cataract
CATARACT
Cataract is the presence of opacity in the crystalline lens of the eye. It causes painless, progressive blurring of vision.
It is the leading cause of blindness worldwide and the most prevalent ocular disease.
The initiating events that lead to loss of transparency of both the cortical and nuclear lens tissue is the oxidation of the membrane lipids, structural or enzymatic proteins or DNA by peroxidases or free radicals induced by UV light.

Introduction

  • Cataract is the presence of opacity in the crystalline lens that causes painless, progressive blurring of vision
  • Leading cause of blindness worldwide & the most prevalent ocular disease
  • Mechanism of cataract formation is multifactorial
  • Chronic & age-related

Signs and Symptoms

  • Decreased vision & increased problems w/ glare are the hallmark symptoms
  • Increased nearsightedness called “myopic shift “before opacity of the lens occur
  • Typically bilateral but often asymmetrical

Etiology

  • Initiating events that lead to loss of transparency of both the cortical & nuclear lens tissue is the oxidation of the membrane lipids, structural or enzymatic proteins or DNA by peroxidases or free radicals induced by ultraviolet (UV) light

Risk Factors

  • Increasing age
  • Ultraviolet (UV) radiation - ultraviolet B (UVB) cumulative lifetime exposure
  • Diabetes mellitus, hypertension, high body mass index
  • Drugs (eg long-term topical, systemic or inhaled corticosteroids, Phenothiazine, Chlorpromazine)
  • Smoking
  • Drinking excessive amounts of alcohol
  • Gender - females are most likely to have cataract & progress to blindness
  • Nutrition - low antioxidant levels is associated w/ increased risk of cataract formation
  • Obesity
  • Dehydration/diarrheal crises
  • Genetics in age-related cataract cases (eg cortical cataracts & nuclear cataracts)
  • Prior intraocular surgery
  • Moderate to high myopia
  • Exposure to ionizing radiation (eg chest x-ray, radiation therapy)
Editor's Recommendations
Most Read Articles
3 days ago
Nonsteroidal anti-inflammatory drugs (NSAIDs) appear to increase the risk of major bleeding, stroke or systemic embolism, and hospitalization among patients with atrial fibrillation (AF), suggest the results of the RE-LY* trial. Moreover, there is no difference in the safety and efficacy of dabigatran etexilate (DE) 150 and 110 mg twice daily relative to warfarin.
Stephen Padilla, 6 days ago
Diabetic patients in a decompensated state and who develop type 2 myocardial infarction (MI) have an increased risk for mortality and major adverse cardiac events (MACE), according to a new study. In addition, these patients are potentially at risk for undiagnosed coronary artery disease.
14 Jul 2018
Chocolate consumption is not associated with risk of coronary heart disease (CHD), stroke or both combined in postmenopausal women free of pre-existing major chronic disease, a study suggests.
Yesterday
Although many patients with atopic dermatitis (AD) use antihistamines, no high-level evidence exists to prove that nonsedating antihistamines reduce itch in patients with AD or provide benefit in controlling AD symptoms, except perhaps sleep and AD comorbidities such as allergic rhinitis, according to a study.