Accuracy of Curvature and Wavefront Aberrations of Posterior Corneal Surface, in Keratoconic and Post-CXL Corneas

NCT01527708 | Completed DMC

• 1 other identifier: 27/27-09-11
• Study Type: observational
• Target: 129
• Locations: 1 country
• Sites: 1

Brief Summary

Primary objective of this study was to assess the intrasession, intersession and interobserver variability of the Pentacam-derived curvature and zernike coefficients in back surface of normal, keratoconic and crosslinked corneas.

Conditions

Keratoconus

Outcome Measures

Primary Outcomes (1)

• Variability of posterior corneal surface curvature and aberrometric measurements within and between sessions and within and between observers.

  The Pentacam Classic (Oculus Optikgerate GmbH, Heidelberg, Germany, software version 1.14r04) was used for the sake of the study. Three consecutive scans were obtained by two experienced operators for the assessment of intrasession and interobserver variability. The same procedure was repeated within two weeks for the assessment of intersession variability.Bland-Altman plots were used to evaluate agreement between the 2 operators. The reliability of all measurements was evaluated by means of the intraclass correlation coefficient(ICC).

  2 weeks

Study Arms (3)

Keratoconus Group (KCG)

Keratoconus group (KCG) included patients with progressive keratoconus.

Collagen-Cross-linking group (CXLG)

Collagen-Cross-linking group (CXLG) included keratoconus patients that had been treated with uneventful corneal collagen cross-linking (CXL) at least on year prior to their enrolment in the study.

Procedure: Corneal Collagen Cross-linking (CXL)

Normal Group (NG)

Normal group (NG) was formed by refractive surgery candidates who visited EIT's refractive surgery service for their preoperative examination. Eligibility for participation in the NG was confirmed by consecutive topographies, while all NG participants had to present uneventful ophthalmologic history, no indications of corneal pathology in slit-lamp biomicroscopy and Placido disk-based videokeratography.

Interventions

Corneal Collagen Cross-linking (CXL) PROCEDURE

Instillation of proparacaine hydrochloride 0.5% drops for topical anaesthesia, application of a sponge saturated with 10% alcohol to the central cornea for 20-30 seconds and subsequent de-epithelialization by means of a hockey knife. Following de-epithelialization, a mixture of 0.1% riboflavin in 20% Dextran solution was instilled to the cornea for 30 minutes (2 drops every 2 minutes) prior to the irradiation. In details, an 8.0mm diameter of central cornea was irradiated for 30 minutes by UVA light with a wavelength of 370nm and an irradiance of 3mW/cm2.The UVA radiation source that was used is the UV-XTM (IROC AG, Zurich, Switzerland). Instillation of riboflavin drops (1 drop every 2 minutes) was continued during irradiation, as well.

Collagen-Cross-linking group (CXLG)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Participants were recruited from the Cornea service of the EIT in a consecutive-if-eligible basis.

You may qualify if:

• Ideal refractive surgery candidate (Normal Group)
• Progressive keratoconus (Keratoconus group)
• Corneal collagen cross linking (CxL) treatment at least one year prior to enrollment (CxL group)

You may not qualify if:

• (Normal Group)
• No indications of corneal pathology in slit-lamp biomicroscopy and Placido disk-based videokeratography
• Uneventful ophthalmologic history
• All groups:
• Glaucoma
• Suspicion of glaucoma
• history of herpetic keratitis
• corneal scarring
• severe eye dryness
• pregnancy or nursing
• current corneal infection
• underlying autoimmune disease

Sponsors & Collaborators

• Democritus University of Thrace: lead

Study Sites (1)

Eye Institute of Thrace (EIT)

Alexandroupoli, Thrace, 68100, Greece

Location

MeSH Terms

Conditions

Keratoconus

Interventions

Corneal Cross-Linking

Condition Hierarchy (Ancestors)

Corneal Diseases; Eye Diseases

Intervention Hierarchy (Ancestors)

Photochemotherapy; Combined Modality Therapy; Therapeutics; Drug Therapy; Phototherapy

Study Officials

• Georgios Labiris, Lecturer

  Democritus University of Thrace

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Lecturer

Study Record Dates

• First Submitted: February 3, 2012
• First Posted: February 7, 2012
• Study Start: September 1, 2011
• Primary Completion: November 1, 2011
• Study Completion: December 1, 2011
• Last Updated: February 7, 2012

Record last verified: 2012-01

Locations

GR (1)