Cataract

A Cataract is a condition that develops in the lens of the eye. Cataracts are made from a protein that has altered from its natural state (denaturation), distorting and eventually prohibiting required light from entering into the retina, the part of the eye that receives light. Often cataracts cause no problems for many years but as the cataracts matures the cloudiness increases on the lens, the light reaching the retina decreases and significant sight loss and perhaps blindness can result.

Cataracts typically progress slowly to cause vision loss and are potentially blinding if untreated. Moreover, with time the cataract cortex liquefies to form a milky white fluid in a Morgagnian Cataract, and can cause severe inflammation if the lens capsule ruptures and leaks. Untreated, the cataract can cause phacomorphic glaucoma.

Classification:

The following is a classification of the various types of cataracts. This is not comprehensive and other unusual types may be noted.

Classified by etiology:
* Age-related cataracts
1) Immature Senile Cataract (IMSC) - partially opaque lens, disc view hazy
2) Mature Senile Cataract (MSC) - Completely opaque lens, no disc view
3) Hypermature Senile Cataract (HMSC)-Liquefied cortical matter: Morgagnian Cataract

* Congenital cataracts
1) Sutural cataract
2) Lamellar cataract
3) Zonular cataract
4) Total cataract

* Secondary cataracts
1) Drug-induced cataract (e.g. Corticosteroids)

* Traumatic cataracts
1) Blunt trauma (capsule usually intact)
2) Penetrating trauma (capsular rupture & leakage of lens material occurs)

Classified by location of opacity within lens structure:
* Anterior cortical cataracts
* Anterior polar cataracts
* Anterior subcapsular cataracts
* Nuclear cataracts
1) Grey
2) Yellow
3) Amber
4) Brown/Black

* Posterior cortical cataracts
* Posterior polar cataracts
* Posterior subcapsular cataracts (PSC)

Causes:
Cataracts develop from a variety of reasons, including long-term ultraviolet exposure, exposure to radiation, secondary effects of diseases such as diabetes, hypertension and advanced age; they are usually a result of denaturation of lens proteins. Genetic factors are often a cause of congenital cataracts and positive family history may also play a role in predisposing someone to cataracts at an earlier age, a phenomenon of "anticipation" in pre-senile cataracts. Cataracts may also be produced by eye injury or physical trauma. A study among Icelandair pilots showed commercial airline pilots as three times more likely to develop cataracts than people with non-flying jobs. This is thought to be caused by excessive exposure to radiation coming from outer space. Cataracts are also unusually common in persons exposed to infrared radiation, such as glassblowers who suffer from "exfoliation syndrome". Exposure to microwave radiation can cause cataracts.

Cataracts may be partial or complete, stationary or progressive, hard or soft.

Some drugs can induce cataract development, such as Corticosteroids and anti-hyperlipidemics like Ezetimibe.

Symptoms:

The most common symptom of cataracts is the noticeable blurring and worsening of vision. Other symptoms include the dimming and fading of colors, decreased night vision, problems with bright lights and sunshine, and in many cases, regular visits to the ophthalmologist for changes in glasses and contact lens prescriptions as vision worsens. Some patients report double vision in the affected eye although this symptom seems to decrease or disappear entirely as the cataracts grows.

If an individual's eyesight grows progressively worse, it is best to schedule a visit to an eye specialist as soon as possible. They will be able to assist with a diagnosis of the problem and available treatments if required.

Diagnosis:

In many cases, the diagnosis of a cataract is fairly simple. However, in the prenatal population, although diagnosis is possible it is a bit more difficult. Ultrasounds have proven an effective method to detect cataracts in unborn children. It is imperative that they be detected early if present as cataracts in babies can result in blindness for life if not treated properly and quickly soon after birth.
The most common way for an age-related cataracts to be diagnosed is during a routine eye exam.
During an eye exam, performed by an ophthalmologist or optometrist, there are several tests which may be administered to check for the presence of a cataracts.

* A visual acuity test will measure how well the individual can see while standing at various lengths from the cue card.
* A slip lamp exam uses a specialized microscope to increase the magnification of the eye. The specialist can then examine the eye in detail and up close.
* A tonometry test is a standard test which measures the fluid pressure inside the eye. The major finding in this test, if an increased pressure is detected, is the possibility of glaucoma.
* A dilated eye exam dilates the pupil. In this manner, the specialist is better able to view the lens to check for the present of a cataracts.

Treatment:
Natural-
* Limit consumption of lactose-containing foods (milk products). In animal studies, galactose, a component of lactose, has been shown to promote cataracts formation.
* A riboflavin deficiency has been implicated in cataracts development. Therefore, a supplemental dosage of riboflavin, 10-50 mg/day, may help treat or at least slow the progression of cataracts formation.
* Quercetin is recommended in a dosage of 500-1000 mg/day. WARNING: Quercetin may increase the possibility of birth defects in pregnant women and is not recommended during pregnancy.
* A supplemental dosage of 15-50 mg/day of zinc along with 2-3 mg/day of copper may help with cataracts.
* Taking Vitamin C, 1000 mg, two times a day may help to decrease damage caused by free radicals, in turn helping to treat cataracts.
* Supplementing the diet with Vitamin E at 400-800 IU/day plus selenium at 200-300 mcg/day has effectively cured cataracts in dogs.
* 200-600 mg/day of N-Acetylcysteine (NAC) along with zinc and copper may treat cataracts by working to destroy free radicals.

Surgery-
The most effective and common treatment is to surgically remove the cloudy lens. There are two types of surgery that can be used to remove cataracts: extra-capsular (extracapsular cataract extraction, or ECCE) and intra-capsular (intracapsular cataract extraction, or ICCE).

Extra-capsular (ECCE) surgery consists of removing the lens but leaving the majority of the lens capsule intact. High frequency sound waves (phacoemulsification) are sometimes used to break up the lens before extraction.

Intra-capsular (ICCE) surgery involves removing the entire lens of the eye, including the lens capsule, but it is rarely performed in modern practice. In either extra-capsular surgery or intra-capsular surgery, the cataractous lens is removed and replaced with a plastic lens (an intraocular lens implant) which stays in the eye permanently.