They did not find any plaque build up in your carotid artery? That is a common reason for this occurring but would imagine a cardiologist checked for that. You have no atherosclerosis?
Hi and welcome,
Silent Migraine and Ocular Migraine are actually the same thing, silent migraine goes by different names eg Isolated visual migraine, Ocular migraine, Optical migraine, Acephalgic migraine and Aura without headache
"Amaurosis fugax (from the Greek "amaurosis," meaning dark, and the Latin "fugax," meaning fleeting) refers to a transient loss of vision in one or both eyes . Varied use of common terminology may cause some confusion when reading the literature. Some suggest that "amaurosis fugax" implies a vascular cause for the visual loss , but the term continues to be used when describing visual loss from any origin and involving one or both eyes. The term "transient monocular blindness" is also often used but is not ideal, since most patients do not experience complete loss of vision with the episode . "Transient monocular visual loss" (TMVL) and "transient binocular visual loss" (TBVL) are preferred to describe abrupt and temporary loss of vision in one or both eyes, since they carry no connotation regarding etiology." https://www.uptodate.com/contents/amaurosis-fugax-transient-monocular-or-binocular-visual-loss
I would recommend you read https://emedicine.medscape.com/article/1435495-overview
"Vasospasm may cause a temporary reduction in blood flow to the visual system and transient vision loss. Some patients have had ocular examinations during the transient vision loss event demonstrating the visible vasospasm on clinical exam, fundus photography, or fluorescein angiography.
"Amaurosis fugax typically consists of a gray curtain that progresses from the periphery and moves toward the center of vision.....amaurosis fugax lasts only a few minutes (rarely longer), with vision returning to normal within 10-30 minutes, a migraine headache tends to last 2-3 hours (rarely more than 12 hours). The visual disturbance in migraine expands slowly over 10-20 minutes and rarely lasts more than 30 minutes.....amaurosis fugax, are classically associated with negative phenomena (eg, a blackout of vision or a curtain across the vision). Migraine tends to produce positive phenomena (eg, sparkling lights or zigzag lines)."
Additional information to read https://www.healio.com/optometry/retina-vitreous/news/print/primary-care-optometry-news/%7Bbf58c956-612d-4057-b93b-d42806f64eb4%7D/determine-cause-of-transient-visual-loss-with-thorough-questioning
"Amaurosis fugax is a painless unilateral loss of vision lasting from 2 to 30 minutes and followed by a total recovery. It is often described by the patient as a curtain of darkness descending over the eye. The visual loss may be complete. Recovery is in the same pattern as the initial loss. The curtain appears to rise or resolve like a clearing fog, and the vision returns to baseline levels. This recovery is usually more gradual than the vision loss progression. Because of the sudden and painless nature of amaurosis fugax, most clinicians associate it with a vascular etiology...."
"Auras are neurologic events seen in patients with classic migraine. Auras usually develop abruptly over 5 to 20 minutes and last less than 1 hour....
"The simplest types of positive visual auras are photopsias, which are white or colored geometric figures that consist of small dots or spots, sparks, unformed flashes of light, streaks of light or wavy lines. These photopsias frequently flicker, glisten, sparkle or shimmer.....often resembles a crescent or horseshoe-shaped visual defect bordered by moving and shining streaks of light. This scintillating scotoma often enlarges as it expands or marches to the periphery. This expansion lasts from 10 to 30 minutes and is known as the “buildup.” It usually leaves an area of impaired or obscured vision behind it."
"Negative visual auras can also occur in patients with classic migraine. These scotomas may take the form of homonymous hemianopic or quadrantic field defects, central scotomas, tunnel vision, altitudinal visual field defects or complete bilateral blindness. Most of these scotomas are patchy and have irregular borders; therefore, patients will describe their vision as being blurred, opaque or foggy as if they are viewing objects through a film of water or heated air."
"The final major neurologic presentations of transient visual loss are transient visual obscurations. These are grey-outs, black-outs or blur-outs of vision lasting only 5 to 15 seconds. They may be monocular or binocular. They are often aggravated by postural changes. A patient may experience only a few of these episodes per day or may have hundreds of them, leading to functional visual incapacitation"
If all the more serious conditions associated with your transient visual loss have been excluded, then i would suggest you consider trialing the known helpful tips and triggers for silent migraine sufferes and see if anything helps reduce the visual disturbances you keep experiencing, there are a lot of online informational sites out there this one i found had some great tips and trigger information but i'm sure there are others with more detailed lists... https://blog.themigrainereliefcenter.com/3-tips-for-dealing-with-a-silent-migraine
I hope that helps........JJ