What are the causes of cataract formation?

From the Guidelines

Cataracts are primarily caused by aging, as well as other significant factors including diabetes, prolonged exposure to ultraviolet light, smoking, long-term use of corticosteroid medications, and certain medical conditions like hypertension. These causes can lead to the breakdown and clumping of proteins in the eye's lens, resulting in clouded vision. Other factors that may contribute to cataract formation include genetic predisposition, radiation exposure, poor nutrition, and previous eye injuries or surgeries 1.

Key Causes of Cataracts

• Aging: The most common cause of cataracts, as the proteins in the lens break down and clump together over time
• Diabetes: Alters lens metabolism, increasing the risk of cataract formation
• Prolonged exposure to ultraviolet light: Damages the lens and increases the risk of cataracts
• Smoking: Introduces oxidative stress, which can contribute to cataract formation
• Long-term use of corticosteroid medications: Increases the risk of cataract formation
• Certain medical conditions: Such as hypertension, which can increase the risk of cataracts
• Genetic factors: Some people may have a hereditary predisposition to developing cataracts
• Radiation exposure: Can damage lens proteins and increase the risk of cataracts
• Poor nutrition: Deficiencies in antioxidants may contribute to cataract formation

According to a recent study published in Ophthalmology in 2022 1, preventive measures such as a healthy diet rich in fruits and vegetables, long-term increased physical activity, and exercise may decrease the risk of cataract. Additionally, cessation of smoking and management of chronic conditions like diabetes can also help reduce the risk of cataract development or progression. Regular eye examinations are essential for early detection, as cataracts develop gradually and may not cause noticeable symptoms initially.

It is also important to note that certain medications, such as phenothiazines, have been associated with anterior subcapsular opacities, and long-term users of inhaled or oral corticosteroids are at higher risk of cataract formation 1. However, the use of intranasal corticosteroids is not associated with a significant risk of incident cataract. A well-balanced diet rich with fruits and vegetables is a reasonable recommendation based on observational studies, and moderate evidence suggests that a multivitamin/mineral supplement may decrease the risk of cataract 1.

From the Research

Causes of Cataract

• Age-related cataract is a leading cause of visual disability and blindness, with older age being the primary risk factor 2
• Additional risk factors for cataracts include:
  • Hereditary or genetic predisposition 2, 3
  • Certain medications (corticosteroids) 2, 4
  • Ocular trauma 2
  • Significant UV exposure or radiation therapy 2
  • Certain medical conditions such as:
    • Uncontrolled diabetes 2, 5, 6
    • Retinitis pigmentosa 2
    • Down syndrome 2
    • Congenital rubella 2
    • Smoking 3
    • Obesity 3
    • Poor nutrition 3
    • Lower socioeconomic status 3
    • Alcohol use 3

Specific Causes

• Prolonged use of glucocorticoids is a significant risk factor for the development of posterior subcapsular cataract 4
• Diabetes mellitus affects different parts of the eye and causes many complications and problems before, during, and after intraocular surgeries 5, 6