Cataract

Cataract

A cataract is a clouding that develops in the crystalline lens of the eye or in its envelope, varying in degree from slight to complete opacity and obstructing the passage of light.

 The natural lens sits behind the colored part of the eye (iris) in the area of the pupil, and cannot be directly seen with the naked eye unless it becomes extremely cloudy. The lens plays a crucial role in focusing unimpeded light on the retina at the back of the eye. The retina transforms light to a neurologic signal that the brain interprets as vision. Significant cataracts block and distort light passing through the lens, causing visual symptoms and complaints.

Early in the development of age-related cataract the power of the lens may be increased, causing near-sightedness (myopia), and the gradual yellowing and opacification of the lens may reduce the perception of blue colours. Cataracts typically progress slowly to cause vision loss and are potentially blinding if untreated. The condition usually affects both eyes, but almost always one eye is affected earlier than the other.

 Many people are in fact unaware that they have cataracts because the changes in their vision have been so gradual.

When people develop cataracts, they begin to have difficulty doing activities they need to do for daily living or for enjoyment. Some of the most common complaints include difficulty driving at night, reading, participating in sports such as golfing, or traveling to unfamiliar areas; these are all activities for which clear vision is essential.

Cataracts are very common, affecting roughly 60% of people over the age of 60, and over 1.5 million cataract surgeries are performed in the United States each year.



Causes of Cataract

Cataracts develop for a variety of reasons, including :

. Long-term exposure to ultraviolet light

. Exposure to radiation

. Secondary effects of diseases such as diabetes, hypertension 

. Advanced age, or trauma (possibly much earlier)

. The use of certain medications, such as oral, topical, or inhaled steroids. Other medications that are more weakly associated with cataracts include the long-term use of statins and phenothiazines.

. Exposure to microwave radiation .

. Atopic or allergic conditions are also known to quicken the progression of cataracts, especially in children.

 They are usually a result of denaturation of lens protein. 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.



Classification of cataract

1.  Age-related cataract

A. Senile Cataract   ( an initial opacity in the lens, subsequent swelling of the lens and final shrinkage with complete loss of transparency in eldery)

a.Cortical Senile Cataract   ( opacities are most visible in the outside of the lens which is called the lens cortex)

·         Immature senile cataract (IMSC): partially opaque lens, disc view hazy

·         Mature senile cataract (MSC): Completely opaque lens, no disc view

·         Hypermature senile cataract (HMSC): Liquefied cortical matter: Morgagnian cataract

b. Senile Nuclear Cataract   ( the central portion of the lens is most affected, which is the most common situation)

·   Cataracta brunescens

·   cataracta nigra

·   cataracta rubra

B. Congenital cataract      ( Cataracts that occur at birth or present very early in life during the first year of life )

·         Sutural cataract

·         Lamellar cataract

·         Zonular cataract

·         Total cataract

These cataracts require prompt surgical correction or they may prevent the vision in the affected eye from developing normally.

2. Secondary cataract

Slit lamp photo of anterior capsular opacification visible a few months after implantation of Intraocular lens in eye, magnified view

·         Drug-induced cataract (e.g. corticosteroids)

      3. Traumatic cataract

·         Blunt trauma (capsule usually intact)

·         Penetrating trauma (capsular rupture & leakage of lens material—calls for an emergency surgery for extraction of lens and leaked material to minimize further damage)

There is an even more specific change that occasionally happens, when the opacity develops immediately next to the lens capsule, either by the anterior, or more commonly the posterior, portion of the capsule; these are called subcapsular cataracts. Unlike most cataracts, posterior subcapsular cataracts can develop rather quickly and affect vision more suddenly than either nuclear or cortical cataracts.

People who have a higher risk of developig this form of cataract are:  people with diabetes, high farsightedness, retinitis pigmentosa or those taking high doses of steroids.

symptoms

Each type of cataract has its own symptoms. With a nuclear cataract you may notice an improvement in your near vision. This is called 'second sight'. However when the cataract gets worse this will disappear.
A subcapsular cataract may not give any symptoms in the beginning, but only in a later stage when it is more developed.

 Symptoms of a cataract

·    Cloudy or blurry vision.

·    Colors seem faded.

·    Glare. Headlights, lamps, or sunlight may appear too bright. A halo may appear around lights.

·    Poor night vision.

·    Double vision or multiple images in one eye. (This symptom may clear as the cataract gets larger.)

·    Frequent prescription changes in your eyeglasses or contact lenses.

·    These symptoms also can be a sign of other eye problems. If you have any of these symptoms, check with your eye care professional.

