Clinical trial NCT02901730: Clinical Study of LPI With Different Laser Wavelengths
Official title: Clinical Study of Laser Peripheral Iridoplasty With Different Laser Wavelengths
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Glaucoma
Keywords: laser peripheral iridoplasty
treatment
Lead sponsor: First Affiliated Hospital of Fujian Medical University
Sponsor class: OTHER
First posted: 2016-09-15
Enrollment: 30
Sex: ALL
Minimum age (years): 30
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: 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 wavelengths of LPI.

Detailed 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.Conventional LPI uses wavelength 532nm laser. However, our preclinical studies have found that the laser penetration of the laser wavelength 561nm is stronger than that of the laser wavelength 532nm. It can produce a stronger contraction effect.

The purpose of this study is to determine the optimum laser wavelengths of LPI. Baseline 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. Baseline and 7days, 1 month, 3 months after LPI, the outflow resistance of aqueous humor are evaluated with C value. Baseline and 1hour, 1days, 3day, 7days, 1 month, 3 months after LPI, intraocular pressure are measured with Goldmann tonometry. Baseline and 3 months after LPI, retinal nerve layer thickness and the optic disc cup disc ratio are measure with optical coherence tomography.

Eligibility criteria: 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.

Primary outcomes:
measure: Change of anterior chamber angle(AA)
timeFrame: Baseline and 3 months after LPI.
Secondary outcomes:
measure: Change of anterior chamber angle opening distance 750(AOD750)
timeFrame: Baseline and 3 months after LPI.
measure: Change of anterior chamber depth(ACD)
timeFrame: Baseline and 3 months after LPI.
measure: Change of intraocular pressure (IOP)
timeFrame: Baseline and 1hour, 1days, 3day, 7days, 1 month, 3 months after LPI.
measure: Change of C value
timeFrame: Baseline and 7days, 1 month, 3 months after LPI.
measure: Change of retinal nerve layer thickness
timeFrame: Baseline and 3 months after LPI.
measure: Change of optic disc cup disc ratio
timeFrame: Baseline and 3 months after LPI.
measure: Change of mean defect
timeFrame: Baseline and 3 months after LPI.
measure: Change of mean sensitivity
timeFrame: Baseline and 3 months after LPI.
measure: Change of scotoma
timeFrame: Baseline and 3 months after LPI.
Other outcomes:
Locations:
Study officials:
affiliation: Department of ophthalmology, First Affilited Hospital of Fujian Medical University
name: Maosong Xie, doctor
role: STUDY_CHAIR
References:
citation: Lai J, Choy BN, Shum JW. Management of Primary Angle-Closure Glaucoma. Asia Pac J Ophthalmol (Phila). 2016 Jan-Feb;5(1):59-62. doi: 10.1097/APO.0000000000000180.
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citation: Marchini G, Chemello F, Berzaghi D, Zampieri A. New findings in the diagnosis and treatment of primary angle-closure glaucoma. Prog Brain Res. 2015;221:191-212. doi: 10.1016/bs.pbr.2015.05.001. Epub 2015 Jun 30.
citation: Sng CC, Aquino MC, Liao J, Zheng C, Ang M, Chew PT. Anterior segment morphology after acute primary angle closure treatment: a randomised study comparing iridoplasty and medical therapy. Br J Ophthalmol. 2016 Apr;100(4):542-8. doi: 10.1136/bjophthalmol-2015-307087. Epub 2015 Aug 20.
citation: Wright C, Tawfik MA, Waisbourd M, Katz LJ. Primary angle-closure glaucoma: an update. Acta Ophthalmol. 2016 May;94(3):217-25. doi: 10.1111/aos.12784. Epub 2015 Jun 27.
citation: Fu J, Qing GP, Wang NL, Wang HZ. Efficacy of laser peripheral iridoplasty and iridotomy on medically refractory patients with acute primary angle closure: a three year outcome. Chin Med J (Engl). 2013 Jan;126(1):41-5.
citation: Lee JR, Choi JY, Kim YD, Choi J. Laser peripheral iridotomy with iridoplasty in primary angle closure suspect: anterior chamber analysis by pentacam. Korean J Ophthalmol. 2011 Aug;25(4):252-6. doi: 10.3341/kjo.2011.25.4.252. Epub 2011 Jul 22.
citation: Mochizuki H, Takenaka J, Sugimoto Y, Takamatsu M, Kiuchi Y. Comparison of the prevalence of plateau iris configurations between angle-closure glaucoma and open-angle glaucoma using ultrasound biomicroscopy. J Glaucoma. 2011 Jun-Jul;20(5):315-8. doi: 10.1097/IJG.0b013e3181e3d2da.