Laser Peripheral Iridotomy Plus Laser Peripheral Iridoplasty for Primary Angle Closure

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

UNKNOWN

Clinical Phase

NA

Total Enrollment

240 participants

Study Classification

INTERVENTIONAL

Study Start Date

2015-10-31

Study Completion Date

2022-04-30

Brief Summary

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This is a 10-centre randomized controlled clinical trial to explore whether laser peripheral iridoplasty (LPIP) plus laser peripheral iridotomy (LPI) is more effective than single LPI to control the progression of primary angle closure with multi-mechanism based on the UBM classification.

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Detailed Description

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Conditions

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Glaucoma, Angle-Closure

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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single LPI

LPI was performed with a VISULAS diode laser of 532 nm (Carl Zeiss Meditec, Dublin, CA). 30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia will be administered. The treatment site was selected in the superior nasal iris or in a crypt, where present. Treatment was initiated with a pulse of 3-5mJ, the power was increased until patency was achieved, the opening of iris \>0.1mm. and patency was determined by direct visualization of the posterior chamber.

Group Type ACTIVE_COMPARATOR

neodymium:yttrium-aluminum- garnet laser

Intervention Type DEVICE

a neodymium:yttrium-aluminum- garnet laser was used to perform the LPI

Pilocarpine

Intervention Type DRUG

30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia (Proparacaine) will be administered

Proparacaine

Intervention Type DRUG

30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia (Proparacaine) will be administered

LPI

Intervention Type PROCEDURE

LPI was performed with a VISULAS diode laser of 532 nm (Carl Zeiss Meditec, Dublin, CA). 30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia (Proparacaine) will be administered. The treatment site was selected in the superior nasal iris or in a crypt, where present. Treatment was initiated with a pulse of 3-5mJ, the power was increased until patency was achieved, the opening of iris \>0.1mm. and patency was determined by direct visualization of the posterior chamber.

LPIP plus LPI

LPIP was applied with a VISULAS diode laser of 532 nm (Carl Zeiss Meditec, Dublin, CA). 30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia will be administered. Twenty to 30 spots of 250-300 mW power with 300-500 microns of size and duration of 400-500 ms were applied. Power was modified arbitrarily until an effective iris contraction was obtained. Effective iris contraction was considered as a concentric movement around the laser spot, with minimal iris pigmentation and immediate angle opening observed through the lens mirrors using a Goldmann lens. Power was lowered if there was any bursting sound perceived, pigment dispersion, air bubbles or considerable pain. LPI was performed after LPIP procedure

Group Type EXPERIMENTAL

neodymium:yttrium-aluminum- garnet laser

Intervention Type DEVICE

a neodymium:yttrium-aluminum- garnet laser was used to perform the LPI

frequency-doubled Q-switched neodymium:yttrium-aluminum-garnet 532-nm laser

Intervention Type DEVICE

a frequency-doubled Q-switched neodymium:yttrium-aluminum-garnet 532-nm laser was used to perform the LPIP

Pilocarpine

Intervention Type DRUG

30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia (Proparacaine) will be administered

LPIP plus LPI

Intervention Type PROCEDURE

LPIP was applied with a VISULAS diode laser of 532 nm (Carl Zeiss Meditec, Dublin, CA). 30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia will be administered. Twenty to 30 spots of 250-300 mW power with 300-500 microns of size and duration of 400-500 ms were applied. Power was modified arbitrarily until an effective iris contraction was obtained. Effective iris contraction was considered as a concentric movement around the laser spot, with minimal iris pigmentation and immediate angle opening observed through the lens mirrors using a Goldmann lens. Power was lowered if there was any bursting sound perceived, pigment dispersion, air bubbles or considerable pain. LPI was performed after LPIP procedure.

