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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Improved near visual acuity in presbyopes using carbachol and brimonidine eye drops.
Scientific title
Clinical outcomes of combined versus separate carbachol and brimonidine drops in correcting presbyopia
Secondary ID [1] 290380 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
presbyopia 300689 0
Condition category
Condition code
Eye 300535 300535 0 0
Normal eye development and function

Study type
Description of intervention(s) / exposure
One drop was administrated per application to the on-dominant eye by the primary investigator who is an ophthalmologist. Each participant received three treatments to the non-dominant eye - 3% carbachol and 0.2% brimonidine in both combined and separate forms, carbachol only, and brimonidine only. It is a cross-over trial, so that, the washout period was one week.
Intervention code [1] 296207 0
Treatment: Drugs
Comparator / control treatment
brimonidine 0.2% is an alpha-2 agonist
Control group

Primary outcome [1] 299955 0
Near visual acuity (NVA) was assessed at 40 cm using a hand-held Rosenbaum chart with Jaeger notation, always employing the same luminosity of 160 cd/m2.
Timepoint [1] 299955 0
1,2,4 and 8 hours post drug administration
Secondary outcome [1] 328881 0
Pupil size (PS) was measured using Colvard handheld Infrared pupillometer (Oasis Medical, Glendora, CA, USA).
Timepoint [1] 328881 0
1,2,4 and 8 hours post drug administration.

Key inclusion criteria
Inclusion criteria were as follows: age between 42 and 58 years, emmetropia [cycloplegic spherical equivalent (SE), +/-0.25 D; astigmatism "equal to" or less than 0.25 D] and binocular uncorrected distance visual acuity "equal to" or greater than 20/20
Minimum age
42 Years
Maximum age
58 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Exclusion criteria concerned patients with myopia, hyperopia and astigmatism higher than 0.25 diopter as well as those with corneal, lens and vitreous opacities, pupil irregularities, anisocoria, amblyopia, chronic general pathologies and medications that would interact unfavorably with carbachol and brimonidine

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
central randomisation by phone/fax/computer
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software (i.e. computerised sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Phase 2 / Phase 3
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 8345 0
Saudi Arabia
State/province [1] 8345 0

Funding & Sponsors
Funding source category [1] 294783 0
Self funded/Unfunded
Name [1] 294783 0
Almamoun Abdelkader is funding the study from his own personal funds
Address [1] 294783 0
Saudi German Hospital, King Fahad Road, Khamis Mushait, Aseer, Kingdom of Saudi Arabia, P.O Box 2355.
Country [1] 294783 0
Primary sponsor type
Almamoun Abdelkader
Saudi German Hospital, King Fahad Road, Khamis Mushait, Aseer, Kingdom of Saudi Arabia, P.O Box 2355.
Secondary sponsor category [1] 293629 0
Name [1] 293629 0
Address [1] 293629 0
Country [1] 293629 0

Ethics approval
Ethics application status
Ethics committee name [1] 296189 0
The RCRC Independent Review Board, LLC
Ethics committee address [1] 296189 0
2111 West Baker Lane, Suite 400
Austin, Texas 78758
Ethics committee country [1] 296189 0
United States of America
Date submitted for ethics approval [1] 296189 0
Approval date [1] 296189 0
Ethics approval number [1] 296189 0
Ethics committee name [2] 296190 0
Abha ethics committee eye centre and research
Ethics committee address [2] 296190 0
Immam Ibn Saud , Abha, Aseer, KSA
Ethics committee country [2] 296190 0
Saudi Arabia
Date submitted for ethics approval [2] 296190 0
Approval date [2] 296190 0
Ethics approval number [2] 296190 0

Brief summary
Background: To test and compare in a masked fashion the efficacy of using a parasympathomimetic drug (3 % Carbachol) and an alpha-2 agonist (0.2 % brimonidine) in both combined and separate forms to create optically beneficial miosis to pharmacologically improve vision in presbyopia.
Methods: A prospective, double-masked, randomized, controlled clinical trial. Ten naturally emmetropic and presbyopic subjects between 42 years and 58 years old with an uncorrected distance visual acuity of at least 20/20 in both eyes without additional ocular pathology are eligible for inclusion. All subjects received 3 % carbachol and 0.2 % brimonidine in both combined and separate forms, 3% carbachol alone and 0.2% brimonidine (control) alone in their non-dominant eye in a crossover manner with one week washout between tests. The subjects’ pupil size and both near and distance visual acuities will be evaluated pre- and posttreatment at 1, 2, 4, and 8 hours, by a masked examiner at the same room illumination.
Results: Statistically significant improvement in mean near visual acuity (NVA) was achieved in all subjects who received combined 3 % Carbachol and brimonidine in the same formula compared to those received separate forms or Carbachol alone or brimonidine alone (P< 0.0001).
Conclusion: Based on the data, the combined solution demonstrated greater efficacy than the other solutions that were tested. Improving the depth of focus by making the pupil small caused statistically significant improvement in near visual acuity, with no change in binocular distance vision.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 69878 0
A/Prof Almamoun Abdelkader
Address 69878 0
Saudi German Hospital, King Fahad Road, Khamis Mushait, Aseer, Kingdom of Saudi Arabia, P.O Box 2355.
Country 69878 0
Saudi Arabia
Phone 69878 0
Fax 69878 0
Email 69878 0
Contact person for public queries
Name 69879 0
A/Prof Almamoun Abdelkader
Address 69879 0
Saudi German Hospital, King Fahad Road, Khamis Mushait, Aseer, Kingdom of Saudi Arabia, P.O Box 2355.
Country 69879 0
Saudi Arabia
Phone 69879 0
Fax 69879 0
Email 69879 0
Contact person for scientific queries
Name 69880 0
A/Prof Almamoun Abdelkader
Address 69880 0
Saudi German Hospital, King Fahad Road, Khamis Mushait, Aseer, Kingdom of Saudi Arabia, P.O Box 2355.
Country 69880 0
Saudi Arabia
Phone 69880 0
Fax 69880 0
Email 69880 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary