Summary: Glaucoma is a condition that harms the optic nerve, typically managed by lowering eye pressure. While homocysteine was thought to play a role, recent studies suggest it’s more of a bystander. Disruptions in metabolism related to the retina’s use of vitamins seem to be the real issue, leading researchers to test supplements of vitamins B6, B9, B12, and choline in animal models. Impressively, this combination appeared to prevent or slow nerve damage independently of eye pressure, and a clinical trial is currently in progress to assess its effects in humans.
Key facts:
- Homocysteine Role Reassessed: Elevated homocysteine levels do not cause glaucoma; instead, they reflect underlying metabolic changes.
- Vitamin Therapy Shows Promise: B vitamins and choline supplements have been effective in halting or slowing optic nerve damage in rodent studies.
- Human Trials Underway: A clinical trial is now actively recruiting participants to investigate this method’s ability to slow the progression of glaucoma.
Details: Glaucoma leads to gradual optic nerve damage, which can result in vision loss or blindness. High intraocular pressure is a significant factor in the disease, prompting treatments like eye drops, laser therapy, or surgery to alleviate pressure. However, treatment outcomes can differ widely among patients.
Researchers at Karolinska Institutet have long speculated about the connection between homocysteine and glaucoma. In new studies, they found that increasing homocysteine levels in rats with glaucoma didn’t worsen their condition.
They also noted that high homocysteine levels in humans didn’t correlate with disease progression, and there wasn’t a higher prevalence of glaucoma among individuals genetically predisposed to elevated homocysteine. This led to the conclusion that homocysteine is not a driving force in glaucoma but rather a consequence of metabolic changes.
The team examined metabolic pathways involving homocysteine in both rats and humans with glaucoma and discovered significant abnormalities, particularly related to the retina’s utilization of certain vitamins. These metabolic issues locally hindered the retina’s function, contributing to disease development.
James Tribble, co-lead on the research, emphasized that homocysteine should be viewed as a bystander in the disease process, indicating that the retina might be struggling to use necessary vitamins for proper metabolism.
To explore whether vitamin supplementation could safeguard the retina, the researchers administered vitamins B6, B9, B12, and choline to rodents with glaucoma. The results were encouraging: in mice with a slower progression of glaucoma, optic nerve damage was entirely halted, while in rats with a more severe form, disease progression slowed.
Notably, these experiments were conducted without treating eye pressure, highlighting a potential new avenue for treatment that differs from conventional pressure-lowering methods.
Encouraged by these findings, the team has initiated a clinical trial at S:t Eriks Eye Hospital in Stockholm, where they are enrolling patients from both primary open-angle glaucoma and pseudoexfoliation glaucoma groups.
Funding: The study received support from various organizations, including the Swedish Research Council, the Swedish Eye Health Fund, and others.
