Phacoemulsification Versus Phacoemulsification With Micro-bypass Stent

Not Applicable

Completed

Conditions: Primary Angle Closure Without Glaucoma Damage
Primary Angle-Closure Glaucoma

Interventions: Device: iStent implantation

Registration Number: NCT03647033

Lead Sponsor: Khoo Teck Puat Hospital

Brief Summary: Assessing the safety and efficacy of a micro-bypass stent in combination with cataract surgery in subjects with primary angle closure. Subjects are randomized into two arms: phacoemulsification cataract surgery alone versus phacoemulsification cataract surgery combined with the micro-bypass stent implantation. Post surgery intraocular eye pressure will be recorded to assess the efficacy of both arms.

Detailed Description: Aim: To assess the safety and efficacy of the iStent trabecular micro-bypass stent (Glaukos Corporation, Laguna Hills, CA) in combination with cataract surgery in subjects with primary angle closure and mild to moderate primary angle closure glaucoma

Method: Prospective, randomised controlled trial, blinded to patient and intra-ocular pressure measuring staff. 32 patients, 1:1 ratio, in 2 arms of phacoemulsification alone compared to phacoemulsification with iStent.

Hypothesis: Phacoemulsification with micro-bypass stent has a better intraocular pressure (IOP) lowering effect compared to phacoemulsification alone in primary angle closure and primary angle closure glaucoma at 1 year after surgery.

Importance: Primary angle closure and primary angle closure glaucoma are conventionally treated with eye drops that lower the intraocular pressure (IOP). Phacoemulsification/lens extraction can often help lower the eye pressure by widening the drainage angle and via ultrasound mechanisms, however, in some cases the IOP is not lowered, or even can cause the IOP to be higher. The iStent implant can be used together with phacoemulsification to lower the IOP and in Primary open angle glaucoma, it gives an additional 20% IOP reduction. It is unclear what effect the iStent has in primary angle closure or primary angle closure glaucoma as it has never been studied. It is important because primary angle closure glaucoma is much more common in the Singaporean Chinese population and the iStent can potentially be used to control the IOP instead of conventional eye drops and glaucoma surgery which have their own potential adverse effects.

Potential Benefits: iStent with phacoemulsification may control the IOP better than phacoemulsification alone, reduce the need for IOP lowering medication after surgery, and prevent the need for glaucoma surgery in the future.

Potential Risks: The iStent has risks of IOP spikes, bleeding in the anterior chamber and iStent dislocation.Phacoemulsification has the risks of: infection, bleeding, reduced vision, inflammation, posterior capsular rupture, vitreous loss, retinal detachment, endophthalmitis, suprachoroidal haemorrhage and Intraocular Lens dislocation.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 32

Inclusion Criteria

able to provide informed consent
Previous diagnosis of Primary Angle Closure or Primary Angle Closure Glaucoma
Intraocular Pressure above 21mmHg at 3 separate visits
On 1 or more hypotensive medications
Pre-operative visual acuity of no better than 6/12

Exclusion Criteria

Other glaucoma diagnosis: Primary Open Angle Glaucoma, secondary glaucoma
Peripheral Anterior Synechiae in the nasal and inferior quadrant
Cloudy cornea affecting view for iStent implantation
Previous glaucoma surgery
History of Ocular trauma
Ocular surface disease
Pre-proliferative or proliferative diabetic retinopathy
Age related macular degeneration with macular scar or macular atrophy

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
phacoemulsification and iStent	iStent implantation	phacoemulsification cataract surgery with intraocular lens implantation combined with iStent implantation

Primary Outcome Measures