Effect of Branched-Chain Amino Acid Supplementation on Myopia Progression

A Randomized Controlled Trial of Branched-Chain Amino Acid Supplementation for Preventing Myopia Progression

This study is a randomized controlled trial designed to evaluate whether branched-chain amino acid (BCAA) supplementation can help slow the progression of myopia in young adults.

Eligible participants will be randomly assigned to receive either BCAA supplementation combined with standard spectacle correction or standard spectacle correction with a matching placebo. The intervention period will last approximately six months.

Participants will undergo regular follow-up examinations, including measurements of visual acuity, refractive error, axial length, intraocular pressure, and other ocular parameters. Additional assessments such as ocular imaging (including OCTA), physical examinations, and blood tests will also be performed to evaluate eye health and metabolic indicators.

The main purpose of this study is to investigate whether BCAA supplementation can provide a safe and effective nutritional strategy to slow myopia progression and improve understanding of the relationship between amino acid metabolism and ocular growth.

Study Overview

• Status: Active, not recruiting
• Conditions: Myopia; Myopia Progressing
• Intervention / Treatment: Dietary supplement: Branched-Chain Amino Acids (BCAA) Supplementation

• Study Type: Interventional
• Enrollment (Estimated): 108
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Jiangsu
    • Nanjing, Jiangsu, China, 210009
      • Zhongda Hospital, Southeast University No. 87 Dingjiaqiao Road, Gulou District, Nanjing, Jiangsu Province, China

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age between 18 and 25 years
• Currently enrolled university students
• Cycloplegic spherical equivalent refractive error: -6.00 D < SE ≤ -0.50 D
• Best corrected visual acuity ≥ 0.8
• Corneal curvature between 40.0 and 46.0 D
• Willing and able to comply with study procedures and follow-up visits
• Signed written informed consent

Exclusion Criteria:

• Strabismus, amblyopia, or other structural ocular abnormalities
• Systemic diseases affecting refractive development (e.g., diabetes, metabolic syndrome, obesity)
• Active ocular disease or history of ocular surgery
• Use of orthokeratology lenses or other myopia control interventions within the past 6 months (washout ≥1 month for low-dose atropine users)
• Use of BCAA supplementation within the past 6 months or abnormal serum BCAA levels
• Known allergy or intolerance to protein/amino acid supplements
• Significant liver or kidney dysfunction
• Any condition deemed unsuitable for participation by the investigator

