A Phase 3 interventional study of 3% Diquafosol ophthalmic solution and 0.1% Cyclosporin A cationic ophthalmic emulsion and 0.1% Cyclosporin A cationic ophthalmic emulsion in Vernal Keratoconjunctivitis, sponsored by The University of Hong Kong. Recruiting at 1 site in Hong Kong. Open to participants aged 6 Years and older. Per ClinicalTrials.gov, last updated 2026-11-09.
Sponsored by The University of Hong Kong · Phase 3, Interventional, and Treatment
The aim of the study is to investigate whether patients with moderate-to-severe VKC and keratitis will benefit from the addition of Diquafosol ophthalmic solution in terms of symptoms and signs of VKC, tear film metrics, ocular surface inflammation and quality of life. Potential beneficial effect of Diquafosol treatment on top of current standard use of topical immunosuppressant therapy in VKC would be studied.
Subject at least aged 6 and above with clinical diagnosis of vernal keratoconjunctivitis would be invited to join this study and perform the following assessments:
All participants will be required to answer a standardised questionnaire relating to severity of VKC and dry eye disease.
Aim To compare the four-month clinical efficacy of topical treatment with 3% Diquafosol ophthalmic solution and 0.1% Cyclosporin A cationic ophthalmic emulsion versus 0.1% Cyclosporin A cationic ophthalmic emulsion in reducing symptoms and signs of active moderate-to-severe vernal keratoconjunctivitis (grade of 2 to 4 on the Bonini severity scale) with keratitis (corneal fluorescein staining score of 1-5 on the modified Oxford scale).
Study design A single-centre prospective double-blinded randomized controlled trial
Hypothesis The addition of topical treatment with 3% Diquafosol ophthalmic solution is superior to 0.1% Cyclosporin cationic ophthalmic emulsion alone in improving symptoms and signs of moderate-to-severe VKC with keratitis at four months of use.
Methods This is a single-centre, prospective, 16-week, randomized, double-blinded controlled clinical trial investigating the clinical efficacy and safety of combined topical treatment with 3% Diquafosol ophthalmic solution and 0.1% Cyclosporin A cationic ophthalmic emulsion and versus topical treatment with 0.1% Cyclosporin A cationic ophthalmic emulsion in patients with moderate-to-severe vernal keratoconjunctivitis and keratitis. The study will also investigate the longitudinal changes in tear cytokines and correlate them with changes in VKC signs and tear film metrics. The study will be performed in accordance with the principles of the Declaration of Helsinki, the International Conference on Harmonization, Good Clinical Practice guidelines, and all applicable laws and regulations. Written informed consent will be obtained from each patient before enrolment in the study. A clinical trials certificate will be obtained from the Department of Health, Hong Kong SAR.
Sample size The study will recruit 94 subjects with moderate-to-severe VKC at eye clinics in Hong Kong West cluster (QMH and GH).
Sample size Calculation Sample size calculation is based on the findings from a prospective study comparing the combined use of 3% Diquafosol and 0.1% Cyclosporin versus 0.1% Cyclosporin alone in the treatment of dry eye disease in 279 subjects [36]. It is anticipated that a similar, if not larger, effective size in VKC patients compared to dry eye patients would be seen. In this study the mean change in cornea staining score between baseline and week 12 was significantly higher in Cyclosporin A and Diquafosol combination therapy (2.91 ± 3.93) than in Cyclosporin A monotherapy (0.93± 2.22). The estimated Cohen's d for this study is approximately 0.620. Based on calculations, approximately 41 participants per group to achieve a study power of 80% with a significance level of 0.05 and the estimated effect size of 0.620 is needed. Considering a 10% dropout rate, the adjusted sample size per group would be approximately 47 participants.
Randomization method Randomisation is conducted by computer-generated random number allocation and will be applied to sequentially enrolled participants. The randomisation schedule is pre-determined, prior to commencing participant recruitment, such that the investigator involved in baseline participant assessment will have no involvement in treatment allocation. Block randomization is performed to ensure 1:1 distribution into treatment groups.
Double-blinding To keep the investigators and subjects blind to the study treatment, all investigational drugs are removed from their commercial packaging, wrapped in aluminium foil, double-wrapped in plastic bags, and distributed to participants by an independent clinical research coordinator.
Rescue Therapy During the study period rescue medication (Loteprednolol 0.5% one drop 4x/day for up to 5 days) is permitted in the event of worsening of ocular surface symptoms. A maximum of 2 courses were allowed between study visits. Any use of rescue therapy is documented in the eyedrop diary and serves as one of the outcome measures.
