What is a Cataract?

A cataract is a clouding of the lens inside the eye, which leads to a decrease in vision. It develops gradually and is often related to aging. Cataracts can affect one or both eyes but do not spread from one eye to another.

Causes of Cataracts

There are several factors that contribute to the development of cataracts, including:

• Aging: Most cataracts are age-related and develop as people get older.
• Trauma: Injury to the eye can cause cataracts to form.
• Genetic factors: A family history of cataracts may increase the risk.
• Medical conditions: Conditions like diabetes can lead to cataract development.
• Prolonged exposure to sunlight: Ultraviolet (UV) light exposure can contribute to cataracts over time.
• Smoking: Increases the risk of cataract formation.
• Medication: Long-term use of corticosteroids may also cause cataracts.

Symptoms of Cataracts

The following are common symptoms experienced by people with cataracts:

• Blurred vision: The vision becomes cloudy or dim.
• Sensitivity to light: Bright lights can cause discomfort or glare.
• Difficulty with night vision: Cataracts can make it harder to see in low-light conditions.
• Seeing halos around lights: Especially in the evening or nighttime.
• Faded colors: Colors may appear less vibrant than before.
• Frequent prescription changes: A need for frequent changes in glasses or contact lenses.

Types of Cataracts

There are different types of cataracts depending on their cause and location in the lens:

• Nuclear cataracts: Develop in the center of the lens and are commonly associated with aging.
• Cortical cataracts: Affect the edges of the lens and often appear as white, wedge-shaped opacities.
• Posterior subcapsular cataracts: Form at the back of the lens and are common among people with diabetes or those taking high doses of steroid medications.
• Congenital cataracts: Present at birth or develop during childhood, often due to genetics or infections.

Diagnosis of Cataracts

Cataracts are diagnosed through a comprehensive eye exam that includes:

• Visual acuity test: Measures the sharpness of your vision.
• Slit-lamp examination: A special microscope allows the doctor to examine the front structures of your eye.
• Retinal exam: After dilating your pupils, the doctor examines the back of your eye (retina).
• Tonometry: Measures the pressure inside your eye.

Diagnostic Testing

When patients are evaluated for cataracts, the primary objective is to determine the following:

1. is there is a visually significant lens opacity;
2. does the lens opacity account for the patients level of vision;
3. would removal of the cataract likely lead to improved vision and improved level of functioning and is the potential improvement enough to warrant the risks of surgery;
4. would the patient tolerate the operation and be able to follow postoperative instructions and follow up care.

If the answers to these questions lead the patient and physician to agree that surgical intervention is warranted, preoperative planning must be done.

Nonsurgical Treatment

No medical treatment has been shown to be effective in the treatment or prevention of cataracts, although this is an active area of research. To slow the development of cataracts it is generally recommended that patients eat a balanced diet, prevent excessive exposure to UV radiation by using good quality UV blocking sunglasses, avoiding injuries by using protective eyewear, and if diabetic closely control blood sugar levels.
Other approaches to temporarily improve visual function include careful refraction to get the best-corrected vision, pharmacological dilation, increased lighting and the use of magnifiers for near work.

Surgical Treatment

Cataract surgery is one of the most common surgical procedures performed around the world and has a very high success rate. The most common type of cataract surgery in the United States utilizes ultrasound energy to break the cataract into particles small enough to aspirate through a handpiece. This technique is referred to as phacoemulsification. Other techniques include manual extracapsular cataract extraction (ECCE) in which the entire nucleus of the cataract is removed from the eye in one piece after extracting it from the capsular bag. While ECCE traditionally involved a large incision that required multiple sutures, a newer technique known by many names (such as manual small incision cataract surgery or small incision ECCE) allows for manual extraction without the need for any sutures.

The goal in modern cataract surgery is not only the removal of the cataract, but also the replacement of the cataract with an intraocular lens (IOL). The IOL is typically placed during the cataract surgery, and may be placed in the capsular bag as a posterior chamber lens (PCIOL), in the ciliary sulcus, as a sulcus lens, or in the anterior chamber anterior to the iris as an anterior chamber lens (ACIOL). There are multiple types of IOLs that may be used in modern cataract surgery, including monofocal, multifocal, accommodative, light-adjustable, and astigmatism-correcting lenses. The goal of all IOLs is to improve vision and limit dependency upon spectacles or contact lenses.

Recently, the femtosecond laser, familiar to the refractive ophthalmologist for its role in LASIK, INTACS, and corneal transplantation, has been adapted to assist in cataract surgery. This procedure still relies upon the cataract surgeon to remove lens material in a manner similar to phacoemulsification, but it replaces several manual steps of the procedure with a more automated laser mechanism.

Treatment Options for Cataracts

Cataracts can only be removed through surgery, but if the condition is mild, vision may be improved with glasses or stronger lighting. Surgical options include:

• Phacoemulsification (Phaco): A small incision is made in the eye, and an ultrasound device is used to break up the cloudy lens for removal.
• Extracapsular cataract surgery: A larger incision is made to remove the cloudy lens in one piece, often used for advanced cataracts.
• Intraocular lens (IOL) implantation: After the cataract is removed, an artificial lens is implanted to restore vision.

Preventing Cataracts

While cataracts cannot always be prevented, you can reduce your risk by:

• Wearing sunglasses: Protect your eyes from UV rays.
• Managing health conditions: Keep medical conditions like diabetes under control.
• Regular eye exams: Early detection can help manage cataract development.
• Avoid smoking: Smoking increases your risk of cataracts.