Difference between PRK, LASIK and ReLEx SMILE laser eye surgery

More about PRK:

A PRK procedure reshapes the cornea thereby reduces dependency on glasses or contact lenses. It is performed for correcting myopia, hyperopia and astigmatism. This refractive error correction is performed using an excimer laser, usually in patients for whom LASIK is not suitable or if they have conditions like thin cornea or severe dry eyes, or have had LASIK surgery done in the past and one cannot lift the ‘ corneal flap’ for a re treatment.

     More on LASIK:

PRK was a procedure earlier to LASIK. LASIK was introduced to tackle the complications of PRK in terms of pain, haze, and other healing issues.

In LASIK a protective corneal flap is created and this flap is lifted and cornea reshaped using the excimer laser. The flap is then placed back and it heals in few days time. The limitation of LASIK was that due to this flap creation, one faced issues such as dryness of eyes, and a serious although extremely rare complication termed “corneal ectasia”. This was attributed to the flap which was made by the ‘cutting’ of the first few layers of the cornea, thereby resulting in weakening it and loss of its corneal integrity. To avoid such complications, the newer method is ReLEx Smile. In this there is no flap, hence no cut, hence no weakening of corneal fibres. Thus ReLEx smile was introduced not to make the vision sharper than what LASIK is achieveing, but in order to remove the complications which came due to ‘flap’ creation.

     More on ReLEx SMILE laser eye surgery

  • A lenticule is created deep in the cornea, thus saving the first layers.
  • It is a flapless procedure and only requires a keyhole incision to remove the lenticue
  • It uses a highly advanced 3rd generation Femtosecond laser viz the Zeiss VisuMax
  • It is suitable for patients with high powers and those prone to dryness due to serious computer related work.
  • Compared to LASIK, ReLEx Smile it is 80 % smaller side keyhole incision.


Comparision between PRK and LASIK and ReLEx Smile:

Let’s look into the major areas they differ in.

  • Visual Outcome: Not much difference between the results after a year of LASIK and PRK cases. A gradual vision improvement could be expected in PRK than in LASIK. LASIK vision improvement is better and faster than PRK. In ReLEx Smile excellent visual results could be expected.
  • Visual Recovery: PRK takes more time than LASIK. ReLEx smile is comparable to LASIK. Visual recovery differs from patient to patient.
  • Post operative Complications: No Flap related complications in PRK while flap related complications could be present in LASIK. However the chances of post surgery infection and inflammation are more in PRK than LASIK. ReLEx Smile has almost no post operative complication and the safest among all.
  • Recovery time: LASIK and ReLEx Smile have faster recovery compared to PRK. ReLEx Smile is the quickest thereby making it possible to return to routine activities very soon. ReLEx Smile has minimal restrictions to get back to contact sports or swimming.
  • Pain: Less pain and more comfort in LASIK compared to PRK. ReLEx Smile is most comfortable out of them.
  • Procedure difference: PRK is directly on the corneal surface hence no flap is created. The entire outer part of the cornea (epithelial layer) is removed and discarded. The corneal architecture is least compromised in ReLEx Smile compared to PRK and LASIK.
  • Cost difference: ReLEx Smile is more expensive than LASIK given the new advancement of technology and PRK. PRK is comparatively the lowest.
  • Flap related issues: PRK and ReLEx Smile have no chance of Flap related issues while LASIK could have chances of the same.
  • Dry Eyes: PRK and ReLEx Smile have least incidence of dry eyes compared with LASIK.

Over the years of research, the latest techniques, the surgical procedures and equipments have evolved in the refractive arena thus empowering precision and expertise to maximize results with minimal concerns.

Do get in touch with us for more details and consultation to get your doubts cleared and get the best treatment for you.

Read More

Common Eye Problems and Disorders


Whenever one notices a symptom related to the eyes, there may be more to see than what meets the eye! An underlining cause may be behind it, and could be skipped in the diagnosis unless you delve deeper. On a thorough eye examination and consultation, it is possible to co-relate the possible cause and effect and provide the right remedy and treatment.

