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

Overview

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 Type

  • Study Type: Observational
  • Study Design
    • Time Perspective: Cross-Sectional
  • Study Primary Completion Date: August 31, 2017

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.

Clinical Trial Outcome Measures

Primary Measures

  • Prevalence of corneal astigmatism
    • Time Frame: During preoperative screening (1 day)
    • 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.

Secondary Measures

  • Prevalence of keratometry
    • Time Frame: During preoperative screening (1 day)
    • 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.
  • Prevalence of axial length
    • Time Frame: During preoperative screening (1 day)
    • 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.

Participating in This Clinical Trial

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.

Gender Eligibility: All

Minimum Age: 40 Years

Maximum Age: 100 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Mingkai Lin
  • Provider of Information About this Clinical Study
    • Sponsor-Investigator: Mingkai Lin, Head of Glaucoma Center – Zhongshan Ophthalmic Center, Sun Yat-sen University
  • Overall Official(s)
    • Mingkai Lin, MD, Principal Investigator, Zhongshan Ophthalmic Center, Sun Yat-sen University

Citations Reporting on Results

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.

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