Achieving spectacle independence or reducing spectacle dependence is a goal for many of our patients undergoing cataract surgery and it is almost always the goal with refractive lens exchange. At Fendalton Eye Clinic we have been offering lifestyle lenses since the late 1990s. There is no intraocular lens that can perform like a 20 year old natural human lens and with every option there are some compromises or side effects.
Each patient is different in what they would like to achieve and which compromises might suit their individual life style.
Fendalton Eye Clinic offers three types of IOLs for reducing dependence on near vision spectacles after cataract surgery or refractive lens exchange with intraocular lenses (IOLs). These are:
Note that all types of IOLs are available as a toric version. Toric means that the IOL has a different curvature in different axes and hence can correct astigmatism.
The FineVision trifocal IOL has three focal points located at infinity, 80cm and 40cm.
Trifocal IOLs are designed to give vision at distance, intermediate and near. All trifocal IOLs split light rays to the three focal points using diffraction grating technology. The design has an asymmetrical light distribution of 50 %, 20 % and 30 % between far, intermediate and near foci. Trifocal IOLs are best suited to people who want the maximum possible freedom from spectacles but are prepared to tolerate night vision disturbances including halos around lights and starburst (a light looks like a large star). I’ve found a high level of patient satisfaction with all three of the widely available trifocal IOL in patients who want to be able to see all distances without glasses and are happy to tolerate or adapt to night time halos. Published studies and my own personal experience is that about 95% of those with a trifocal IOL are independent from spectacles and 97% are happy or satisfied. About three percent will not be as satisfied or be dissatisfied. The main reasons include:
I started using this EDoF IOL from Germany company Oculentis in October 2012. This is a segmented multifocal IOL with the top segment of the IOL for distance vision and the bottom segment for intermediate vision. The Oculentis Comfort MF 15 has a single blended transition zone, works to give the same kind of distance vision as with a standard monofocal IOL, but with the addition of intermediate vision. It provided enhanced intermediate vision at 60cm or more. The IOL offers good contrast sensitivity for night time vision.
As with other EDoF IOLs, the Oculentis Comfort is designed to give spectacle independence that is between a standard IOL and trifocal IOL. Its biggest advantage is that it provides independence at the intermediate range that patients are looking for when wanting to work at computer screens, use a cell phone or a tablet. Some people find that they don’t require reading glasses for reading as long as the print has good contrast and size and there is good lighting. However, I cannot promise that you will not need reading glasses with the Oculentis Comfort.
The Oculentis Acunex Vario is the same optical design as the Oculentis Comfort IOL. The main difference is that instead of being made from hydrophilic acrylic plastic, it is made using hydrophobic acrylic plastic.
Monovision is where one eye can see clearly in the distance and the other eye is intentionally made short-sighted so that it has either near reading vision (full monovision) or intermediate (arms-length) distance vision (limited monovision). It is a good option for those who have successfully practiced monovision with contact lenses and are happy with it. If you have higher amounts of astigmatism, then monovision can be achieved using toric IOLs that correct astigmatism.
We only use monovision with monofocal IOLs in patients who have practiced monovision with either contact lenses, following laser refractive surgery (LASIK, SMILE or PRK) or have had it naturally and want to continue with the same.
Monovision does focus your two eyes at difference distances and this may affect binocularity or the ability to judge depth or distances.
Monovision is a compromise because the distance eye does not read without glasses and the near eye cannot see in the distance. There may still be times when top-up glasses will be required such as:
Published studies have shown about a quarter of patients given monovision with monofocal IOLs are spectacle independent.
The main advantages of monovision are that using modern aspheric monofocal IOLs or toric IOLs usually gives good optical quality without halos, ghosting or glare. With monovision you can still wear glasses that correct both eyes for distance or both eyes for near vision and achieve good optical quality.