The Predicting Glaucoma Development Project: Examining the utility of an Ibopamine challenge test to predict glaucoma development in glaucoma suspects.

A study to examine the utility of an Ibopamine challenge test, to predict who might develop glaucoma from those patients who are glaucoma suspects.

Status

Not yet recruiting

Phases

Phase 4

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12615000767505

Enrollment

100

Registered

2015-07-24

Start date

2015-09-01

Completion date

Unknown

Last updated

2020-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

It’s a clinical trial of a drug called Ibopamine, to be used in a challenge test in much the same way as a water drinking test. Ibopamine is an alpha, beta and dopamine receptor agonist, which causes a brief increase in aqueous production for about 4 hours after a single drop. Among normal patients, this causes no change in intraocular pressure, but in glaucoma patients, IOP will increase. My suspicion is that the degree of IOP rise might be related to the patient’s likelihood of further progression in the future. I have recently completed a pilot case-control study which has successfully shown that an ibopamine challenge can differentiate between glaucoma suspects, stable glaucoma patients and patients whose glaucoma is rapidly worsening. Now, I would like to commence a longitudinal study investigating the predictive value of a positive ibopamine challenge among glaucoma suspects and early glaucoma patients.

Interventions

Intraocular pressure (IOP) is dependent on the balance between the production of aqueous fluid within the eye and the rate at which aqueous leaves the eye through the trabecular meshwork (TM) in the angle of the eye’s anterior chamber. The medication Ibopamine (Trazyl: Pharmainvest SpA, Milano, Italy) which is a dopamine receptor agonist, will temporarily increase aqueous production and dilate the pupil. A healthy eye with healthy TM cells will overcome this increase, pump aqueous out of the eye at an increased rate and the patient will demonstrate no IOP rise when Ibopamine drops are applied topically to the eye, however there is evidence that those with glaucoma will exhibit a rise in IOP. It may be that patients whose glaucoma is progressively worsening, will demonstrate a larger increase in IOP when Ibopamine drops are applied topically to their eye compared with stable patients. To undertake an Ibopamine challenge, the patient has their IOP measured and recorded using goldmann applanation tonometry seated at the slit lamp; they then had two drops of Ibopamine 2% solution instilled into both of their eyes; lastly their IOP is re-measured 45 minutes after receiving the Ibopamine eye drops and the IOP results pre and post the challenge are compared.

Study design

Allocation

Non-randomised trial

Intervention model

Single group

Primary purpose

Diagnosis

Masking

Open (masking not used)

Eligibility

Sex/Gender

All

Age

18 Years to 90 Years

Healthy volunteers

Inclusion criteria

Inclusion criteria for glaucoma suspects will be: an elevated IOP above 21 mmHg or an optic nerve head whose parameters are highly suspicious and resembling glaucoma. Patients will need to have a normal visual field test and therefore not have glaucoma at the time of entry into the study.

Exclusion criteria

Exclusion criteria will include: those with secondary glaucoma, those who have undergone previous intraocular surgery (except cataract surgery), those who were unable to perform a reliable visual field test and those who were unable to give informed consent.

Outcome results