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Predicting the Effect of Laser Peripheral Iridotomy

Prediction of the Degree of Angle Opening Distance in Patients With Primary Angle Closure Suspect After Laser Peripheral Iridotomy

Status
UNKNOWN
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT04495491
Enrollment
200
Registered
2020-07-31
Start date
2020-07-01
Completion date
2021-03-31
Last updated
2020-07-31

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Glaucoma

Keywords

laser peripheral iridotomy, primary angle closure suspect, angle closure mechanism

Brief summary

This study will compare the angle parameters of patients with PACS before and after LPI. The investigators will analyze the results of patients with different angle closure mechanisms before and after LPI, and participants hope to find the structural parameters for predicting the effect of LPI.

Detailed description

Primary angle-closure glaucoma is the leading cause of blindness worldwide. It is associated with increased intraocular pressure, which causes optic nerve damage and field defects if untreated. The aqueous humor leaves the anterior chamber through the trabecular meshwork and flows into the aqueous vein and the superior scleral vein through the collector channels and Schlemm's canal. If the trabecular meshwork is not blocked, a wide angle allows enough aqueous humor to drain out. The iris corneal translocation may lead to angle-closure glaucoma. Laser peripheral iridectomy is recognized as the best surgical method to relieve pupil block. Previous studies have shown increased anterior chamber depth (ACD), area (ACA), and volume (ACV), and increased Angle open distance (AOD) after LPI surgery. However, postoperative outcomes of LPI were not the same for patients with different angle closure mechanisms. Postoperative outcomes for LPI were best for patients with pupillary block type, but were moderate for patients with plateau iris group and mixed group. The purpose of this study, conducted in Chinese subjects, aims to use UBM to evaluate changes in the anterior segment parameters of LPI, and to propose methods to predict postoperative outcomes of LPI.

Interventions

OTHERpupillary block group

According to the configurations of angle closure, the pupillary block group is defined as the iris bombe.

OTHERplateau iris group

According to the configurations of angle closure, the plateau iris group is defined as the thickness of the peripheral iris.

OTHERmixing mechanism group

According to the configurations of angle closure, the mixing mechanism group is defined as the iris bombe plus thickening of the peripheral iris.

Sponsors

Zhongshan Ophthalmic Center, Sun Yat-sen University
Lead SponsorOTHER

Study design

Observational model
OTHER
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
20 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Patient was diagnosed of primary angle closure angle suspect; 2. received ultrasound Biomicroscopy before and after laser peripheral iridotomy; 3. Voluntary participation in this study; 4. Have enough language comprehension ability; 5. Patient or his legal representative has sign the informed consent.

Exclusion criteria

1. severe health problems resulting in a life expectancy of less than 1 year; 2. previous intraocular surgery or penetrating eye injury; 3. media opacity preventing laser peripheral iridotomy; 4. Researchers think not suitable to participate in this clinical trial subjects; 5. Refused to sign the informed consent.; 6. There are important viscera function failure or other serious disease, including clinical related coronary artery disease, cardiovascular disease or myocardial infarction into the group of the first six months; serious neurological or psychiatric illness; serious infections; coagulant function abnormality; general active infectious diseases; malignant tumor; serious immune diseases.

Design outcomes

Primary

MeasureTime frameDescription
the changes in anterior opening distance before and after LPIbetween the baseline and 1 hour before dischargeTo compare the difference of anterior opening distance after LPI and baseline parameters before LPI. Anterior opening distance, measured on a line perpendicular to the plane of the trabecular surface 500 μm anterior to the scleral spur and extended to meet the surface of the iris

Countries

China

Contacts

Primary ContactYuying Zhou, Master
2053552500@qq.com8615270988097

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026