At first, the amount of tinting may be small and may not cause a vision problem. Over time, increased tinting may make it more difficult to read and perform other routine activities. This gradual change in the amount of tinting does however not affect the sharpness of the image transmitted to the retina.

In advanced lens discoloration the ability to identify blues and purples is decreased. Black is seen instead of purple or blue.

Treatment of Cataract

A diet high in antioxidants, such as beta-carotene (vitamin A), selenium and vitamins C and E, may forestall cataract development. Meanwhile, eating a lot of salt may increase your risk.Eating high amounts of meat increase the risk of Cataract too. 

   The study examined the dietary surveys filled out by 27,670 self-reported nondiabetic people aged 40 or over and monitored their medical records to see if and when cataracts developed. Strong correlations showed up between cataract risk and diet type.

The risk was greatest for high meat eaters (who ate more than 3.5 ounces of meat each day), and it decreased from one group to the next, in this order: moderate meat eaters, low meat eaters, fish eaters (people who eat fish but no other meat), vegetarians and vegans. In fact, the risk for vegans was roughly 40 percent lower than for the high meat eaters.

          

 you should only consider surgery when your cataracts have progressed so far that they seriously impair your vision.

Cataract surgery

 is very successful in restoring vision. In fact, it is the most frequently performed surgery in the United States, with more than 3 million Americans undergoing cataract surgery each year. Nine out of 10 people who have cataract surgery regain very good vision, somewhere between 20/20 and 20/40.

During surgery, the surgeon will remove your clouded lens and in most cases replace it with a clear, plastic intraocular lens (IOL).

New IOLs are being developed all the time to make the surgery less complicated for surgeons and the lenses more helpful to patients. Presbyopia-correcting IOLs potentially help you see at all distances, not just one. Another new type of IOL blocks both ultraviolet and blue light rays, which research indicates may damage the retina.

Risks of surgery

Some common problems can occur after surgery. These may include increased pressure, blurring from swelling, inflammation (pain, redness, swelling), and sometimes bleeding. More rare and serious problems include infection, loss of vision, or light flashes. If you experience increasing pain or a worsening of vision after surgery, you should contact your eye doctor. With prompt medical attention, almost all problems can be treated successfully.

Cataract surgery slightly increases your risk of retinal detachment. Other eye disorders, such as high myopia (nearsightedness), can further increase your risk of retinal detachment after cataract surgery.

Sometimes the eye tissue that encloses the IOL becomes cloudy after the operation and may blur your vision. This condition, called an after-cataract, can develop months or years after cataract surgery.

eye

Description

Eyes are organs that detect light, and convert it to electro-chemical impulses in neurons.

 In higher organisms the eye is a complex optical system which collects light from the surrounding environment; regulates its intensity through a diaphragm; focuses it through an adjustable assembly of lenses to form an image; converts this image into a set of electrical signals; and transmits these signals to the brain, through complex neural pathways that connect the eye, via the optic nerve, to the visual cortex and other areas of the brain.

-The eye is not properly a sphere, rather it is a fused two-piece unit. The smaller frontal unit, more curved, called the cornea is linked to the larger unit called the sclera. The cornea and sclera are connected by a ring called the limbus.

-The iris ( the color of the eye )and  the pupil (its black center)are seen instead of the cornea due to the cornea's transparency.

-The fundus (area opposite the pupil) shows the characteristic pale optic disk ,papilla, where vessels entering the eye pass across and optic nerve fibers depart the globe.

The eye is made up of three coats, enclosing three transparent structures:

1. The outermost layer is composed of the cornea and sclera.

2. The middle layer consists of the choroid, ciliary body, and iris.

3. The innermost is the retina, which gets its circulation from the vessels of the choroid as well as the retinal vessels, which can be seen in an ophthalmoscope.

Within these coats are the aqueous humor, the vitreous body, and the flexible lens.

1. The aqueous humor is a clear fluid that is contained in two areas: the anterior chamber between the cornea and the iris and exposed area of the lens; and the posterior chamber, behind the iris and the rest.                 2. The vitreous body is a clear jelly that is much larger than the aqueous humor, and is bordered by the sclera, zonule, and lens. They are connected via the pupil.

 3. The lens is suspended to the ciliary body by the suspensory ligament (Zonule of Zinn), made up of fine transparent fibers.

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Eye irritation

Eye irritation has been defined as “the magnitude of any stinging, scratching, burning, or other irritating sensation from the eye”.

