The tree · Broken proteins and waste
Eye drops dissolve the clouded protein of a cataract
A cataract is the clearest everyday case of a broken protein: the crystallins that keep the lens of the eye transparent misfold and clump with age until the lens goes cloudy, and the only treatment is to cut the lens out and put in a plastic one. In 2015 a group in San Diego and Guangzhou reported that lanosterol, a natural molecule, dissolved the clumps in a dish and cleared the lenses of dogs with cataracts when given as drops. Two later laboratories could not repeat the effect, and no human trial has been published. A controlled pilot trial of a drop derived from lanosterol (ZOC2017217, from the company Ocusun) in about 40 people has been running in the United States since 2026-02-10, with its first results expected from 2027-02; its makers also cite an unpublished exploratory study in China. The leaf is on the tree because cataract surgery is the most common operation in the world, and a drop that undid the protein damage would be the first drug anywhere to reverse an age-related protein clump.
What would count
A living animal with cataracts given eye drops afterwards has measurably clearer lenses, in a peer-reviewed report that a second group has repeated. The first-human rung is the same in a person, in a controlled trial. For the clinic rung: a regulator approves a drug that reverses or halts cataract.
Who settles it: Peer-reviewed reports, with a replication; the regulator's approval record for the clinic rung.
Where it stands
Shown in animals. Reached 22 July 2015, on the record of doi.org. Next rung more than 20 years away, if ever.
When it reaches the clinic: the project's estimate
This is the one thing on this page that is a judgment rather than a record. The project's estimate of the year it reaches the clinic is 2050, no earlier than 2035 and no later than not this century; the model draws from that range every run, with the likely year the most probable draw. Set 16 October 2026, a first pass awaiting an outside review.
| Rung | No earlier than | Most likely | No later than | |
|---|---|---|---|---|
| First human | 2029 | 2036 | 2060 | |
| In clinical use | 2035 | 2050 | not this century | feeds the year at the top |
Why. With the animal result contested and no human trial registered, the likely year for the clinic is distant: 2050 assumes a different molecule reaches a controlled human trial in the 2030s and an approval follows. The earliest assumes a trial starts within three years; the latest allows for the biology (dissolving a clump without harming the lens) never being solved, in which case surgery stays the answer and the rung is never reached. [Note 2026-10-17, from the weekly reading of that date: the reasoning above rests on there being no registered human trial. That premise no longer holds: a randomised, double-masked, placebo-controlled phase 2 pilot of a lanosterol-derived drop has been registered and running since 2026-02-10 (ocusun-2026), with a first patient announced on 2026-07-14, 8 people enrolled by the registry's last update and a primary completion estimated for 2027-02. The earliest first-human year (2029), set on the premise that a trial would start within three years, was therefore met early. The years are unchanged; whether the first-human years should move, and whether this company's drop answers the replication question about the 2015 dog result, are John's to weigh.]
Changes to this record
- 17 October 2026, description: repeat the effect, and no human trial has been published. became repeat the effect, and no human trial has been published. A controlled pilot trial of a drop derived from lanosterol (ZOC2017217, from the company Ocusun) in about 40 people has been running in the United States since 2026-02-10, with its first results expected from 2027-02; its makers also cite an unpublished exploratory study in China.. [reading 2026-10-17] The description said no human trial had been published, which is still true, but left out the registered trial under way. The stage stays at shown in animals: the first-human step asks for a peer-reviewed controlled report of clearer lenses in people. Source: (sponsor), 9 February 2026.
- 17 October 2026, estimate.why: (nothing; a dated note added at the end of the reasoning; no year changed) became [Note 2026-10-17, from the weekly reading of that date: the reasoning above rests on there being no registered human trial. That premise no longer holds: a randomised, double-masked, placebo-controlled phase 2 pilot of a lanosterol-derived drop has been registered and running since 2026-02-10 (ocusun-2026), with a first patient announced on 2026-07-14, 8 people enrolled by the registry's last update and a primary completion estimated for 2027-02. The earliest first-human year (2029), set on the premise that a trial would start within three years, was therefore met early. The years are unchanged; whether the first-human years should move, and whether this company's drop answers the replication question about the 2015 dog result, are John's to weigh.]. [reading 2026-10-17] A dated note that the estimate's premise of no registered human trial no longer holds; no year changed. Source: (sponsor), 9 February 2026.
The last readings
- 17 October 2026 Left for the author
Nothing dated in the window. A record older than the window contradicts the leaf: a randomised, double-masked, placebo-controlled pilot trial of a lanosterol-derived eye drop (the investigational drop ZOC2017217, from Ocusun with Lexitas Pharma Services) in about 40 people aged 50 and over with age-related cataract is registered at ClinicalTrials.gov as NCT07395986, with an actual start date of 2026-02-10, status active and not recruiting, and an estimated primary completion of 2027-02; the companies announced the first patient enrolled on 2026-07-14 at a site in Petaluma, California, and said the pilot is to shape a later Phase 3 programme. The leaf's description says no human trial has been published, which is still true, but its estimate says no human trial is registered, which is not. The companies also cite an exploratory study in China in which 50.0 to 86.4 per cent of participants reached 20/40 vision twelve to twenty-four weeks after treatment; that is a company claim with no paper found, so it is press-only. No result from the pilot, no replication of the 2015 dog result and no regulator's record appeared, so the stage does not move. Left for the author, resolved on 17 October 2026: I would correct the estimate's "why", which rests on "no human trial registered": a controlled human trial of a lanosterol-derived drop has been running since 2026-02-10 (registry entry NCT07395986, first patient announced 2026-07-14), so the earliest first-human year of 2029 ("a trial starts within three years") is built on a premise that no longer holds, and the author may want to add a dated line to the description noting the registered pilot and the unpublished Chinese exploratory study the company cites. The stage stays at shown-in-animals: the test for first-human asks for a peer-reviewed controlled report of clearer lenses in people, and the pilot's primary completion is estimated for 2027-02. Changing the estimate and the description is the author's; I could not open the registry page or the company release to check them. To log in the publications log once its page has been read, as the reading's rule asks: A Multicenter, Randomized, Double-Masked, Placebo-Controlled Pilot Study to Evaluate the Efficacy and Safety of ZOC2017217 in Subjects With Age-Related Cataract (ClinicalTrials.gov NCT07395986, 2026-02-10; https://clinicaltrials.gov/study/NCT07395986).source 1, source 2, source 3, source 4, source 5
What the story so far says about it
On the record
Notes
A related compound, a sterol called compound 29, was reported in Science in 2015 to do the same in mice, by a different group; it is not the record here because the dog result came first, and it has the same replication question. The reader should take this leaf as the branch's warning case: one striking animal result, not confirmed, a decade on. Two later laboratories could not repeat the clearing: one in 2015 on human cataract lenses in a dish (Indian Journal of Ophthalmology), one in 2019 on rat and human lenses in a dish (Scientific Reports). Neither tried dogs, so the dog result is contested but has not itself been retested.
Not yet verified
These facts in the record were written from memory or from a secondary source and have not yet been checked against the paper, the regulator's record or the registry. Nothing here is presented as settled until it is cleared, by checking it and either deleting the line or correcting the record.
- That the drop is derived from lanosterol, and the company's exploratory study in China (50.0 to 86.4 per cent reaching 20/40 vision at 12 to 24 weeks), are the sponsor's and its research partner's account in their release of 2026-07-14, which cites no paper; the registry entry itself does not name lanosterol.