KeratoconusNCT00347074
A Clinical Study of Keratoconus in Asian Patients and Assessment of Different Topographic Patterns of Keratoconus in Asian Patients
An observational study of Keratoconus, run by Singapore National Eye Centre at 1 site in Singapore.
Trial summary
A clinical study of keratoconus in Asian Patients and assessment of different topographic patterns of keratoconus in Asian patients Read more about this study
- Who is it for?
- Ages 0 years and olderHealthy volunteers can take part
- Conditions the study is for
- Keratoconus
- How many people
- 120 participants
- Where
- 1 siteSingapore
- Study dates
- Sep 2003to Mar 2005
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 0 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- Patients with keratoconus and keratoconus suspect presenting to the Singapore National Eye Centre who are willing to participate in the study
Who cannot join
- Patients with previous ocular surgery or trauma. Patients unwilling to participate in the study.
Trial locations and contacts
1 site in 1 country.
About this study
A clinical study of keratoconus in Asian Patients and assessment of different topographic patterns of keratoconus in Asian patients
Read the 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:
- Demographic characteristics of patients with keratoconus
- Quality of life assessment in patients with keratoconus
- Visual Outcome and management of keratoconus in terms of contact lens fitting
- Corneal topographic patterns of patients with keratoconus
- 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).
- Conditions
- Keratoconus
- Keywords
- Keratoconus, corneal topography, ocular aberrometry, visual outcome, contact lens wear, quality of life
- Medical subject headings
- Keratoconus
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jul 2006 (estimated)
- Study startSep 2003
- Study completionMar 2005
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (10)Papers the sponsor has linked to this study.
- Other trials for KeratoconusStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Other
- Enrolment
- 120 participants
Sponsor and investigators
- Lead sponsor
- Singapore National Eye Centre
- Sponsor type
- Other government
- Investigators
- Li - Lim, FRCS(Ed), Principal investigator, Singapore National Eye Centre
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00347074
- Sponsor's protocol ID
- R317/10/03
- Status last verified
- Sep 2003
- First submitted
- 30 Jun 2006
- Last updated
- 7 Jul 2006
- Results posted
- No
Publications
Krachmer JH, Feder RS, Belin MW. Keratoconus and related noninflammatory corneal thinning disorders. Surv Ophthalmol. 1984 Jan-Feb;28(4):293-322. doi: 10.1016/0039-6257(84)90094-8.
PubMed 6230745Rabinowitz YS. Keratoconus. Surv Ophthalmol. 1998 Jan-Feb;42(4):297-319. doi: 10.1016/s0039-6257(97)00119-7.
PubMed 9493273Maeda N, Klyce SD, Smolek MK. Comparison of methods for detecting keratoconus using videokeratography. Arch Ophthalmol. 1995 Jul;113(7):870-4. doi: 10.1001/archopht.1995.01100070044023.
PubMed 7605277Zadnik K, Barr JT, Edrington TB, Everett DF, Jameson M, McMahon TT, Shin JA, Sterling JL, Wagner H, Gordon MO. Baseline findings in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. Invest Ophthalmol Vis Sci. 1998 Dec;39(13):2537-46.
PubMed 9856763Rabinowitz YS. Videokeratographic indices to aid in screening for keratoconus. J Refract Surg. 1995 Sep-Oct;11(5):371-9. doi: 10.3928/1081-597X-19950901-14. No abstract available.
PubMed 8528916Maeda N, Klyce SD, Smolek MK, Thompson HW. Automated keratoconus screening with corneal topography analysis. Invest Ophthalmol Vis Sci. 1994 May;35(6):2749-57.
PubMed 8188468Smolek MK, Klyce SD. Current keratoconus detection methods compared with a neural network approach. Invest Ophthalmol Vis Sci. 1997 Oct;38(11):2290-9.
PubMed 9344352Rao SN, Raviv T, Majmudar PA, Epstein RJ. Role of Orbscan II in screening keratoconus suspects before refractive corneal surgery. Ophthalmology. 2002 Sep;109(9):1642-6. doi: 10.1016/s0161-6420(02)01121-1.
PubMed 12208710Pflugfelder SC, Liu Z, Feuer W, Verm A. Corneal thickness indices discriminate between keratoconus and contact lens-induced corneal thinning. Ophthalmology. 2002 Dec;109(12):2336-41. doi: 10.1016/s0161-6420(02)01276-9.
PubMed 12466180Maeda N, Fujikado T, Kuroda T, Mihashi T, Hirohara Y, Nishida K, Watanabe H, Tano Y. Wavefront aberrations measured with Hartmann-Shack sensor in patients with keratoconus. Ophthalmology. 2002 Nov;109(11):1996-2003. doi: 10.1016/s0161-6420(02)01279-4.