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BCAA Supplementation Group; Participants receive daily oral branched-chain amino acid (BCAA) supplementation in addition to standard spectacle correction. The intervention is administered for approximately 6 months to evaluate its effect on myopia progression and ocular parameters.	Dietary supplement: Branched-Chain Amino Acids (BCAA) Supplementation; Participants will receive oral branched-chain amino acids (BCAA), including leucine, isoleucine, and valine, as a dietary supplement in addition to standard spectacle correction. The intervention is administered daily for approximately 6 months. The supplement is a commercially available nutritional product obtained via cross-border e-commerce channels and is not intended as a therapeutic drug. The aim is to evaluate the effect of BCAA supplementation on myopia progression and ocular biometric parameters.; Other Names: BCAA; Branched-chain amino acids
No Intervention: Control Group; Participants in the control group will receive standard spectacle correction combined with a placebo identical in appearance to the BCAA supplement, without active BCAA ingredients. They will be followed for approximately 6 months to evaluate myopia progression and ocular outcomes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in axial length	Axial length (AL) will be measured in both eyes using optical biometry at baseline, 3 months, and 6 months. The primary outcome is the change in axial length from baseline to 6 months, comparing the BCAA supplementation plus spectacle correction group with the spectacle correction only group.	Baseline to 6 months
Change in spherical equivalent refractive error	Cycloplegic spherical equivalent (SE) will be measured using autorefractometry under cycloplegia at baseline, 3 months, and 6 months. The primary outcome is the change in spherical equivalent refractive error from baseline to 6 months, comparing the BCAA supplementation group with the control group.	Baseline to 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Superficial retinal vessel density	Superficial retinal vessel density will be measured in both eyes using OCTA in foveal, parafoveal, and perifoveal regions. Sectoral measurements (temporal, superior, nasal, and inferior) will be obtained, and the final value will be calculated as the mean of all regions, reported as a percentage (%).	Baseline and 6 months
Deep retinal vessel density	Deep retinal vessel density will be measured in both eyes using OCTA across ETDRS regions. Sectoral measurements will be obtained, and the final value will be calculated as the mean of all regions, reported as a percentage (%).	Baseline and 6 months
Choriocapillaris perfusion density	Choriocapillaris perfusion will be measured in both eyes using OCTA across foveal, parafoveal, and perifoveal regions. Sectoral measurements will be obtained, and the final value will be calculated as the mean of all regions, reported as a percentage (%).	Baseline and 6 months
Retinal perfusion density	Retinal perfusion density will be measured in both eyes using OCTA across ETDRS regions, including full retinal perfusion and large-vessel-excluded perfusion. Sectoral measurements will be obtained, and the final value will be calculated as the mean of all regions, reported as a percentage (%).	Baseline and 6 months
Family Ocular History	Definition: Baseline refractive status of parents based on self-reported highest degree of myopia in either eye. Variable type: Categorical Measurement: Self-reported parental myopia status categorized as none, low (≤300°), moderate (300-600°), and high (≥600°).	Baseline
Nutritional Supplement Use	Definition: Baseline information on participants' use of any nutritional or dietary supplements. Variable type: Binary (Yes/No) Measurement: Self-reported use of dietary or nutritional supplements (Yes/No).	Baseline
Protein Allergy History	Definition: Baseline assessment of whether participants have a documented or self-reported history of protein allergy. Variable type: Binary (Yes/No) Measurement: Self-reported history of protein allergy (Yes/No).	Baseline
Parental Education Level	Parental education level at baseline, self-reported via structured questionnaire. Education levels are categorized as: primary school or below, junior/high school, university, and master's degree or above.Variable Type：Categorical	Baseline
Daily Screen Time	Average daily time spent using electronic devices (including television, mobile phone, computer, and projection screen) over the past week, assessed by questionnaire. Variable type: Categorical.	Baseline
Eye Rest and Break Behavior	Definition: Frequency of eye breaks during near work activities. Variable type: Categorical Measurement: Self-reported duration of continuous near work before rest (≤30 min, 30-60 min, 1-2 h, 2-3 h, ≥3 h).	Baseline
Sleep Duration	Definition: Average daily sleep duration over the past week. Variable type: Continuous Measurement: Self-reported average sleep time (hours and minutes per day).	Baseline
Staple food intake frequency	Frequency and quantity of staple food intake, including rice, wheat-based products, corn products, mixed beans, tubers, and fried flour-based foods, assessed using a semi-quantitative food frequency questionnaire.	Baseline
Protein-rich food intake frequency	Frequency and quantity of protein-rich food consumption, including soybeans and soy products, meat (pork, beef, lamb, poultry), aquatic products (fish, shrimp, shellfish), eggs, and dairy products, assessed using a semi-quantitative food frequency questionnaire.	Baseline
Vegetable intake frequency	Frequency and quantity of vegetable intake, including dark green vegetables, red/orange vegetables, purple vegetables, and light-colored vegetables, assessed using a semi-quantitative food frequency questionnaire.	Baseline
