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OpenTrials
Completed

NCT Number: NCT07269704

Effect of Nutritional Supplement Alpha-ketoglutarate for Age-related Ocular Disease

The aims of the study are as follows:

1. Determine how the eye absorbs supplements taken orally. 2. Look for specific signs in the proteins and substances in the eyes of people with eye diseases who are also taking nutritional supplements.

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Key information

Conditions

Eye Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

Byers Eye Institute

Palo Alto, California, 94303, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Able and willing to give written informed consent
  • Able to attend all study visits and complete the study procedures
  • Women of child-bearing potential must have a negative pregnancy test within 2 weeks before cataract surgery. A pregnancy test is not required for postmenopausal women (defined as being at least 12 consecutive months without menses) or those surgically sterilized (those having a bilateral tubal ligation/bilateral salpingectomy, bilateral tubal occlusive procedure, hysterectomy, or bilateral oophorectomy).

Exclusion criteria

  • Diabetes and/or thyroid, liver, kidney, bowel, and metabolic diseases or disorders
  • History of supplement allergy or planned major surgery
  • Received any other clinical trial drug within 4 months
  • Calculated creatinine clearance of less than 30 ml/min

Treatment and study plan

Calcium alpha-ketoglutarate

Drug

Participants took 2 g/day of calcium alpha-ketoglutarate orally, twice daily, for 7 days.

Other names: Prohealth Longevity

Primary outcomes

  1. Mean change in aqueous humor aKG level

    Time frame: Baseline and post-supplementation, approximately 28 days

    To evaluate the mean difference in fold-change in aKG levels from baseline to post-supplementation in eye fluid

Secondary outcomes

  1. Mean fold-change in metabolic and retinal pathways

    Time frame: Baseline and post-supplementation, approximately 28 days

    To calculate mean fold-change in retinal metabolic and protein pathways from baseline to post-supplementation in eye fluid

Sponsors and collaborators

Lead sponsor

Stanford University

Other

Registry information

Official study title

Effect of Nutritional Supplement Alpha-ketoglutarate for Age-related Ocular Disease: An Open Label, Single Arm Study to Evaluate the Effect of Alpha-ketoglutarate Administered Orally in Patients With Age-related Ocular Diseases (Metabolic Eye Therapy)

Acronym: OAK AGE

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Dec 8, 2025
Registry last updated
Apr 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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