Cataract

Cataract is a disease that causes the lens in the eye to become cloudy due to aging or other factors. The incidence increases with age, Early onset in people in their 40’s and most people in their 80’s and older showing symptoms.

“What can cataract symptoms look like?”
“Can I check if I have cataract by myself?”
“Is it a disease that can be cured by surgery?”

This article answers the above questions.

What is cataract?
Symptoms and causes
Cataract treatment and progression

Advances in intraocular lenses and surgical methods have now made cataract surgery safer and faster. Regular eye visits are recommended for the early detection and early treatment of cataracts and others for individuals who are 40 and over.

The lens in the eye is a colorless, transparent tissue that serves as a lens. A cataract is a disease in which this transparent lens becomes cloudy white, resulting in vision loss. It is predominantly caused by aging, which leads accumulation of waste products and denaturation of proteins in the lens.

Vision is reduced because when the lens becomes cloudy, light entering the eye is diffusely reflected and does not reach the retina properly. It has been noted that cataracts begin to appear as early as 40 years of age, and that most people over the age of 80 have cataracts.

Approximately 90% of the causes of cataracts are age-related (aging cataracts). In addition, the other eye diseases, trauma or steroid drug side-effects may also be a trigger.

< Cataract classification by cause of development>

• Age-related cataracts are the most common cause and account for about 90% of all diagnoses. Aging causes progressive lens opacity.
• Complicated　cataract　caused by other eye diseases such as retinal detachment or uveitis
• Atopic cataracts are caused by atopic dermatitis and is also related to irritation such as scratching the eye due to itching.
• Diabetic cataracts – Diabetes can cause cataracts.
• Traumatic cataract – Caused by impact or trauma, such as striking something on the eye. Traumas can also accelerate cataract progression
• Juvenile cataracts may form in an individuals’ 20’s and 30’s. UV rays, stress, and developmental cataracts are also possible
• Steroid cataracts are caused by oral medications used to treat systemic diseases and inhaled medications used for asthma

Cataracts are a progressive disease. It can be classified into four stages according to the stage of progression.

The more advanced the cataract, the greater the impact on daily life and the more difficult to treat. In advanced cases, there is an increased risk of difficulty in restoring vision after treatment, so if you notice any change in vision, see an ophthalmologist as soon as possible.

This section describes the tests performed by an ophthalmologist to diagnose a suspected cataract.

Visual Acuity/Contrast Sensitivity Test

These tests measure both visual acuities with the naked eye and the corrected vision with spectacles etc. When people feel that their glasses no longer fit or that they have difficulty seeing, they tend to think that their nearsightedness (myopia) has progressed, but depending on their age, there is no denying that cataracts may have developed or progressed.
When cataracts develop, there is a decrease in ‘contrast sensitivity’ to clearly distinguish objects, not just visual acuity. Contrast sensitivity testing is also important because symptoms such as difficulty driving on dark night roads or glare from sunlight can appear.

Refractive Examination

Refraction exams measure the type and degree of refraction, including farsightedness, nearsightedness and astigmatism. It is to check if any abnormal refractions in the eye due to cataracts.

Intraocular Pressure Examination

The intraocular pressure is the pressure exerted from inside of the eye. It is mainly used in glaucoma testing, but is also used in cataract testing, as intraocular pressure can be elevated in some cases when cataract develops.
Intraocular pressure is measured by sending compressed air to temporarily indent the surface of the eye.

Slit-lamp examination

This is a microscopic examination performed by shining a long, thin light called a slit lamp into the eye. Not only the lens, but also the cornea and iris are observed.

For early cataracts with milder symptoms, such as blurred eyes or poor vision, it is common to have a follow-up exam conducted. However, surgery is required for fundamental treatment of cataracts.

Follow-up notes

In the early stages of cataracts, there are cases of lens power change in nearsightedness, farsightedness, or astigmatism. Visiting an ophthalmologist and having suitable glasses made may make it easier to see.
However, when it is difficult to see an object even with glasses, or when double or triple vision is observed, surgical treatment may be selected.

Cataract surgery

A common operation for cataracts is phacoemulsification. In this surgery, the lens is crushed and aspirated out, and an intraocular lens is newly placed instead.
Due to the increasing aging population, according to Japan Ministry of Health, Labor and Welfare’s publications, approximately 1.5 to 1.7 million cataract surgeries per year in the country. With advances in intraocular lenses and surgical techniques, day surgery is often applicable. Local anesthesia is administered to the eye only, and the procedure can be completed in as little as 10 to 20 minutes.
The surgery is performed not only in large hospitals but also in ophthalmology clinics. It is a delicate procedure performed by ophthalmologists who specialize in cataract surgery using specialized surgical equipment.

The1950’s saw the creation of intraocular lenses, essential for cataract surgery. Until then, only the surgery to remove the lens from the patient was possible.
Along with advances in surgical techniques, lenses have also evolved into to be more sophisticated. Especially with the development of lenses called multifocal lenses, a growing number of people are reducing the use of glasses after surgery.

Intraocular lens safety

Intraocular lens replace the crystalline lens and provide long-term visual support after surgery. Because it’s part of your body, it’s no surprise that you care about quality and safety.
Generally, intraocular lenses used in Japan are medical devices approved by the Ministry of Health, Labour and Welfare, and are highly safe, having passed rigorous reviews.
The questions below have been confirmed, as well as other factors before the actual surgery. To minimize damage to the cornea, the intraocular lens is folded and inserted, after insertion,

• Return to original shape?
• Be strong enough?
• No lens deterioration inside the eye?
• Allergic reactions and toxicity to the human body

The material is often soft acrylic, and the lens lifespan is considered to be “longer than the patient’s life expectancy”.

Although the onset of the age-related cataracts can happen to anyone, it is possible to reduce the risk of onset and progression depending on one’s daily activities.

Protect from UV rays

It is said that oxidation and denaturation of proteins causes the crystalline lens to become cloudy. Ultraviolet rays are a factor in their oxidation, so when going outside, use sunglasses and hats to protect from UV rays reaching the eyes as much as possible.

Quit smoking

Studies have shown that smoking increases the risk of cataract development, while quit-smoking can reduce such risks.
Nicotine in cigarettes not only constricts capillary blood vessels and worsens blood flow, but the components of the smoke are said to destroy vitamin C. Vitamin C has antioxidant properties that can limit the development of cataracts but smoking also prevents these effects.

Take measures to prevent diabetes

Diabetes is one of the causes of cataracts. The onset of diabetes can be as early as people’s 30’s or 40’s, which can lead to the development of cataracts at a young age.
High blood sugar levels can also make it easier to accumulate sugar in the lens, which can lead to cataracts that develop and progress. Adequate measures against diabetes can also slow the development and progression of cataracts.
It is important to review your lifestyle and control your blood sugar levels with a balanced diet and moderate exercise habits.

Q: Who is prone to cataracts?

Cataracts caused by aging and senescence are more likely to occur in older people. There is also a risk of complications and UV radiation, and young people may develop cataracts if they have diabetes or atopic dermatitis.

Q: What are the early symptoms of cataracts?

Age-related cataracts begin to gradually cloud around the lens of the eyes. In most cases, there are no subjective symptoms in early cataracts. As the cloudiness of the crystalline lens progresses, symptoms such as white hazy vision, foggy vision, and double vision or blurring of objects appear.

Q: I want to treat cataracts without surgery. Is it possible?

A cataract has progressed to the point where the white, cloudy lens cannot be cured by any means other than surgery. If the condition is advanced, it can be treated by replacing the crystalline lens with an artificial intraocular lens.