High Myopia, Keratoconus
Conditions
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.
Interventions
OTHERpentacam 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.
Sponsors
Assiut University
Study design
Observational model
CASE_CROSSOVER
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
15 Years to 50 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| overall corneal mean difference thickness between keratoconus and mopc astigmatism | baseline | 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 |
Countries
Egypt
Contacts
Primary Contactyoustena w saied, resident
Backup ContactMohamed s abdalrahman, professor
Outcome results
None listed