Why am I being invited?
You are being invited to this study because you have cataracts in both eyes and meet the other inclusion criteria of the study.
We are looking for participants who are keen to reduce their dependence on glasses and require cataract surgery. To take part, patients should not have any other eye problems that could affect their vision after surgery (free of any other eye diseases; for instance, amblyopia, glaucoma, squint, macular degeneration, etc.), and who have corneal astigmatism not much greater than 2.50 dioptres.
What is the purpose for the study?
The purpose of this study is to compare two modern multifocal intraocular lenses to see which if any of the two provides the best quality vision with the least chance of unwanted visual side effects.
The two multifocal intraocular lenses under investigation are:
Alcon Clareon PanOptix intraocular lens – an established trifocal intraocular lens made from a hydrophobic acrylic material.
Rayner Galaxy Spiral intraocular lens – a modern multifocal intraocular lens made from a hydrophilic acrylic material.
Studies suggest that hydrophobic acrylic lenses, such as the PanOptix lens, may be associated with a slightly lower risk of developing posterior capsule opacification (PCO), whereas hydrophilic acrylic lenses, such as the Galaxy Spiral lens, may carry a slightly higher risk. PCO - the thickening of the natural lens capsule that holds the artificial lens in place – is a common and almost inevitable consequence of cataract surgery. It may lead to a gradual blurring of vision. If this occurs, it can be treated with a quick and effective laser procedure called a YAG laser capsulotomy, which is routinely performed in the outpatient clinic. Although the procedure carries some risks, these are generally minimal.
The two study lenses also differ in their optical design, which may influence how light is focused within the eye and how patients perceive contrast, glare, or halos. The PanOptix lens uses a diffractive trifocal design to provide three focal points (near, intermediate, and distance), while the Galaxy Spiral lens uses a non-diffractive spiral pattern intended to create a continuous range of vision and reduce halos.
Comparing these two lenses in a structured, masked study will help determine whether the different design provides comparable visual performance and patient satisfaction under real-world conditions.
If you decide to take part in this study, you will be "randomised" into one of the lens groups described above. Randomisation means that you are allocated to a group by chance (like flipping a coin). There is no way to predict which group you will be assigned to. You will have a 1 in 2 chance (or 50% chance) of being placed in either group. A computer-generated programme will decide which of the two multifocal implants will be used for you.
The surgeon who performs your operation will know which lens is being implanted, because the surgical team needs this information to prepare and order the lens safely. However, you will not be told which lens was implanted until the end of the study. Similarly, the study team who examine your vision and collect your results will not know which lens was implanted.
This approach helps make sure that the study results are fair and unbiased when comparing visual and quality-of-life outcomes between the two lenses. If it becomes medically necessary for safety reasons, the study doctor can immediately find out which lens you have received.
What are the possible benefits of taking part?
Multifocal intraocular lenses are designed to provide clear vision at several distances - near, intermediate, and far - reducing the need for glasses after cataract surgery. Many people who receive these lenses find that they can manage most daily activities, such as reading, driving, or using a computer, without spectacles. In previous studies, up to eight in ten patients reported being completely free from glasses after multifocal intraocular lens implantation.
Although these lenses are widely used in private practice, they are more expensive than conventional single-focus (monofocal) lenses and are not routinely available to NHS patients, primarily because of associated costs. By taking part in this study, NHS patients will be offered multifocal lens implantation free of charge, as part of the research.
In addition, participating in this study will allow your vision to be monitored closely through detailed tests and follow-up visits, providing information that may help improve cataract care for future patients.
Do I have to take part?
No, participation in this study is voluntary. It is up to you to decide whether to take part. You can stop taking part in the study at any time without giving a reason.
If you decide you want to take part in the study, you will be asked to keep this participant information sheet and sign an informed consent form. You will be given a copy of the signed informed consent form to keep.
If you decide not to take part, this will not affect the standard of care you receive and you will continue receiving your normal standard of care.
The rest of this participant information sheet provides more information to help you decide if you want to join.
How many people will be in this study?
Around 310 people are expected to take part in this study, which will run in two stages:
Phase 1 (Pilot Study) - The first 60 people. This pilot study inform us that all study procedures work well and that we can smoothly deliver the main study later.
Phase 2 (Main Study) - The remaining 250 participants
What will happen if I decide to take part?
If you decide to take part, you will be asked to sign the consent form which you received before your NHS consultation, or that was given at your NHS pre-operative visit. A member of the study team will explain the study and answer any questions. You will receive copies of both the consent form and this information leaflet to keep, and a signed copy of your consent form will be safely stored in your medical records.
Only once you have given consent will the study team be able to look at your medical records to move forward.
The study lasts for about three months, during which you will attend your usual cataract appointments (NHS Standard of care at Moorfields) as well as a few extra visits arranged for research purposes.
Multifocal intraocular lens in bilateral cataract surgery is the G-PERFECT study. The study is sponsored by Moorfields Eye Hospital NHS Foundation Trust and funded by Alcon Eye Care UK Limited.
