u/aHumanRaisedByHumans

The incidence is rare anyway so the effect size is small, but it's good to know.

Bryan Johnson also takes daily low dose tadalafil for longevity benefits.

David Sinclair clip and third party discussion here:

https://youtu.be/C-Twr2WlZCA

From AI:

The sudden vision loss linked to PDE5 inhibitors (like Cialis/tadalafil and Viagra/sildenafil) is known medically as Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION). It is essentially an "eye stroke," where the blood supply to the front of the optic nerve is abruptly compromised. This results in sudden, painless, and usually permanent vision loss, often presenting as a dark curtain or shadow across the lower or upper half of the visual field in one eye.

How Rare Is It?

In absolute terms, NAION is extremely rare:

* Baseline Incidence: In the general population aged 50 and older, NAION occurs naturally in about 2 to 10 people per 100,000 per year.

* Incidence with PDE5 Inhibitors: Large epidemiological studies estimate that regular use of PDE5 inhibitors may increase the relative risk roughly 1.5 to 2 times, translating to only about 1 to 3 additional cases per 100,000 person-years.

* Causation vs. Correlation: Because hundreds of millions of doses have been prescribed and only hundreds of cases have ever been documented, the FDA and ophthalmologists consider it a potential but exceedingly rare risk. Furthermore, the underlying cardiovascular issues that lead people to take PDE5 inhibitors are the same issues that independently cause NAION, making direct causality difficult to prove definitively.

Why Does It Happen?

The proposed mechanism is related to perfusion pressure. Tadalafil causes vasodilation and a modest drop in systemic blood pressure. Blood pressure naturally dips during sleep (nocturnal hypotension). In an individual whose blood vessels cannot properly regulate pressure to the eye, this drop can starve the optic nerve head of oxygenated blood overnight, which is why patients typically wake up with the vision deficit.

Key Risk Factors

NAION almost never happens in a healthy eye with normal anatomy. It nearly always occurs when specific structural and vascular risk factors collide:

* Anatomical "Disc at Risk": The strongest single risk factor is a "crowded optic disc" (a small cup-to-disc ratio). In these eyes, all the nerve fibers and tiny blood vessels are tightly packed through a smaller-than-average opening in the sclera. Any minor swelling quickly cuts off circulation. An eye doctor can easily spot this during a routine dilated exam.

* Vascular Conditions: Pre-existing hypertension, type 2 diabetes, high cholesterol, coronary artery disease, or a history of heart attack.

* Sleep Apnea & Smoking: Both conditions independently reduce nocturnal oxygenation and impair microvascular health.

* Age: It predominantly affects individuals over age 50.

* Prior NAION Episode: Anyone who has already experienced NAION in one eye is strongly advised against taking any PDE5 inhibitor, as the risk of losing vision in the second eye is significantly elevated.

In clinical practice, a basic dilated eye exam by an optometrist or ophthalmologist can confirm whether someone has a crowded optic disc before starting long-term daily use.

... ...

David Sinclair highlighted the exact same condition—Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION)—in discussions surrounding GLP-1 receptor agonists (such as semaglutide/Ozempic and Wegovy). This debate gained widespread attention following a Harvard / Massachusetts Eye and Ear study published in JAMA Ophthalmology. The researchers observed a statistical association where patients prescribed semaglutide showed an increased relative risk (hazard ratios of roughly 4x in type 2 diabetes cohorts and up to 7x in overweight/obese cohorts) of developing NAION compared to those on non-GLP-1 treatments. Broader epidemiological reviews later estimated this translates to roughly 1 to 2 additional cases per 10,000 patient-years—a magnitude and rarity very similar to the PDE5 inhibitor data. The key parallels between the two medication classes include:

• The Same Pathological Endpoint: In both cases, the concern is sudden ischemia (loss of blood flow) to the optic nerve head, leading to painless, largely irreversible vision loss.
• Low Absolute Risk vs. High Relative Risk: While relative risk multipliers (like 2x to 4x) sound alarming, the baseline incidence of NAION is low enough that more than 99.9% of users never experience it.
• Confounding Risk Profiles: The patient populations taking these medications (individuals with metabolic dysfunction, type 2 diabetes, hypertension, or vascular disease) are already at an elevated baseline risk for optic nerve ischemia regardless of medication status.
• Different Proposed Mechanisms: While PDE5 inhibitors are thought to contribute via nocturnal blood pressure drops and vasodilation, hypotheses for GLP-1 agonists include rapid shifts in glycemic control, changes in microvascular autonomic tone, or direct GLP-1 receptor activity in the optic nerve tissue. Because the absolute risk remains very low across both drug classes, regulatory bodies and medical societies currently view NAION as a rare signal to monitor rather than a reason to avoid these medications, though extra caution and ophthalmic screening are advised for anyone with an existing crowded optic disc or a history of optic neuropathy in one eye.

This is just to document how it started, I am only one month into consistent vinegar soaks and ciclopirox. I used an electric nail file to get a lot of the bad nails thinned. It bled in a couple places so I think it was about as low as I could get it.

By chance, I have one reference toe on each foot. The long toe next to my big toe -- those both remain uninfected. The rest are infected.

I think after I run out of ciclopirox I might transition to 20% urea and vaporub but I'll wait to see if I get progress with this at least.

I soak with undiluted white vinegar for 10-15 minutes once a day, quick water rinse, dry with a towel and fan, then ciclopirox.

I will be throwing all my actively used shoes out soon. And making sure to use Lysol sanitizing additive to my washer for all my socks and towels. And I read that for shower disinfecting to kill the spores, the surface needs to remain damp with the Lysol or pine oil cleaner (pine sol doesn't use pine oil anymore!) for 4 or 10 minutes respectively so I will wipe it down then cover with plastic so it doesn't evaporate quickly. Apparently bathroom floors are important too.

My foot sole finally looks good after one month of the vinegar and ciclopirox so I know it at least works on my skin!