An observational study in Corneal Higher-order Aberrations, sponsored by Assiut University. Not yet recruiting at 1 site in Egypt. Open to participants aged 18 Years to 45 Years. Per ClinicalTrials.gov, last updated 2024-02-28.
Sponsored by Assiut University · Observational
Aim of work:
To assess the agreement between placido-based topographer (wavelight allegro topolyzer vario) and scheimpflug -based (Oculus Pentacam ) regard measuring corneal higher order aberrations before and after LASIK.
Higher-order aberrations (HOAs) are small optical irregularities of the eye, which can have an impact on the quality of the retinal image. In contrast to lower order aberrations, these errors cannot be corrected with regular spectacles and most contact lenses. Additionally, HOAs are responsible for an array of visual symptoms including dysphotopsia, glare, as well as a reduction in contrast sensitivity. The cornea accounts for approximately 90% of ocular aberrations.Advances and breakthroughs in wavefront aberration measurement technology can help clinicians to better understand and manage corneal higher-order aberrations (HOAs), especially for the preoperative planning of corneal refractive surgery and cataract surgery.A recent study has shown that corneal HOAs can be a sensitive parameter to differentiate early keratoconus from normal eyes. Furthermore, corneal aberrations have been widely used to evaluate dry eye and orthokeratology.LASIK surgery is widely used in the correction of refractive errors It is well known that LASIK surgery induces high-order aberrations (HOA) .The main eye element involved in the generation of such aberrations is the first corneal surface. Currently, devices based on Placido-disc, Hartmann- Shack, ray tracing, or Scheimpflug are routinely used in clinical aberration measurement. Of which Pentacam is one of common instruments that can only measure corneal aberration (including anterior and posterior corneal surface) based on Scheimpflug technology. Also Allegro Topolyzer is a Placido-based topographer that can measure anterior corneal higher order aberrations (HOAs). A better understanding of the agreement of device measurements can provide clinicians with useful information for measuring, correcting, and monitoring aberrations around refractive and cataract surgery. Investigators , therefore, aimed to study the agreement between the two instruments in anterior corneal aberration measurement.
Assiut University is the lead sponsor of 4,901 studies on the registry; 2,098 are open to participants now.
Of its 13 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
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Patients who will undergo LASIK
Exclusion Criteria:
An informed written consent will be obtained from all patients that will be included in this study. Patients in this study will undergo pentacam and topolyzer examination to asses corneal high order aberrations before LASIK procedure. Patients will be assigned to undergo LASIK. Follow up pentacam and topolyzer examination will be done 3 months after LASIK.
Agreement between placido-based topographer (wavelight allegro topolyzer vario) and scheimpflug -based (pentacam)
Agreement between placido-based topographer (wavelight allegro topolyzer vario) and scheimpflug -based (pentacam) regard measuring corneal high order aberrations before and after LASIK.
Time frame: Before LASIK and 3 months after LASIK
Changes in high order aberrations after LASIK.
Changes in high order aberrations after LASIK using pentacam and topolyzer
Time frame: Before LASIK and 3 months after LASIK
This study is not yet recruiting, as verified in Feb 2024. You cannot join it, but the record below documents what was studied.
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Assiut University