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# What Treatment Can Keep, and What It Can't Bring Back
- URL: https://cadenceletters.com/en/what-glaucoma-takes-for-good/
- Published: 2026-10-25T11:50:06.000Z
- Updated: 2026-10-25T11:50:06.000Z
- Description: My left eye has both glaucoma and a cataract. On the question of what medicine can undo today, the two give opposite answers.
- Author: Ryan Sungho Kim
- Tags: en, longevity, #pair-2026-10-25-what-glaucoma-takes

My first letter ended with a question. What can today's treatments preserve, and what can they still not restore?

Both answers are sitting inside my left eye. It has glaucoma and a cataract at the same time, and the two give opposite answers.

## The cells that don't come back

Glaucoma slowly kills the cells that connect the eye to the brain: the retinal ganglion cells, whose fibers make up the optic nerve. They don't grow back.

The order of events is what scares me. One study found that by the time a standard visual field test turns abnormal, 25 to 35 percent of those cells may already be gone. ([study](https://pubmed.ncbi.nlm.nih.gov/10711689/?ref=cadenceletters.com)) That is part of why more than half of the people with glaucoma found in population surveys around the world didn't know they had it, and why the odds of going undetected were higher in Asia than in Europe. ([study](https://pubmed.ncbi.nlm.nih.gov/33865875/?ref=cadenceletters.com))

The US National Eye Institute puts it plainly: there is no cure for glaucoma, and treatment won't undo damage that has already happened. ([NEI](https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/glaucoma?ref=cadenceletters.com))

## What medicine preserves: slower, not stopped

So what does treatment do? It lowers eye pressure so that the remaining cells die more slowly. Drops, laser (SLT) and surgery all come down to that one job.

That effect has been measured with some precision.

- EMGT, the first trial to compare treatment with no treatment, cut pressure by 25 percent. Over about six years, the share of patients whose disease progressed fell from 62 percent to 45 percent. The risk of progression roughly halved, and each 1 mmHg of pressure lowered cut it by about 10 percent. ([trial](https://pubmed.ncbi.nlm.nih.gov/12365904/?ref=cadenceletters.com), [analysis](https://pubmed.ncbi.nlm.nih.gov/12523884/?ref=cadenceletters.com))
- The UK's UKGTS compared a pressure-lowering drop with a placebo and found it cut the risk of visual field loss within two years by 56 percent. ([trial](https://pubmed.ncbi.nlm.nih.gov/25533656/?ref=cadenceletters.com))
- Even in glaucoma at "normal" pressure, lowering pressure by 30 percent cut progression from 35 percent to 12 percent. ([trial](https://pubmed.ncbi.nlm.nih.gov/9780093/?ref=cadenceletters.com))
- When laser came first instead of drops, about 70 percent of eyes were still at their target pressure six years later without drops or surgery. ([trial](https://pubmed.ncbi.nlm.nih.gov/36122660/?ref=cadenceletters.com))

After staring at these numbers for a while, one line stayed with me: 45 percent of treated patients still got worse within six years. What medicine offers today is not a stop but a slowdown. In glaucoma, time is never on my side. Treatment turns the clock a little in my favor.

## What surgery can give back: the cataract

A cataract is the opposite. You remove the clouded lens and put in an artificial one, and nine out of ten people see better afterward. ([NEI](https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/cataracts?ref=cadenceletters.com)) I got that clarity back in my right eye in 2023.

But the American Academy of Ophthalmology draws a clear line: cataract surgery will not restore vision lost to other conditions such as glaucoma. ([AAO](https://www.aao.org/eye-health/treatments/what-is-cataract-surgery?ref=cadenceletters.com)) In my left eye, what cataract surgery can give back ends at the clouded lens.

A few more things I learned:

- The membrane that holds the new lens can cloud over again. In a Finnish registry of more than 10,000 eyes, 13.2 percent needed a quick laser fix within five years. ([study](https://pubmed.ncbi.nlm.nih.gov/30689988/?ref=cadenceletters.com))
- Glaucoma narrows the choice of replacement lens. Multifocal lenses are not routinely recommended for eyes with established glaucoma. ([review](https://pubmed.ncbi.nlm.nih.gov/42558001/?ref=cadenceletters.com))
- My left eye still has the ICL I got in 2009\. The current model, with a tiny hole in the center, has been in use since 2011, so mine is most likely an older one. ([study](https://pubmed.ncbi.nlm.nih.gov/30568421/?ref=cadenceletters.com)) What that means for future surgery is a question for my doctor.

## Where the line is moving

Will the line on the side of what can't be restored stay where it is forever? In 2026, it has started to move.

