View clinical trials related to Corneal Wavefront Aberration.
Filter by:To explore whether cornea structure, and optical quality are affected by the covid-19 infection.
The investigators are proposing this research project to: 1. Screen a set of patients after normal cataract surgery with a single focus lens aimed at good distance vision at 3 months after surgery to identify patients who are able to see and read well without glasses. 2. Identify the combination of factors responsible for this phenomenon in the patients who are achieving this. Potentially eligible patients will be given an invitation letter and patient information sheet on the day they arrive for surgery. They will then be asked if they are happy to be contacted by phone 2-4 weeks post-surgery with a view to booking them into an additional research visit at 3 months after their surgery. At 3 months after surgery they will have their un-corrected vision checked. They will also have their reading speed assessed without any glasses. They will undergo a through refractive check by an optometrist to assess the power of the spectacles (if needed) and following this they will have a scan of the eye (a technique known as wave front analysis which uses very sophisticated optics) to capture the optical distortions in the structures of the eye. If this study is able identify factor/s responsible for giving good unaided reading and distance vision then this factor can be reproduced in eyes undergoing cataract surgery. This will mean that the patients can have an increased option of spectacle independence without the need for expensive multifocal IOLs and their associated side effects such as glare and halos, particularly at night.
Aberrations play a significant role in the visual process and can be divided in lower-order and higher-order aberrations. The former can be measured using the commercially available IOL Master (Carl Zeiss Meditec AG, Germany) and have profound influence on visual acuity. Higher-order aberrations do not significantly influence visual acuity but affect the quality of vision and can cause halos, double vision, and night vision disturbances. Background Cataract surgery has become a routine procedure in the developed countries. During this surgery, a foldable intraocular lens is usually inserted into the capsular bag. However, these lenses do not account for individual optical biometry data or aberrations. Therefore, it is important to provide data for ametropic and emmetropic eyes as this information might improve future intraocular lens design and lead to individually adapted lenses for yielding optimal visual acuity and quality results. The aim of the present study is to clarify the correlation between refractive errors/axial eye length and spherical aberrations of the cornea.