None listed
Conditions
Brief summary
The aim of this project is to assess the reflux and retention of a therapeutic substance delivered into the sub-retinal space via two different techniques. We hypothesise that defining the space to be injected using an inert fluid (balanced salt solution) first (so-called 2-step injection) results in less drug wastage than attempting to inject directly under the retina with a drug-containing solution (so-called 1-step injection).
Interventions
The overall objective of this study is to assess the reflux and retention of a therapeutic substance (Actilyse) delivered via two different techniques into the sub-retinal space to determine the optimum approach for sub-retinal injections.
Patients diagnosed with sub-macular haemorrhage and identified as suitable for this study will be approached. Only the affected eye will undergo surgery; therefore subjects will be randomised to one or other arm of the study. We will be recruiting from Sydne
The overall objective of this study is to assess the reflux and retention of a therapeutic substance (Actilyse) delivered via two different techniques into the sub-retinal space to determine the optimum approach for sub-retinal injections. Patients diagnosed with sub-macular haemorrhage and identified as suitable for this study will be approached. Only the affected eye will undergo surgery; therefore subjects will be randomised to one or other arm of the study. We will be recruiting from Sydney Eye Hospital. The surgical procedure will be identical to that undertaken in the routine management of significant sub-macular haemorrhage. The only difference between standard of care in the current study is that sodium fluorescein will be used to track the flow of Actilyse. The surgery takes approximately 30 minutes to complete and the duration is similar in both arms of the study. All study medications will be delivered via a 38g teflon tipped sub-retinal cannula using the viscous fluid control syringe of the Alcon Constellation Vision System. The surgeon will be either the Principal Investigator (Vitreo-retinal Surgeon and Visiting Medical Officer at Sydney Eye Hospital), or one of the Sub-Investigators (Vitreo-retinal Fellow employed by Sydney Eye Hospital). Arm 1: A two-step approach, in which a physiologically inert fluid (0.2mL of balanced salt solution) is used to open the potential sub-retinal space, immediately after which Actilyse (50 micrograms) is delivered. Arm 2: A one-step approach, in which Actilyse (50 micrograms in 0.1mL) itself is used to create a limited iatrogenic retinal detachment, thereby opening up the subretinal space. In order to compare these two methods, sodium fluorescein (0.01mg in 0.1mL) will be mixed with Actilyse to track its distribution. Fluid samples will be taken from the eye at the completion of surgery to compare how much fluid has leaked during the surgical procedure. The samples will be taken from the fluid-air exchange, a standard step in vitrectomy surgery. Instead of discarding the fluid extracted, it will be collected instead. The total volume of fluid will be measured, as well as the concentration of fluorescein in this solution, using a fluorophotometer. Once measurements are taken, the fluid will be destroyed. The procedure will be video-recorded in order to provide a means of subjectively assessing reflux at the time of injection of the Actilyse. Participants will be assessed with respect to safety outcomes for which standardised procedure have been developed. Standard of care post-surgery visits will be conducted as per normal through the Outpatient Department, Sydney Eye Hospital. There will be no additional study-specific visits post-surgery.
Sponsors
The University of Sydney
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
• Participants will be patients with either a new or an established diagnosis of age-related macular degeneration and with a 7 day or less history of vision loss secondary to sub-macular haemorrhage. • Age greater than or equal to 18 years (Participants with sub-macular haemorrhage or retinal arteriolar macroaneurysm are typically over 60 years of age.) • Area of haemorrhage of greater than 1 disc area but not meeting the criteria for massive sub-retinal haemorrhage (haemorrhage extending beyond the temporal vascular arcades). • Density of haemorrhage sufficient to obscure the RPE and choroidal detail. • Haemorrhage involving the fovea. • BCVA equal to, or worse than 6/60 • Written informed consent has been obtained
Exclusion criteria
• Symptoms suggestive of sub-macular haemorrhage for > 7 days. • Amblyopia in the study eye. • Presence of another ocular disease affecting vision in the study eye. • Known allergy to fluorescein • Women who are pregnant, nursing or planning pregnancy or who are of childbearing potential and not using reliable means of contraception. (A woman is considered of childbearing potential unless she is post-menopausal and without menses for 12 months or is surgically sterilised) • Participants unable to adhere to post-operative posturing. • BCVA < HM • Known allergy to agents used in the study e.g. fluorescein sodium • Known history of significant cardio-pulmonary disease • Multiple concomitant drug therapies – in particular, beta-blockers (including eye drops) • Patients who, in the opinion of the treating surgeon and anaesthetist, are unfit for a surgical procedure, with a condition that may put the patient at considerable risk, may confound the study results or may interfere significantly with the patient’s participation in the study.
Outcome results
None listed