HYPEROPIA - LONG SIGHTEDNESS
Hyperopia is caused by one or a combination of the following:
- Flat cornea
- Short eyeball
Consequently light rays are focused behind instead of on the retina.
Long sighted people are able to see images in the distance more clearly than they can see images at close. Though most hypermetropic people are unable to see at either distance clearly without their glasses. Laser surgery corrects hyperopia by making the cornea steeper so the rays of light are refocused on the back of the eye.
There is a limit on the degree of hyperopia that can be fully corrected, approximately 6 dioptres. If you are above the level of treatment it is still worthwhile coming for a consultation. The doctors may be able to give you less dependence on glasses and contact lenses, or outline other treatment options available to you.
MYOPIA - SHORT SIGHTEDNESS
Myopia is caused by one or a combination of the following:
- Steep cornea
- Long eyeball
- Powerful lens
Consequently, light rays focus in front of the retina, instead of directly on it.
Short-sighted people are able to see close up objects clearly, but objects in the distance are blurry and indistinct. People with moderate to high levels of myopia are unable to recognise things beyond arm’s length without their glasses on. Laser surgery corrects myopia by making the central cornea flatter, thereby refocussing light rays onto the retina.
There are different degrees of myopia. They are classified as:
- Low = 0 to -4
- Moderate = -4 to -8
- High = -8 and above
All of the above can be improved, but those in the higher range of myopia, may still need to wear a small prescription for certain activities. The laser is used to treat up to about 10 dioptres of myopia.
Presbyopia occurs in all adults after 40 years as part of the ageing process. It signifies an inability to focus on near objects. This occurs due to reduction of the accommodative power of the eye resulting in shifting away of the nearest point at which the patients can focus. To bring this point to the original place reading glasses are required.
Patients who have no glasses for far and those who have plus power glasses for far require Bifocal or Progressive spectacles but those with near sightedness can manage to read without glasses.
Various surgical techniques have been devised to correct presbyopia some of which are:
- Conductive Keratoplasty
- Presbyopic Lens Exchange (Prelex)
The inside of the eyelids as well as the white of the eye (Sclera) are lined by a thin, transparent membrane called Conjunctiva. Any inflammation of this layer is called as Conjunctivitis. This is by far the most common cause of “Red Eye”.
WHAT CAUSES CONJUNCTIVITIS?
- Infections: Bacterial, Viral and rarely parasitic infections are a very common cause of conjunctivitis. In the presence of infection, redness of the eye is associated with watering and excess mucoid discharge which can cause matting of eyelashes and sticking together of eyelids.
- Allergy is another common cause of conjunctivitis. The main symptom of allergic conjunctivitis is itching but in some long standing cases only redness may persist in the absence of any itching
- Irritants in the environment like noxious fumes, smoke etc. can act as stimuli to produce conjunctivitis. These cases are aggravated if an underlying dryness is present in the eye.
As cases of infective conjunctivitis are contagious, strict personal hygiene by the patient is important to prevent rapid spread of organisms within the family and community members. Some important things to remember are:
- The patient should not touch the other eye
- Tissues/ disposable napkins used to wipe the discharge from the eye should be promptly discarded.
- If cloth is used, then care should be taken to wash it separately
- Patient should avoid touching commonly shared things like remote control, phone etc.
- Eye drops should be instilled regularly as advised and with total cleanliness.
OTHER CAUSES OF RED EYES:
Though conjunctivitis mostly runs a mild course and responds to treatment with eye drops red eye can be associated with more critical conditions which can result in permanent reduction of vision or even blindness. Therefore any patient with red eye having additional symptoms like pain, decreased vision and extreme sensitivity to light should get themselves checked by a competent ophthalmologist to rule out serious conditions like Glaucoma, Corneal Ulcer and Iridocyclitis (inflammation inside the eye).
Persistent inflammation of the eyelids giving rise to symptoms like watering, irritation, itching, and occasionally a red eye.
- Individuals with oily skin
- Dandruff or
- Dry eyes
It can begin in early childhood or develop later in life and continue as a chronic condition.
BLEPHARITIS OCCURS IN TWO FORMS:
- Anterior blepharitis affects the outside front of the eyelid, where the eyelashes are attached. The two most common causes of anterior blepharitis are bacteria (Staphylococcus) and scalp dandruff.
- Posterior blepharitis affects the inner eyelid (the moist part that makes contact with the eye) and is caused by problems with the oil (meibomian) glands in this part of the eyelid. Two skin disorders can cause this form of blepharitis: acne rosacea, which leads to red and inflamed skin, and scalp dandruff (seborrheic dermatitis).
COMPLICATIONS FROM BLEPHARITIS INCLUDE:
Stye/Chalazion /Problems with the tear film
HOW IS BLEPHARITIS TREATED?
Treatment for both forms of blepharitis involves keeping the lids clean and free of crusts. Warm compresses should be applied to the lid to loosen the crusts, followed by a light scrubbing of the eyelid with a cotton swab and a mixture of water and baby shampoo. Because blepharitis rarely goes away completely, most patients must maintain an eyelid hygiene routine for life
Additional medications might be needed in some cases like:
- Artificial tears may be used to relieve symptoms of dry eye.
- Steroid eye drops may be used short-term to decrease inflammation.
- Antibiotic ointment may be used to decrease the bacterial content of the eyelids.
- Antibiotic tablets may be used to decrease the oil production from the meibomian gland
Glaucoma is a group of diseases that can damage your eye’s optic nerve and result in vision loss and blindness. It is one of the leading causes of blindness in Australia, affecting approximately 3% of the population.
It is more common with advancing age, and in women. Nearly half of people with glaucoma do not even know they have the disease.
While there is no cure for glaucoma, the good news is that if diagnosed early, the disease can usually be controlled with ongoing treatment (eye drops, laser, surgery) and blindness can be prevented.
HERPES SIMPLEX OF THE EYE
The most common herpes simplex eye disease caused by HSV Type I is a recurrent eye infection of the cornea, the clear front window of the eye, which can potentially threaten sight. The infection varies in duration, severity and response to treatment, depending in part on which of several different strains of HSV Type I caused the original infection.
The disease usually begins on the surface of the cornea. The eye turns red, and it is sensitive to light. For most people this will be the only episode. Unfortunately, one out of four people who have a corneal infection are likely to have a recurrence within two years. The process may go deeper into the cornea and cause permanent scarring or inflammation inside the eye. Chronic ulcers, which are sometimes very difficult to heal, may also develop on the cornea.
Herpes simplex eye disease usually occurs in only one eye and rarely spreads to the other eye. Spreading the infection to another person is unlikely. In people with poor immunity, the herpes simplex virus may infect other parts of the eye or body, such as the retina or brain, but this occurs infrequently.
It is important to remember that herpes simplex eye disease is not usually caused by HSV Type II, the sexually transmitted herpes. While possible, sexual transmission of herpes eye disease is extremely rare.
Treatment depends on the extent of the disease. Anti-viral eye medications are commonly used and may need to be applied frequently. At times it may be necessary to scrape the surface of the cornea, to patch the eye, or to use a variety of medications. These may need to be continued for many months. Occasionally therapeutic excimer laser treatment is required and, in cases of severe scarring and vision loss, a corneal transplant may be required.