Glaucoma refers to an eye disorders that damages the optic nerve. Glaucoma is usually associated with high intraocular pressure (IOP) which damages the optic nerve. If glaucoma is not treated it causes narrowing of vision field and eventually, blindness. Unfortunately, there are rarely any warning symptoms, and the patient may not even know he or she has glaucoma.Did you know that glaucoma is the second most frequent cause of blindness- after cataract worldwide, and after macular degeneration in the US?

What is a cataract?

An eye cataract is a condition in which the lens of the eye becomes cloudy, thereby permitting less light to pass through to the eye screen. Normally chances of a cataract increase with age. Nearly 68% Americans above 80 have had a cataract during their lifetime. A cataract cannot be corrected by glasses, contact lenses, or LASIK surgery. While research is going on for medicines which will reduce the cloudiness, currently, IOL surgery is the only solution to cataracts.

Cataract surgery

Cataract surgery is now a very routine procedure which lasts about 15 minutes (apart from the preparatory steps) as an outpatient. In cataract surgery, the lens inside your eye that has become cloudy is removed and replaced with an artificial lens (called an intraocular lens, or IOL) to restore clear vision.

The procedure

Cataract surgery is preceded by a rigorous examination, measurement of eye parameters, and history-taking to ensure suitability, and to determine the appropriate power of the lens to be placed. During the surgery:

·         The clouded natural lens is broken into small pieces by ultrasound (phaco) emulsifiation or lasers.

·         A very small incision is made and these pieces are sucked out

·         The selected artificial lens is inserted through the incision positioned (normally) behind the iris and the pupil of the eye.

·         The incision is closed (with or without stiches).

·         A protective shield is put over the eye for physical safety of the eye.

After the surgery

·         You will be kept in rest for about an hour so that the anesthetic effect reduces. You will be given dark glasses to wear outdoors and in bright light.

·         You can get someone to drive home.

·         You can remove the eye shield at home but must wear it at night.

·         In case there is some abnormality, report it the next day.

·         You should see quite clear images by the next day or even earlier.

·         Normally far vision will be corrected, but you may be prescribed reading glasses after about a month.

Glasses correct many vision defects. But they have disadvantages. Imagine you are looking your glasses and cannot find them because you can’t see without them. This can be particularly frustrating if your glasses fell off accidentally in an emergent situation. Would you like your glasses to be inside your eyes rather than over them? That is what implantable collamer lenses (ICL) can do for you.

What is an implantable collamer lens?

A pair of implantable collamer lenses are just like your pair of glasses, but they reside inside your eyes always. You do not have to remove them for wiping, and you won’t misplace them! It is a tiny, foldable lens made of a biocompatible material called collamer, which is placed inside your eye, normally behind the iris and in front of the lens.

LASIK is currently the most common and popular laser vision correction surgery. Except for very severe abnormalities, LASIK will reduce or even eliminate the need for glasses or contact lenses in the following problems, such as: 

•             Near vision

•             Far vision 

•             Astigmatism

Types of LASIK Surgery Procedures :

Several types of LASIK surgery are available. The type chosen by the surgeon will depend on the nature of your eye problems, and the technology available to him. 

•             Wavefront Optimized LASIK, 

•             Wavefront-Guided LASIK, 

•             Topography-Guided LASIK,

Who can benefit from LASIK Eye Correction Surgery?

Most people with ages between 18 and 50 years who have mild to moderate vision problems can benefit from LASIK surgery. However, LASIK treatment may not be advised if you:

•             Have severe focusing problems

•             Are under 18, i.e., your eyesight is still changing.

•             Have dry eyes.

•             Have a thin cornea

•             Have cataracts or advanced level glaucoma, or have had ocular herpes.

•             Have immunity disorders

•             Possess large pupils

Possible side effects of LASIK Eye Correction Treatment 

LASIK surgery is effective and safe, but may have some side effects which your eye surgeon will explain to you before surgery. In some situations, these possible effects may preclude LASIK operation.

•             Dry eyes- The treatment can temporarily reduce tear output. If you are already suffering from reduced tear output your ophthalmologist may think of other solutions.

•             Under- or over-correction- The treatment will give you a definite improvement but your vision may be under-corrected or overcorrected.

•             Night vision problems- Even though you perfectly in daylight you may experience glare at night. These symptoms may reduce over time.

•             Temporary Eye infections- Eye infection may arise after treatment but can be treated easily with antibiotic eye drops or steroids.

Vision Correction Options

Eyeglasses

Eyeglasses are the oldest and most common vision correction option. A corrective lens is a lens worn in front of the eye, mainly used to treat myopia, hyperopia, astigmatism, and presbyopia. Glasses or "spectacles" are worn on the face a short distance in front of the eye. Nowadays, there are corrective lenses that can even protect your eyes from the sun's ultraviolet radiation.

Contact Lenses

A contact lens is a hydrophilic (water-loving) disc that floats on your cornea. Like prescription glasses, a contact lens is specifically shaped to focus light into the retina of your eye (and to fit your eye). But because the lens covers your cornea, it actually corrects your entire field of vision (unlike glasses, which you can see over and under). Contact lenses float on the tears that bathe the eye when you blink - so you want to keep your eye well-moisturized when you're wearing contact lenses.

