Atropine for Adult Myopia: Separating Evidence from Extrapolation

MyopiaTracker | Evidence-based myopia education | References at end of article

Atropine eye drops are the most widely discussed pharmacological option for myopia control. You may have been told they "work" for adult myopia, or that your clinician can prescribe them if your prescription is still changing. What the evidence actually supports — and where the evidence runs out — is worth understanding clearly before making a treatment decision.

The fundamental issue stated upfront: As of the time of writing, there are no published randomized controlled trials (RCTs) that have specifically evaluated atropine efficacy for myopia control in adults aged 18–40. All adult use is extrapolated from pediatric evidence. This is not a reason to dismiss atropine as a consideration — but it is a reason to understand what you are being offered.

What the Pediatric Evidence Actually Shows

The evidence base for atropine in children is substantial. Two large trials dominate the literature:

ATOM2 (Singapore, 2012)

The Atropine for the Treatment of Myopia 2 study (Chia et al.) randomized 400 myopic children aged 6–12 to 0.5%, 0.1%, or 0.01% atropine nightly for 2 years, followed by a washout phase. It established that 0.01% atropine produced significant clinical effects on myopia progression — on refraction specifically, with weaker and more controversial axial-length effects — and this was in the context of no true placebo control arm, which limits interpretation.

LAMP Study (Hong Kong, 2019–ongoing)

The Low-Concentration Atropine for Myopia Progression study (Yam et al.) is the largest placebo-controlled RCT of low-dose atropine to date. It randomized 438 myopic children aged 4–12 to 0.05%, 0.025%, 0.01% atropine, or placebo, with nightly dosing.

Year 1 results (published 2019):

Concentration Refractive Change (Mean) Reduction vs Placebo Axial Length Change AL Reduction vs Placebo
Placebo −0.81 D — 0.41 mm —
0.01% atropine −0.59 D 27.2% reduction 0.36 mm 12.2% (non-significant)
0.025% atropine −0.46 D 43.2% reduction 0.29 mm 29.3% reduction
0.05% atropine −0.27 D 66.7% reduction 0.20 mm 51.2% reduction

The IMI 2025 Interventions report (Bullimore et al.) makes an important observation about percentage efficacy figures: in the LAMP study, the 1-year absolute reduction from 0.05% atropine was 0.54D regardless of age — but when expressed as a percentage relative to the control group's progression, this translated to 40% efficacy in the youngest children (who progressed fastest) and 130% in the oldest (who progressed slowest). This illustrates why percentage efficacy figures are misleading when applied across different populations or progression rates.

The dose-response relationship is clear in children: 0.05% atropine consistently outperforms 0.025% which consistently outperforms 0.01% on both refractive and axial length endpoints. The question for adults is whether this hierarchy translates.

The Adult Evidence Gap: What Exists and What Doesn't

The IMI 2023 White Paper on myopia in young adults is explicit: "There are no large clinical studies investigating myopia control in this age group [18–40]." This is the most authoritative statement on the current state of the literature.

What does exist in adults is limited and indirect:

Tolerability in Adults

A small prospective placebo-controlled study of 30 myopic adults (mean age 23.3 ± 2.9 years, myopia −1.00 to −6.00D; published in Frontiers in Neuroscience, PMC7933202) assessed the effect of 0.01% atropine on contrast sensitivity over 4 weeks. It found no statistically significant differences in contrast sensitivity between the atropine and placebo groups at any time point — suggesting 0.01% atropine is well-tolerated visually in young adults. However, this study measured tolerability, not myopia control efficacy.

Bullimore 2021 — Comparing Benefits and Risks Across Treatments

Mark Bullimore's 2021 Contact Lens and Anterior Eye paper compared benefit-risk profiles across myopia control modalities. This is a comparative and conceptual review, not an adult-specific clinical trial. It supports 0.05% atropine as the concentration with the best evidence base (primarily from the LAMP study) but does not provide efficacy data for adults specifically.

Brennan et al. 2021 — Efficacy in Myopia Control (Meta-framework)

Brennan, Toubouti, Cheng & Bullimore (2021, Progress in Retinal and Eye Research) published a comprehensive meta-analysis and framework for evaluating myopia control efficacy. This work provides the theoretical basis for understanding how treatment effects translate across populations — but again, it does not constitute adult-specific trial data.

What this means for adult prescribing: Clinicians who prescribe atropine for adult myopia progression are making a reasonable clinical judgment based on: They are not basing this on adult-specific RCT efficacy data, because that data does not yet exist.

Why Extrapolating from Children May Be Imperfect

There are biological reasons to expect that atropine efficacy in adults might differ from children — not necessarily worse, but different:

Practical Summary: Questions Worth Asking Your Clinician

If your clinician has recommended or discussed atropine for adult myopia control, these are evidence-grounded questions worth raising:

  1. "Is my progression confirmed on axial length, or only on refraction?" — Atropine is intended to reduce progression associated with ocular growth. If progression is being tracked by refraction alone, an axial length measurement helps confirm whether true structural change is occurring — ideally obtained before starting treatment to establish a baseline.
  2. "What concentration are you recommending, and why?" — 0.05% has the strongest pediatric evidence for axial length control; 0.01% has the lowest side-effect profile but weaker evidence for axial benefit. The choice involves a trade-off worth discussing explicitly.
  3. "How will we know if it's working?" — Without a control arm (you can't have one in clinical care), assessing whether atropine has slowed your personal progression requires at least 1–2 years of pre-treatment baseline data and consistent axial length monitoring during treatment.
  4. "What are the stopping criteria?" — If your myopia stabilizes naturally, continuing atropine provides no additional benefit. A plan for reassessment is reasonable.
Evidence summary by concentration, for adult use:
Concentration Adult-specific RCT evidence Pediatric evidence quality Tolerability in adults
0.01% None (off-label extrapolation) Moderate — LAMP and ATOM2; refractive benefit established, axial benefit weaker Good; minimal pupil dilation, no significant contrast sensitivity impact (adult tolerability study)
0.025% None (off-label extrapolation) Moderate — LAMP Year 1; significant refractive and axial benefit Likely good; modest pupil effect
0.05% None (off-label extrapolation) Best available — LAMP; strongest refractive and axial benefit (66.7% / 51.2% vs placebo at Year 1) Acceptable; some photophobia and near blur possible; discuss with your prescriber
Bottom line: Atropine is a reasonable conversation to have with your eye care provider if you have documented adult myopia progression — ideally with axial length confirmation where available, though refractive progression alone is clinically meaningful. It is not a validated adult treatment in the way it is validated in children — but the absence of adult RCT data reflects a research gap, not evidence of inefficacy. Clinical judgment guided by pediatric evidence, individual progression rate, and shared decision-making is the appropriate framework. Adult-specific trials are an active area of research interest.

Key References