NCT07269704

Brief Summary

The aims of the study are as follows:

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

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
17

participants targeted

Target at below P25 for phase_1

Timeline
Completed

Started Aug 2023

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

August 15, 2023

Completed
1.8 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 10, 2025

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

June 10, 2025

Completed
6 months until next milestone

First Submitted

Initial submission to the registry

November 25, 2025

Completed
13 days until next milestone

First Posted

Study publicly available on registry

December 8, 2025

Completed
Last Updated

December 8, 2025

Status Verified

October 1, 2025

Enrollment Period

1.8 years

First QC Date

November 25, 2025

Last Update Submit

November 25, 2025

Conditions

Eye Diseases

Outcome Measures

Primary Outcomes (1)

  • Mean change in aqueous humor aKG concentration

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

    Baseline and post-supplementation, approximately 28 days

Secondary Outcomes (1)

  • Mean fold-change in metabolic and retinal pathways

    Baseline and post-supplementation, approximately 28 days

Study Arms (1)

Calcium alpha-ketoglutarate (Ca-aKG)

EXPERIMENTAL

At the first and second cataract surgery of the participant, a small amount of tissue (eye fluid \~0.1 ml or 1-2 drops) is removed for analysis. Beginning one week (7 days) prior to their second cataract extraction surgery, the patient takes an oral nutritional supplement (calcium alpha-ketoglutarate) 2 times a day.

Drug: Calcium alpha-ketoglutarate

Interventions

Calcium alpha-ketoglutarateDRUG

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

Also known as: Prohealth Longevity
Calcium alpha-ketoglutarate (Ca-aKG)

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • 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).

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Byers Eye Institute

Palo Alto, California, 94303, United States

Location

Related Publications (4)

  • Filip RS, Pierzynowski SG, Lindegard B, Wernerman J, Haratym-Maj A, Podgurniak M. Alpha-ketoglutarate decreases serum levels of C-terminal cross-linking telopeptide of type I collagen (CTX) in postmenopausal women with osteopenia: six-month study. Int J Vitam Nutr Res. 2007 Mar;77(2):89-97. doi: 10.1024/0300-9831.77.2.89.

    PMID: 17896582BACKGROUND

  • Riedel E, Nundel M, Hampl H. alpha-Ketoglutarate application in hemodialysis patients improves amino acid metabolism. Nephron. 1996;74(2):261-5. doi: 10.1159/000189319.

    PMID: 8893139BACKGROUND

  • Wert KJ, Velez G, Kanchustambham VL, Shankar V, Evans LP, Sengillo JD, Zare RN, Bassuk AG, Tsang SH, Mahajan VB. Metabolite therapy guided by liquid biopsy proteomics delays retinal neurodegeneration. EBioMedicine. 2020 Feb;52:102636. doi: 10.1016/j.ebiom.2020.102636. Epub 2020 Feb 3.

    PMID: 32028070BACKGROUND

  • Hou XW, Wang Y, Pan CW. Metabolomics in Age-Related Macular Degeneration: A Systematic Review. Invest Ophthalmol Vis Sci. 2020 Dec 1;61(14):13. doi: 10.1167/iovs.61.14.13.

    PMID: 33315052BACKGROUND

MeSH Terms

Conditions

Eye Diseases

Interventions

Ketoglutaric Acids

Intervention Hierarchy (Ancestors)

GlutaratesDicarboxylic AcidsAcids, AcyclicCarboxylic AcidsOrganic ChemicalsKeto Acids

Study Officials

  • Vinit Mahajan, MD, PhD

    Stanford University

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
phase 1
Allocation
NA
Masking
NONE
Purpose
PREVENTION
Intervention Model
SINGLE GROUP
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor of Ophthalmology

Study Record Dates

First Submitted

November 25, 2025

First Posted

December 8, 2025

Study Start

August 15, 2023

Primary Completion

June 10, 2025

Study Completion

June 10, 2025

Last Updated

December 8, 2025

Record last verified: 2025-10

Data Sharing

IPD Sharing
Will share

Age, sex, BMI, Medical history, ocular history

Shared Documents
STUDY PROTOCOL, ICF
Time Frame
The data will be made available upon study registration with CTgov, and will remain available for at least 5 years.
Access Criteria
Results

Locations

US(1)