AstigmatismNCT02155556
Diurnal Changes of the Cornea - a Pilot Study
An observational study of Astigmatism, run by Prim. Prof. Dr. Oliver Findl, MBA at 1 site in Austria.
Trial summary
Aim of this study is to gain a better understanding of the diurnal changes of the cornea to improve toric IOL power calculations. Read more about this study
- Who is it for?
- Ages 21 to 100 yearsHealthy volunteers can take part
- Conditions the study is for
- Astigmatism
- How many people
- 20 participants
- Where
- 1 siteAustria
- Study dates
- Jun 2014to Aug 2014
- 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 21 to 100 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: 20 volunteers/patients (10 patients >50 years old; 5 patients with a corneal astigmatism of >1 D)
Who may be able to join
- 21 years, or above
- Signed informed consent
Who cannot join
- Ophthalmic diseases such as significant macular degeneration, glaucoma, diabetic retinopathy, etc.
Trial locations and contacts
1 site in 1 country.
Austria1 site
VIROS - Vienna Institute for Research in Ocular Surgers - Departement of Opthalmology - Hanusch Hospital
Vienna, 1140
About this study
Aim of this study is to gain a better understanding of the diurnal changes of the cornea to improve toric IOL power calculations.
Read the detailed description
Higher patient expectations concerning unaided visual acuity after cataract surgery has led to an increase in use of toric intraocular lenses (toric IOLs) for the correction of corneal astigmatism. Although it was shown that toric IOLs significantly reduce astigmatism, there is still some difficulty in predicting the remaining astigmatism correctly. The main source of error appears to be the pre-operative measurement of the cornea. However, it is questionable, if this error derives from a measurement error due to the imprecise measurement technique, or natural diurnal changes of the cornea. Additionally, measurements of the cornea pose several challenges: different corneal biometry devices cannot be used interchangeably and it is difficult to decide, which device is measuring the cornea correctly as there is no gold standard.
Especially, in eyes with small corneal astigmatism the error increases. Recently it was shown that the astigmatism meridian was on median 9° off for corneas with 1.0D of astigmatism and only 4° for corneas with 2.0D of astigmatism. Similar findings were observed by Shammas et al. Norrby furthermore showed that 5% of all corneas show more than 0.5D of fluctuations between measurements at different (post-operative) time-points. The reasons are not explored, but diurnal changes, temperature and humidity potentially influencing the tear film, as well as pupil size and asphericity of the cornea could play a role. Read and Collins observed diurnal changes of corneal radii within 24 hours, but in their study only young healthy volunteers were included and only one measurement device (Scheimpflug imaging, Pentacam HR) was used. Lau and Pye and Shen et al. measured the diurnal changes of the cornea, but no data concerning corneal radii were reported. Harper et al. observed diurnal changes of the central corneal thickness. However, none of these studies investigated on diurnal changes of the corneal radii in the elderly population. Aim of this study is to gain a better understanding of the diurnal changes of the cornea to improve toric IOL power calculations.
- Conditions
- Astigmatism
- Medical subject headings
- Astigmatism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Healthy volunteers | Not described |
What is being measured
The primary outcome is the main question the study is designed to answer.
Descriptive analysis of diurnal changes of the corneal radii (in diopters) and orientation of the steep meridian (in degrees) in young healthy subjects and elderly patients
Measured: 24 hours
Secondary outcomes (1)
Comparison of the corneal radii (in diopters) and orientation of the steep meridian (in degrees) between different measuring devices
Measured: 24 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jun 2014 (estimated)
- Study startJun 2014
- Primary completionAug 2014
- Study completionAug 2014
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AstigmatismStudies 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Prim. Prof. Dr. Oliver Findl, MBA
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Prim. Prof. Dr. Oliver Findl, MBA, Vienna Institute for Research in Ocular Surgery
- Investigators
- Oliver Findl, MD, MBA, Principal investigator, VIROS - Vienna Institute for Research in Ocular Surgers - Departement of Opthalmology - Hanusch Hospital Vienna, Vienna, Austria 1140
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02155556
- Sponsor's protocol ID
- DIU
- Status last verified
- Mar 2020
- First submitted
- 2 Jun 2014
- Last updated
- 16 Mar 2020
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 16 Mar 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Diurnal Changes of the Cornea - a Pilot Study
- ClinicalTrials.gov ID
- NCT02155556
- Acronym / sponsor ID
- DIU
- Conditions
- Astigmatism
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Prim. Prof. Dr. Oliver Findl, MBAUniversity, hospital or other
- Study start
- Jun 2014
- Primary completion
- Aug 2014 (actual)
- Study completion
- Aug 2014 (actual)
- First posted
- 4 Jun 2014 (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.
