Talk:Mydriasis

RE: Mydriasis is "mainly caused by stimulation of the sympathetic system"

To say that mydriasis is "mainly caused by stimulation of the sympathetic system" is not entirely correct. SNS directly causes mydriasis and PNS interruption indirectly causes mydriasis - neither action is the main one. I'm not a neurologist but I believe mydriasis, whether pharmacologically induced or due to injury or other pathology, due to an interruption or blockade of the the parasympathetic system is much more common. I'm pretty sure tropicamide (PNS inhibitor) will usually open a pupil more than pilocarpine (SNS stimulant), too. Edwardian 20:33, 3 September 2005 (UTC) I believe that combining blown pupil with mydriasis is not justified as mydriasis is usually self limiting and blown pupil requires imediate medical invervention. User:farmia 12:36, 11 October, 2010

Is excessive overdilation of the pupils damaging to the eye?

There should be a section either saying it is or isnt.... but i dont know the answer.

One would assume that constricting of the pupil is for both sight and safety reasons. We know bright light for prolonged times can damage the eye (arc eye or sun eye). A permanently dilated pupil would excellerate these effects, no? Needless to say, having mine dilated for only a few hours is pretty painful without sunglasses. 82.93.133.130 11:27, 30 November 2006 (UTC)

Dilation can cause aggravation of glaucoma, or even cause glaucoma in some cases. To treat acute angle glaucoma, a pupil constrictor (to cause Miosis) is often given to open the Canal of Schlemm to allow aqueous humor to drain from the eyeball, relieving increased intraocular pressure. 69.142.105.156 (talk) 08:37, 21 December 2008 (UTC)

Hallucinations caused by mydriasis

The dilated pupil takes in more light and this I believe plays a part in the hallucinations (especially increased brightness and vividness of color)created by psychedelic drugs that dilate the pupil,(like LSD, psychedelic mushrooms, mescaline, MDMA, Datura stramonium.) Is there any research on this?

You can believe that, but it's unfounded and somewhat fantastical. Thus, there would be no research to back this up, sorry. I think everyone who has consumed a psychedelic has come up with some hallucinogen-inspired hypothesis as to what mechanism is responsible for the actual hallucinatory response. I remember a long and tedious conversation with someone who believed: "It's all about memory, man... it like, changes your memory from second to second. So that everything changes. Yeah." So... yeah. 76.114.172.199 11:11, 31 July 2007 (UTC)

== dilation of pupils- any answers would

I doubt research has been done on your particular hypothesis, as its not based on anything other than a weak correlation; science generally examines more fundamental systems and only tests hypothesises like yours where incidental to the former or where the hypothesis is well-supported or accepted. Given that we can induce the same states in people with and without vision, optic nerves, eyelids open et cet it is doubtful that your explanation is correct. Fundamentally, the fact that the other effects of hallucinogens of the type you refer to are generally mediated by seretonin, provides a convieniant common mechanism for the hallucinations that have nothing to do with eye dilation. Why would LSD, for example, induce hallucinations in someone with their eyes shut momentarily or all day? Its clear that the eyes themselves have nothing to do with it- mydriasis, if anything, suppresses hallucinations.--Δζ (talk) 02:15, 20 March 2010 (UTC)

Changed Sentence Regarding Serotonergic Hallucinogens.

I forgot to add an edit summary. I changed the sentence listing some hallucinogens which induce mydriasis to refer to them as the serotonergic hallucinogens, since psychedelic is unspecific and likely not useful as the general category as both under and overinclusive in various examples, and relatively culturally dependent. I also expanded the section to give brief examples of the preparations people might recognize that contain the specific active agent- as had already been done in part, though it might be better to chop some of these. The example referring to psilocybin as 'the active substance in psychedelic mushrooms' (something to that effect) was changed to a more accurate statement, as psilocybin is not found in all psychedelic mushrooms, psilocybin is not found only in mushrooms, and other active constituents of psychotropic fungi induce mydriasis.--Δζ (talk) 02:10, 20 March 2010 (UTC)

