Laser Peripheral Iridotomy Plus Laser Peripheral Iridoplasty for Primary Angle Closure

Sponsor
Sun Yat-sen University (Other)
Overall Status
Unknown status
CT.gov ID
NCT02613013
Collaborator
Beijing Tongren Hospital (Other), Wenzhou Medical University (Other), The Second Affiliated Hospital of Harbin Medical University (Other), Huazhong University of Science and Technology (Other), The Third Hospital of HanDan (Other), Third Affiliated Hospital of Third Military Medical University (Other), Central South University (Other), He University (Other), Hebei Provincial Eye Hospital (Other)
240
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2
78
3.1

Study Details

Study Description

Brief Summary

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.

Condition or Disease Intervention/Treatment Phase
  • Device: neodymium:yttrium-aluminum- garnet laser
  • Device: frequency-doubled Q-switched neodymium:yttrium-aluminum-garnet 532-nm laser
  • Drug: Pilocarpine
  • Procedure: LPIP plus LPI
  • Drug: Proparacaine
  • Procedure: LPI
N/A

Study Design

Study Type:
Interventional
Anticipated Enrollment :
240 participants
Allocation:
Randomized
Intervention Model:
Parallel Assignment
Masking:
None (Open Label)
Primary Purpose:
Treatment
Official Title:
Laser Peripheral Iridotomy Plus Laser Peripheral Iridoplasty for Primary Angle Closure With Multi-mechanism Based on UBM: A Randomized Controlled Trial
Study Start Date :
Oct 1, 2015
Anticipated Primary Completion Date :
Mar 1, 2020
Anticipated Study Completion Date :
Apr 1, 2022

Arms and Interventions

Arm Intervention/Treatment
Active Comparator: 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.

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

Drug: 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

Drug: 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

Procedure: 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.

Experimental: 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

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

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

Drug: 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

Procedure: 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.

Drug: 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

Outcome Measures

Primary Outcome Measures

  1. Progression rate determined by number of patients who progress after laser treatment for each group. [3 years]

    PAC progression defined as presence of any of the following: Acute angle closure crisis Intraocular (IOP) was 8mmHg higher than initiation 1 month after the laser procedure IOP was ≥22mmHg when measured three times of continuous 1 month after the lase procedure The progression of peripheral anterior synechiae ≥ 1 clock hour within 3 years after the laser procedure as measured by gonioscopic examination. glaucomatous neuropathy within 3 years after the laser procedure

Secondary Outcome Measures

  1. Additional medication or surgery required questionnaire [3 years]

    the medication required to control the IOP the additional surgery required to control the progression of the PAC

  2. The change of the best corrected visual acuity after the laser procedure [3 years]

  3. The number of the cornea endothelial cells [3 years]

  4. The change in angle width and configuration as measured by ultrasound biomicroscopy (UBM) [3 years]

Eligibility Criteria

Criteria

Ages Eligible for Study:
40 Years to 75 Years
Sexes Eligible for Study:
All
Accepts Healthy Volunteers:
No
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.

Contacts and Locations

Locations

Site City State Country Postal Code
1 Zhongshan Ophthalmic Center Guangzhou Guangdong China 510060

Sponsors and Collaborators

  • Sun Yat-sen University
  • Beijing Tongren Hospital
  • Wenzhou Medical University
  • The Second Affiliated Hospital of Harbin Medical University
  • Huazhong University of Science and Technology
  • The Third Hospital of HanDan
  • Third Affiliated Hospital of Third Military Medical University
  • Central South University
  • He University
  • Hebei Provincial Eye Hospital

Investigators

None specified.

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.
Responsible Party:
xiulan zhang, MD,PhD, Sun Yat-sen University
ClinicalTrials.gov Identifier:
NCT02613013
Other Study ID Numbers:
  • 2015019
First Posted:
Nov 24, 2015
Last Update Posted:
Sep 6, 2018
Last Verified:
Sep 1, 2018
Additional relevant MeSH terms:

Study Results

No Results Posted as of Sep 6, 2018