Summary

	TransPRK	LASIK	ReLEx SMILE	Implantable Collamer Lens (ICL)
Track Record Since	1992	1994	2012	1993
Procedure Time Per Eye	3-5 mins per eye	15 to 20 min	10 to 15 min	20 to 30 min
Corneal Thickness Criteria	Cornea must be at least 475 microns thick. Suitable for thinner cornea.	Cornea must be at least 500 microns thick.	Cornea must be at least 500 microns thick.	N.A No corneal thickness requirements (ICL is not a corneal based procedure).
Degree Correction Criteria (Based on average corneal thickness of 550 microns	Myopia: Up to 1,000 deg Hyperopia: Up to 400 deg Astigmatism: Up to 500 deg	Myopia: Up to 800 deg Hyperopia: Up to 400 deg Astigmatism: Up to 500 deg	Myopia: 200 to 700 deg ONLY Hyperopia: N.A. Astigmatism: Up to 500 deg	Myopia: Up to 1,800 deg Hyperopia: N.A. Astigmatism: Up to 600 deg
ʻNo Eyeball Touchʼ Surgery?	Yes	No A suction ring with high pressure is applied.	No A suction ring with medium pressure is applied.	No A small side incision is made for insertion of the lens.
Invasiveness	Least invasive True no-cut surface-based procedure.	Moderately invasive LASIK takes place beneath a cut corneal flap.	Minimally invasive ReLEx SMILE takes place via a removed lenticule ('internal flap')	Most invasive ICL is inserted inside the eye, beyond the cornea and deep behind the pupil.
Flap-Related/lenticule ('internal flap') complications?	No Zero flap-related complications since no corneal flap cut at all.	Yes This include: flap dislodgement, flap wrinkles, flap inflammations and flap interface problems.	Yes. Lenticule ('internal flap') complications can occur	N.A. The ICL procedure is not a corneal based surgery.
Dry Eyes?	Least likely TransPRK is a surface- based procedure with no nerve endings being cut, greatly reducing the risk of dry eyes.	Most likely Thousands of cornea nerve endings are cut when the cornea flap is created, resulting in the risk of permanent LASIK-induced dry eyes.	Moderately likely There is no big external cut made in the cornea, thus incidence of dry eyes is lower compared to LASIK.	N.A. The ICL procedure is not a corneal based surgery.
Ability To Achieve True Wavefront/ Topographical Correction	Yes	No The cut corneal flap during Lasik will introduce new Wavefront & Topographical errors.	No Current technology unable to correct Wavefront/ Topographical errors.	No There is no wavefront-enabled ICL.
Ability To Do Crosslinking To Prevent Future Corneal Thinning Problem i.e. Keratectasia	Yes Can be incorporated in TransPRK procedure.	Yes Can be incorporated in LASIK procedure.	No Cannot be incorporated in ReLEx SMILE procedure.	No Cannot be incorporated in ICL procedure.
Can Go Back To Work	4 to 5 days	2 to 3 days	2 to 3 days	2 to 3 days
Full Visual Recovery	Slower Generally takes around 1 to 3 months.	Fast Generally take 2 to 3 weeks.	Slower Generally takes about 1 to 3 months.	Fast Generally take 2 to 3 weeks.
Resume Light Sports e.g. Jogging, Gym, Cycling	5 days	5 days	5 days	5 days
Can Do More Active Sports e.g. Swimming, Diving, Bungee Jumping, Football	2 weeks (Important to avoid sun’s uv rays for 6 to 10 weeks)	1 month	1 month	3 month
Participate In Rugged And Contact Sports	2 weeks	It is not advisable to participate in contact sports as the cut corneal flap will never fully heals.	3 months	It is not advisable to participate in contact sports as the ICL may dislodge or injure internal structures.
Nutshell Summary	Good for anyone who prefers a safe surface-based procedure. Suitable for active sportsperson, especially those participating in contact sports. Suitable for those who are risk adverse to corneal flap complications, wish to minimise risk of dry eye, have thin cornea and high myopia, and those who are afraid of having their eyes cut can also consider TransPRK. Very important to avoid the sun’s uv rays for two months post-op and to use the recovery eye drops provided for six to ten weeks depending on the eye power corrected.	Good for those who wish to have a fast visual recovery. Not suitable for those who are risk adverse to the cut corneal flap complications. Not suitable for those who wishes to participate in contact sports, or suffer from dry eye, or who have a fear of having their cornea cut.	An improvement over LASIK, in that it does not cut an open flap, and thus, lowers the risk of flap- related complications and dry eyes. However, visual recovery is slower. ReLEx SMILE cannot perform Wavefront and Topographical corrections, also no adjunct cross- linking can be done at same time to strengthen thin cornea. If fine- tuning enhancement is needed in the future, it is done using ASA techniques like TransPRK. Accuracy is a concern for those with high astigmatism. Lenticule ('internal flap') flap complication is a concern for those with low myopia.	This is an invasive procedure as it is an intra-ocular procedure. It increases the risk of developing cataracts and glaucoma. There is a real 1 in 1,000 eyes fear of the eye going fully blind from a bad post-op infection. Hence, in my opinion, it is an option to consider only for those patients who are found to be not suitable for cornea-based laser vision correction procedures. e.g. patients, with very thin cornea, high refractive errors or cornea scarring.