Clinical trial NCT06739018: Anterior Segment and Corneal Parameters in Keratoconus and High Myopic Astigmatism Using Schiempflug Imaging
Official title: Comparison of Anterior Segment and Corneal Parameters in Keratoconus and High Myopic Astigmatism Using Schiempflug Imaging
Study type: OBSERVATIONAL
Overall status: NOT_YET_RECRUITING
Conditions: Keratoconus
High Myopia
Lead sponsor: Assiut University
Sponsor class: OTHER
First posted: 2024-12-18
Enrollment: 66
Sex: ALL
Minimum age (years): 15
Maximum age (years): 50
Standard ages: CHILD
ADULT
Accepts healthy volunteers: no
Observational model: CASE_CROSSOVER
Time perspective: PROSPECTIVE
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 .

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.

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

Primary outcomes:
measure: overall corneal mean difference thickness between keratoconus and mopc astigmatism
timeFrame: baseline
Secondary outcomes:
Other outcomes:
Locations:
city: Assiut
country: Egypt
facility: Assiut university
state: Asyut
city: Assiut
country: Egypt
facility: Assiut university
Study officials:
affiliation: Assiut University
name: Momen Aly, lecturer
role: STUDY_DIRECTOR
References:
citation: 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.