It is a common problem experienced by people of all ages. Related eye symptoms and signs of irritation are e.g. discomfort, dryness, excess tearing, itching, grating, sandy sensation, smarting, ocular fatigue, pain, scratchiness, soreness, redness, swollen eyelids, and tiredness, etc. These eye symptoms are reported with intensities from severe to less severe. It has been suggested that these eye symptoms are related to different causal mechanisms.

Several suspected causal factors in our environment have been studied so far:

-One hypothesis is that indoor air pollution may cause eye and airway irritation.

-Occupational factors are also likely to influence the perception of eye irritation. Some of these are lighting (glare and poor contrast), gaze position, a limited number of breaks, and a constant function of accommodation, musculoskeletal burden, and impairment of the visual nervous system.

-In addition, psychological factors have been found in multivariate analyses to be associated with an increase in eye irritation among VDU users.

-Other risk factors, such as chemical toxins/irritants, e.g. Amines, Formaldehyde, Acetaldehyde, Acrolein, N-decane, VOCs; Ozone, Pesticides and preservatives, Allergens, etc might cause eye irritation as well.

 -Personal factors (e.g., use of contact lenses, eye make-up, and certain medications) may also affect destabilization of the tear film and possibly result in more eye symptoms.

- Contact lenses and gender differences, there are more and more people wearing contact lens now and dry eyes appear to be the most common complaint among contact lens wearers. Although both contact lens wearers and spectacle wearers experience similar eye irritation symptoms, dryness, redness, and grittiness have been reported far more frequently among contact lens wearers and with greater severity than among spectacle wearers.

The incidence of dry eyes increases with age. Tear film stability (eg. break-up time) is significantly lower among women than among men. In addition, women have a higher blink frequency while reading.

eye irritation was the most frequent symptom in industrial building spaces. Since the 1970s, reports have linked mucosal, skin, and general symptoms to work with self-copying paper. Emission of various particulate and volatile substances has been suggested as specific causes. These symptoms have been related to Sick Building Syndrome (SBS), which involves symptoms such as irritation to the eyes, skin, and upper airways, headache and fatigue.

 Conditions of eye irritation 
1 . Conjunctivitis (Pink Eye)

Conjunctivitis, or pink eye, is an inflammation of the conjunctiva. The conjunctiva is a clear mucus membrane that lines the inside of the eyelid and covers the white part of the eye. The most obvious symptom of pink eye is a red or "pink" colored eye. Inflammation causes small blood vessels in the conjunctiva to darken, resulting in a pink or red tint to the white of the eye.


2 . Eye Allergies

Many people complaining of eye irritation are diagnosed with seasonal eye allergies. Eye allergies sometimes cause significant discomfort, often interrupting daily activities with annoying symptoms.



3 . Dry Eye Syndrome

If your eyes feel dry, have a stinging sensation, or feel scratchy, you may have dry eye syndrome. Dry eye syndrome is a condition that can occur when the tear glands don't produce the correct quantity or quality of tears.

 4 .Blepharitis

Blepharitis commonly causes red, crusty eyelids. If you have blepharitis, your symptoms are probably most noticeable upon awakening in the morning.



5 .Corneal Ulcer

A corneal ulcer is an erosion or open sore on the surface of the cornea. Corneal ulcers are common in people who wear contact lenses, especially if they wear them overnight.

Prevention of eye irritation

Several actions can be taken to prevent eye irritation:

.Trying to maintain normal blinking by avoiding room temperatures that are too high; avoiding relative humidities that are too high or too low, because they reduce blink frequency or may increase water evaporation.

.Trying to maintain an intact tear film by the following actions:

1) blinking and short breaks may be beneficial for VDU users. 

2) downward gazing is recommended to reduce the ocular surface area and water evaporation.

3) the distance between the VDU and keyboard should be kept as short as possible to minimize evaporation from the ocular surface area by a low direction of the gaze.

4) blink training can be beneficial.

Treatment for eye irritation

Artificial tears eye drops

Apply cold compresses:

• Apply for 20-30 minutes, every 1-2 hours, for the first few days.

Avoid exposure to smoke.

Avoid rubbing the eyes.

Avoid using eye makeup.

Do not use contact lenses until your symptoms are gone.

Take an antihistamine for itching:

• Diphenhydramine (Benadryl)

Dandruff

Dandruff

 is the shedding of dead skin cells from the scalp (not to be confused with a dry scalp). Dandruff is sometimes caused by frequent exposure to extreme heat and cold. As it is normal for skin cells to die and flake off, a small amount of flaking is normal and common and get released normally after detergent treatment. Some people, however, either chronically or as a result of certain triggers, experience an unusually large amount of flaking which can also be accompanied by redness and irritation. Most cases of dandruff can be easily treated with specialized shampoos.

