A Clinical Study of Keratoconus in Asian Patients and Assessment of Different Topographic Patterns of Keratoconus in Asian Patients

July 3, 2006 updated by: Singapore National Eye Centre
A clinical study of keratoconus in Asian Patients and assessment of different topographic patterns of keratoconus in Asian patients

Study Overview

Status

Completed

Conditions

Detailed Description

This hospital-based observational prospective study was designed to describe the characteristics of patients with keratoconus in an Asian population, Patients with keratoconus and keratoconus suspects presenting to the Singapore National Eye Centre who met the eligibility criteria are were recruited for this study. The following data were assessed:

  1. Demographic characteristics of patients with keratoconus
  2. Quality of life assessment in patients with keratoconus
  3. Visual Outcome and management of keratoconus in terms of contact lens fitting
  4. Corneal topographic patterns of patients with keratoconus
  5. Aberrometry studies with regards to diagnosis of keratoconus and quality of vision in patients with keratoconus.

The patients not wearing contact lenses completed the study within one visit whereas the patients wearing contact lenses required 2 visits (one with contact lens wear and one without contact lens wear) to complete the study. For patients wearing contact lenses, they were advised to stop soft or rigid contact lens wear for 3 days before the initial visual acuity, subjective refraction, keratometry, Tomey and Orbscan II topography examinations and Wavefront aberrometry tests were performed.

Informed consent was obtained from all subjects after the nature of the study had been fully explained. The study gained approval from the Ethics Committee of the Singapore Eye Research Institute .

Each study participant was asked to answer the demography questionnaire form regarding their daily habit, medical history, economic and educational level and vision-related quality of life, and the Visual Function Index (VF-14).

Visual acuity was assessed in each eye using a logMAR chart. The visual acuity with manifest refraction was deemed the best corrected visual acuity(BCVA) for those patients who did not wear contact lenses, and the visual acuity with over-refraction (refraction over their contact lenses) for contact lens wearers.

Contrast sensitivity was examined only in patients with their habitual contact lenses in each eye using the Vision Contrast Test System (VCTS) chart (VCTS 6500 contrast sensitivity Chart) in 6 spatial frequencies.

Slit lamp evaluation and contact lens fit assessment were performed. Type of contact lens wear was recorded.

Corneal topography was performed using Tomey keratoconus screening system (Topographic Modeling System, software version 2.4.2J) without pupil dilation and without contact lens wear and the Orbscan II corneal topography system (Bausch &Lomb Surgical).

Ocular wavefront aberrations were measured across the central 6-mm dilated pupil (1% Tropicamide) of each eye with the Bausch and Lomb Technolas Zywave aberrometer with Zywave software version 4.45 (ZYOPTIX Diagnostic Workstation, Bausch & Lomb).

Study Type

Observational

Enrollment

120

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Singapore
      • Singapore, Singapore, 168751
        • Singapore National Eye Centre

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

1 second and older (Child, Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients with keratoconus and keratoconus suspect presenting to the Singapore National Eye Centre who are willing to participate in the study

Exclusion Criteria:

  • Patients with previous ocular surgery or trauma. Patients unwilling to participate in the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Singapore National Eye Centre

Investigators

  • Principal Investigator: Li - Lim, FRCS(Ed), Singapore National Eye Centre

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2003

Study Completion

March 1, 2005

Study Registration Dates

First Submitted

June 30, 2006

First Submitted That Met QC Criteria

June 30, 2006

First Posted (Estimate)

July 4, 2006

Study Record Updates

Last Update Posted (Estimate)

July 7, 2006

Last Update Submitted That Met QC Criteria

July 3, 2006

Last Verified

September 1, 2003

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • R317/10/03

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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