It is always best to treat at the early stage of any eye disorder in order to protect eyes and other organs from further damage. Patients have various kinds of problems, some minor while some are major or it could even be a life threatening condition, not to be ignored. Let’s discuss them in the trailing series of topics in order to have a better understanding and insight on these common complaints which could mean more.

In this blog we understand the common eye issues that we normally come across, but these blogs are mainly for general education purpose and cannot replace the ophthalmologist consultation and advice.

      Common patient eye issues:

  1. Discomfort and tiredness in both eyes

            What it may mean?

  • Computer Vision Syndrome: Tiredness in the eyes is a common problem reported by those who use computers for a prolonged time without much eye blinking. If unattended could lead to Computer Vision Syndrome.
  • Eye Fatigue: This is caused mainly due to prolonged strain on the eyes due to reading, writing or driving.
  • Dry Eyes: Needs quantitative and qualitative tests on the tear film for final diagnosis

Depending on the extent and severity of discomfort and when it is associated with redness or pain the diagnosis changes and so with the treatment too.  Eye strain may lead to other problems, such as headaches, difficulty in concentrating, irritability, photophobia.

  1. Headache

      What it may mean?

  • Long sightedness/ Astigmatism/ Refractive errors: One of the simplest causes to treat is when you have some spectacle prescription or a change in the older prescription and the eye strain leads to headaches. These can be easily diagnosed with the help of an eye examination and also very easily treated by wearing the correct glass prescription.
  • Sinusitis: Sinuses are air spaces around the eyes with a mucus lining. Any inflammation of these areas is referred to as an eye pain, pull inside the eyeball or heaviness in the eyes. Patients assume that this is due to a change in prescription and hence visit the eye specialist. However, the cause is an inflammation of the sinuses around the eyes and not from inside the eye per se. This inflammation is usually caused due to allergy, change in weather, associated with colds etc and simple steps like steam inhalations and staying away from cold foods and drinks is the first step in treatment.
  • Ocular Migraine: When headache is followed by visual disturbances, it could be an ocular migraine. These are episodic and can cause temporary blindness, which is very frightening. Spasms in the blood vessels of the eye lead to these symptoms. It is important to get your eyes checked and also check if you have fluctuations in blood pressure.
  • Other causes: Continuous headaches, or those which are progressive, associated with epileptic attacks or muscular spasms; those in young age group (early onset), or those which wake you up from sleep etc are the kind of headaches one should not ignore. It could also be a symptom which preceded viral fever, dengue etc. Exploration of cause should be focused on finding systemic causes, neurological conditions etc for this one may need help of a good physician with sound clinical expertise to guide you properly regarding the investigations that would need to be done to find the cause.


  1. Redness:

What it may mean?

Redness could be at a specific time of the day like in the evening only or the entire day. It could be signs of inflammation, infection, injury to the eye. Conjunctivitis is the commonest cause. It could be unilateral or bilateral (in both eyes). There are different types of conjunctivitis such as viral, bacterial and the most common which is allergic. Sometimes redness could be an indication of other eye conditions like uveitis or glaucoma.

  1. Haziness in Eyes:

What it may mean?

Haziness or cloudy vision could be possibilities of damage in the cornea, indications to several eye disorders including cataract, glaucoma etc. They could also indicate sign and symptom of possible refractive error, which is the simplest to treat using correct spectacle prescription. Other conditions such as optic nerve inflammations, drug reactions, etc need further tests and deeper examination.

The eye being a very delicate and sensitive vital organ of the body, it is not worth neglecting or ignoring any symptoms associated with vision.

We should be watchful and alert for minor symptoms and warnings. When our eyes talk in the form of symptoms like the ones discussed above, we need to pay attention and listen to the call and take the necessary action quickly. An immediate consultation depending on the urgency of the situation would help in resolving many complications. It is prudent and always advisable to avoid self treatment and consult with the ophthalmologist at the right time.

Read More