Clinical Study of LPI on Different Sites of Iris

Fujian Medical University (FJMU)

Status: Unknown

Conditions: Glaucoma

Treatments: Procedure: Corneoscleral limbus group; Procedure: one spot group; Procedure: two spots group

Study type: Interventional

Funder types: Other

Identifiers

NCT02870504

[2016]102-1

Details and patient eligibility

About

Glaucoma is the second cause of blindness worldwide. Laser peripheral iridoplasty (LPI) is a simple and effective treatment for angle closure glaucoma. LPI can widen or reopen an existing angle close or angle adhesion in order to reduce the risk of attack of the angle closure glaucoma. However, there are very little research on the laser site, laser wavelengths, laser energy and laser spot intervals. The purpose of this study is to determine the optimum laser site of LPI.

Full description

Glaucoma is the second cause of blindness worldwide. Laser peripheral iridoplasty (LPI) is a simple and effective treatment for angle closure glaucoma. LPI can widen or reopen an existing angle close or angle adhesion in order to reduce the risk of attack of the angle closure glaucoma. However, there are very little research on the laser site, laser wavelengths, laser energy and laser spot intervals.

The purpose of this study is to determine the optimum laser site of LPI. Before and 7days, 1 month, 3 months after LPI, the structure of anterior chamber, including angle anterior chamber depth(ACD), angle of anterior chamber (AA), anterior chamber angle opening distance 750(AOD750) are measured with ultrasound biomicroscopy. Before and 7days, 1 month, 3 months after LPI, the outflow resistance of aqueous humor are evaluated with C value. Before and 1hour, 1days, 3day, 7days, 1 month, 3 months after LPI, intraocular pressure are measured with Goldmann tonometry. Before and 3 months after LPI, retinal nerve layer thickness and the optic disc cup disc ratio are measure with optical coherence tomography.

Enrollment: 60 estimated patients

Sex: All

Ages: 30 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients with primary angle closure suspect (PACS), primary angle closure (PAC) or primary angle closure glaucoma (PACG).
• PACS is diagnosed in eyes with an occludable angle but no other abnormality.
• PAC is diagnosed in eyes with an occludable angle, normal optic discs and visual fields and any of the following: raised IOP (>19 mm Hg), PAS, pigment smearing in the superior angle, or sequelae of acute angle closure (iris whirling or glaucomatous fleck).
• PACG is diagnosed in eyes with an occludable angle and glaucomatous optic neuropathy. Evidence of glaucomatous optic neuropathy is defined as a cup: disc ratio (CDR) of >0.7 or >0.2 CDR asymmetry.
• An occludable angle is defined as one in which three quarters of the posterior pigmented trabecular meshwork is not visible on viewing with a Goldmann two mirror lens in the primary position of gaze without indentation.

Exclusion criteria

• Patients with previous ocular surgery, and those with secondary angle closure, such as lens intumescence or subluxation, iris neovascularisation and a history of uveitis.
• Patients who have systemic contraindications to medical therapy (including renal impairment, sulfur allergy, asthma and heart failure), pre-existing corneal opacities obstructing laser access to more than one quadrant of the peripheral iris and single-eyed patients are also excluded.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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60 participants in 3 patient groups

corneoscleral limbus group

Experimental group

Description:

Laser spot locates on the corneoscleral limbus.

Treatment:

Procedure: Corneoscleral limbus group

One spot group

Experimental group

Description:

Laser spot locates on one spot away from the corneoscleral limbus

Treatment:

Procedure: one spot group

Two spots group

Experimental group

Description:

Laser spot locates on two spots away from the corneoscleral limbus

Treatment:

Procedure: two spots group