Phacoemulsification Versus Phacoemulsification With Micro-bypass Stent

Primary Angle-Closure Glaucoma Clinical Trial

Official title:

Phacoemulsification Versus Phacoemulsification With Micro-bypass Stent Implantation in Primary Angle Closure and Primary Angle Closure Glaucoma: Randomized Double-masked Clinical Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03647033
• Other study ID #: 2015/00644
• Status: Completed
• Phase: N/A
• Start date: October 14, 2015
• Est. completion date: August 12, 2017

Study information

• Verified date: September 2018
• Source: Khoo Teck Puat Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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 information / eligibility

• Status: Completed
• Enrollment: 32
• Est. completion date: August 12, 2017
• Est. primary completion date: August 12, 2016
• Accepts healthy volunteers: No
• Gender: All
• Age group: 21 Years to 80 Years

Eligibility

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

Related Conditions & MeSH terms

• Glaucoma
• Glaucoma, Angle-Closure
• Primary Angle Closure Without Glaucoma Damage
• Primary Angle-Closure Glaucoma

Intervention

Device:
• iStent implantation
The iStent is a FDA and Health Sciences Authority (HSA) approved micro-bypass stent device that bypasses the trabecular meshwork (filtration membrane of the aqueous fluid exit pathway) and reroutes aqueous from the anterior chamber directly into canal of Schlemm and out of the eye. It lowers the intraocular pressure (IOP) by increasing the outflow of fluid from the eye from the micro-bypass. In angle closure, the lens has to be removed to create enough space for the iStent to be inserted.

Locations

Country	Name	City	State
Singapore	Khoo Teck Puat Hospital	Singapore

Sponsors (1)

Lead Sponsor	Collaborator
Khoo Teck Puat Hospital

Country where clinical trial is conducted

Singapore, 

References & Publications (4)

Craven ER, Katz LJ, Wells JM, Giamporcaro JE; iStent Study Group. Cataract surgery with trabecular micro-bypass stent implantation in patients with mild-to-moderate open-angle glaucoma and cataract: two-year follow-up. J Cataract Refract Surg. 2012 Aug;38(8):1339-45. doi: 10.1016/j.jcrs.2012.03.025. — View Citation

Fea AM. Phacoemulsification versus phacoemulsification with micro-bypass stent implantation in primary open-angle glaucoma: randomized double-masked clinical trial. J Cataract Refract Surg. 2010 Mar;36(3):407-12. doi: 10.1016/j.jcrs.2009.10.031. — View Citation

Malvankar-Mehta MS, Iordanous Y, Chen YN, Wang WW, Patel SS, Costella J, Hutnik CM. iStent with Phacoemulsification versus Phacoemulsification Alone for Patients with Glaucoma and Cataract: A Meta-Analysis. PLoS One. 2015 Jul 6;10(7):e0131770. doi: 10.1371/journal.pone.0131770. eCollection 2015. — View Citation

Samuelson TW, Katz LJ, Wells JM, Duh YJ, Giamporcaro JE; US iStent Study Group. Randomized evaluation of the trabecular micro-bypass stent with phacoemulsification in patients with glaucoma and cataract. Ophthalmology. 2011 Mar;118(3):459-67. doi: 10.1016/j.ophtha.2010.07.007. Epub 2010 Sep 15. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in Intraocular Pressure Between Baseline and 1 Year	change in mean unmedicated intraocular pressure between baseline and 1 year	1 year
Secondary	Change in Glaucoma Medications	change in number of topical glaucoma medications at 1 year post operation	1 year