Bill Ackman, the billionaire investor, publicly confirmed in early September — in a post on X and in comments to reporters — that his 26-year-old daughter Lucy is the patient at the center of a first-of-its-kind medical case: doctors at Mount Sinai injected mitochondria taken from her own leg muscle into her eyes, trying to reverse blindness caused by a brain hemorrhage. The injections were followed by a brief, partial response. They did not restore her vision.
Key facts
- Patient: Lucy Ackman, 26, daughter of billionaire investor Bill Ackman
- Injury: A massive brain hemorrhage in February 2026 left her in a coma for weeks and completely blind
- Procedure: Mount Sinai doctors injected mitochondria taken from her own thigh muscle into each eye, about 24 hours apart, roughly three months after her injury, under an FDA (Food and Drug Administration) emergency authorization for a single patient
- Early response: Her pupils briefly began reacting normally to light, and she reported perceiving shapes and shadows in her left eye
- Outcome: The response faded within about a month; her measured vision never rose above the ability to detect light
- Evidence status: Reported in a preprint posted August 10, 2026, not yet peer-reviewed; the authors say a single case cannot prove the injections caused the improvement
- Related project: Ackman and his wife, Neri Oxman, have committed roughly $400 million to a new brain-research center, the Ackman Oxman Institute, inspired by Lucy’s injury
What happened to Lucy
In February 2026, Lucy suffered a massive brain hemorrhage and was found unconscious in her Brooklyn apartment; more than 19 hours passed before emergency surgery. Ackman has said his older daughter, Eloise, found her. Lucy underwent emergency surgery to relieve pressure on her brain and remove blood, then spent weeks in a coma. The hemorrhage damaged her optic nerves: she came out of the coma completely blind, with pupils that no longer responded to light. In the months since, she has also been slowly relearning to walk and speak.
The procedure
Roughly three months after her injury, a Mount Sinai team led by neurosurgeon Christopher Kellner and rehabilitation neuroscientist David Putrino tried something that, according to the researchers, had never been attempted in a human eye. They took a small biopsy of muscle from Lucy’s thigh, isolated mitochondria — the structures inside cells that generate energy — and injected them into the vitreous fluid, the gel that fills the eyeball, one eye at a time about 24 hours apart. Their idea was simple: give the damaged retinal cells a fresh supply of the tiny structures that power them, and see whether that was enough to get the cells working again. The procedure was done under an FDA emergency authorization that allows doctors to try an unapproved treatment on a specific patient outside a formal clinical trial.
What the research actually shows
The case was described in a paper posted August 10, 2026 — about six months after the hemorrhage — to Research Square, a preprint server. ScienceAlert covered the case anonymously on August 25, before Ackman identified Lucy. The paper had not yet undergone peer review. In the days after the injections, Lucy’s pupils began reacting normally to light for the first time. Doctors had tested her pupillary response repeatedly in the weeks before the injections, and none of those tests had shown a normal response. According to the case report, she reported perceiving shapes and shadows through her left eye. The report also recorded organized activity in the brain’s visual cortex on certain days after the injections. No serious side effects, inflammation or rejection were reported.
That improvement did not last. The response faded within about a month: the left eye’s last normal pupillary response was recorded on day 11, while the right eye showed intermittent normal responses through about day 39. Her measured visual acuity never rose above the ability to detect light — normal sight was not restored. The paper’s own authors caution that this is a single patient with no comparison group, and no direct evidence that the transplanted mitochondria reached the retinal cells they were meant to help. They describe the case as insufficient, on its own, to prove the injections caused what they observed.
Ackman has said a weaker version of the benefit has continued since then. “We have seen a sustained benefit from the initial injection, but not as strong as the immediate response,” he wrote, adding that the family is now working on a way to inject her eyes more often.
Independent scientists are skeptical
Outside researchers have pushed back on whether the approach makes biological sense at all. Daria Mochly-Rosen, a Stanford professor who studies mitochondria, has questioned whether transplanting a relatively small number of mitochondria could produce a meaningful effect, given that the body already has trillions of its own. She has also questioned whether transplanted mitochondria can even survive being implanted in the first place. “There are people pushing back on whether it is all real,” she said.
This procedure is not the same thing as “mitochondrial replacement therapy,” the fertility technique sometimes called three-parent IVF (In vitro fertilization) that is used to prevent inherited mitochondrial disease. Lucy’s treatment used her own mitochondria, transplanted into her own eyes, for a different purpose entirely.
Her recovery beyond her eyes
A Washington Post profile published September 6, 2026, reported that about seven months after the hemorrhage, Lucy had regained awareness of her surroundings, could walk more than 100 steps with assistance, and was beginning to produce sounds and early speech. Her sight has not returned.
Why the family is also building the Ackman Oxman Institute
Separately from Lucy’s own treatment, Ackman and his wife, architect Neri Oxman, have committed roughly $400 million — including a transfer of 10 million Pershing Square shares — toward a new brain-research and rehabilitation center in Manhattan, the Ackman Oxman Institute, which they say was inspired directly by Lucy’s injury and recovery. Ackman has said a second gift of comparable or greater size is planned for later. It is aimed at brain-injury research more broadly rather than the eye procedure specifically.