CHOICE OF SUBJECTIVE OCULAR REFRACTION TECHNIQUE AND CORNEAL TOPOGRAPHY OF KERATOCONUS

NCT ID: NCT04174209

Last Updated: 2020-03-20

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

52 participants

Study Classification

INTERVENTIONAL

Study Start Date

2019-11-18

Study Completion Date

2020-03-06

Brief Summary

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Keratoconus is a rare evolving corneal ectasia that alters visual acuity. To improve spectacle-corrected visual acuity, various subjective refraction techniques can be used.

The subjective refraction techniques of keratoconus-carrying patients have never been studied.

The main hypothesis is that the most suitable subjective ocular refraction method varies with the corneal topography of the keratoconus.

The main objective is to define the most appropriate refractive technique(s) based on corneal topographies in order to provide keratoconus-affected patients with the best spectacle-corrected visual acuity.

Detailed Description

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Keratoconus is a rare evolving corneal ectasia that alters visual acuity. To improve spectacle-corrected visual acuity, various subjective refraction techniques can be used. The Jackson Cylinder Cross Method, the Astigmatic Dial Technique and the Stenopeic Slit are three validated subjective refraction techniques for measuring astigmatism. The subjective refraction techniques of keratoconus-carrying patients have never been studied.

The main hypothesis is that the most suitable subjective ocular refraction method varies with the corneal topography of the keratoconus.

The investigators collect several characteristics of corneal topography of the keratoconus : the average value of the keratometry of the 3 central mm called Km ; the value of the point corresponding to the maximum keratometry (called Kmax), the distance between the center and the point of Kmax, (called d\_Kmax) ; the corneal surface variance index called ISV ; the Belin/Ambrósio Enhanced Ectasia Display (called BAD-D).

The main objective is to define the most appropriate refractive technique(s) based on corneal topographies in order to provide keratoconus-affected patients with the best spectacle-corrected visual acuity.

Conditions

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Keratoconus Alteration of Visual Acuity

Study Design

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Allocation Method

NA

Intervention Model

SINGLE_GROUP

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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Cohort 1

70 patients are involved and will perform the three conditions.

Group Type EXPERIMENTAL

Cylinder

Intervention Type BEHAVIORAL

Patients who receive the Jackson Cross Cylinder Method

Dial

Intervention Type BEHAVIORAL

Patients who receive the Astigmatic Dial Technique Method.

Slit

Intervention Type BEHAVIORAL

Patients who receive the Stenopeic slit Method.

Interventions

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Cylinder

Patients who receive the Jackson Cross Cylinder Method

Intervention Type BEHAVIORAL

Dial

Patients who receive the Astigmatic Dial Technique Method.

Intervention Type BEHAVIORAL

Slit

Patients who receive the Stenopeic slit Method.

Intervention Type BEHAVIORAL

Eligibility Criteria

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Inclusion Criteria

* adult persons
* patients with keratoconus
* patients with alteration of visual acuity
* ability to give informed consent to participate in the study
* affiliation to a social security scheme

Exclusion Criteria

* Keratoconus grafted with cornea or with intracorneal rings.
* Central corneal opacities.
* Presence of other eye diseases affecting visual acuity.
* Patients under guardianship, curatorship or justice protection.
* Pregnant or breastfeeding women.
* Refusal to participate in the study.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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University Hospital, Clermont-Ferrand

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Frédéric Chiambaretta

Role: PRINCIPAL_INVESTIGATOR

University Hospital, Clermont-Ferrand

Locations

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Chu Clermont Ferrand

Clermont-Ferrand, , France

Site Status

Countries

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France

References

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Metzger M, Navel V, Barriere JV, Kwiatkowski F, Hebraud J, Mulliez A, Beral L, Chiambaretta F, Dutheil F. Benefits of using corneal topography to choose subjective refraction technique in keratoconus (RE-CON): a prospective comparative crossover clinical study. Graefes Arch Clin Exp Ophthalmol. 2022 Jan;260(1):197-207. doi: 10.1007/s00417-021-05382-y. Epub 2021 Aug 20.

Reference Type DERIVED
PMID: 34415365 (View on PubMed)

Other Identifiers

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2019-A01624-53

Identifier Type: OTHER

Identifier Source: secondary_id

RBHP 2019 CHIAMBARETTA

Identifier Type: -

Identifier Source: org_study_id

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