Aim of this study is to gain a better understanding of the diurnal changes of the cornea to improve toric IOL power calculations.
Detailed description
Higher patient expectations concerning unaided visual acuity after cataract surgery has led to an increase in use of toric intraocular lenses (toric IOLs) for the correction of corneal astigmatism. Although it was shown that toric IOLs significantly reduce astigmatism, there is still some difficulty in predicting the remaining astigmatism correctly. The main source of error appears to be the pre-operative measurement of the cornea. However, it is questionable, if this error derives from a measurement error due to the imprecise measurement technique, or natural diurnal changes of the cornea. Additionally, measurements of the cornea pose several challenges: different corneal biometry devices cannot be used interchangeably and it is difficult to decide, which device is measuring the cornea correctly as there is no gold standard.
Especially, in eyes with small corneal astigmatism the error increases. Recently it was shown that the astigmatism meridian was on median 9° off for corneas with 1.0D of astigmatism and only 4° for corneas with 2.0D of astigmatism. Similar findings were observed by Shammas et al. Norrby furthermore showed that 5% of all corneas show more than 0.5D of fluctuations between measurements at different (post-operative) time-points. The reasons are not explored, but diurnal changes, temperature and humidity potentially influencing the tear film, as well as pupil size and asphericity of the cornea could play a role. Read and Collins observed diurnal changes of corneal radii within 24 hours, but in their study only young healthy volunteers were included and only one measurement device (Scheimpflug imaging, Pentacam HR) was used. Lau and Pye and Shen et al. measured the diurnal changes of the cornea, but no data concerning corneal radii were reported. Harper et al. observed diurnal changes of the central corneal thickness. However, none of these studies investigated on diurnal changes of the corneal radii in the elderly population. Aim of this study is to gain a better understanding of the diurnal changes of the cornea to improve toric IOL power calculations.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Healthy volunteers | – | – |
Who may qualify
- Ages
- 21 to 100 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- 20 volunteers/patients (10 patients >50 years old; 5 patients with a corneal astigmatism of >1 D)
Key inclusion criteria (2 listed)
- 21 years, or above
- Signed informed consent
Key exclusion criteria (1 listed)
- Ophthalmic diseases such as significant macular degeneration, glaucoma, diabetic retinopathy, etc.
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
Descriptive analysis of diurnal changes of the corneal radii (in diopters) and orientation of the steep meridian (in degrees) in young healthy subjects and elderly patients
Time frame: 24 hours
1 secondary outcome
Comparison of the corneal radii (in diopters) and orientation of the steep meridian (in degrees) between different measuring devices
Time frame: 24 hours
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 16 Mar 2020.
Related trials for Astigmatism
Recruiting
Evaluation of Two Monthly Silicone Hydrogel Multifocal Toric in Soft Contact Lens Wearers
Astigmatism, Myopia
Not yet recruiting
The EYERISING Study
Myopia, Astigmatism
Active, not recruiting
P1 Toric Vs. Max 1day
Eye, Astigmatism
Recruiting
Clareon TruPlus Study
Aphakia, Astigmatism
Not yet recruiting
Clinical Performance and Outcomes After Toric Lens Transition
Astigmatism
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.
Oliver Findl, MD, MBA principal investigator
VIROS - Vienna Institute for Research in Ocular Surgers - Departement of Opthalmology - Hanusch Hospital Vienna, Vienna, Austria 1140
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 Astigmatism, run by Prim. Prof. Dr. Oliver Findl, MBA at 1 site in Austria.
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 2 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 16 Mar 2020. 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 Austria. 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.
What does the primary outcome measure?
Descriptive analysis of diurnal changes of the corneal radii (in diopters) and orientation of the steep meridian (in degrees) in young healthy subjects and elderly patients (time frame: 24 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 16 Mar 2020.