The severity of dandruff may fluctuate with season as it often worsens in winter.

Those affected by dandruff find that it can cause social or self-esteem problems. Treatment may be important for both physiological and psychological reasons.

As the epidermal layer continually replaces itself, cells are pushed outward where they eventually die and flake off. In most people, these flakes of skin are too small to be visible. However, certain conditions cause cell turnover to be unusually rapid, especially in the scalp. For people with dandruff, skin cells may mature and be shed in 2–7 days, as opposed to around a month in people without dandruff. The result is that dead skin cells are shed in large, oily clumps, which appear as white or grayish patches on the scalp, skin and clothes.

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Causes

Dandruff has been shown to be the result of three required factors:

1. Skin oil commonly referred to as sebum or sebaceous secretions.

2. The metabolic by-products of skin micro-organisms (most specifically Malassezia yeasts)

 Fungus Malassezia furfur (previously known as Pityrosporum ovale) is mostely the cause of dandruff. While this species does occur naturally on the skin surface of both healthy people and those with dandruff, in 2007 it was discovered that the responsible agent is a scalp specific fungus. During dandruff, the levels of Malassezia increase by 1.5 to 2 times its normal level.

 Malassezia globosa, that metabolizes triglycerides present in sebum by the expression of lipase, resulting in a lipid byproduct oleic acid (OA)which penetrate the top layer of the epidermis( the stratum corneum)results in an inflammatory response in susceptible persons which disturbs homeostasis and results in erratic cleavage of stratum corneum cells.

3. Individual susceptibility.

**Rarely, dandruff can be a manifestation of an allergic reaction to chemicals in hair gels, sprays, and shampoos, hair oils, or sometimes even dandruff medications like ketoconazole.
There is some evidence that excessive perspiration and climate have significant roles in the pathogenesis of dandruff.

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Treatment

1. Salicylic acid

 Selsun Blue Naturals Dandruff Shampoo

It contains 3% salicylic acid, and salicylic acid shampoo is known to be good for acne prone scalp. It’s a great exfoliator for the scalp by removing oily residue and styling products. You can even apply this shampoo as a body wash for those back acne that come up during the summer.

2. Kairos Acne Care Solutions Shampoo

Kairos is a hair care product line made for scalp acne healing and prevention. It will help avoiding scalp acne and removes factors on the hair that might be the trigger of the condition.

It contains 0.5% concentration of salicylic acid and a cocktail of natural ingradients such as tea tree oil, apple amino acids and sapndus mukurossi which has antibacterial properties.

Do NOT use Salicylic Acid Shampoo if:

• you are allergic to any ingredient in Salicylic Acid Shampoo
• the patient is a child or teenager with the flu, chickenpox, or shingles
• the patient is younger than 2 years old

Contact your doctor or health care provider right away if any of these apply to you.

Before using Salicylic Acid Shampoo:

Some medical conditions may interact with Salicylic Acid Shampoo. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have had a severe allergic reaction (eg, severe rash, hives, difficulty breathing, dizziness) to aspirin or a nonsteroidal anti-inflammatory drug (NSAID) (eg, ibuprofen, naproxen, celecoxib)
• if you have liver or kidney problems, a skin infection, skin irritation, diabetes, or poor blood circulation
• if you have a history of Reye syndrome

Some MEDICINES MAY INTERACT with Salicylic Acid Shampoo. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Ammonium sulfate because it may increase the risk of Salicylic Acid Shampoo's side effects
• Corticosteroids (eg, prednisone) because they may decrease Salicylic Acid Shampoo's effectiveness
• Anticoagulants, (eg, heparin, warfarin), aspirin, methotrexate, or sulfonylureas (eg, glipizide) because the risk of their side effects may be increased by Salicylic Acid Shampoo
• Phenylbutazone, probenecid, pyrazinamide, or sulfinpyrazone because their effectiveness may be decreased by Salicylic Acid Shampoo

This may not be a complete list of all interactions that may occur. Ask your health care provider if Salicylic Acid Shampoo may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

2. Coal tar

Ionil-T : Helps eliminate dandruff problems due to seborrhea and psoriasis.It appears to work by slowing down the production of skin cells, and has an anti-inflammatory effect.

 Tar helps reduce the production of skin cells, giving you a healthier looking scalp. Reduces itching and flaking. Contains the equivalent of 1% Coal Tar. For best results use at least twice a week or as directed by a physician.
Many other coal tar shampoos are available in market like Coal Tar shampoo , Polytar shampoo , T/Gel shampoo.

