To understand the pathology of cataract it is important to have a basic knowledge about eye lenses.
What is the eye lens?
The eye lens, also known as the crystalline lens, is an essential part of the eye’s anatomy that aids in focusing on objects at different distances
As cataracts are a condition in which the eye lens is affected, it is helpful to provide a brief overview of the eye lens to enhance the understanding of cataracts.
The eye lens consists of three main parts:
- The lens capsule,
- The lens epithelium
- and the lens fibers.
- About 60% of the lens is made up of proteins.
Where is the eye lens located?
The eye lens is located behind the colored part of the eye, called the iris. It is situated just behind the pupil and is held in place by tiny ligaments.
What is the anatomical structure of the lens?
Anatomically, the lens consists of transparent, flexible layers of protein and water, enabling it to change shape for focusing. It is suspended behind the iris and pupil and has a biconvex structure.
What is the primary purpose of the eye lens?
The main function of the eye lens is to bend and focus light rays onto the retina of the eye to create a sharp image.
Why do the shapes of the lens change?
The shape of the eye lens changes to focus light on the retina thus it can create sharp images.
What happens when the light crosses the eye lens?
The retina converts light into signals and then transmits these signals to the optic nerve, which is responsible for carrying them to the brain.
What is the main pathology of cataracts?
When proteins in the eye clump together, they can hinder the lens from transmitting clear images to the retina.
What are the 3 types of cataracts?
- Cortical cataracts,
- Posterior Subcapsular cataracts,
- Nuclear Sclerotic Cataracts.
Which cataract is the most common type of age-related?
A nuclear cataract is the most frequent type of age-related cataract, which is caused by the hardness and darkening of the eye lens.
Causes of Cataracts:
- Ultraviolet radiation,
- Eye injury,
- Ultraviolet (UV) radiation
- Eye injury or trauma
- Medical conditions
- Radiation exposure
- Poor nutrition
- Heavy alcohol consumption
- Other environmental factors
- Radiation therapy,
- Long-term use of medication i.e., steroids
- Occur as a complication of some chronic diseases such as diabetes.
- Cataracts are developed when aging or injury changes in the tissue that is involved to make up the eye’s lens.
Are cataracts genetic?
Cataracts may be genetic because some people are born with cataracts. But these may be associated with trauma or intrauterine infection.
What kind of radiation can cause cataracts?
Ionizing radiations (e.g., gamma and X-rays) may induce cataracts.
Sign and Symptoms:
- Blurred, clouded vision,
- Sensitivity of light,
- Double vision in the affected eye,
- Trouble seeing at night,
- Seeing halos around lights,
- Cloudy or hazy vision
- Difficulty seeing at night,
- Sensitivity to glare,
- Fading or yellowing of colors,
- Halo effects around lights,
- Poor depth perception,
- Decreased visual acuity,
- Frequent changes in eyeglass or contact lens prescription,
- For people who are suffering from cataracts, is a bit like looking through a fogged-up or frosty window.
How fast do cataracts grow?
Most age-related cataracts can grow gradually over a period of years but predicting the exact time period of progression time is not possible. Diabetic patients having cataracts may progress rapidly over a short period of time.
What happens if the eye lens becomes completely opaque due to cataracts?
As the function of the eye lens is to focus light and images clearly onto the retina when the eye lens becomes damaged for any reason then the formation of a clear image of any object is not possible.
When to see a doctor?
When you feel any changes in your vision, you should take an appointment with a doctor.
Can cataract blindness be reversed?
Yes, cataract surgery can frequently restore vision in those who have developed cataracts. The clouded natural lens of the eye is removed during cataract surgery and replaced with an artificial intraocular lens (IOL), a common and extremely successful treatment. This procedure, which is usually done as an outpatient, can restore good eyesight. After cataract surgery, the majority of patients notice a considerable improvement in their vision, and it can successfully prevent further vision loss brought on by cataracts.
How cataract is diagnosed?
Medical History: The eye care provider will begin by taking a detailed medical history, including information about any symptoms, existing eye conditions, family history of eye problems, and any medications you are taking.
Visual Acuity Test: This is a standard eye chart test where you read letters or symbols on an eye chart to determine how well you can see at various distances.
Slit-Lamp Examination: A slit-lamp examination allows the eye care provider to magnify and closely examine the structures of the eye, including the lens, to detect any signs of cataracts.
Pupil Dilation: Your eye care provider may use special eye drops to dilate (widen) your pupils. This allows for a better view of the lens and the back of the eye.
Retinal Examination: The eye care provider will examine the retina and other structures at the back of the eye to rule out any other eye conditions that might be contributing to your vision problems.
Tonometry: This test measures the pressure inside the eye (intraocular pressure) to screen for glaucoma, which can coexist with cataracts.
Refraction Test: This test determines your exact eyeglass or contact lens prescription, which can help identify changes in vision due to cataracts.
Based on the findings from these examinations, your eye care provider will determine the presence and severity of cataracts.
Is there a non-surgical technique to treat cataracts?
Unfortunately till now, cataract surgery is the only way of treatment for the cataract patient.
Modern Cataract surgery:
One of the true medical miracles of our day is modern cataract surgery. These days, cataract surgery is done without an overnight stay(performed on an outpatient basis). And most patients can resume their normal activities very soon after surgery.
The operation takes an hour or longer but with the small incision approach, the surgery is quicker and much easier for the patients.
Does the natural eye lens remove in cataract surgery?
Yes by cataract surgery the natural eye lens is removed by using a high-frequency ultrasound device or laser. In cataracts, the natural eye lens becomes cloudy so it is broken down into small fragments, then replaced with an artificial lens.
What is the success rate of cataract surgery?
The success rate of cataract surgery is 99%.
Is cataract surgery painful?
Before surgery, a mild sedative is administered so cataract surgery is not painful.
Will I still need glasses after cataract surgery?
If you select the lens correctly for surgery then you don’t need glasses after surgery.
After cataract surgery how much time does it take to do normal activities?
Generally, it is safe to do light activities after the first week of cataract surgery. But a heavy working load is not allowed. The activities include light exercise, walking, and stretching without bending at the waist. By the second week, moderate-intensity activity can be done. By 4 to 5 weeks when you fully heal you can do normal life activities.
Some preventions which may reduce the risk of cataracts:
- Manage health problems properly,
- Wear sunglasses,
- Stop smoking and alcohol use,
- Eating foods that contain healthy vitamins C and E,
- Regular eye examination,
- Protect eyes from injury and trauma,
- A diet rich in antioxidants, vitamins, and minerals may support eye health. Include foods like fruits, vegetables, and foods high in vitamins C and E in your diet.
- Routine eye examinations can help detect cataracts and other eye conditions at an early stage, allowing for timely intervention if necessary.