Corneal Topography
15
Jun

Dry Eye

Post in WPOC (English)
by Super User

What is Dry eye?

Dry eye is a condition in which a person doesn't have enough quality tears to lubricate and nourish the eye. Tears are necessary for maintaining the health of the front surface of the eye and for providing clear vision.

Dry eye is a common and often chronic problem, particularly in older adults.

(Reference from American Optometric Association)


What causes dry eyes?

Dry eyes can develop for many reasons, including:

  • Age. Dry eyes are a part of the natural aging process. The majority of people over age 65 experience some symptoms of dry eyes.
  • Gender. women are more likely to develop dry eyes due to hormonal changes caused by pregnancy, the use of oral contraceptives, and menopause.
  • Medications. certain medicines, including antihistamines, decongestants, blood pressure medications and antidepressants, can reduce tear production.
  • Medical conditions . People with rheumatoid arthritis, diabetes and thyroid problems are more likely to have symptoms of dry eyes.
  • Life style. Staring at computer screens, televisions, or electronic readers for long periods of time, exposure to air conditioning, wind, smoke, and dry climates
  • Other factors. Long term use of contact lenses, refractive eye surgery, some medications, medical conditions, such as, rheumatoid arthritis, diabetes, thyroid problems and inflammation of the eyelids.

(Reference from American Optometric Association)

How is dry eye diagnosed?


Dry Eye Treatment

How are dry eyes treated?

  • Artificial tear. The primary approaches used to manage and treat mild dry eyes. Preservative-free artificial tear solutions are recommended because they contain fewer additives, which can further irritate the eyes.
  • Warm Compresses. A study out of Oxford University found that heating the lids about 9ºF significantly increased meibomian oil production, and result to relief the dry eye.
  • Lid Massage. It can dramatically improve symptoms by helping re-establish tear film stability. The technique: Extend finger and apply light pressure. Roll the finger upward on the lower lid two times while in upgaze, then roll the finger downward on the upper lid two times while in downgaze.
(Reference from Review of Optometry)



Tips to reduce symptoms of dry eyes:

  • Remember to blink regularly when reading or staring at a computer screen for long periods of time.
  • Increase the humidity in the air at work and at home.
  • Wear sunglasses outdoors, particularly those with wraparound frames, to reduce exposure to drying winds and the sun.
  • Nutritional supplements containing essential fatty acids may help decrease dry eye symptoms in some people. Ask your optometrist if taking dietary supplements could help your dry eye problems.
  • Avoiding becoming dehydrated by drinking plenty of water (8 to 10 glasses) each day.
(Reference from American Optometric Association)

The content in this article is for reference only, it does not provide any professional diagnosis or treatment advice.
15
Jun

Diabetic retinopathy

Diabetic retinopathy is the damage to the retina caused by diabetes mellitus (DM). Diabetic retinopathy often has no obvious symptoms in the early stage. If not detected early, when symptoms do appear, the condition may have been developed to later stages and vision would be affected seriously. The worse scenario is blindness.

The longer a person has diabetes, the more prone he is to have diabetic retinopathy. About one-third of patients with over 10 years of DM have some degree of retinopathy. With the disease for more than 20 years, the chance of complication increases to two-third. Regular comprehensive eye examinations is vital for early detection and early treatment, hence greatly reduce the serious complication of diabetes.

We strongly advise patients with diabetes mellitus to undergo a comprehensive eye examination every year.

The content in this article is for reference only, it does not provide any professional diagnosis or treatment advice.
15
Jun

Glaucoma

Post in WPOC (English)
by Super User

What is glaucoma?

Glaucoma is an eye disease in which the optic nerve is damaged, causing permanent vision loss. Most commonly caused by raised intraocular pressure that lead to visual loss, which over time can progress to blindness. Worldwide, glaucoma is one of the leading cause of blindness.

Risk factors for glaucoma:

  • Age: Six times more likely to get glaucoma if you are over 40 years old.
  • Immediate family member with glaucoma: The most common type of glaucoma, primary open angle glaucoma, is hereditary.
  • Diabetes: Some diseases that impact the entire body, such as diabetes, anaemia, or hardening of the arteries, increase the risk of the condition.
  • Incorrect usage of steroid: Studies indicate Steroids increase intraocular pressure.
  • Injury, infection or tumor in or around the eye
  • High myopia
  • Hypertension

Unfortunately, any vision lost as a result of glaucoma usually cannot be restored. This is why regular preventive eye examinations are so important. Low-vision rehabilitation services, which include the use of specialized optical devices and training, may benefit people with severe vision loss from glaucoma.

How is glaucoma detected?

The content in this article is for reference only, it does not provide any professional diagnosis or treatment advice.

Contact lenses & Special Contact Lenses Fitting

Most refractive errors such as nearsightedness, farsightedness, astigmatism and presbyopia can be corrected with contact lenses. We will fitting with consideration of your overall vision problems, the health of your eyes, your specific visual needs and lifestyles.


Soft contact lenses

Soft contact lensesare made of soft, flexible plastics that allow oxygen to pass through to the cornea. Newer soft lens materials include silicone-hydrogels to provide more oxygen to your eye while you wear your lenses.

Classified by Disposable (Replacement) Schedule

  • Daily disposable
  • Bi-Weekly disposable
  • Monthly disposable
  • Annually disposable


Rigid gas permeable contact lenses (RGP/ GP)

Rigid gas permeable contact lenses (RGPs) are more durable and resistant to deposit buildup, and generally give a clearer, crisper vision.They are easier to handle and less likely to tear. However, they are not as comfortable initially as soft contacts and it may take a few weeks to get used to wearing RGPs, compared to several days for soft contacts.

