According to the International Agency for Prevention of Blindness [IAPB], cataracts are a leading cause of vision loss.  A cataract is a clouding of the natural lens of the eye.  Several types of cataracts can form, but most are due to age-related causes.  Age-related cataracts develop because of biological changes in the eye starting around age 40.  Proteins in the eye’s lens begin to break down and cause the lens to become cloudy.  Cataracts are a natural part of the aging process, and most people will eventually develop cataracts.  Around the age of 60, people typically start to have some clouding of their lenses.   However, vision problems may not happen until years when the clouding worsens.  At that point, patients will require surgery.

Most age-related cataracts will develop gradually over time.  However, other types of cataracts may develop more quickly, such as those in younger people or those with diabetes.  No matter what type of cataract is present, the treatment is always surgery2.  One may not recognize that a cataract is present until vision is disrupted.  Symptoms may include cloudy or blurry vision, faded colors, difficulty seeing at night, bright lights that are too bright, glare or haloes present around lights, double vision, or the continued need for prescription changes.

Credit: NIH Image Gallery from Bethesda, Maryland, USA, Public domain, via Wikimedia Commons

An ophthalmologist diagnoses cataracts through a comprehensive dilated eye exam.  The ophthalmologist will examine the health of the eye with the help of a slit lamp. A slit lamp is a microscope used by the doctor for the exam.

Cataract surgery is one of the most common and oldest procedures performed worldwide, and due to the rapid advancement in surgery and intraocular lens implants (IOL), cataract surgery is considered one of the most successful treatments in medicine today.  However, successful and good surgical postoperative outcomes still involve a thorough preoperative assessment, precise IOL determination and calculations, and proper intraoperative and postoperative management.

Globally, cataracts are responsible for the blindness of approximately 20 million people.  Another 74 million people are visually impaired; of these, 90% live in low- and middle-income countries (LMICs).  Cataracts account for the leading cause of avoidable blindness worldwide, despite the wealth of evidence showing the cost-effectiveness, socioeconomic benefits, and ease of performing surgery.  Additionally, it is one of the most widely undertaken surgical procedures globally.  The World Bank recently recognized cataract surgery as an “essential surgery.”

Risk Factors.

Age is the most significant risk factor for developing a cataract.  If individuals live long enough, they will eventually experience cataracts.  Vision may or may not be affected by the developing cataracts and may be subjective.  Other risk factors include:

• Diabetes or elevated blood sugar;
• Steroid use (oral, intravenous, or inhaled);
• Ultraviolet exposure;
• Smoking;
• Ocular diseases: Retinitis Pigmentosa, Uveitis;
• Ocular trauma;
• Prior ocular surgery;
• Genetic predisposition;
• Cataracts associated with dermatologic diseases; and
• Radiation or chemo treatment.

Top image Credit: Paul Holden, Lubango Angola, CC BY-SA 4.0 via Wikimedia Commons