Anterior Segment and Corneal Parameters in Keratoconus and High Myopic Astigmatism Using Schiempflug Imaging

Comparison of Anterior Segment and Corneal Parameters in Keratoconus and High Myopic Astigmatism Using Schiempflug Imaging

The purpose of this study was to compare Scheimpflug corneal tomography findings in keratoconus and high myopic astigmatic eyes, as well as to establish the parameters distinguishing keratoconus from high myopic astigmatism.

Study Overview

• Status: Not yet recruiting
• Conditions: Keratoconus; High Myopia
• Intervention / Treatment: Other: pentacam scheimpflug tomography

Detailed Description

Keratoconus is a progressive, non-inflammatory corneal ecstatic disorder caused by alteration in the structure and organization of corneal collagen fibers. It results in uneven steepening of the cornea, resulting in irregular astigmatism that cannot be totally corrected with glasses, impairing the quality of life . However, in many cases, increased axial length adds to the myopic component of refractive error . Thereafter, keratoconus patients frequently have axial high myopia with irregular astigmatism . Furthermore, early diagnosis of keratoconus aids in the timely management of the condition, thus improving patients' quality of life. According to research, high myopia, in addition to the degree of astigmatism, is an alarming sign that requires further corneal assessment to rule out any corneal abnormalities such as keratoconus. Furthermore, keratoconus could be misdiagnosed as meridional amblyopia attributable to myopic astigmatism due to the lack of corneal tomography measurements . As a result, it is critical to evaluate all high myopia patients, particularly those considering refractive surgery, for high-risk corneas.

The criteria for diagnosing and classifying keratoconus are based on anterior corneal curvature data obtained using Placido-based corneal topography . Early alterations in eyes with keratoconus, however, have been found on the posterior corneal surface . Scheimpflug imaging uses a revolving Scheimpflug camera to determine the front and back surfaces of the cornea, hence measuring the overall thickness. Several studies have utilized Scheimpflug tomography to evaluate anterior segment parameters between normal eyes and eyes with keratoconus , but the utility of Scheimpflug imaging to distinguish between keratoconus and high myopic astigmatism has not been thoroughly examined.

• Study Type: Observational
• Enrollment (Estimated): 66

Contacts and Locations

• Study Contact: Name: youstena w saied, resident; Phone Number: 02+01229887036; Email: youstenasaied@gmail.com
• Study Contact Backup: Name: Mohamed s abdalrahman, professor; Phone Number: +201222414233; Email: mohamed66saad@gmail.com

Study Locations

• Egypt
  • Assiut, Egypt, 71515
    • Assiut University
  • Asyut
    • Assiut, Asyut, Egypt, 71526
      • Assiut University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

The population represents individuals either have keratoconus or high mopic astigmatism and fit the inclusion and exclusion criteria to ensure proper comparison of corneal parameters .

Description

Inclusion Criteria:

• keratoconus patient
• virgin clear cornea with high myopic astigmatism
• normal cornea with high myopic astigmatism

Exclusion Criteria:

• patients had previous ocular surgery
• ocular diseases rather than keratoconus
• contact lens wearer
• corneal opacity and corneal dystrophy

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
keratoconic group; patients with keratoconus	Other: pentacam scheimpflug tomography; Pentacam tomography is not radiation-based. It uses Scheimpflug imaging, which involves a rotating camera that captures multiple images of the anterior segment of the eye. The system employs light-based technology to measure the front and back surfaces of the cornea, along with the anterior chamber and lens, creating a 3D model of the anterior eye structures. it uses light instead of ionizing radiation (like X-rays), it is considered safe and non-invasive for routine use in ophthalmology.; It was used to assess 23 parameters from topographic maps and 15 parameters from Belin-Ambrosio enhanced ectasia (BAD) display maps.; Parameters included keratometry readings, anterior and posterior sagittal curvature, corneal thickness, anterior chamber volume, and several indices from the BAD display map.; These parameters were analyzed to discriminate between keratoconus and high myopic astigmatism using Receiver Operating Characteristic (ROC) curves for diagnostic accuracy.
high myopic astigmatim group; patients with high myopic astigmatism	Other: pentacam scheimpflug tomography; Pentacam tomography is not radiation-based. It uses Scheimpflug imaging, which involves a rotating camera that captures multiple images of the anterior segment of the eye. The system employs light-based technology to measure the front and back surfaces of the cornea, along with the anterior chamber and lens, creating a 3D model of the anterior eye structures. it uses light instead of ionizing radiation (like X-rays), it is considered safe and non-invasive for routine use in ophthalmology.; It was used to assess 23 parameters from topographic maps and 15 parameters from Belin-Ambrosio enhanced ectasia (BAD) display maps.; Parameters included keratometry readings, anterior and posterior sagittal curvature, corneal thickness, anterior chamber volume, and several indices from the BAD display map.; These parameters were analyzed to discriminate between keratoconus and high myopic astigmatism using Receiver Operating Characteristic (ROC) curves for diagnostic accuracy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
overall corneal mean difference thickness between keratoconus and mopc astigmatism	Scheimpflug imaging uses a revolving Scheimpflug camera to determine the front and back surfaces of the cornea, hence measuring the overall corneal mean difference thickness between keratoconus and mopc astigmatism as regarding central anterior chamber depth	baseline

Collaborators and Investigators

• Sponsor: Assiut University
• Investigators: Study Director: Momen Aly, lecturer, Assiut University

Publications and helpful links

General Publications

• Zaabaar E, Kyei S, Parkson Brew MAA, Boadi-Kusi SB, Assiamah F, Asiedu K. The utility of measures of anterior segment parameters of a Pentacam Scheimpflug tomographer in discriminating high myopic astigmatism from keratoconus. PLoS One. 2021 Dec 2;16(12):e0260648. doi: 10.1371/journal.pone.0260648. eCollection 2021.

Study record dates

Study Major Dates

• Study Start (Estimated): December 1, 2024
• Primary Completion (Estimated): October 1, 2025
• Study Completion (Estimated): October 1, 2025

Study Registration Dates

• First Submitted: November 27, 2024
• First Submitted That Met QC Criteria: December 16, 2024
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 16, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors; Corneal Diseases; Astigmatism; Keratoconus
• Other Study ID Numbers: pentacam parameters compare

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