LASIK VS SMILE

what is the difference between LASIK and SMILE?

LASIK in it’s most advanced form as performed at Sharif Eye  Center Laser utilises two separate lasers, a Femtosecond laser creates a hinged flap that is elevated and the base underneath the flap is remodelled with an excimer laser. The flap creation allows for next day vision recovery. The excimer laser that performs the reshaping element allows us to utilise the most advanced treatment algorithm, Contura Vision, that simultaneously perfects the corneal shape whilst correcting the glasses prescription. This has allowed for a new paradigm of visual quality outcomes, representing the first time one can achieve vision 2 lines better than the vision achievable with glasses.

 

SMILE is an attempt to use just a Femtosecond laser to perform the entire correction as opposed to just the flap creation. The femtosecond laser cuts a lenticle of tissue from the substance of the cornea that is then extracted through an access incision.

 

Both correct Myopia. SMILE was originally conceived to create less dry eye and potentially have a reduced risk of an unstable cornea (ectasia.) As time has progressed and a more accurate evaluation of the efficacy of SMILE has emerged, it appears these advantages have not been correct. Studies have shown an incidence of both dry eye and ectasia that is statistically similar to LASIK.

 

Considering SMILE does not have advantages over LASIK, what about its disadvantages?

Firstly it is inherently less accurate than Femtosecond LASIK with Contura Vision.

 

Approximately 98% of patients achieve vision equal to or better than 20/20 vision after a single treatment at Sharif Eye  Center with Contura Vision LASIK

 

The ReLEx SMILE only achieves 20/20 vision in about 60-85% of patients in recent studies. The inherent inaccuracy of ReLex SMILE stems from the fact the smallest amount of tissue removed with a femtosecond laser is to 4 microns compared to the 0.25 microns achievable with an Excimer laser. This equates to at least 16 times finer accuracy for an Excimer Laser.

 

This inherent lack of accuracy with SMILE also explains the increased frequency of requiring enhancement, at up to 40% in studies vs less than 2% at Sharif Eye  Center Unlike the next day recovery with minimal discomfort that can be achieved with Femtosecond LASIK, the enhancement is performed with PRK or surface based laser that is painful; for over 2 days and can take 6-8 weeks to recover.

 

Even when SMILE is effective, it generally takes 3 weeks to settle as opposed to next day recovery encountered with LASIK.

 

SMILE has a significantly reduced treatment range. It can only effectively correct up to 0.5 diopters of astigmatism compared to 6 diopters with LASIK. It cannot correct hyperopia or mixed astigmatism. It is incapable of the sophisticated surface perfecting ability of Contura Vision and as a result, can not provide this level of visual quality.