure. There have also been reports of visual scotomas due to retinal damage and maculopathy in patients taking topiramate. It is worthwhile to obtain a baseline perimetry in patients being considered for topiramate therapy in order to gauge any changes in their peripheral field of vision during the treatment. Changes in visual fields during the course of medication use and after cessation can be easily compared especially if there are other possible confounders such as refractive errors or a history of migraine.

Topiramate maculopathy

The purpose of this study is to present the first case of a pure 'topiramate maculopathy' without acute glaucoma and/or myopia, which form the classical syndrome.

DESIGN

Interventional/observational case report.

SETTING

Institutional University Teaching Hospital.

PATIENT

A 22-year-old American female, after taking 100 mg of topiramate (Topamax®) a day for 6 days because of a migraine attack, complained of severe visual acuity deterioration of sudden onset in both eyes, regardless of distance (far or near), during the span of 1 day. A complete ocular examination was carried out. Best-corrected visual acuity (BCVA) in the right eye was hand motion and in the left eye was counting fingers. Cycloplegic refraction and pinhole did not improve the visual acuity of patient's eyes. The anterior chamber depth was normal in both eyes. Tonometry was 14 mmHg in both eyes. Fundus biomicroscopy disclosed a maculopathy with macular striae and a cellophane-like reflex. Optical coherence tomography (OCT) showed an undulating profile with congruent retinal folds and choroidal layers plicae. INTERVENTIONAL/OBSERVATION PROCEDURE: Immediate discontinuation of Topamax and steroid therapy.

MAIN OUTCOME MEASURES

BCVA, cycloplegic refraction, tonometry, fundus photography, and OCT. Three days after suspension of Topomax and steroid therapy the patient's BCVA was 6/6 in both eyes. Tonometry was 14 mmHg in both eyes. Fundus appearance and OCT features were nearly normal. After 2 years of follow-up, the patient's BCVA, tonometry, macula, and OCT are stable in both eyes. In conclusion, an isolated (unassociated with glaucoma and/or induced myopia) acute maculopathy, previously known as being part of a rare syndrome, has been identified, described, and documented.

Ocular toxicity from systemically administered xenobiotics

INTRODUCTION

The eye is considered as the most privileged organ because of the blood-ocular barrier that acts as a barrier to systemically administered xenobiotics. However, there has been a significant increase in the number of reports on systemic drug-induced ocular complications. If such complications are left untreated, then it may cause permanent damage to vision. Hence, knowledge of most recent updates on ever-increasing reports of such toxicities has become imperative to develop better therapy while minimizing toxicities.

AREAS COVERED

The article is mainly divided into anterior and posterior segment manifestations caused by systemically administered drugs. The anterior segment is further elaborated on corneal complications where as the posterior segment is focused on optic nerve, retinal and vitreous complications. Furthermore, this article includes recent updates on acute and chronic ocular predicaments, in addition to discussing various associated symptoms caused by drugs.

EXPERT OPINION

Direct correlation of ocular toxicities due to systemic drug therapy is evident from current literature. Therefore, it is necessary to have detailed documentation of these complications to improve understanding and predict toxicities. We made an attempt to ensure that the reader is aware of the characteristic ocular complications, the potential for irreversible drug toxicity and indications for cessation.

Topiramate and the vision: a systematic review

BACKGROUND AND PURPOSE

Topiramate (TPM) is a sulfa-derivative monosaccharide that is used mainly for treating epilepsy and preventing migraine. Within the gamut of side effects attributable to this drug, ophthalmologic manifestations are of crucial importance. In this study, for the first time, the aim was to provide a systematic literature review regarding this issue.

METHODS

For the time period 1996-2011, a PubMed search was made for the studies concerning the adverse/beneficial effects of TPM on vision. Overall, 404 citations out of a total of 2756 TPM-related studies were examined for relevance.

RESULTS

A total of 74 relevant studies were reviewed, 65 of which comprise small observational studies describing the ophthalmic side effects of TPM in 84 patients. Of these patients, 66 were affected by ciliochoroidal effusion syndrome as the cardinal ocular side effect of TPM (17 cases of myopic shift and 49 cases of angle closure glaucoma). A comprehensive statistical analysis is provided on these 66 subjects. Other rare side effects of TPM on the vision were also reviewed, including massive choroidal effusion, ocular inflammatory reactions, visual field defects, probable effects on retina, cornea, and sclera, and neuroophthalmologic complications. In addition, a framework is provided to classify these results.

DISCUSSION

Due to the expanding spectrum of indications for the administration of TPM, neurologists and psychiatrists should be aware of its diverse ocular side effects. In conclusion, ocular complications following this drug should be taken seriously and be subjected to ophthalmic counseling.

Topiramate and visual loss in a patient carrying a Leber hereditary optic neuropathy mutation

We describe a 43-year-old patient who experienced visual loss 4 years after beginning antiepileptic therapy with topiramate. Ophthalmological and neurological examinations led to a preliminary diagnosis of bilateral toxic optic neuritis. Mitochondrial genome sequence analysis detected a Leber hereditary optic neuropathy 11778G>A mutation. The possibility that topiramate might favor a conversion disease, alerts physicians to seek a history of blindness in patients undergoing chronic antiepileptic therapy.

Topiramate-induced angle closure with acute myopia, macular striae

Topiramate is a sulfamate-substituted monosaccharide used in the treatment of seizures, and prophylaxis of migraine. A number of ocular side-effects have been described with use of topiramate, like bilateral angle closure, acute myopia and macular striae. Ultrasound biomicroscopy (UBM) clinches the diagnosis after ruling out other causes of shallow anterior chamber. Previous studies have not demonstrated internal limiting membrane folds presenting as macular striae. We report a case of topiramate-induced acute myopia with angle closure and macular striae in a young adult. This is the first report wherein striae formation after low doses of topiramate and their resolution have been documented by Optical Coherence Tomography (OCT).