3. Sulfur

Sulfur is a non-metallic element, has both keratolytic and antimicrobial activity. The keratolytic effect is thought to be mediated by the reaction between the sulfur and the cysteine amino acid in the keratinocytes, whereas the antimicrobial effect may depend on the conversion of sulfur to pentathionic acid by normal flora or keratinocytes. A normal chicken egg can be used to solve dandruff utilising the sulphurous element of egg white which attracts dandruff when rubbed into the scalp.

 KAVI Sulfur Shampoo is made with colloidal sulfur to help reduce the scaling and itching associated with dandruff and seborrheic dermatitis of the scalp. Additionally, colloidal sulfur will enhance the hydrolipidic layer’s acidity and protect the scalp’s pores from acne and other bacterial infections.

Designed for daily use, the KAVI Sulfur Shampoo is easy on the senses and a practical replacement to traditional shampoos.  

4. Regulators of keratinization

  Zinc pyrithione is best known for its use in treating dandruff and seborrhoeic dermatitis. It also has antibacterial properties and is effective against many pathogens from the streptococcus and staphylococcus class.

 Some studies have shown a significant reduction in the number of yeasts after use of ZPT, which is an antifungal  agent.
 A dramatic reduction of structural abnormalities found in dandruff with the use of ZPT; the population abundance of Malassezia decreases, parakeratosis gets eliminated and corneocytes lipid inclusions are diminished.

Zinc pyrithione is approved for over-the-counter topical use in the United States as a treatment for dandruff. It is the active ingredient in several anti-dandruff shampoos such as Cedel , Pantene , Head &Sholders and Clear.                                                                                                       

                                                                                                                                            

5. Selenium sulfide

It is believed that selenium sulfide controls dandruff via its anti Malassezia effect rather than by its antiproliferative effect, although it has an effect in reducing cell turnover. It has anti-seborrheic properties as well as cytostatic effect on cells of the epidermal and follicular epithelium. The excessive oiliness after use of this agent has been reported in many patients as adverse drug effect.

Head&Shoulders and Selsun blue in market contain seleniun sulfide

6. Imidazole antifungal agents

Imidazole topical antifungals such as ketoconazole act by blocking the biosynthesis of ergosterol, the primary sterol derivative of the fungal cell membrane. Changes in membrane permeability caused by ergosterol depletion are incompatible with fungal growth and survival.
Ketoconazole is a broad spectrum, antimycotic agent that is active against both Candida and M. furfur . Of all the imidazoles, ketoconazole has become the leading contender among treatment options because of its effectiveness in treating seborrheic dermatitis as well.

Nizoral is a shampoo that contains a broad-spectrum antifungal, which inhibits the growth of yeast and other fungal infections providing relief from dandruff. Ketaconazole is also known to have anti-androgenic effects and Ketoconozole can cause a reduction in the production of testosterone and other androgens by the adrenal gland and by the male and female reproductive organs. Nizoral shampoo contains 2% Ketoconazole and is often prescribed for the treatment of fungal infections of the scalp and sebbhoreic dermatitis

 Nizoral shampoo is also unique because it's effect is long lasting. Even after rinsing, Nizoral carries on working for several days. This means that you don't need to use Nizoral every day making it extremely cost-effective. And unlike some other anti-dandruff treatments, Nizoral shampoo has a pleasant fragrance and is pH balanced leaving hair soft, healthy and clean.

7. Hydroxypyridones
In contrast to the imidazole antifungals, the hydroxypyridones do not affect sterol biosynthesis; instead they interfere with the active transport of essential macromolecule precursor, cell membrane integrity and the respiratory process of cells. Ciclopirox is widely used as an AD agent in most preparations.
 Ciclopirox Shampoo, 1%, is an antifungal indicated for the treatment of seborrheic dermatitis of the scalp in adults. Patients should be advised to avoid contact with the eyes and mucous membranes. If contact does occur, the patient should rinse thoroughly with water.
8. Naturopathic agents

There are several naturopathic agents which have been claimed to have antidandruff activity. However, in most cases, these naturopathic agents are used in combination with synthetic agents. Studies from India have shown that the herbal preparations are as effective as synthetic substances in controlling dandruff both by in vitro and in vivo studies.

9. Topsoil
The living organisms commonly found in topsoil are beneficial for controlling the production of sebum by the scalp. Mix topsoil with filtered (non chlorine) water until a mud paste the consistency of oatmeal is achieved. Apply paste directly to the scalp and allow contact for ten minutes. Application once a week will control dandruff.

10. Water temperature

Like other skin conditions, hot water can exacerbate dandruff or itching. Using slightly cooler water (not cold) during regular hair washing and rinsing has been found to reduce dandruff in some individuals.