Age-related macular degeneration (AMD) affects more than 100 million people worldwide. The lack of cure restricts the central vision and ultimately leads to blindness. The current treatment modalities only suppress the disease and require repeat administrations. But they fail to restore or even improve vision.

Stem cells for macular degeneration treatment have achieved breakthrough results by improving eyesight in both types of AMD. Ongoing research is refining this intervention to maximize its therapeutic benefits. A Stem Cell Patch for Macular Degeneration is one such advancement in this field.

Age-related macular degeneration (AMD)

AMD occurs due to deterioration in the macula- the region of the retina crucial for central vision. It can either result from deposits (dry AMD) or blood vessel leakage (wet AMD). Retinal pigment epithelium (RPE) cells that support the photoreceptors also atrophy, damaging photoreceptors and causing vision loss. The irreversible loss of vision cannot be restored by a conventional approach.

Regenerative Medicine

Regenerative medicine takes a different approach. Instead of medications, it delivers stem cells that regenerate into RPE. In addition, they also protect the optic nerve, remodel blood vessels, suppress inflammation, and neutralize oxidative stress, which addresses the mechanisms of the eye disorder. Clinical trials on these cells have shown significant though modest improvements in eyesight.

Stem Cell Patch for Macular Degeneration

Scientists have been researching extensively to tap the full potential of stem cells. Stem cell patch is an innovative product that takes the regenerative AMD treatment a step further. The research on this avenue began as early as the early 2000s, although the scientists at the time employed retinal cells. However, they have shifted their focus to stem cells due to their higher availability and easy extraction. A stem cell patch is a layer of RPE formed by growing stem cells on a scaffold. Scaffold is a 3D nanostructure that mimics the basement membrane beneath RPE in the retina. As a result, a layer of RPE cells is produced with a close anatomical configuration of the retina. Scientists have also developed the appropriate surgical tools to implant these patches. Two groups –one in the USA and the other in the UK- have successfully engineered these patches.

Clinical Evidence

Studies on animals have yielded positive outcomes with the stem cell patches, encouraging scientists to venture into clinical studies. Cruz et al. showed that transplanting the patch resulted in visual improvement in two patients with wet AMD without developing any serious effects of transplantation after one year of follow-up. In a study by Kashani et al., five patients with dry AMD experienced halted progression of vision loss, improvement in reading ability, and increased visual functions after transplantation of these patches. Researchers are now advancing further by using patients' own cells and transforming them into stem cells (iPSCs) to create bioengineered retinal epithelium.

Comparison with Stem Cell Treatment

The rationale behind the stem cell patches is to increase the survival of stem cells after transplantation. Several research studies have reported that they do not survive longer after transplant, thus impeding their regenerative ability. A patch offers a membrane supporting cell viability and proliferation in the retina. Cells from the patch also migrate to the damaged retinal regions while not interfering with the intact ones. However, the procedure of transplantation is invasive and requires surgery.

On the other hand, Stem Cells for Macular Degeneration are injected via the intravenous route, minimizing pain and surgical implications. Both strategies have their own set of benefits and drawbacks. Only further research and clinical trials will give proper estimates of the suitability of the therapies.

Challenges

Stem cell patches have received attention, and many laboratories are working in this direction. However, there are a few challenges to overcome-

• The population size used to assess the patches is relatively small. Large sample size studies that account for variation in the population are important to establish the efficacy of the treatment.

• The transplant procedure requires surgery, which is a significant drawback. Despite its favorable results, better surgical techniques should be developed for an easy transplant procedure.

• Large-scale production of engineered patches will need streamlining within the regulatory framework.

In Conclusion

Regenerative medicine has been a much-explored avenue for AMD, owing to the resulting regeneration of retinal cells and improved visual acuity. However, studies have reported the low survival of transplanted cells. Therefore, scientists have been attempting to enhance cell viability. Stem cell patches for macular degeneration have appeared as the new frontier amidst these efforts.

Instead of cells, the patch facilitates the formation of a complete retinal layer and transplants it surgically. It boosts cell survival and integrates into the retina. However, patches require extensive clinical studies before their translation into mainstream treatment. It has quite a few challenges ahead like developing surgical techniques with low invasiveness. The future might witness the introduction of many such therapies that can enhance eyesight instead of delaying visual loss. Keeping up with latest developments, Advancells manufacturers high-quality, ethically sourced stem cells for macular degeneration.