Measurement of High Order Aberrations in Late Stages Keratoconus

Study Overview
=================
Brief Summary
-----------------
The instrument that will be used in the study is the Murcia monocular Adaptive Optics Visual simulator (AOVIS-I). The system provides an objective characterization of the optical quality of the patient's eye by application of wave-front sensing technology. The optical condition of every eye is represented by its wave aberration. This characterization overcomes the current description based only in refractive errors. This provides an accurate description of the optics of the eye based on the assessment of the whole set of ocular aberrations. The particular wave-front sensor is of a Hartmann-Shack type. One characteristics of this wave-front sensor is its high dynamic range allowing measuring highly aberrated eyes, such as patients with keratoconus.

Detailed Description
-----------------
The complete procedure in one patient takes less than 5 minutes and is completely non-invasive.

Official Title
-----------------
Feasibility of Measurement of High Order Aberrations in Late Stages Keratoconus by Using an Adaptive Optics Visual Simulator AOVIS-I

Conditions
-----------------
Keratoconus

Intervention / Treatment
-----------------
* Device: classic aberrometer and aberrometer AOVIS-1
* Device: Aberrometer AOVIS-I


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: to be able to understand an information and give a consent patients over 18 patients with keratoconus affiliated to medical insurance. Exclusion Criteria: non keratoconus patients patients under 18 pregnant women or nursing mothers ocular surgery 90 days before inclusion ocular infection keratitis restless patients

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Group 1<br>Measurement of aberrations in patients with keratoconus of grade 1 | Device: classic aberrometer and aberrometer AOVIS-1<br>* Measurement of aberrations in early stages (1 and 2) of keratoconus as compared aberrometer AOVIS-1 with a classic aberrometer.<br>|
| Active Comparator: Group 2<br>patients with keratoconus of grade 2 | Device: classic aberrometer and aberrometer AOVIS-1<br>* Measurement of aberrations in early stages (1 and 2) of keratoconus as compared aberrometer AOVIS-1 with a classic aberrometer.<br>|
| Experimental: Group 3<br>patients with keratoconus of grade 3 | Device: Aberrometer AOVIS-I<br>* Measurement of aberrations in high stages (3 and 4) of keratoconus. Objective characterization of the optical quality of the patient eye by application of wave-front sensing technology in late stage keratoconus The complete procedure in one patient takes less than 5 minutes in only one consultation and is completely non invasive. The optical measurements only involve the use of low power infrared laser<br>|
| Experimental: Group 4<br>patients with keratoconus of grade 4 | Device: Aberrometer AOVIS-I<br>* Measurement of aberrations in high stages (3 and 4) of keratoconus. Objective characterization of the optical quality of the patient eye by application of wave-front sensing technology in late stage keratoconus The complete procedure in one patient takes less than 5 minutes in only one consultation and is completely non invasive. The optical measurements only involve the use of low power infrared laser<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The primary outcome of the study is to evaluate the AOVIS-I and its wave-front sensor with high dynamic range for measuring high-order aberrations in patients with late stages (3 and 4) of keratoconus |  | at the 1st day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To evaluate the reliability of the measures in early stages (1 and 2) of keratoconus as compared with a classic aberrometer. |  | at the 1st day | 
| To describe the measures obtained in advanced stages (3 and 4) of keratoconus. |  | at the 1st day | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
keratoconus, wave-front sensing technology, aberrometer