|Year : 2022 | Volume
| Issue : 1 | Page : 179-180
Ivabradine-induced photosensitivity and phosphenes: Case report
Nikunj K Bhatt1, Aniruddha Phadke2, Sourabh D Patwardhan1, Nidhi S Patwardhan1
1 Nandadeep Eye Hospital, Ratnagiri, Maharashtra, India
2 Department of Medicine, Chirayu Hospital, Ratnagiri, Maharashtra, India
|Date of Submission||09-Jun-2021|
|Date of Acceptance||07-Jul-2021|
|Date of Web Publication||07-Jan-2022|
Dr. Nikunj K Bhatt
A/12, Dignity, Mogallane, Mahim, Mumbai - 400 016, Maharashtra
Source of Support: None, Conflict of Interest: None
Ivabradine is a novel antianginal drug that acts by reducing the heart rate of the patient by acting on hyperpolarization-activated cyclic nucleotide–gated ion channels. Here, we report a case of a 39-year-old female who was taking ivabradine for the prevention of heart failure due to dilated cardiomyopathy and was noticing an increased photosensitivity and phosphenes after 1 year of treatment. The side effects of the medication were serious enough to affect the quality of the life of the patient. The patient became asymptomatic after stopping the medication.
Keywords: HCN channel, heart failure, Ivabradine, phosphenes, photosensitivity
|How to cite this article:|
Bhatt NK, Phadke A, Patwardhan SD, Patwardhan NS. Ivabradine-induced photosensitivity and phosphenes: Case report. Indian J Ophthalmol Case Rep 2022;2:179-80
|How to cite this URL:|
Bhatt NK, Phadke A, Patwardhan SD, Patwardhan NS. Ivabradine-induced photosensitivity and phosphenes: Case report. Indian J Ophthalmol Case Rep [serial online] 2022 [cited 2022 Jan 16];2:179-80. Available from: https://www.ijoreports.in/text.asp?2022/2/1/179/334892
Ivabradine is a heart-rate lowering agent that acts by inhibiting the sinoatrial node current. It is a sodium–potassium inward current that controls spontaneous diastolic depolarization. By this mechanism, it regulates the heart rate. Ivabradine is used in patients with symptoms due to stable heart failure and an ejection fraction of 35% or less to reduce their risk of hospital admission for worsening heart failure., Ivabradine is known to cause various side effects such as bradycardia, hypertension, atrial fibrillations, and phosphenes., Phosphenes typically appear within the first 2 months of therapy. Most cases are mild to moderate in severity and disappear spontaneously during or after treatment. However, ocular side effects affecting the quality of life are exceedingly rare.
| Case Report|| |
A 39-year-old female, on ivabradine treatment 5 mg twice a day for the past 1 year for the prevention of heart failure due to dilated cardiomyopathy, came to us with a complaint of difficulty in facing bright light. She was not able to watch outside the window comfortably during broad daylight; she used to experience enhanced brightness for the past few weeks. Her complaints increased whenever there was a sudden variation in light intensity. On examination, her visual acuity was 6/6 and N6 in both eyes. Her adnexa in both eyes were normal. Her cornea and lens were clear in both the eyes. Her posterior segment was also essentially normal. We reassured the patient and sent her back. She again came to us after 1 month stating that photosensitivity had increased and she had started developing other visual symptoms. She had started developing colored hallucinations. As per her complaint, colors on walls of her house and on her clothes were becoming wavy on and off. Because of these complaints, she could not do her household work properly and was feeling helpless. Her ocular examination again did not reveal anything causative. We did a literature search and found out that ivabradine is known to cause visual symptoms such as increased photosensitivity, colored halos, phosphene formation, and so on. We discussed the issue with her treating physician, and he agreed to switch the patient to another class of drug. The patient started noticing improvement in her symptoms within 15 days and was asymptomatic within a month.
| Discussion|| |
Ivabradine blocks the channel responsible for the cardiac pacemaker current that regulates the heart rate. This results in prolonged diastolic time and reduced heart rate. Rapid resting heart rate can lead to detrimental effects on the left ventricular function and has been associated with negative outcomes in patients with cardiovascular disease. Hyperpolarization-activated cyclic nucleotide–gated (HCN) channels are voltage-gated ion channels with the unusual characteristic that they become activated on hyperpolarization of the cell membrane., They are primarily found in the central nervous system and in the heart. Since retina is also a part of the central nervous system, HCN receptors are located here too. Retina expresses all the four subtypes of HCN receptors (HCN 1–4). Ivabradine acts as a selective antagonist of HCN channel. Visual side effects produced by ivabradine are thought to arise from the block of HCN channels in retinal photoreceptors. However, the underlying neurological mechanism is not fully understood. One possible explanation is that ivabradine differentially affects the sensitivity of on and off ganglion cells, which leads to visual side effects. Ivabradine is initially started at a dose of 5 mg twice a day; the maximum permissible dose is 7.5 mg twice a day. In the SHIFT (Systolic Heart Failure Treatment With the IF Inhibitor Ivabradine) trial, it was observed that systemic and ocular side effects of 7.5 mg ivabradine were more compared with placebo and conventional dose of ivabradine. Approximately 15% of the patients on ivabradine have noted some or other kind of phosphene phenomenon. However, our patient noted a significant amount of photosensitivity and phosphenes that were significantly affecting her quality of life. It is important to take a thorough medical history of the patient. Timely intervention in cases like this can improve the quality of life of the patients. It is a common tendency to refer such unexplained cases to a neurologist or psychiatrist for further evaluation, but before that careful medical history should be taken and all the probable causes should be ruled out. Since ivabradine is a newer drug, more studies will be required to know about its various ocular side effects.
| Conclusion|| |
It is important to take thorough medical history of the patient. Timely intervention in case like this can improve the quality of life of the patient. It's common tendency to refer such unexplained case to a neurologist/psychiatrist for further evaluation, but before that careful medical history should be taken and all the probable causes should be ruled out. Since Ivabradine is a newer drug, more studies will be required to know about it's various ocular side effects.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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