Blindness Reversed with Adult Stem Cells

Success with rabbits and with children offers promising cures for blindness in humans, using ethical stem cells.

The headlines are really eye-grabbing:

• Vision restored in rabbits following stem cell transplantation (Science Daily).
• Eye Lenses Regenerated Using Infants’ Own Stem Cells (Live Science).
• Stem cells regenerate human lens after cataract surgery, restoring vision (Science Daily): “Approach may have broad therapeutic implications on tissue and organ repair.”

The results from international teams publishing in Nature are truly spectacular. Live Science says,

They found that the infants’ incisions healed within one month, and the transparency of their line of vision was more than 20 times better, compared to infants with congenital cataracts who received the current, standard treatment.

The finding shows that “we can harness our own stem cells to regenerate a tissue or organ,” Dr. Kang Zhang, who led the study and is an ophthalmologist at the University of California, San Diego, told Live Science.

Another benefit is that the stem cells are already there. They just need to be removed, nursed, and re-inserted. Science Daily says,

Unlike other stem cell approaches that involve creating stem cells in the lab and introducing them back into the patient, with potential hurdles like pathogen transmission and immune rejection, endogenous stem cells are stem cells already naturally in place at the site of the injury or problem. In the case of the human eye, lens epithelial stem cells or LECs generate replacement lens cells throughout a person’s life, though production declines with age.

In a similar development, Japanese researchers also reporting in Nature have found a way to use induced pluripotent stem cells (iPSCs) to restore the cornea. Julie T. Daniels summarizes these “visionary stem cell therapies” in a companion piece in Nature. A diagram in her article shows how the insertion of these stem cells repairs the real lens and cornea of patients. Current treatments for cataracts remove the living lens for an artificial one. The new way is like turning back the clock and letting the body develop the eye the way it was meant to be.

Incidentally, PhysOrg reports that a “novel reprogramming factor yields [a] more efficient induction of human pluripotent stem cells,” meaning that it’s getting easier to deliver the goods to the surgeon. Adding to the celebration, Science Daily reports on a new drug that can return stem cells to their embryonic state.

Who needs embryonic stem cells?

This is great news, and more may be coming. We’ve already seen rapid advances with adult stem cells and iPS cells. The finding that our own eyes have the cells needed to repair a lens or cornea suggests that the original creation was outfitted for regeneration, but those abilities have degenerated since. Whether or not that is the case, the cure for blindness may have been staring us in the eye.