Proparacaine

Intervention Type DRUG

30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia (Proparacaine) will be administered

Interventions

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neodymium:yttrium-aluminum- garnet laser

a neodymium:yttrium-aluminum- garnet laser was used to perform the LPI

Intervention Type DEVICE

frequency-doubled Q-switched neodymium:yttrium-aluminum-garnet 532-nm laser

a frequency-doubled Q-switched neodymium:yttrium-aluminum-garnet 532-nm laser was used to perform the LPIP

Intervention Type DEVICE

Pilocarpine

30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia (Proparacaine) will be administered

Intervention Type DRUG

LPIP plus LPI

LPIP was applied with a VISULAS diode laser of 532 nm (Carl Zeiss Meditec, Dublin, CA). 30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia will be administered. Twenty to 30 spots of 250-300 mW power with 300-500 microns of size and duration of 400-500 ms were applied. Power was modified arbitrarily until an effective iris contraction was obtained. Effective iris contraction was considered as a concentric movement around the laser spot, with minimal iris pigmentation and immediate angle opening observed through the lens mirrors using a Goldmann lens. Power was lowered if there was any bursting sound perceived, pigment dispersion, air bubbles or considerable pain. LPI was performed after LPIP procedure.

Intervention Type PROCEDURE

Proparacaine

30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia (Proparacaine) will be administered

Intervention Type DRUG

LPI

LPI was performed with a VISULAS diode laser of 532 nm (Carl Zeiss Meditec, Dublin, CA). 30 minutes prior to the procedure, a drop of 2% pilocarpine will be instilled into the eye every 15 minutes, Topical anaesthesia (Proparacaine) will be administered. The treatment site was selected in the superior nasal iris or in a crypt, where present. Treatment was initiated with a pulse of 3-5mJ, the power was increased until patency was achieved, the opening of iris \>0.1mm. and patency was determined by direct visualization of the posterior chamber.

Intervention Type PROCEDURE

Eligibility Criteria

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Inclusion Criteria

1. Clinical diagnosis of primary angle closure (PAC), with IOP≤30mmHg and PAS≤270°.
2. PAC with multi-mechanism based on UBM examination (multi-mechanism is defined as primary angle closure is caused by pupil block plus at least one kind of non-pupil block factors like (relative anterior position and thick of the ciliary body, the big volume of the iris, the anterior location of the iris insertion into the ciliary body)or any two or more kinds of combination.
3. Visual acuity≥ 20/40
4. Age between 40-75 years old Chinese people

If both eyes of a patient are eligible for the study, the e eye had worse visual acuity will be selected. Only one eye per patient is eligible for the study.

Drug washout:

Eligible patients who are already on anti-glaucoma medications are required to have drug washout before being randomized. Various medications have different washout periods: Prostaglandin analogues 4 weeks, Beta blockers 3 weeks, Adrenergic agonist 2 weeks, Cholinergic agonist 5 days, Carbonic Anhydrase Inhibitors 5 days. Patients whose IOP\>30 mm Hg during this washout period will be stopped from further washout and be withdrawn from the study.

Exclusion Criteria

1. Unwilling or unable to give consent, unwilling to accept randomization, or unable to return for scheduled protocol visits.
2. Angle closure due to secondary causes (subluxed lens, neovascular, uveitic, traumatic, post-operative)
3. Previous incisional intraocular surgery or ocular laser in study eye (LPI or LPIP, cyclodestructive procedure, cataract surgery)
4. Primary angle closure with glaucomatous neuropathy.
5. Have cataract in the studying eye and anticipated to have cataract surgery in the coming 3 years; the existing cataract affect visual field examination and fundus examination; the visual acuity \<20/40 due to the existing cataract.
6. Who are using IOP lowing drugs and do not have drug washout
7. Need for glaucoma surgery combined with other ocular procedures (i.e. cataract surgery, penetrating keratoplasty, or retinal surgery) or anticipated need for urgent additional ocular surgery
8. Coexisting other ocular diseases (i.e. cornea abnormal or cornea infection, Iridocorneal endothelial syndrome or anterior segment dysgenesis, nanophthalmos, high myopia (\>6.0D), Chronic or recurrent uveitis, ocular cancer, trauma, central retinal vein occlusion, central retinal artery occlusion, retinal detachment)
9. cornea endothelium counting \<1000/mm2
10. need local or systemic steroid long-term use
11. Unwilling to discontinue contact lens use after surgery
12. Who are taking parting in other drug clinical trials
13. Pregnant or nursing women
14. Severe systemic disease (i.e. diabetes mellitus, hypertension, the end stage of cardiac disease, nephropathy disease, respiratory disease and cancer.
15. Allergic to pilocarpine or alcaine
16. Contraindication to ocular laser diseases.

Minimum Eligible Age

40 Years

Maximum Eligible Age

75 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No