Refractive Surgery

LASIK

LASIK is an acronym and actually stands for Laser in-situ keratomileusis, which is the most commonly performed type of laser eye surgery. This eye surgery procedure is generally safe, effective, and has very few side effects. LASIK is a great option for many individuals considering laser vision correction for a variety of very personal and professional reasons. LASIK may not promise perfect vision, however; it is a highly successful procedure that can at the very least reduce a person's dependence on glasses or contact lenses. The lifestyle benefits can be tremendous for active and social people. These benefits can bring great value and ease in life. If you are an active person please feel free to consult our LASIK coordinators if you have questions about life after LASIK. They will be happy to answer any questions that may affect your lifestyle or any questions about the LASIK eye surgery procedure itself.

Visian ICL

Not everyone is a candidate for LASIK eye surgery. Sometimes people have thin corneas or excessive dry eyes and it makes them simply not a good candidate for LASIK eye surgery. Your eye doctors will examine your eyes and determine what the best vision correction option should be. It is our goal at OPN to make sure that you know all your options. Depending on your refractive error we may suggest different types of vision correction. The Visian ICL represents a great option for many patients that may not be good LASIK candidates but also those that have high levels of myopia.

Visian ICL also called the Implantable Collamer Lens. Collamer Lens), created by STAAR® Surgical Company, is a phakic intraocular lens (IOL) for the treatment of myopia and other refractive errors.

PRK (Photorefractive Keratectomy)

PRK (Photorefractive Keratectomy) differs from LASIK vision correction in that it does not involve the creation of a flap to reshape the cornea. The advantage of PRK is that patients who are not candidates for LASIK may still regain better vision through refractive laser eye surgery. However, PRK does require a longer recovery process, and vision is not restored as quickly as LASIK vision correction. Also, a temporary, protective contact lens is worn after PRK to reduce postoperative discomfort.

LASEK

LASEK (laser sub-epithelial keratomileusis), epi-LASIK (epithelial LASIK) and ASA (Advanced Surface Ablation) are variations of PRK. LASEK involves removing the surface (epithelial) layer of cells using the same solution used in PRK. Instead of discarding the cells, the sheet of cells are replaced after the excimer laser treatment.

Bladeless LASIK

When LASIK first arrived as a laser vision correction procedure, a microkeratome was used to create the corneal flap. (To learn more about traditional LASIK please visit our LASIK eye surgery page) Over the years ophthalmologists have found that when complications arise from LASIK they are typically from a poorly created corneal flap. Now we have femtosecond lasers that can create the corneal flap and we refer to this as Bladeless LASIK.

Wavefront LASIK

Wavefront Custom LASIK is the most advanced laser technology available. Custom LASIK laser treatments are based upon the unique visual characteristics of your eye. Up until now, with glasses, contacts and conventional LASIK surgery, corrections were quite similar for each type of prescription. Custom LASIK involves measuring the eye from front to back with a special laser, using what's called "wavefront" technology, to create a three-dimensional (3-D) image of the eye. The information contained in the Wavefront-map guides the laser in customizing the treatment to your individual visual system.

Monovision

Monovision is a unique method of treating vision when people experience visual problems at both close and far distances or when presbyopia causes accommodation issues. Presbyopia occurs as part of the natural aging process. The eye's crystalline lens loses its ability to bring close objects into clear focus. Monovision used to involve wearing one contact for close vision and the other contact for far vision. Not all patients like monovision because it requires some adjustment and training of your eyes, however; most patients are able to make this adjustment. Patients that suffer from presbyopia often use bi-focal glasses as a treatment option. Bifocal contact lenses are now available. Monovision LASIK can also be an option. The FDA has approved CustomVue Monovision LASIK.

Refractive lens exchange, also called lens replacement surgery or clear lens extraction, may be a better option than LASIK, PRK or phakic IOL refractive surgery for people with presbyopia and high hyperopia (farsightedness).

Implantable Collamer Lens (ICL)

The implantable collamer lens procedure, or ICL for short, differs from cataract surgery in that it is a phakic procedure, meaning the eye’s natural lens is not removed. An ICL is an artificial lens, similar in function to a contact lens, which is implanted in front of the eye’s natural lens, but behind the iris, so that it is practically invisible to outside observers. The ICL procedure corrects moderate to severe myopia (nearsightedness).

It is believed that today more than 50,000 individuals in 40 countries world-wide have benefited from the relatively new LASIK Xtra eye surgery. The surgery is approved in Europe, the Middle East, Australia, Asia and Canada and is expected to get the go-ahead in the United States soon. That’s because surgeons performing LASIK in combination with cross-linking are achieving extremely promising results.

LASIK, which stands for laser in-situ keratomileusis, is a popular surgery used to correct vision in people who are nearsighted, farsighted, or have astigmatism.

