Thick Cornea with High Back Elevation

Long Term Follow-up Study on Thick Cornea with High Back Elevation

To follow up cases of thick cornea with high back elevation by pentacam.

Study Overview

• Status: Not yet recruiting
• Conditions: Corneal Thickness Measurement
• Intervention / Treatment: Device: pentacam

Detailed Description

The cornea plays a crucial role in refraction and so help in good visual acuity. with its thickness and back elevation being essential parameters in diagnosing and managing corneal diseases such as keratoconus.

The normal human cornea has a central thickness of approximately 540-550 µm. The periphery is generally thicker, reaching up to 700 µm. Corneal thickness is influenced by genetics, hydration, and intraocular pressure.Thick Cornea (> 540 µm): Seen in conditions such as corneal edema and Fuchs' dystrophy. Thin Cornea (< 500 µm): Observed in keratoconus, LASIK-induced thinning, and corneal ectasia.

Back corneal elevation is assessed using corneal topography or tomography, typically referenced to a best-fit sphere (BFS). In normal cases, Back corneal elevation is usually ≤12 µm above the BFS, indicating a structurally healthy cornea without signs of ectasia. Susceptible elevation ranges between 12-20 µm, which may be an early indicator of corneal instability, such as subclinical keratoconus. Therefore, it should be evaluated alongside other parameters, including pachymetry, anterior curvature, and biomechanical properties. Abnormal back corneal elevation is generally considered >20 µm, particularly if localized or asymmetric, and is strongly associated with corneal ectatic disorders such as keratoconus, pellucid marginal degeneration, or post-LASIK ectasia. This abnormal elevation is often accompanied by other risk factors, including increased posterior corneal curvature, corneal thinning, and significant asymmetry, necessitating further assessment and monitoring.

Many cases of thick cornea are associated with high back elevation and this discourage refractive surgery in such cases so in investigator's study the investigator will follow up these cases to determine if these corneas are considered normal corneas or not.

• Study Type: Observational
• Enrollment (Estimated): 40

Contacts and Locations

• Study Contact: Name: Merna Fily; Phone Number: 01226081248; Email: mernamagdyfily24@gmail.com
• Study Contact Backup: Name: Ahmed Fathalla, Professor; Phone Number: 01223971401; Email: ahmedfathalla308@aun.edu.eg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

any age can interact with pentacam device

Description

Inclusion Criteria:

Any patient can interact with pentacam. Both Genders: include both males and females. Patients with thick cornea (>540 µm) with high back elevation.

Exclusion Criteria:

• Patients with any eye disease (significant cataract or unstable glaucoma)
• Uncontrolled external disease such as blepharitis , moderate to severe dry eye and allergy.
• Patient with ocular disease such as uveitis, post herpetic infection and corneal opacity

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measurement of corneal thickness and back corneal elevation by pentacam device	The investigator will image the cornea to measure corneal thickness and back corneal elevation using the Pentacam device and follow up for cases of thick corneas with high back elevation at 3 months, 6 months, and 1 year.	Baseline

Collaborators and Investigators

• Sponsor: Assiut University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2025
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: March 14, 2025
• First Submitted That Met QC Criteria: March 25, 2025
• First Posted (Actual): April 2, 2025

Study Record Updates

• Last Update Posted (Actual): April 2, 2025
• Last Update Submitted That Met QC Criteria: March 25, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: Thick cornea

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