Fruit intake frequency	Frequency and quantity of fruit intake, including pome fruits, citrus fruits, stone fruits, berries, melons, and tropical fruits, assessed using a semi-quantitative food frequency questionnaire.	Baseline
Dairy product intake frequency	Frequency and quantity of dairy product consumption, including liquid milk, milk powder, and yogurt, assessed using a semi-quantitative food frequency questionnaire.	Baseline
Snack and sugary food intake frequency	Frequency and quantity of intake of snacks and sugary foods, including baked goods, nuts, processed snacks, sweets, and sugar-sweetened beverages, assessed using a semi-quantitative food frequency questionnaire.	Baseline
Temporal Superior RNFL Thickness	Peripapillary retinal nerve fiber layer (RNFL) thickness in the temporal superior (TU) sector measured by optical coherence tomography angiography (OCTA), reported in micrometers (µm).	Baseline and 6 months
Superior Temporal RNFL Thickness	Peripapillary RNFL thickness in the superior temporal (ST) sector measured by OCTA, reported in micrometers (µm).	Baseline and 6 months
Superior Nasal RNFL Thickness	Peripapillary RNFL thickness in the superior nasal (SN) sector measured by OCTA, reported in micrometers (µm).	Baseline and 6 months
Nasal Superior RNFL Thickness	Peripapillary RNFL thickness in the nasal superior (NU) sector measured by OCTA, reported in micrometers (µm).	Baseline and 6 months
Nasal Inferior RNFL Thickness	Peripapillary RNFL thickness in the nasal inferior (NL) sector measured by OCTA, reported in micrometers (µm).	Baseline and 6 months
Inferior Nasal RNFL Thickness	Peripapillary RNFL thickness in the inferior nasal (IN) sector measured by OCTA, reported in micrometers (µm).	Baseline and 6 months
Inferior Temporal RNFL Thickness	Peripapillary RNFL thickness in the inferior temporal (IT) sector measured by OCTA, reported in micrometers (µm).	Baseline and 6 months
Temporal Inferior RNFL Thickness	Peripapillary RNFL thickness in the temporal inferior (TL) sector measured by OCTA, reported in micrometers (µm).	Baseline and 6 months
Global Average Peripapillary RNFL Thickness	Global average peripapillary retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography angiography (OCTA), calculated as the mean thickness across all peripapillary regions, and reported in micrometers (µm).	Baseline and 6 months
Optic Disc Area	Optic disc area measured in both eyes using optical coherence tomography angiography (OCTA), reported in square millimeters (mm²).	Baseline and 6 months
Neuroretinal Rim Area	Neuroretinal rim area measured in both eyes using OCTA, reported in square millimeters (mm²).	Baseline and 6 months
Optic Cup Volume	Optic cup volume measured in both eyes using OCTA, reported in cubic millimeters (mm³).	Baseline and 6 months
Cup-to-Disc Ratio	Cup-to-disc ratio measured in both eyes using OCTA, defined as the ratio of optic cup diameter to optic disc diameter (unitless).	Baseline and 6 months
Vertical Cup-to-Disc Ratio	Vertical cup-to-disc ratio measured in both eyes using OCTA (unitless).	Baseline and 6 months
Horizontal Cup-to-Disc Ratio	Horizontal cup-to-disc ratio measured in both eyes using OCTA (unitless).	Baseline and 6 months
Peripapillary Temporal Superior Sector Vessel Density	Peripapillary microvascular vessel density in the temporal superior (TU) sector measured in both eyes using optical coherence tomography angiography (OCTA), reported as vessel density percentage (%).	Baseline and 6 months
Peripapillary Superior Temporal Sector Vessel Density	OCTA-derived vessel density in the superior temporal (ST) peripapillary sector in both eyes,reported as vessel density percentage (%).	Baseline and 6 months
Peripapillary Superior Nasal Sector Vessel Density	OCTA-derived vessel density in the superior nasal (SN) peripapillary sector in both eyes,reported as vessel density percentage (%).	Baseline and 6 months
Peripapillary Nasal Superior Sector Vessel Density	OCTA-derived vessel density in the nasal superior (NU) peripapillary sector in both eyes,reported as vessel density percentage (%).	Baseline and 6 months
Peripapillary Nasal Inferior Sector Vessel Density	OCTA-derived vessel density in the nasal inferior (NL) peripapillary sector in both eyes,	Baseline and 6 months
Peripapillary Inferior Nasal Sector Vessel Density	OCTA-derived vessel density in the inferior nasal (IN) peripapillary sector in both eyes,reported as vessel density percentage (%).	Baseline and 6 months
Peripapillary Inferior Temporal Sector Vessel Density	OCTA-derived vessel density in the inferior temporal (IT) peripapillary sector in both eyes,reported as vessel density percentage (%).	Baseline and 6 months
Peripapillary Temporal Inferior Sector Vessel Density	OCTA-derived vessel density in the temporal inferior (TL) peripapillary sector in both eyes,reported as vessel density percentage (%).	Baseline and 6 months
Global Peripapillary Vessel Density	Mean peripapillary microvascular vessel density calculated across all peripapillary sectors in both eyes using OCTA,reported as vessel density percentage (%).	Baseline and 6 months
Full Macular Retinal Thickness	Full retinal thickness in the macular region measured in both eyes using optical coherence tomography angiography (OCTA), including foveal, parafoveal, and perifoveal regions across temporal, superior, nasal, and inferior sectors.	Baseline and 6 months
Macular Inner Retinal Layer Thickness	Inner retinal layer thickness in the macular region measured in both eyes using OCTA, assessed at foveal, parafoveal, and perifoveal regions across four quadrants (temporal, superior, nasal, inferior).	Baseline and 6 months
Macular Outer Retinal Layer Thickness	Outer retinal layer thickness in the macular region measured in both eyes using OCTA, including foveal, parafoveal, and perifoveal regions across temporal, superior, nasal, and inferior sectors.	Baseline and 6 months
Foveal Avascular Zone Area	Foveal avascular zone (FAZ) area measured in both eyes using optical coherence tomography angiography (OCTA).	Baseline and 6 months
