CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-19). The draft was written by AI, the existence of all 4 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 591 · Search date 2026-07-19 · Methodology v0.6

Diquafosol sodium ophthalmic solution,
does it really help with Improvement of dry-eye symptoms by increasing fluid and mucin secretion?

30-Second Summary
C
Evidence Grade C · 58 · Safety caution
Prescription diquafosol improves short-term dry-eye measures and some symptoms, but long-term disease modification is unproven
What the
research shows
Diquafosol sodium ophthalmic solution is rated C because evidence is limited to small short-term changes in staining, tear-film measures, and subjective endpoints. In the 14-trial meta-analysis, eight postoperative cataract-surgery trials found no significant OSDI benefit. A nine-trial meta-analysis versus hyaluronic acid found small differences: OSDI -3.59 points, Schirmer +1.08 mm, and tear-film breakup time +0.60 seconds. Long-term clinical efficacy and disease modification remain unestablished.
What the
ads claim
Marketing can turn short-term test improvement into a claim that the drug creates tears and mucin to cure dry eye at its root. The evidence applies to short-term symptom, staining, and tear-film improvement in selected patients using a prescription product, not every cause of dry eye or guaranteed long-term recovery.
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Useful facts when choosing a product

  • Diquafosol sodium 3% ophthalmic solution, sold under names including Diquas, is a prescription P2Y2 receptor agonist that promotes fluid and mucin secretion from the conjunctiva.
  • Unlike the nonprescription trehalose artificial tears in verdict 581, this is a prescription ophthalmic drug. Dosing and preservative content can differ by product, so the prescription and label take priority.
  • Instillation can cause irritation, discharge, itching, redness, pain, or a foreign-body sensation. The bottle tip should not touch the eye or skin.
  • Patients using other eye drops or contact lenses should confirm spacing and lens instructions with a clinician. Worsening pain, reduced vision, or failure to improve warrants reassessment.
Gap Measurement · Verdict 591 · C 58
What advertising claims
What independent, higher-quality research supports
△ GAP
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What the research actually shows

A 14-trial meta-analysis reported short-term signals in ocular-surface staining, tear-film measures, and tear production, but eight postoperative cataract-surgery trials showed no significant OSDI benefit. A nine-trial meta-analysis against hyaluronic acid found small differences of -3.59 OSDI points, +1.08 mm on Schirmer testing, and +0.60 seconds in tear-film breakup time. Individual placebo- and active-controlled trials mainly measured four- to six-week staining and tear-film outcomes rather than long-term quality of life or disease course.

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Why this is classified as C (58)

Multiple trials show short-term staining and tear-film signals, but OSDI was null in the postoperative subset and the OSDI, Schirmer, and tear-film differences versus hyaluronic acid were small. Evidence remains limited to short-term subjective and surrogate outcomes without established long-term clinical efficacy. The applicable evidence ceiling is C, giving 58 points.

Counterpoint. The drug can be a useful prescription option when tear-film instability or mucin deficiency contributes to disease. Meibomian-gland dysfunction, autoimmune disease, medication effects, and postoperative dry eye may still require cause-specific treatment and eyelid or environmental measures.

Rejudgment record. Reassessment (cross-check reflected) — Applied C because eight postoperative trials found no significant OSDI benefit, a nine-trial comparison with hyaluronic acid showed only small OSDI, Schirmer, and tear-film differences, and evidence remained confined to short-term subjective and surrogate outcomes without long-term clinical efficacy

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Improvement in dry-eye symptoms, corneal staining, and tear-film measuresCShort-term surrogate signals are positive, but OSDI was null and effects were small.
Disease modification and long-term quality-of-life improvement?Trials of long-term clinical course are absent.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Liu S et al. 2023Systematic review and meta-analysis of randomized trials14Academic study; conflicts varied across included trialsCorneal and conjunctival staining, Schirmer testing, tear-film breakup time, symptoms, and adverse eventsThree-percent diquafosol showed an overall favorable signal across ocular-surface, tear-film, and symptom measures.Key short-term synthesis
Matsumoto Y et al. 2012Multicenter randomized double-masked placebo-controlled phase 2 trial286Development-trial context with limited independenceFour-week fluorescein and rose-bengal staining, tear-film breakup time, and subjective symptomsThe 3% group improved fluorescein and rose-bengal staining and symptoms versus vehicle, but tear-film breakup time did not differ significantly.Direct placebo-controlled evidence
Takamura E et al. 2012Multicenter randomized double-masked active-controlled phase 3 trial286Phase 3 development contextFour-week fluorescein and rose-bengal staining and adverse eventsDiquafosol was noninferior for fluorescein staining and superior for rose-bengal staining, but outcomes were staining surrogates.Active-control replication evidence
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Receipt — 4 References

All 4 cited sources were verified for existence at the original page (as of 2026-07-19).

Liu S, Yang G, Li Q, Tang S. Safety and efficacy of topical diquafosol for the treatment of dry eye disease: An updated meta-analysis of randomized controlled trials. Indian J Ophthalmol. 2023;71(4):1304-1315. PMID: 37026262. PMCID: PMC10276678. DOI: 10.4103/IJO.IJO_268_23.
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Wu D, Chen WQ, Li R, Wang Y. Efficacy and safety of topical diquafosol ophthalmic solution for treatment of dry eye: a systematic review of randomized clinical trials. Cornea. 2015;34(6):644-650. PMID: 25909234. DOI: 10.1097/ICO.0000000000000429.
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Matsumoto Y, Ohashi Y, Watanabe H, Tsubota K; Diquafosol Ophthalmic Solution Phase 2 Study Group. Efficacy and safety of diquafosol ophthalmic solution in patients with dry eye syndrome: a Japanese phase 2 clinical trial. Ophthalmology. 2012;119(10):1954-1960. PMID: 22739038. DOI: 10.1016/j.ophtha.2012.04.010.
checked
Takamura E, Tsubota K, Watanabe H, Ohashi Y; Diquafosol Ophthalmic Solution Phase 3 Study Group. A randomised, double-masked comparison study of diquafosol versus sodium hyaluronate ophthalmic solutions in dry eye patients. Br J Ophthalmol. 2012;96(10):1310-1315. PMID: 22914501. PMCID: PMC3463860. DOI: 10.1136/bjophthalmol-2011-301448.
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Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-19 · Corrections: none

Cite this verdict

Diquafosol sodium ophthalmic solution x dry-eye symptom improvement Evidence Grade C card
[Chamgap] Diquafosol sodium ophthalmic solution x dry-eye symptom improvement — Evidence Grade C·58. 4 cited sources checked. Source: https://chamgap.com/en/verdicts/eye/diquafosol-sodium-dry-eye-tear-mucin-secretion/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.