Macropsia has a wide range of causes, from prescription and illicit drugs, to migraines and (rarely) complex partial epilepsy, and to different retinal conditions, such as epiretinal membrane.
Some patients claim that symptoms may be eased if an attempt is made to physically touch the object which appears enormous in size.
[citation needed] Dysmetropsia in one eye, a case of aniseikonia, can present with symptoms such as headaches, asthenopia, reading difficulties, depth perception problems, or double vision.
Without suppression of one of the images symptoms from mild poor stereopsis, binocular diplopia and intolerable rivalry can occur.
One competing theory has radically stated that macropsia may be an entirely psychological pathological phenomenon without any structural defect or definite cause.
Those affected may experience extreme anxiety both during and after episodes as a result of the overwhelming nature of his or her distorted visual field.
The patient may feel that he or she must unfairly contend with hostile and aggressive forces due to the gigantic nature of the surrounding environment.
The psychological impact of macropsia on long-time people who have had the condition since childhood may be greater and lead to severe ego-deficiencies.
[1][7][8][9][10] Vitreomacular traction caused by the excessive adhesion of vitreous fluid to the retina is related to aniseikonia due to the separation and compression of photoreceptor cells.
[3] There is evidence that a lesion appearing in the posterior area of the ventral occipitotemporal visual pathway can cause macropsia.
Zolpidem is a drug prescribed for insomnia, and although it has proven beneficial effects, there have been numerous reported cases of adverse perceptual reactions.
[13] One of these cases discusses an anorexic woman's episode of macropsia, which occurred twenty minutes after taking 10 mg zolpidem.
Adolescents who are deemed to have multiple distortions per episode, such as slow motion vision and macropsia, are even more likely to be people with migraine.
[18] The macropsia episodes associated with migraine are typically equivalent to the duration of the aura, which can range from moments to 15 minutes.
The pathophysiology of the condition is not fully understood, but the timing of some episodic occurrences with the headaches suggests that there is a connection between macropsia and the vasoconstrictive phase of a migraine.
Children who experience nocturnal hallucinations accompanied by macropsia may seek medical care for panic attack disorders and instead are diagnosed with forms of epilepsy.
[22] Patients with both Epstein-Barr virus and infectious mononucleosis have cited an increase in the sizes of perceived objects, coinciding with other symptoms of Alice in Wonderland Syndrome.
Patients with Coxsackievirus B1 have reported numerous symptoms of Alice in Wonderland Syndrome, the most common of which being macropsia and micropsia.
[20] Macropsia may be a result of optical magnification differences between the eyes, retinal receptor distribution,[3] or the cortical processing of the sampled image.
Macropsia caused by surgical re-attachment of macula-off rhegmatogenous retinal detachment is not symmetrical around the fovea, resulting in differences size changes in the horizontal and vertical meridians.
[3] Macropsia is generally diagnosed once a patient complains of the characteristic symptoms, such as disproportionally large objects in their visual field.
[27] The New Aniseikonia Test (NAT) can quantify the degree of macropsia or micropsia independently in the vertical and horizontal meridians.
[3] The most common way to treat forms of aniseikonia, including macropsia, is through the use of auxiliary optics to correct for the magnification properties of the eyes.
[citation needed] Future research may focus on ways to limit the occurrence of retinally-induced macropsia due to surgery.
[citation needed] In terms of treatment, the most effective optical correction is still being researched with respect to visual field angles and direction to a target.