Advantages of RGP

  • Crisper vision
  • Easy care and handling
  • Deposit resistance
  • Excellence eye health
  • Good value


Contact Lenses For Astigmatism

There are many brands and styles of soft lenses for astigmatism, including:

  • Disposable contact lenses, that are available for monthly, biweekly and even daily replacement.
  • Toric bifocal contact lenses, that correct both astigmatism and presbyopia.
  • Scleral lenses, special large-diameter gas permeable contacts are extremely effective to unusual or high amounts of astigmatism
  • Custom contact lenses, made of hydrogel and silicone hydrogel materials for to unusual or high amounts of astigmatism


Contact Lenses For High Myopia

The preferred method of correction of High Myopia is contact lenses. Contact lenses can restore vision with complete peripheral vision and little minification error. (Minification error is when looking through a high minus prescription all images are smaller) Contact lenses of the same correction will allow images to be much larger than a high prescription eyeglass would be, reducing minification error.

  • Disposable contact lenses, which are now available as high as -20D , and for torics about -9D of sphere. This translates to a maximum spectacle power of -22D and -10D respectively, taking into account a vertex distance of 12mm.
  • Rigid gas permeable contact lenses (RGP/ GP) which are smaller, thinner, more oxygen permeable than soft lenses, and which do not absorb tears from the surface of the eye.


Contact Lenses For Presbyopia

Presbyopia, a word that meant “the elderly eye” in Greek, is a symptom of aging eyes. After early to mid-40s, the lens of your eye becomes increasingly rigid and inflexible: it can no longer adjust its shape as easily to allow you to focus on both near and distant objects. Contact lenses options for presbyopia:

  • Monovision contact lenses, one contact lens is prescribed for near vision and the other contact lens for distance.
  • Multifocal contact lenses, like bifocal or progressive eyeglasses, have multiple focal points.
  • Reading glasses worn over standard contact lenses for normal (distance) viewing.


Contact Lenses For Color Vision Deficiency

Color deficiency could be significantly enhanced the color perception by a monocular contact lens. A specialty contact lenses which tinted in deep red is worn in the nondominant eye and intensifies the color of red and green objects.

This lens does not cure the vision problem of color blindness, it only aids in the perception of colors.


Contact Lenses For Keratoconus

There is no one design that is best for every type or stage of keratoconus. The “best lens” is the one that fits your eye, corrects your vision and is comfortable to wear. Here is a brief outline of the types of lenses available for keratoconus:

  • Rigid gas permeable contact lenses (RGP/ GP), Primary option for correcting KC vision. The rigid lens masks the underlying irregular cornea and functions as the new refractive surface of the eye, with the tear film filling in the space between the back of the contact lens andthe front of the eye.
  • Soft lenses, latest soft lens in silicone hydrogel materials and complex mathematics to offer comfortable wear and excellent vision.
  • Piggy-backs, a two lens system; an RGP lens which provides crisp vision, worn on top of a soft lens, which acts as a cushion providing comfort.
  • Hybrid lenses, lens design combination that has an RGP center surrounded by a soft peripheral “skirt”.
  • Scleral lenses, large diameter lenses that rest on the white part of the eye, called the sclera, and vaults over the cornea. That is surprisingly comfortable to wear because the edges of the lens rests above and below the eye lid margins so there is no lens awareness.


Cosmetic Contact Lenses

Cosmetic contact lenses are actually medical devices oversees by the U.S. Food and Drug Administration(FDA). Just like corrective contact lenses you should never buy contact lenses from a street vendor or a beauty supply store, and you should always have a prescription.

Wearing any kind of contact lenses, including Cosmetic contact lenses, can cause serious damage to your eyes if the lenses are obtained without a prescription or not used correctly. These risks include:

  • A cut or scratch on the top layer of your eyeball (Corneal Abrasion)
  • Allergic reactions like itchy, watery red eyes
  • Decreased vision
  • Infection
  • Blindness


Remember:
" Buying contact lenses without a prescription is dangerous!"


FAQ

What is the appropriate wearing schedule for me?
Our Optometrist will prescribe your wearing schedule based on the health of your cornea, your lifestyle, your preference, and the type of lens you want to wear.
After lasik surgery, can I wear contacts lenses?
Our Optometrist will to advise you on glasses vs. contact lenses based on your individual needs and the feasibility of wearing contact lenses.
How Young is Too Young for kid to wear contact lenses?
The age at which they’re mature enough to handle for contact lenses will vary from child to child. Your child will need to be responsible for careful and regular upkeep of his contact lenses to protect them and his eyes.
Will the contact lenses slipping behind my eyes?
No! Your conjunctiva, the transparent cover for your eyes’ exterior, prevents this.
The content in this article is for reference only, it does not provide any professional diagnosis or treatment advice.

What is Color Blindness, or Color Vision Deficiency?

This is refers to the inability of a person to correctly distinguish certain colors.

Complete color blindness, to view the world in only black and white, is rare.

Most of them are color deficiency, which has problems distinguishing between the colors red and green, mistaking them for the same color. A less common type of color deficiency involves the colors blue and yellow.


What causes Color Blindness, or Color Vision Deficiency?

Inherited Colour Vision Deficiency

Color blindness is usually hereditary(you are born with it). More males are affected by the disorder than females.

  • approximately 1 in 12 men (8%)
  • approximately 1 in 200 women (0.005%)


Acquired Colour Vision Defects

Occasionally, certain eye diseases cause color blindness, referred to as "Acquired Color Deficiency."

The content in this article is for reference only, it does not provide any professional diagnosis or treatment advice.

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