Evaluation of Tomographic and Genetic Aspects of Keratoconus Patients Compared to Sounds Corneas

February 28, 2017 updated by: Gildasio Castello de Almeida Junior, Sao Jose do Rio Preto Medical School
Evaluation of tomographic (Pentacam) parameters and genetic parameters of Visual System Homeobox 1 (VSX1), Superoxide Dismutase (SOD1), Tissue Inhibitors of Metalloproteinases (TIMP3) genes of keratoconus patients diagnosed by clinical exam and topographic pattern. Basically we are screening patients that don't have keratoconus that those have keratoconus. The pentacam index of corneal curvature, thinnest point, corneal high order aberrations, posterior and anterior elevation, corneal densitometry, corneal volume were investigated. To analyze the genes, we took corneal epithelium samples of patients submitted to cross linking compared to (PRK) Photo Refractive Keratectomy ones. Also will be evaluated the genes of peripheral blood.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Keratoconus is a common disease that affects the cornea in both genders in all ethnic groups and that can manifest unilaterally or bilaterally in patients. Keratoconus due to a degenerative disease, its progression can be fast in various situations, affecting 1 in every 2,000 people, what results in severe structural changes of the cornea, which reduces its thickness and modify its normal curvature to a more conical shape. Keratoconus arises in adolescence and lasts for thirty to forty years of age, where it stabilizes and it is considered a major cause of corneal transplantation. Factors such as atopy, overuse of contact lenses and the act of rubbing the eyes are also related to the disease. The clinical picture consists of a lot of varied symptoms and it depends on the stage of disease progression. Currently it is known that genetic and environmental factors are involved in the desease emergence. Recently several genetic studies have aimed to identify mutations in genes which are directly linked to Keratoconus, such as VSX1, SOD1 and TIMP3 genes. However, despite the efforts directed towards the understanding of the genetic aspects of this disease, involving many genes, there are still many questions about the role of these genes in Keratoconus etiology. Thus, the present study aims to identify the presence of mutations in VSX1, SOD1 and TIMP3 genes, which are considered important candidates for the origin and development of this eye anomaly, through the analysis of their nucleotide sequences in corneal tissue and peripheral blood in Keratoconus patients, in their unilateral and bilateral forms. The results will allow to compare the presented mutations in different analysed tissues for unilateral and bilateral forms of Keratoconus and also compare them with the same tissues in healthy patients, in an attempt to establish what the likely inherited and/or acquired genetic mutations are causing this condition. Thus providing genetic data, still unpublished in Brazilian populations, which may offer subsidies for the characterization of the mutation dynamics and their patterns, on the origin and development of Keratoconus. Also will be evaluated the tomographic index as corneal curvature, thinnest point, corneal high order aberrations, posterior and anterior elevation, corneal densitometry, corneal volume. The idea is focused on that suspicious cornea that has the fellow eye with unequivocal keratoconus.

Study Type

Interventional

Enrollment (Actual)

210

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Brazil
    • Sao Paulo
      • Sao Jose do Rio Preto, Sao Paulo, Brazil, 15015-020
        • Visum Eye Center / Immunogenetic laboratory of FAMERP

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

10 years to 60 years (ADULT, CHILD)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients diagnosed with keratoconus in clinical examination, topography and tomography
  • Patients with clinical examination, topography, and tomography aspect of sound cornea in one eye, and the fellow eye diagnosed with keratoconus by clinical examination, topography, and tomography.

Patients diagnosed with keratoconus by clinical examination, topography, and tomography in both eyes (OU).

  • Patients with some degree of ametropia that underwent to PRK and LASIK

Exclusion Criteria:

  • History of eye trauma, glaucoma, dysfunctional tear syndrome, rosacea, neurotrophic keratopathy, systemic or topical use of immunosuppressive drugs, previous ocular surgeries.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: SCREENING
  • Allocation: NON_RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: NONE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
ACTIVE_COMPARATOR: keratoconus

Evaluation of Visual System Homeobox 1 (VSX1), Superoxide Dismutase (SOD1), Tissue Inhibitors of Metalloproteinases (TIMP3) genes. Keratoconus with fellow eye without topographic and tomographic keratoconous pattern.Evaluation of tomographic datas. Sometimes we picked up the sample of corneal epithelium, and peripheral blood sample from corneal cross linking surgeries, in that case of keratoconus progression.

