Prevalence of Corneal Astigmatism Before Glaucoma Surgery in Chinese Patients With Primary Angle-closure Glaucoma

Clear-lens extraction has been considered as first-line therapy for primary angle closure glaucoma(PACG) and application of toric intraocular lens (IOLs) leads to better postoperative visual acuity, yet little is known about the prevalence of corneal astigmatism in PACG patients. We intend to make biometry examination for Chinese PACG patients, to obtain keratometry (K) , axial length (AL) and so on, and demographics data will also be recorded. We will study the prevalence of corneal astigmatism before glaucoma surgery in Chinese patients with PACG. Furthermore, differences of corneal astigmatism between primary angle-closure glaucoma and cataract patients will be explored. Finally, the prevalence of corneal astigmatism before glaucoma surgery in Chinese patients with PACG will be portrayed and can be instructive to the IOLs' manufactering.

Study Overview

• Status: Completed
• Conditions: Glaucoma, Angle-Closure; Astigmatism

Detailed Description

Biometry examination contains keratometry (K) , axial length (AL), central anterior chamber depth, visual field loss(mean deviation, MD), choroidal thickness(CT), range of goniosynechia, and stage of PACG.

Demographics data contains age, gender, and eye.

• Study Type: Observational
• Enrollment (Actual): 808

Contacts and Locations

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China, 510060
      • Zhongshan Ophthalmic Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 100 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Primary angle closure was defi ned as iridotrabecular contact, either appositional or synechial, of at least 180° on gonioscopy, and primary angle-closure glaucoma as reproducible glaucomatous visual fi eld defects, glaucomatous optic neuropathy, or both, and intraocular pressure greater than 21 mm Hg on at least one occasion.

Description

Inclusion Criteria:

• Patients who are phakic and aged 40 years or older , and had newly diagnosed primary angle closure with intraocular pressure 30 mm Hg or greater or primary angle-closure glaucoma, will be recruited during preoperative screening at Zhongshan Ophthalmic Center.

Exclusion Criteria:

• Patients with corneal disease, irregular astigmatism, previous corneal or intraocular surgery, or a history of ocular inflammation will be excluded.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Prevalence of corneal astigmatism	Data of corneal astigmatism will be acquired through examination,and different types of corneal astigmatism will be diagnosed and seperated.Moreover,we will analyse the prevalence of corneal astigmatism,and compare among different age groups and different genders.Correlation between demographic features and data will be analysed,too.	During preoperative screening (1 day)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Prevalence of keratometry	Flat,steep and mean keratometry will be examined before glaucoma surgery. Moreover,we will analyse the prevalence of corneal astigmatism,and compare among different age groups and different genders.	During preoperative screening (1 day)
Prevalence of axial length	Axial length will be measured by both IOL Master and A-scan, and data will be compared between different measurements,different genders and different age groups.	During preoperative screening (1 day)

Collaborators and Investigators

• Sponsor: Mingkai Lin
• Investigators: Principal Investigator: Mingkai Lin, MD, Zhongshan Ophthalmic Center, Sun Yat-sen University

Publications and helpful links

General Publications

• Azuara-Blanco A, Burr J, Ramsay C, Cooper D, Foster PJ, Friedman DS, Scotland G, Javanbakht M, Cochrane C, Norrie J; EAGLE study group. Effectiveness of early lens extraction for the treatment of primary angle-closure glaucoma (EAGLE): a randomised controlled trial. Lancet. 2016 Oct 1;388(10052):1389-1397. doi: 10.1016/S0140-6736(16)30956-4.
• Gao X, Huang W, Wang W, Zhou M, Wang J, Du S, Chen S, Zhang X. Topographic profile of choroid in eyes after acute primary angle-closure. Can J Ophthalmol. 2016 Oct;51(5):354-361. doi: 10.1016/j.jcjo.2016.02.025. Epub 2016 Sep 3.
• Chen W, Zuo C, Chen C, Su J, Luo L, Congdon N, Liu Y. Prevalence of corneal astigmatism before cataract surgery in Chinese patients. J Cataract Refract Surg. 2013 Feb;39(2):188-92. doi: 10.1016/j.jcrs.2012.08.060. Epub 2012 Nov 7.
• Zuo C, Gong R, Chen W, Chen C, Su J, Wei K, Gao X, Lin M, Ge J. Investigation of Corneal Astigmatism in Chinese Patients With Primary Angle Closure Disease. J Glaucoma. 2018 Dec;27(12):1131-1135. doi: 10.1097/IJG.0000000000001061.

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2017
• Primary Completion (Actual): August 31, 2017
• Study Completion (Actual): August 31, 2017

Study Registration Dates

• First Submitted: May 17, 2017
• First Submitted That Met QC Criteria: May 18, 2017
• First Posted (Actual): May 19, 2017

Study Record Updates

• Last Update Posted (Actual): October 31, 2017
• Last Update Submitted That Met QC Criteria: October 30, 2017
• Last Verified: October 1, 2017

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Ocular Hypertension; Refractive Errors; Glaucoma; Astigmatism; Glaucoma, Angle-Closure
• Other Study ID Numbers: ZhongshanOC20170503

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No