View clinical trials related to Aberration, Corneal Wavefront.
Filter by:Aberrations are the spreading of light from a point focus. Aberrations of the eyes can be objectively evaluated with a wavefront aberrometer. Lower order aberrations such as defocus and astigmatism can be corrected with glasses and traditional/disposable soft contact lenses. Patients with ectatic corneal disease, such as keratoconus, or irregular astigmatism cause by surgery, trauma or disease, experience vision that is unlikely to be adequately corrected with glasses or disposable soft contact lenses due to higher order aberrations (HOA). HOA's cause halos, flare, glare, starbursts, doubling, smearing or ghosting of vision. Specialty contact lenses, such as scleral lenses, can be used to mask the irregularity of the cornea, reducing HOA's and improving vision. In many patients the resultant vision, though improved, still has some level of residual HOA's affecting the quality of vision. Custom scleral lenses with customized wavefront guided optics can be used to reduce residual HOA's and improve vision further. These lenses have been referred to as higher order aberration correcting scleral lenses or HOA correcting sclerals and wavefront guided scleral lenses or WFG sclerals.
Refractive surgeries can be divided into two distinct categories: 1) corneal surgeries (superficial and deep procedures) carried on the surface of the eye and 2) lens surgeries (phakic IOL, refractive lens exchange) - an intraocular intervention, performed in the anterior or posterior chamber or on the lens. In the proposed protocol focus is on the corneal refractive surgeries impact on monochromatic higher-order aberrations on the one hand and chromatic aberrations on the other. During the surgery in order to get the patient emmetropic, refractive surgery corrects optical defects by decreasing aberrations of lower orders ) simultaneously increases high-order aberrations (that is perceived by the patient as halo, glare or starburst). Informations about prevalence and causes of higher order aberrations after refractive surgery are numerous but there is no information about chromatic aberrations.