Brief Title
Retrospective Observational Study of Posterior Keratometry Measured
Official Title
Retrospective Observational Study of Posterior Keratometry Measured by IOLMaster 700 in Patients With Keratoconus
Brief Summary
Keratoconus is a progressive bilateral disease leading to an apical stromal thinning and an
irregular astigmatism by a steepening of the cornea, causing visual impairment. The causes
are not yet well known, but it seems to be linked to several comorbidities. Keratoconus is a
rare and for a long-time asymptomatic condition and its diagnosis needs meticulous screening
for the early stages. Detecting it as soon as possible is a goal as it could lead to earlier
avoiding of contributing factors such as eye rubbing and earlier treatment if needed.
The gold standard for keratoconus screening and staging is computerized videotography. It
gives information about anterior and posterior corneal bulging, steepening, and thinning. It
can be completed by anterior segment optical coherence tomography, which can show corneal
scarring. Since recently, some biometry devices can give some information about the posterior
corneal keratometry trough swept source optical coherence tomography measures. The
measurement of the total corneal power instead of an extrapolation lead to better precision
in refractive results after cataract surgery in some cases. It also helped to increase our
knowledge about posterior corneal astigmatism. In normal eyes, average posterior corneal
astigmatism is 0.37 diopters and against the rule in 91 percent of eyes. There is a
correlation between the magnitude of anterior and posterior astigmatism.
In keratoconus eyes, several studies have shown that there is an alignment between axes of
the anterior and posterior corneal astigmatism. These studies have been performed on
computerized videotopography devices.
The goal of this study was to confirm or deny previous observations about posterior
astigmatism in keratoconus eyes, and to assess if the rotation of axis between anterior and
posterior astigmatism measured by IOL Master 700® can be a good sign for detection of early
stages and fruste keratoconus.
Study Type
Observational
Primary Outcome
Posterior keratometry
Secondary Outcome
Total keratometry
Condition
Keratoconus
Study Arms / Comparison Groups
Keratoconus patient
Description: Patient with keratoconus disease diagnosed on videotopography
Publications
* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.
Recruitment Information
Estimated Enrollment
200
Start Date
November 1, 2019
Completion Date
June 3, 2020
Primary Completion Date
June 1, 2020
Eligibility Criteria
Inclusion criteria:
- Keratoconus diagnosed on videotopography
Exclusion criteria:
- loss of sight due to another condition than keratoconus, corneal scarring leading to lack
or mistaken data, corneal graft, non-keratoconus related corneal ectasia such as post Laser
in Situ Keratomileusis (LASIK) ectasia or keratoglobus
Gender
All
Ages
18 Years - N/A
Accepts Healthy Volunteers
No
Contacts
Arnaud : MUYL CIPOLLINA, Internship of ophthalmology, ,
Location Countries
France
Location Countries
France
Administrative Informations
NCT ID
NCT04422080
Organization ID
RECHMPL20_0338
Responsible Party
Sponsor
Study Sponsor
University Hospital, Montpellier
Study Sponsor
Arnaud : MUYL CIPOLLINA, Internship of ophthalmology, Principal Investigator, University Hospitals of Montpellier
Verification Date
June 2020