Surgically Induced Keratometric Effect in Cataract Surgery
Research type
Research Study
Full title
Surgically Induced Keratometric Effect in Cataract Surgery (SIKECS): a paired-eye randomised control trial to investigate the refractive outcomes in patients undergoing cataract surgery
IRAS ID
249584
Contact name
Esmaeil Arbabi
Contact email
Sponsor organisation
Royal Liverpool University Hospital
Duration of Study in the UK
1 years, 10 months, 28 days
Research summary
Cataract surgery replaces the cloudy lens inside the eye with an artificial lens (IOL: Intraocular lens). Various calculations are available to determine the strength of the IOL required to attain a target refractive outcome after surgery (i.e. equivalent to the patient’s glasses prescription). These are generally based on measurements taken prior to surgery including the length of the eye and the curvature of the cornea (keratometry).
However, the actual refractive outcome achieved following surgery can be significantly different from the surgeon’s target refractive outcome. Modern advances in surgical techniques including smaller incisions and improved prostheses have increased the importance of controlling refractive outcomes for patients undergoing cataract surgery.
Our previous study on 199 eyes demonstrated that the incisions made in the cornea during cataract surgery change its curvature by a significant and predictable amount; this is the Surgically Induced Keratometric Effect (SIKE). We hypothesis that the precision of the actual refractive outcome will be more comparable to the target refractive outcome if the average the change in curvature for the cornea is factored into the calculation.
We propose a multicentre, randomised control trial in 106 patients (212 eyes) aged over 18 that are awaiting cataract surgery in both eyes. Patients will undergo a standardised cataract operation but their eyes will be randomised to receive an IOL of strength determined by either a modified or unmodifed IOL calculation. The unmodified IOL calculation is the standard IOL power calculation using the pre-operative corneal curvature. The modified IOL calculation is the standard IOL power calculation modified by the change in the curvature of the cornea due to the surgical incision.
We aim to reduced the difference between the target and actual refractive outcome, and determine if factoring the SIKE into the equation will give a more precise refractive outcome in cataract surgery.REC name
North West - Liverpool Central Research Ethics Committee
REC reference
19/NW/0241
Date of REC Opinion
10 Sep 2019
REC opinion
Further Information Favourable Opinion