**Vitamin B3.** Research keeps building on whether a form of vitamin B3 called nicotinamide can protect these nerve cells. In March, a Korean team published a trial in normal-tension glaucoma. In April, a 378-patient phase 3 trial in the UK finished enrolling. In August, an analysis of US health records found that people who took B3 were later diagnosed with glaucoma less often. ([Korean trial](https://pubmed.ncbi.nlm.nih.gov/41167798/?ref=cadenceletters.com), [UK phase 3](https://www.ucl.ac.uk/population-health-sciences/comprehensive-clinical-trials-unit/our-trials/naming?ref=cadenceletters.com), [US analysis](https://pubmed.ncbi.nlm.nih.gov/42424069/?ref=cadenceletters.com))

None of it is proven yet. A systematic review in September concluded the evidence is insufficient, and the phase 3 results are due between 2027 and 2029\. ([review](https://pubmed.ncbi.nlm.nih.gov/42739057/?ref=cadenceletters.com)) The American Glaucoma Society and the AAO advise against taking 3 grams a day or more outside a trial, because liver injury was reported in trial participants. ([position statement](https://pubmed.ncbi.nlm.nih.gov/39800263/?ref=cadenceletters.com))

**ER-100.** This is the candidate from my first letter that aims to return optic nerve cells to a younger state. In an October 8 announcement, the company said all three glaucoma patients tolerated it through day 56, and that two of them showed "preliminary signals of improvement" on visual field tests, with at least 28 percent of test points improving by more than 4 dB. ([company announcement](https://www.lifebiosciences.com/life-biosciences-announces-first-in-human-data-from-ongoing-phase-1-trial-evaluating-er-100-in-optic-neuropathies/?ref=cadenceletters.com))

I read those numbers carefully. Three patients, no comparison group, and a press release from the company itself. Visual field tests in damaged eyes also swing quite a bit when the same person repeats them. Still, it is worth noting that the word "improvement" has appeared in human glaucoma data at all.

**Everything else is still in animals.** Regrowing a damaged optic nerve is being studied in mice, and no human trial of replacing these nerve cells is registered. ([Stanford](https://med.stanford.edu/ophthalmology/news-media/news-archive/2026news/a-new-path-for-regenerating-and-protecting-the-optic-nerve-.html?ref=cadenceletters.com)) On the other side, there are documented cases of people losing much of their vision after unproven stem-cell injections. ([NEJM](https://pubmed.ncbi.nlm.nih.gov/28296617/?ref=cadenceletters.com))

**Two conditions, one lens.** This one isn't about bringing anything back, but it is the news closest to my left eye. SpyGlass Pharma, a US company, attaches small drug pads to the artificial lens implanted during cataract surgery. The pads release a glaucoma drug, bimatoprost, a little at a time over several years. In an October 19 announcement, the company said that four years into its first human trial, average eye pressure had fallen 37 percent, from 25.1 to 15.9 mmHg, and 18 of 21 patients were off glaucoma drops. ([company announcement](https://ir.spyglasspharma.com/news-releases/news-release-details/spyglass-pharma-announces-positive-4-year-data-first-human-trial?ref=cadenceletters.com))

It was a single-center trial of 23 patients with no comparison group, and the numbers come from the company. Phase 3 trials are under way, and the lens is not approved. It is an attempt to treat an eye with both a cataract and glaucoma in a single surgery.

## What we can do now

With a disease you can't reverse, the strongest tool is finding it early. Two numbers surprised me most.

- In Korea's Namil study, about 77 percent of open-angle glaucoma occurred at normal eye pressure. ([study](https://pubmed.ncbi.nlm.nih.gov/21269703/?ref=cadenceletters.com)) A check that only measures pressure would miss most cases. The AAO says the same: a pressure-only screening is not enough to find glaucoma. You need an optic nerve exam, OCT imaging and a visual field test. ([AAO](https://www.aao.org/eye-health/diseases/glaucoma-diagnosis?ref=cadenceletters.com))
- Nearsightedness roughly doubles the odds of open-angle glaucoma, and the risk climbs with the degree of myopia. ([study](https://pubmed.ncbi.nlm.nih.gov/21684603/?ref=cadenceletters.com), [meta-analysis](https://pubmed.ncbi.nlm.nih.gov/34648776/?ref=cadenceletters.com))

At my next appointment, these are the questions I plan to ask. What type of glaucoma do I have? What is my target pressure? Which ICL model do I have, and what does it mean for future surgery? Should the cataract and glaucoma surgery be combined? Which lens suits an eye with glaucoma?

What's lost doesn't come back yet. So for now, what matters is how well I protect what remains. And I'll keep watching where that line moves.

I am neither a doctor nor a scientist. This is my record of the research I've read, not medical advice. If I got something wrong, please tell me.