Cataract

Introduction

A cataract is a clouding in the lens of the eye, which changes the way light passes through the lens.

• It usually develops slowly and may occur in one or both eyes.

Risk Factors

Risk factors for cataracts include

• Increasing age - the most common cause
• Family history of cataracts
• Smoking
• Alcohol consumption
• Long-term sunlight exposure
• Certain medical conditions, e.g. diabetes
• Certain medicines, e.g. prednisolone

Symptoms

At first, you may not notice that you have a cataract. But over time, cataracts can cause symptoms such as

• Cloudy, blurred or double vision
• Fading or yellowing of colours
• Poor night vision
• Increased sensitivity to glare. A halo may appear around lights

Management

Initially, cataracts may be managed with

• New spectacles,
• Brighter lighting,
• Anti-glare sunglasses and
• Magnifying lenses for reading and other activities.

When cataract symptoms interferes with daily living activities, cataract surgery and placement of an intraocular lens should be considered.

• Once a cataract is removed, it cannot grow back.
• The artificial lens requires no care and can significantly improve vision.
• People who have had cataract surgery may have their vision become hazy again years later. This is usually because the eye's capsule has become cloudy. Ophthalmologists can use a laser to open the cloudy capsule and restore clear vision. This is called a capsulotomy.

Supplements

The role of diet and antioxidant supplements has been studied with mixed conclusions.

• A 2012 Cochrane Systematic Review of nine randomized controlled trials found no evidence to support high doses of vitamin E, vitamin C, or beta-carotene in preventing development or progression of cataract.
• In a 2015 randomized clinical trial, neither selenium nor vitamin E supplementation appear to reduce incidence of age-related cataract in men >50 years old
• A 2019 systematic review about the role of nutrient supplementation on lens pathology found that vitamin C, beta-carotene, and lutein and zeaxanthin had a protective effect against cataract, but this analysis included observational data.

Summary

External Links

• American Academy of Ophthalmology - Cataracts
  
• MSD Manual Professional - Cataract
  
• National Eye Institute - Cataracts
• Antioxidant vitamin supplementation for preventing and slowing the progression of age-related cataract, 2012
  
• Age-related cataract in men in the selenium and vitamin e cancer prevention trial eye endpoints study: a randomized clinical trial, 2015
  
• The potential role of nutrition on lens pathology: a systematic review and meta-analysis, 2019
  
• Cataract in the Adult Eye Preferred Practice Pattern, 2022