PubMed 12414405
Study at a glance
From the registry record, last updated by the sponsor on 7 Jul 2006. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Clinical Study of Keratoconus in Asian Patients and Assessment of Different Topographic Patterns of Keratoconus in Asian Patients
- ClinicalTrials.gov ID
- NCT00347074
- Acronym / sponsor ID
- R317/10/03
- Conditions
- Keratoconus
- Keywords
- Keratoconus, corneal topography, ocular aberrometry, visual outcome, contact lens wear, quality of life
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 120 participants
- Lead sponsor
- Singapore National Eye CentreOther government
- Study start
- Sep 2003
- Study completion
- Mar 2005
- First posted
- 4 Jul 2006 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A clinical study of keratoconus in Asian Patients and assessment of different topographic patterns of keratoconus in Asian patients
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:
- Demographic characteristics of patients with keratoconus
- Quality of life assessment in patients with keratoconus
- Visual Outcome and management of keratoconus in terms of contact lens fitting
- Corneal topographic patterns of patients with keratoconus
- 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 design
- Observational model
- Case-control
- Time perspective
- Other
Who may qualify
- Ages
- 0 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (1 listed)
- Patients with keratoconus and keratoconus suspect presenting to the Singapore National Eye Centre who are willing to participate in the study
Key exclusion criteria (1 listed)
- Patients with previous ocular surgery or trauma. Patients unwilling to participate in the study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Not reported in the source record.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jul 2006.
- Background: PubMed 6230745Krachmer JH, Feder RS, Belin MW. Keratoconus and related noninflammatory corneal thinning disorders. Surv Ophthalmol. 1984 Jan-Feb;28(4):293-322. doi: 10.1016/0039-6257(84)90094-8.
- Background: PubMed 9493273Rabinowitz YS. Keratoconus. Surv Ophthalmol. 1998 Jan-Feb;42(4):297-319. doi: 10.1016/s0039-6257(97)00119-7.
- Background: PubMed 7605277Maeda N, Klyce SD, Smolek MK. Comparison of methods for detecting keratoconus using videokeratography. Arch Ophthalmol. 1995 Jul;113(7):870-4. doi: 10.1001/archopht.1995.01100070044023.
- Background: PubMed 9856763Zadnik K, Barr JT, Edrington TB, Everett DF, Jameson M, McMahon TT, Shin JA, Sterling JL, Wagner H, Gordon MO. Baseline findings in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. Invest Ophthalmol Vis Sci. 1998 Dec;39(13):2537-46.
- Background: PubMed 8528916Rabinowitz YS. Videokeratographic indices to aid in screening for keratoconus. J Refract Surg. 1995 Sep-Oct;11(5):371-9. doi: 10.3928/1081-597X-19950901-14. No abstract available.
- Background: PubMed 8188468Maeda N, Klyce SD, Smolek MK, Thompson HW. Automated keratoconus screening with corneal topography analysis. Invest Ophthalmol Vis Sci. 1994 May;35(6):2749-57.
- Background: PubMed 9344352Smolek MK, Klyce SD. Current keratoconus detection methods compared with a neural network approach. Invest Ophthalmol Vis Sci. 1997 Oct;38(11):2290-9.
- Background: PubMed 12208710Rao SN, Raviv T, Majmudar PA, Epstein RJ. Role of Orbscan II in screening keratoconus suspects before refractive corneal surgery. Ophthalmology. 2002 Sep;109(9):1642-6. doi: 10.1016/s0161-6420(02)01121-1.
- Background: PubMed 12466180Pflugfelder SC, Liu Z, Feuer W, Verm A. Corneal thickness indices discriminate between keratoconus and contact lens-induced corneal thinning. Ophthalmology. 2002 Dec;109(12):2336-41. doi: 10.1016/s0161-6420(02)01276-9.
- Background: PubMed 12414405Maeda N, Fujikado T, Kuroda T, Mihashi T, Hirohara Y, Nishida K, Watanabe H, Tano Y. Wavefront aberrations measured with Hartmann-Shack sensor in patients with keratoconus. Ophthalmology. 2002 Nov;109(11):1996-2003. doi: 10.1016/s0161-6420(02)01279-4.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Li - Lim, FRCS(Ed) principal investigator
Singapore National Eye Centre
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Keratoconus, run by Singapore National Eye Centre at 1 site in Singapore.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 7 Jul 2006. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00347074, which also lists 10 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Jul 2006.