Astigmatism Symptoms

Astigmatism usually causes vision to be blurred or distorted to some degree at all distances.
Symptoms of uncorrected astigmatism are eye strain and headaches, especially after reading or other prolonged visual tasks.
Squinting also is a very common symptom.

What Causes Astigmatism?

Astigmatism usually is caused by an irregularly shaped cornea. Instead of the cornea having a symmetrically round shape (like a baseball), it is shaped more like a football, with one meridian being significantly more curved than the meridian perpendicular to it.

(To understand what meridians are, think of the front of the eye like the face of a clock. A line connecting the 12 and 6 is one meridian; a line connecting the 3 and 9 is another.)

The steepest and flattest meridians of an eye with astigmatism are called the principal meridians.

In some cases, astigmatism is caused by the shape of the lens inside the eye. This is called lenticular astigmatism, to differentiate it from the more common corneal astigmatism.

Types of Astigmatism

There are three primary types of astigmatism:

Myopic astigmatism. One or both principal meridians of the eye are nearsighted. (If both meridians are nearsighted, they are myopic in differing degree.)
Hyperopic astigmatism. One or both principal meridians are farsighted. (If both are farsighted, they are hyperopic in differing degree.)
Mixed astigmatism. One prinicipal meridian is nearsighted, and the other is farsighted.
Astigmatism also is classified as regular or irregular. In regular astigmatism, the principal meridians are 90 degrees apart (perpendicular to each other). In irregular astigmatism, the principal meridians are not perpendicular. Most astigmatism is regular corneal astigmatism, which gives the front surface of the eye a football shape.

Irregular astigmatism can result from an eye injury that has caused scarring on the cornea, from certain types of eye surgery or from keratoconus, a disease that causes a gradual thinning of the cornea.

How Common Is Astigmatism?

Astigmatism often occurs early in life, so it is important to schedule an eye exam for your child to avoid vision problems in school from uncorrected astigmatism.

In a recent study of 2,523 American children ages 5 to 17 years, more than 28 percent had astigmatism of 1.0 diopter (D) or greater.

Also, there were significant differences in astigmatism prevalence based on ethnicity. Asian and Hispanic children had the highest prevalences (33.6 and 36.9 percent, respectively), followed by whites (26.4 percent) and African-Americans (20.0 percent).

In another study of more than 11,000 eyeglass wearers in the UK (both children and adults), 47.4 percent had astigmatism of 0.75 D or greater in at least one eye, and 24.1 percent had this amount of astigmatism in both eyes. The prevalence of myopic astigmatism (31.7 percent) was approximately double that of hyperopic astigmatism (15.7 percent).

Astigmatism Test

Astigmatism is detected during a routine eye exam with the same instruments and techniques used for the detection of nearsightedness and farsightedness.

Your eye doctor can estimate the amount of astigmatism you have by shining a light into your eye while manually introducing a series of lenses between the light and your eye. This test is called retinoscopy.

Though many eye doctors continue to perform retinoscopy, this manual procedure has been replaced or supplemented in many eye care practices with automated instruments that provide a faster preliminary test for astigmatism and other refractive errors.

Whether your eye exam includes retinoscopy, an automated refraction, or both, your optometrist or ophthalmologist will perform another test called a manual refraction to refine the results of these preliminary astigmatism tests.

In a manual refraction (also called a manifest refraction or subjective refraction), your eye doctor places an instrument called a phoropter in front of your eyes. The phoropter contains many lenses that can be introduced in front of your eyes one at a time so you can compare them.

As you look through the phoropter at an eye chart at the end of the exam room, your eye doctor will show you different lenses and ask you questions along the lines of, "Which of these two lenses makes the letters on the chart look clearer, lens A or lens B?" Your answers to these questions help determine your eyeglasses prescription.

Astigmatism Correction Options

Astigmatism, like nearsightedness and farsightedness, usually can be corrected with eyeglasses, contact lenses or refractive surgery.

In addition to the spherical lens power used to correct nearsightedness or farsightedness, astigmatism requires an additional "cylinder" lens power to correct the difference between the powers of the two principal meridians of the eye.

So an eyeglasses prescription for the correction of myopic astigmatism, for example, could look like this: -2.50 -1.00 x 90.

• The first number (-2.50) is the sphere power (in diopters) for the correction of myopia in the flatter (less nearsighted) principal meridian of the eye.
• The second number (-1.00) is the cylinder power for the additional myopia correction required for the more curved principal meridian. In this case, the total correction required for this meridian is -3.50 D (-2.50 + -1.00 = -3.50 D).
• The third number (90) is called the axis of astigmatism. This is the location (in degrees) of the flatter principal meridian, on a 180-degree rotary scale where 90 degrees designates the vertical meridian of the eye, and 180 degrees designates the horizontal meridian.

If you wear soft toric contact lenses for astigmatism correction, your contact lens prescription will likewise include a sphere power, cylinder power and axis designation.

Gas permeable contact lenses are also an option. Because these lenses are rigid and optically replace the cornea as the refracting surface of the eye, a cylinder power and axis may or may not be needed, depending on the type and severity of astigmatism correction required. The same is true for hybrid contact lenses.