David Bowie

How about adding a "Trivia" section mentioning David Bowie? Probably the most commonly-known case of Mydriasis :-) He's often said to have a light and a dark eye but actually suffered some kind of accident (if I'm informed correctly) and has mydriasis in one eye. —Preceding unsigned comment added by 95.117.238.123 (talk) 05:57, 22 July 2010 (UTC)

Traumatic Mydriasis

I was poked in the left eye during a rugby match in September 2010. My opthamolgist diagnosed as Traumatic Mydriasis and has placed me on a battery of eye drops, including Xybrom (twice daily), Durazol (four times daily...since stopped), Azopt (thrice daily...since stopped), and Combigan (thrice daily). Due to increased pressure in the left eye, I was prescribed Combigan (in lieu of Azopt) and told to reduce and ultimately end my use of Durazol. After 5 weeks, we have seen some progression...the pupil is beginning to contract but seemingly has a long way to go. My question, how long should I expect the pupil to remain dilated? Are there any "exercises" I can do to help strengthen the muscle in the eye? Any permanent side-effects? —Preceding unsigned comment added by 65.91.186.196 (talk) 18:25, 22 October 2010 (UTC)

It is more prudent to consult an eye doctor. 84.205.241.2 (talk) 21:30, 25 February 2021 (UTC)

Removal of dubious information from Drugs subsection

Nearly the entire Drugs subsection has been unsourced for at least two years. One source is also no longer available. While I do not want to remove the entire section, I will at least remove what is least accurate.

Drugs that increase overall serotonin levels in general are capable of causing mydriasis in the same way as the 5-HT2A-mediated psychedelics. This is because serotonin itself is naturally responsible for normal 5-HT2A stimulation. Hence, in sufficient quantities serotonin is mydriatic and can even be mildly psychedelic[medical citation needed], though the potentially fatal serotonin syndrome usually ensues before the psychedelia becomes overly-pronounced. Examples of such drugs include MDMA (as well as other MDxx compounds), fenfluramine, chlorphentermine, stimulants (including cocaine and amphetamines), and some antidepressants (such as SSRIs, SNRIs, and MAOIs). Natural serotonin-boosting supplements such as L-Tryptophan and 5-HTP are also capable of this, but usually only in excessive doses.

5-HT2A is not responsible for the mydriatic effect of the substances listed. Rather, it is through common adrenergic/noradrenergic activity that this occurs (see: Norepinephrine#Sympathetic_nervous_system). Citalopram#Pharmacology is a good example, note the values for the NET and alpha-1 receptors. The articles on Serotonin and 5-HT2A make no mention of mydriasis or other effects on the pupil. The term "psychedelia" is a vague one and describes a subjective mental state not easily quantified. Serotonin syndrome, however, is easily quantified. To say that serotonin syndrome sets in as a result of taking sufficient quantities of psychedelic drugs before "psychedelia becomes overly-pronounced" is both unnecessarily vague (define "overly-pronounced"), and goes against the common knowledge that people often take psychedelic drugs to experience psychedlia (hence their namesake), and do not often die from serotonin syndrome as a result. Serotonin syndrome is described more consistently in the literature as often being the result of taking multiple primarily serotonergic substances concurrently and possibly with a substance that inhibits the production of necessary liver enzymes responsible for their metabolism, resulting in toxic levels of extracellular serotonin.

While it is fairly common knowledge that mydriasis is a common side effect of many primarily serotonergic drugs I cannot leave this paragraph in as it is now. I recommend it be a little shorter, with less extraneous detail, i.e. we do not need to know unnecessary details about the drugs listed, just that they are known to cause mydriasis. A common mechanism of action can be listed. Going beyond a simple summary of information already available on Wikipedia would require the new material to be adequately sourced.

68.197.59.144 (talk) 02:47, 18 June 2017 (UTC)

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