Dr. Swartz is Affiliate Faculty, Oregon Health & Science University, Portland; Emeritus Faculty, Southern Illinois University School of Medicine, Springfield, Illinois; and Medical Director, Lutheran Community Services Northwest, Vancouver, Washington.
TO THE EDITOR
The visual hallucinations reported from timolol eye drops1 apparently resulted from local effects on retinal circulation rather than systemic effects. The hallucinations reported were of geometric shapes. This resembles phosphenes, an ordinary response to disruption of retinal circulation, as from closing eyelids tightly for 5 to 10 seconds or from orthostasis. Phosphenes can also result from diseases affecting the retina, such as multiple sclerosis.
For mechanism, the Psychiatric Times report hypothesized only similar systemic effects of eye drops and a 10 mg oral dose. A drop of timolol 0.5% in each eye contains just one twentieth of 10 mg, so its systemic effects cannot be comparable. Moreover, timolol is hydrophilic, so after systemic absorption, it does not normally enter the brain.
In treating anxiety disorders over 25 years, I have given CNS-active beta-blockers to over 2000 patients with clinical benefit. For elderly patients I prefer pindolol, in younger adults betaxolol.2,3 No patient reported visual hallucinations or showed (or mentioned) cognitive impairment. Beta-blockers are well tolerated and safer than antipsychotics in anxiety disorders. The report about timolol should not be understood as timolol causes psychosis.
Finally, changes in color vision are distortions, and your article should not have called them hallucinations.
1. Hackethal V. Visual hallucinations linked to timolol eye drops. Psychiatric Times. 2018;35(1):1,12.
2. Swartz CM. Betaxolol in anxiety disorders. Ann Clin Psychiatry. 1998;10:9-14.
3. Swartz CM. Sympathy for the sympathetic (nervous system). In series "Clinical Controversies." Psychiatric Times. 2003;20:48-51.