FAZ-300 Superficial Capillary Plexus Perfusion Density	Perfusion density in a 300 μm annular region surrounding the FAZ in the superficial capillary plexus measured using OCTA.	Baseline and 6 months
FAZ-300 Deep Capillary Plexus Perfusion Density	Perfusion density in a 300 μm annular region surrounding the FAZ in the deep capillary plexus measured using OCTA.	Baseline and 6 months
FAZ-300 Full Retinal Perfusion Density	Perfusion density in a 300 μm annular region surrounding the FAZ across full retinal layers measured using OCTA.	Baseline and 6 months
Alanine Aminotransferase (ALT)	Serum alanine aminotransferase (ALT) measured in fasting venous blood using standard laboratory methods. Values will be analyzed as continuous variables and categorized as normal or abnormal based on clinical reference ranges.	Baseline and 6 months
Aspartate Aminotransferase (AST)	Serum AST measured using standard laboratory methods in fasting venous blood. Values will be analyzed as continuous variables and categorized as normal or abnormal based on clinical reference ranges.	Baseline and 6 months
Total Bilirubin (TBil)	Serum total bilirubin measured in fasting venous blood. Values will be analyzed as continuous variables and categorized as normal or abnormal based on clinical reference ranges.	Baseline and 6 months
Serum Creatinine (Scr)	Serum creatinine measured in fasting venous blood using standard laboratory methods. Values will be analyzed as continuous variables and categorized as normal or abnormal based on clinical reference ranges.	Baseline and 6 months
Blood Urea Nitrogen (BUN)	BUN measured in fasting venous blood using standard laboratory methods. Values will be analyzed as continuous variables and categorized as normal or abnormal based on clinical reference ranges.	Baseline and 6 months
Uric Acid (UA)	Serum uric acid measured in fasting venous blood using standard laboratory methods. Values will be analyzed as continuous variables and categorized as normal or abnormal based on clinical reference ranges.	Baseline and 6 months
Fasting Plasma Glucose (FPG)	Fasting plasma glucose measured in fasting venous blood using standard laboratory methods. Values will be analyzed as continuous variables and categorized as normal or abnormal based on clinical reference ranges.	Baseline and 6 months
Total Cholesterol (TC)	Serum total cholesterol measured in fasting venous blood using standard laboratory methods. Values will be analyzed as continuous variables and categorized as normal or abnormal based on clinical reference ranges.	Baseline and 6 months
Triglycerides (TG)	Serum triglycerides measured in fasting venous blood using standard laboratory methods. Values will be analyzed as continuous variables and categorized as normal or abnormal based on clinical reference ranges.	Baseline and 6 months
High-Density Lipoprotein Cholesterol (HDL-C)	HDL cholesterol measured in fasting venous blood using standard laboratory methods. Values will be analyzed as continuous variables and categorized as normal or abnormal based on clinical reference ranges.	Baseline and 6 months
Low-Density Lipoprotein Cholesterol (LDL-C)	LDL cholesterol measured in fasting venous blood using standard laboratory methods. Values will be analyzed as continuous variables and categorized as normal or abnormal based on clinical reference ranges.	Baseline and 6 months
Sex of Participants	Participant sex recorded at baseline using structured questionnaire.	Baseline
Age of Participants	Age calculated from date of birth at baseline using structured questionnaire.	Baseline
Ethnicity of Participants	Ethnicity recorded at baseline using structured questionnaire.	Baseline
Body Mass Index (BMI)	BMI calculated from weight and height measured at baseline.Units：kg/m², Type：Continuous	Baseline
Household Residence	Household residence (urban/rural) recorded at baseline using structured questionnaire.Type：Categorical	Baseline
Annual Household Income	Annual household income recorded at baseline using structured questionnaire.Type : categorical	Baseline
Study Pressure Level	Self-reported level of study pressure and workload, assessed by questionnaire with four levels ranging from low to high. Variable type: Categorical.	Baseline
Unhealthy Visual Habits	Presence of unhealthy visual habits (e.g., reading under strong sunlight, using screens in dark environments, improper posture during near work), assessed by multiple-choice questionnaire. Variable type: Categorical (multiple response).	Baseline
Lighting Conditions During Nighttime Near Work	Lighting conditions used during near-work activities after dark (e.g., desk lamp, ceiling light), assessed by questionnaire. Variable type: Categorical.	Baseline
Moderate-to-Vigorous Physical Activity Duration	Average daily duration of moderate-to-vigorous physical activity (e.g., brisk walking, running, jumping rope, cycling) over the past week, assessed by questionnaire. Variable type: Categorical.	Baseline

Collaborators and Investigators

• Sponsor: Zhongda Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 5, 2026
• Primary Completion (Estimated): December 30, 2026
• Study Completion (Estimated): January 30, 2027

Study Registration Dates

• First Submitted: April 23, 2026
• First Submitted That Met QC Criteria: May 6, 2026
• First Posted (Actual): May 14, 2026

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 6, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: OCTA; Randomized controlled trial; Nutritional supplementation; Branched-chain amino acids; Axial length; Myopia Progression
• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors; Myopia; Amino Acids, Peptides, and Proteins; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages; Amino Acids; Amino Acids, Branched-Chain; Dietary Supplements
• Other Study ID Numbers: 2025ZDSYLL321-PO1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No