Presbyopia & Cataract Treatment

Presbyopia and Cataract treatment with Multifocal Intraocular lenses (Multifocal IOLs)

For those who have developed cataract and feel the inconvenience of everyday life that glasses are not enough.

Currently there are several kinds of cataract therapeutic drugs used in Japan, but no basic treatment is provided as a cure. If cataract develops and parts of your everyday life begin to feel inconvenient, it is the right timing to undergo cataract surgery. If there are no problems with the other parts of the eye such as the cornea, retina or optic nerves, a smooth visual recovery should be expected.

What is Cataract?

Cataract is an eye disease in which the clear lens of the eye becomes cloudy and opaque, causing decrease in vision. These images describe the comparisons between a normal eye and an eye with cataract. In a normal eye, light passes through a transparent lens to the retina. If the lens is clouded by the effects of cataract, the light passing through is disturbed.

Once cataract occurs, vision decreases and the following symptoms appear due to clouding of the eye lens.

Treatment and surgery of the cataract

Cataract can be easily identified through a doctor's counseling and eye exam. Currently, several kinds of cataract therapeutic drugs are used in Japan, but no fundamental treatment is provided as a cure. Medication for cataract can slow down the progression of the disease, but it is impossible to remove the opacity in the lens. The basics of a cataract treatment are to remove the opaque lens after emulsification using high frequency sound waves.
When you feel that parts of your daily life are inconvenienced or that using glasses are not enough because of the effects from cataract, it is the right time to undergo cataract treatment. A cataract treatment is to remove the opaque lens, and to replace it with an artificial lens (IOL) in the lens capsule.

Visual recovery without any problems is expected if there are no problems with the other parts of the eye such as cornea, retina or optic nerves. Once the intraocular lens is implanted, it will not be necessary to change it. The artificial lens (intraocular lens) to be implanted to substitute the cloudy crystalline lens are available in two types.

Type of artificial lenses - Monofocal IOLs and Multifocal IOLs

The crystalline lens plays a role to adjust perspective by contracting when seeing in the distance and expanding when seeing near. Vision after surgery varies by the function of the implanted artificial lens (IOL) since the function to adjust perspective is lost after removing the opaque lens by cataract surgery. Currently, the two types of artificial lens' (IOL) used in cataract surgeries are monofocal IOLs and multifocal IOLs.

Monofocal IOLs

As described in the name, monofocal IOLs is an artificial lens (IOL) that focuses on a single distance. Vision becomes very bright and easy to see since the cataract cloud has disappeared after implanting the monofocal IOL. However, vision will not be crystal clear for vision such as reading newspapers and distant signboards, due to having only one focus point. When focusing on near objects, distant vision will become blurry; when focusing on the distance, near objects will become blurry. While reading glasses may be required when reading a book in your hand; in case of focusing on far distance (several meters ahead).

Multifocal IOLs (Bifocal IOLs)

This lens is for those who wish to live without depending on glasses as much as possible after cataract surgery

This treatment is currently gathering attention as it combines conventional cataract surgery and the technology of bi-focal IOLs to focus on both distances of near and far, but not full distances. The number of the cases in Japan is expected to increase, since the FDA approved multifocal IOLs in 2005 and the Ministry of Health, Labor and Welfare in Japan approved it in 2007. Conventional "monofocal IOLs" require a choice of a dominant distance to focus on, between near or far. Although vision becomes bright and clear after the cloudiness of a lens has been removed through a cataract surgery, to wear glasses in addition to or wearing reading glasses will be necessary due to being unable to see both a newspaper in hand and a signboard from afar, due to being able to focus on only one distance.
Meanwhile, multifocal IOLs are designed to focus on near and far distances that can improve the quality of your life by decreasing the frequency of use of reading glasses after cataract surgery.

Multifocal IOLs can focus on near and far distances. It differs from monofocal IOLs which can only focus on one distance point.
As shown in the photo, the dependency on glasses will decrease as focusing on a mobile phone's display and scenery in the background will be possible.

Comparisons of focal points after an IOL implantation

※1 In cataract surgery, emulsifying and aspirating the clouded lens with an ultrasonic instrument, and the implantation of an artificial lens. Visual acuity and brightness will significantly improve but could fall short of the target vision such as 1.5 (20/12.5) when compared with refractive surgeries. Please consult with the doctor on the distance you would like to see the most after the treatment.

※2 Dependency on glasses decreases after multifocal IOL (bifocal IOL) surgery. However, it is different from a natural crystalline lens from one's younger days that freely focused on all distances; glasses would be required in cases which you have difficulty seeing in the distance.

Cataract surgery after the refractive surgery (LASIK / ICL)

In general, refractive surgery cannot affect the development or progression of cataract.

Even after undergoing vision correction such as LASIK or ICL for myopia, hyperopia and astigmatism, you will be able to undergo cataract surgery through the same manner of a normal cataract surgery, in a case which cataract occurs due to age or traumatic injury in the future.
Although visual acuity and brightness will significantly improve after a cataract surgery, the target vision could fall short when compared with refractive surgeries, since the cataract surgery is to emulsify and aspirate a cloudy lens by high ultrasonic waves, and replaced with the implantation of an artificial lens.
Please consult with the doctor on the distance you would like to see the most after the treatment.

*If cataract occurs after refractive surgery, the doctor will determine when you should undergo cataract surgery, depending on the progression.