Patient Workflow The patient workflow is aimed at obtaining clear and comprehensive documentation of symptoms and signs baseline and each subsequent visit after initiation of intervention. Furthermore, documentation of adverse events is achieved via assessment of best corrected visual acuity, intraocular pressure measurement, general periorbital area assessment and slit lamp biomicroscope assessment. See Figure 1. Study Workflow
In particular, the sequence of clinical assessments must be done in order of sequence from least invasive to most invasive, as any touching of the ocular surface or manipulation of the eyelids will stimulate tear secretion. Least invasive tests include imaging-based assessments without manipulation or touching of the ocular surface, include best corrected visual acuity, slit lamp biomicroscope assessment, NIKBUT and tear meniscus height. Mildly invasive tests include those that require gentle touching of the ocular surface, such as fluorescein cornea staining. Moderately invasive tests include those with prolonged ocular surface contact, such as the Schirmer's I test for tear collection
210 studies on the registry are indexed under Conjunctivitis, Allergic; 18 are open to participants now.
This study's planned enrollment of 94 is close to the median of 87 across 174 interventional studies indexed under Conjunctivitis, Allergic.
Browse Conjunctivitis, Allergic studies →The University of Hong Kong is the lead sponsor of 1,292 studies on the registry; 348 are open to participants now.
Of its 9 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
3% Diquafosol eyedrops 6x/day + 0.1% Cyclosporin A twice a day
Drug: 3% Diquafosol ophthalmic solution and 0.1% Cyclosporin A cationic ophthalmic emulsion
0.1% Cyclosporin A eyedrops twice a day + preservative free sodium hyaluronate eyedrops 6x/day
Drug: 0.1% Cyclosporin A cationic ophthalmic emulsion
This arm is to investigate whether patients with moderate-to-severe VKC and keratitis will benefit from the addition of Diquafosol ophthalmic solution
This arm is a control group to investigate whether patients with moderate-to-severe VKC and keratitis will benefit from the addition of Diquafosol ophthalmic solution
Change in Cornea Fluorescein Staining (CFS) score from baseline to 4 weeks, 8 weeks and 16 weeks between study groups
Higher values mean inferior outcomes. Graded according to the modified Oxford grading scale (range 0, 0.5, 1, 2, 3, 4, 5). A difference in score of at least 2 levels (i.e. 4 to 2) or complete resolution of staining (i.e. 0) are both considered clinically significant endpoints.
Time frame: From baseline to 4 months post- treatment between study groups
Percentage of patients requiring rescue topical steroid therapy at 4 weeks, 8 weeks and 16 weeks
Number of patients requiring rescue topical steroid therapy divided by all patients participated in this study
Time frame: From baseline to 4 months post- treatment between study groups
Percentage of patients with improvement in Cornea Fluorescein Staining (CSF) at 4 weeks, 8 weeks and 16 weeks
Number of patients with improvement in CFS requiring rescue topical steroid therapy divided by all patients participated in this study
Time frame: From baseline to 4 months post- treatment between study groups
Change in best corrected visual acuity from baseline to 4 weeks, 8 weeks and 16 weeks
From logmar(1.0 to -0.1)
Time frame: From baseline to 4 months post- treatment between study groups
Change in Standard Patient Evaluation of Eye Dryness Questionnaire (SPEED) score from baseline to 4 weeks, 8 weeks and 16 weeks
Range from 0-28, one mark was collected per patient, with higher scores meaning worse
Time frame: From baseline to 4 months post- treatment between study groups
Change in Quality of Life in Children with Vernal Keratoconjunctivitis (QUICK) score from baseline to 4 weeks, 8 weeks and 16 weeks
Range from 0-48, one mark was collected per patient, with higher scores meaning worse outcomes
Time frame: From baseline to 4 months post- treatment between study groups
Change in NIKBUT from baseline to 4 weeks, 8 weeks and 16 weeks
NIKBUT is measured in seconds and average of 3 consecutive readings is taken. Higher values mean better outcomes.
Time frame: From baseline to 4 months post- treatment between study groups
Change in tear meniscus height from baseline to 4 weeks, 8 weeks and 16 weeks
In millimetres. Readings serve as objective parameters for tear volume
Time frame: From baseline to 4 months post- treatment between study groups
Change in tear cytokines from baseline to 4 weeks, 8 weeks and 16 weeks
Percentage change in tear cytokines analysis done in lab
Time frame: From baseline to 4 months post- treatment between study groups
Incidence of ocular adverse events
Number of patients with ocular adverse events divided by all patients participated in this study
Time frame: From baseline to 4 months post- treatment between study groups
Incidence of non-ocular adverse events
Number of patients with non-ocular adverse events divided by all patients participated in this study
Time frame: From baseline to 4 months post- treatment between study groups
• Incremental cost-effectiveness ratio (ICER) in cost per quality-adjusted life year (QALYs) gained.
It is defined by the difference in cost between two possible interventions, divided by the difference in their effect.
Time frame: From baseline to 4 months post- treatment between study groups
Started Feb 2026 (actual). Primary completion is estimated for Jun 2028, 28 months after the start.
Of 21 phase 3 interventional studies under Conjunctivitis, Allergic, half reached primary completion within 6 months of starting (the median), counting those still running; a quarter within 4 and three quarters within 14. This study's planned 28 months is above that.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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