Ophthalmological Abnormalities in Hereditary Ichthyosis (ICHTYO-KERATO)

December 23, 2025 updated by: University Hospital, Toulouse

Prevalence of Ophthalmological Abnormalities in Children and Adults Suffering From Hereditary Ichthyosis

Presence/absence of subclinical keratoconus with corneal topographic abnormalities (skewed radial axes for forme fruste keratoconus, and inferior steepening for keratoconus suspect) on axial specular topography (TMS-4 Tomey), and elevation topographies: Pentacam (Oculus) and Orbscan (Bausch & Lomb).

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Background: Hereditary ichthyosis are rare genetic diseases characterized by an abnormal epithelial keratinization due to mutations in gene involved in skin barrier. Patients present with scales on the whole body. Recent classification basically distinguishes syndromic from non-syndromic forms. Ichthyoses are severe diseases with significant impact on quality of life, due to troublesome symptoms (pruritus, pain), lack of effective therapy and complications such as ophthalmological anomalies. Among ophthalmological abnormalities, some are well known, such as eyelid abnormalities, including ectropion, and sicca syndrome. Conversely, corneal abnormalities such as keratoconus are not or very partially described in ichthyosis. The keratoconus is characterized by a corneal thickening and bulging with progressive loss of vision that may require a corneal transplantation. Its prevalence is 0.05% in its symptomatic presentation but may reach 10% when considering subclinical keratoconus diagnosed on basis of corneal topographies. These forme fruste keratoconus or keratoconus suspect may remain subclinical or instead progress to severe keratoconus. Corneal collagen crosslinking has been shown to strengthen the cornea in order to halt progressive keratoconus, justifying the need for early screening. Keratoconus is a complex condition of multifactorial etiology. With regards to the pathophysiology of the keratoconus, some hypotheses incriminate the corneal epithelial differentiation that is similar to the epidermal differentiation altered in ichthyosis. This link between both dermatological and ophthalmological abnormalities is supported by clinical experience. It's was observed that ichthyosis patients have frequently a subclinical keratoconus. In clinical practice, ophthalmological abnormalities are not commonly investigated in ichthyosis patients and there are no data on prevalence in the literature. Furthermore, there are no guidelines on screening or therapy of ophthalmological abnormities in ichthyosis.

The purpose of this project is to demonstrate that the prevalence of subclinical keratoconus (including forme fruste keratoconus and keratoconus suspect) is higher in ichthyosis compared to healthy controls.

Descriptive analysis of the studied population for primary outcome: The proportion of patients with subclinical keratoconus (including form fruste keratoconus and keratoconus suspect) will be described in each study-group and compared between study-groups using Mac Nemar Test.

Study Type

Interventional

Enrollment (Actual)

152

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 Contact

Study Contact Backup

Study Locations

      • Toulouse, France, 31000
        • University Hospital of Toulouse

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

2 years and older (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

For ichthyosis population:

  • Hereditary ichthyosis, whatever form or ongoing therapy.
  • Parental permission for minors

For controls:

  • Patients who consult an ophthalmologist for refractive surgery screening or systematic eye examination
  • Parental permission for minors

Exclusion Criteria:

For both populations:

  • Patient who cannot stay seated
  • Wearing contact lens within the last 7 days
  • No social security
  • Past medical history of corneal or eye surgery or eye condition (glaucoma, uveitis, keratoconus, retinal diseases)
  • Impossibility to fill the questionnaires

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: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: ichthyosis patients
patients presenting an Hereditary ichthyosis, whatever form or ongoing therapy will have an ophthalmological examination.
  • Refraction
  • Best corrected visual acuity
  • Intraocular pressure
  • Slit lamp examination with vital dye (Oxford grading)
  • Tear break-up time (TBUT)
  • Schirmer I testing
  • Specular (TMS-4 Tomey) and elevation (pentacam Oculus and Orbscan Bausch & Lomb) corneal videotopographies
  • Pachymetry
  • Questionnaires: Ocular surface disease index, quality of vision (visual analogic scale), and quality of life (NEI-VFQ25)
  • questionnaire about ichthyosis severity
  • questionnaire about life quality specifically for patient presenting ichthyosis
Other: control population
patient without ichthyosis disease and consulting an ophthalmologist for refractive surgery screening or systematic eye examination will have an ophthalmological examination
  • Refraction
  • Best corrected visual acuity
  • Intraocular pressure
  • Slit lamp examination with vital dye (Oxford grading)
  • Tear break-up time (TBUT)
  • Schirmer I testing
  • Specular (TMS-4 Tomey) and elevation (pentacam Oculus and Orbscan Bausch & Lomb) corneal videotopographies
  • Pachymetry
  • Questionnaires: Ocular surface disease index, quality of vision (visual analogic scale), and quality of life (NEI-VFQ25)
  • questionnaire about ichthyosis severity
  • questionnaire about life quality specifically for patient presenting ichthyosis

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Presence/absence of subclinical keratoconus
Time Frame: 10 mn
Presence/absence of subclinical keratoconus with corneal topographic abnormalities (skewed radial axes for forme fruste keratoconus, and inferior steepening for keratoconus suspect) on axial specular topography (TMS-4 Tomey), and elevation topographies: Pentacam (Oculus) and Orbscan (Bausch & Lomb).
10 mn

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Presence/absence of symptomatic keratoconus with irregular topographic maps
Time Frame: 10 mn
Evaluation by corneal videotopographies
10 mn
Presence/absence of an abnormality of corneal transparency
Time Frame: 10 mn
Evaluated by the measurement of the refraction,
10 mn
Presence/absence of sicca syndrome
Time Frame: 10 mn
Examination with the slit lamp of eyelids and eyelashes
10 mn
Evaluation of quality of vision
Time Frame: 10 mn
-Ocular Surface Disease Index (OSDI) : Self administered form to evaluate the impact of dry eye on visual function : 12 questions rated from 0 (never) to 4 (all the time)
10 mn
Quality of life for adults
Time Frame: 10 mn
-Quality of life by the National Eye Institute Visual Function Questionnaire (NEI-VFQ) : Self-administered questionnaire witch incorporates a wider range of data in relation to quality of life related to vision. Each question leads to an answer that is either dichotomous (yes / no), or graduated in 3, 4.5 and 6 points. The score of each item is transformed from 0 to 100, and the average of the scores by domain is established.
10 mn

Collaborators and Investigators

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

Sponsor

Collaborators

Investigators

  • Principal Investigator: Juliette MAZEREEUW, MD, University Hospital, Toulouse

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)

July 18, 2017

Primary Completion (Actual)

June 30, 2022

Study Completion (Actual)

June 30, 2022

Study Registration Dates

First Submitted

November 18, 2017

First Submitted That Met QC Criteria

March 7, 2018

First Posted (Actual)

March 14, 2018

Study Record Updates

Last Update Posted (Actual)

December 31, 2025

Last Update Submitted That Met QC Criteria

December 23, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

  • RC31/17/0067
  • 2017-A00605-48 (Other Identifier: ID-RCB)

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

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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