A Randomised, Controlled Study to Compare Visual Performance Following Bilateral, Micro-monovision Insertion of Two Monofocal, Aspheric, Hydrophobic Acrylic Intraocular Lenses: The TECNIS Eyhance® ICB00 and the Alcon IQ SN60WF Lenses

This study is a clinical trial, designed to compare visual outcomes after cataract surgery with two different intraocular lenses. As previously described, modern day cataract surgery is composed of two main components: removal of the cataract, and insertion of an intraocular lens (IOL). The role of the intraocular lens is to replace the focusing power of the natural crystalline lens inside the eye. It is this lens that becomes a cataract. Removing a cataract alone helps light enter the eye, but does not focus it well. Prior to the invention of intraocular lenses, patients required extremely thick and strong glasses for both distance and near vision.

Currently only monofocal intraocular lenses are available on the NHS. Different strengths of lens can be chosen to give the patient good distance, intermediate or near vision. That means the ability to focus on objects in the distance, middle distance or near. Most patients opt for good distance vision, enabling them to mobilise easily, watch TV and drive, and require glasses for reading.

As described above, most patients over the age of 50, have some element of presbyopia, which is the inability to focus on near objects, resulting in the need for reading glasses. Inserting extended depth of focus (EDoF IOLs) intraocular lenses during cataract surgery, can help improve their reading vision without reading glasses.

The TECNIS Eyhance ICB00 IOL is a new EDoF IOL which has an enhanced depth of focus through its novel 'enhanced aspheric' design. This will help treat presbyopia. The Alcon Acrysof IQ SN60WF IOL is an established IOL which gives good monofocal vision, i.e. good distance or near vision, but not both.

Our trial will investigate the effect of a new Extended depth of focus lens on vision and compare it to a commonly used Monofocal IOL. The investigators will recruit patients who have bilateral cataracts. These patients will have otherwise healthy eyes. Patients who have been referred to St Thomas' Hospital for assessment for cataracts will be considered for the trial. If they fulfil the criteria for acceptance to the trial, the consulting doctor will discuss this with the patient. If the patient expresses interest, they will be referred to the Research department. The cataract research fellow will review them and consider them for admission to the trial. This review will happen on the day of the original appointment, or the patient will be given an another appointment time and date for further assessment. If a patient would like further information about the study, but cannot speak to the Cataract Research Fellow that same day, they will be asked to fill in a Consent to Contact form, which will allow the research department to contact the patient for consideration for entry to the study.