Group A Keratoconus/ like sound cornea. Group C Keratoconus / Keratoconus

Group C Keratoconus / Keratoconus
Other: EVALUATION OF VSX1, SOD1, and TIMP3 genes
Evaluation of VISX1, SOD1, TIMP3 genes in corneal epithelium, and in peripheral blood. Evaluation of pentacam parameters
Other Names:
  • pentacam and gene evaluation
PLACEBO_COMPARATOR: sound cornea

Evaluation of VSX1, SOD1, and TIMP3 genes. To analyze tomographic aspects, we evaluated the patients that underwent to LASIK (Lasei in situ Keratomileusis) with 2 year with follow up without any sign of ectasia To analyze the genes we picked up the sample of corneal epithelium, and peripheral blood sample from PRK (PhotoRefractive Keratectomy) surgeries. These patients showed topographic and tomographic normal pattern.

Group B Sound Cornea / Sound Cornea
Other: EVALUATION OF VSX1, SOD1, and TIMP3 genes
Evaluation of VISX1, SOD1, TIMP3 genes in corneal epithelium, and in peripheral blood. Evaluation of pentacam parameters
Other Names:
  • pentacam and gene evaluation

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Evaluate the tomographic parameters of keratoconus, subclinical keratoconus in relation to sound corneas and identify the mutations present in the genes VSX1, SOD1 and TIMP3 in individuals affected by keratoconus.
Time Frame: 18 months
The aim of this study was to evaluate Evaluate the tomographic parameters of keratoconus, subclinical keratoconus in relation to sound corneas and identify the mutations present in the genes VSX1, SOD1 and TIMP3 in individuals affected by keratoconus in several forms of manifestation.
18 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Tomographic parameters
Time Frame: 18 months

Evaluating whether cross-referencing of known indexes may improve sensitivity and specificity in the detection of subclinical keratoconus;

- Evaluate if there is a correlation between the different tomographic indices; To evaluate the cornea densitometry in patients with keratoconus and its absence.
18 months
Genetic evaluation, VISX1, SOD1, TIMP3
Time Frame: 18 months

Avalue if after removal of the epithelium there is a very large change in the curvature, elevations and topometry of the cornea;

  • Identify the presence of mutations in the VSX1, SOD1 and TIMP3 genes, from nucleotide sequence analysis in tissues of the affected cornea, normal cornea and peripheral blood, in patients with this pathology in their several forms.
  • Compare the mutations present in the different tissues analyzed, for the unilateral and bilateral forms of keratoconus and also to compare them with the same tissues in healthy patients;
  • Establish which are the probable inherited and / or acquired genetic mutations that cause this pathology, from the analysis of the same in the peripheral blood of the affected individuals.
18 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sao Jose do Rio Preto Medical School

Collaborators

Fundação de Amparo à Pesquisa do Estado de São Paulo

Investigators

  • Principal Investigator: Gildasio C Almeida Jr, MD, PhD, FAMERP, Visum Eye Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ACTUAL)

August 1, 2015

Primary Completion (ACTUAL)

December 31, 2016

Study Completion (ACTUAL)

December 31, 2016

Study Registration Dates

First Submitted

February 28, 2017

First Submitted That Met QC Criteria

February 28, 2017

First Posted (ACTUAL)

March 6, 2017

Study Record Updates

Last Update Posted (ACTUAL)

March 6, 2017

Last Update Submitted That Met QC Criteria

February 28, 2017

Last Verified

February 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CAAE 44071315.7.0000.5415
  • 2015/17226-7 (OTHER_GRANT: FAPESP)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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