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

NCT ID: NCT06739018

Last Updated: 2024-12-18

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Total Enrollment: 66 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2024-12-31
• Study Completion Date: 2025-10-31

Brief Summary

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.

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.

Conditions

Keratoconus; High Myopia

Study Design

• Observational Model Type: CASE_CROSSOVER
• Study Time Perspective: PROSPECTIVE

Study Groups

keratoconic group

patients with keratoconus

pentacam scheimpflug tomography

Intervention Type: OTHER

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

pentacam scheimpflug tomography

Intervention Type: OTHER

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.

Interventions

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.

Intervention Type: OTHER

Eligibility Criteria

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

• Minimum Eligible Age: 15 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Assiut University

OTHER

Sponsor Role: lead

Responsible Party

Youstena Saied Waheb

DR

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Momen Aly, lecturer

Role: STUDY_DIRECTOR

Assiut University

Locations

Assiut university

Asyut, Asyut Governorate, Egypt

Assiut university

Asyut, , Egypt

Countries

Egypt

Central Contacts

youstena w saied, resident

Role: CONTACT

Phone: 02+01229887036

Email: youstenasaied@gmail.com

Mohamed s abdalrahman, professor

Role: CONTACT

Phone: +201222414233

Email: mohamed66saad@gmail.com

References

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.

Reference Type: BACKGROUND

PMID: 34855828 (View on PubMed)

Other Identifiers

pentacam parameters compare

Identifier Type: -

Identifier Source: org_study_id