Epi Lasik and Lasek Eye Surgery
Epi Lasik and Lasek Eye Surgery
Epi lasik is a new corneal surface refractive surgery. In this procedure, an ultra thin flap of 30-50 Micron will be created by special motorized blade. This flap contains only corneal epithelial layer, which is the superficial layer of the cornea and it does not contain corneal stroma.
In another words, in this procedure there will be separation of corneal epithelial layer from the rest of the cornea without dissecting the corneal stroma, not like lasik in which the created flap contain both the epithelial layer and corneal stroma because the cutting will be through the corneal stroma.
Patient Evaluation for Epi Lasik and Lasek Eye Surgery
Patient evaluation is done in the doctor clinic and it is very important because not every one is a good candidate for this kind of surgery.
Before you visit your eye doctor, it would be better for you to have a general concept about the surgery to be able to interact with your surgeon and to avoid serious complications. Read more about Patient Evaluation for Lasik.
Before the Surgery
Before the surgery starts, a topical antibiotics can be applied prophylactically and also NSAIDs can be applied for pain.
Patient is positioned on the operating table and the fellow eye is covered.
Epi Lasik Procedure
Skin surround the eye is cleaned and drop of topical anesthesia is applied and the eye is widely opened with lid speculum.
The periphery of the cornea is marked with circles to allow the surgeon to know the reference points to replace the epithelial flap over the corneal bed at the exact position.
Suction ring is applied to the cornea to stabilize the eye then epikeratome or an epithelial separator is applied to the cornea.
This special motorized blade will separate the epithelial layer from the underlying corneal stroma and then the suction is removed.
Epi-keratome and microkeratome are not the same, epi-keratome will not cut through the stroma and only will act to separate the epithelial layer from the stroma without cutting through the stroma while the microkeratome will cut through corneal stroma.
The epithelial flap is lifted and the underlying corneal stroma is revealed. Corneal ablation is initiated with excimer laser and then the corneal bed and the epithelial flap are hydrated. After that the epithelial flap is replaced back to the same place and the eye is left to dry for 2-5 minutes to allow adhesion with the underlying cornea.
Post operation care of Epi Lasik and Lasek Eye Surgery
Post operation care consists of eye drops, bandage contact lenses and follow up visits to the clinic.
Combinations of antibiotics eye drops such as tobramycin or ciprofloxacin, Corticosteroid Eye Drops such as dexamethazone or prednisolone and NSAIDs such as diclofenac sodium are applied to the eye.
Bandage contact lens is placed on the operated eye and kept in place till complete healing occur which is usually after 3 to 5 days.
Medications that will be used after surgery are antibiotics, steroid and NSAIDs. They should be used four times daily for the first week.
Frequent lubrication and artificial tears should also be applied. After 1 week the antibiotics should be stopped while the steroid should be tapered over 2 weeks. Follow-up visits should be 1 day, 1 week, 1 month and then after 3-6 months.
Patient should revisit the clinic as soon as possible if he or she noticed any unusual symptoms like severe pain, redness, blurred vision and eye discharge.
Advantages of Lasek and Epi-lasik over Lasik and PRK
There are several advantages of Lasek and Epi-lasik over Lasik and PRK.
Limitations of PRK are postoperative pain, prolonged or slow visual rehabilitation and the corneal haze in which its incidence will increase with higher refractive error. Stabilization period of vision is long in PRK.
Lasik overcome PRK due to less or no postoperative pain, faster recovery period and less corneal haze even in high myopia.
Lasik has complications like complications related to microkeratome and flap creation, interface related complications ,which are the complications that occur in the space between the cornea flap and the residual corneal bed.
Example of interface complication is diffuse lamellar. Also in patient with thin cornea, the risk of corneal ectasia will increase. Read more about Lasik Complication.
Doctors can consider Lasek and Epi-lasik when the patient is not a good candidate for lasik treatment as in:
1- Patient with thin cornea but there is no sign of keratoconus . Patients with keratoconus should undergo corneal cross linking to stabilize the cornea before Epi lasik or lasek surgery.
With thin cornea,the remaining part of the cornea after laser ablation in lasik will not be enough to protect the cornea from minor trauma and also will not protect the cornea from normal intraocular pressure which will keep pushing forward on the thin cornea causing cone shape cornea and high refractive errors and also these patient will be at risk of perforated cornea with minor trauma
2- Patients with steep and flat cornea. Because the risk of flap related complications will increase
3- Patients with narrow palpebral fissure or deep set eyes because the microkeratome won't fit properly on the cornea
4- Patients who are more predispose to trauma like military personal and athletes because the flap will not healed completely and with trauma there will be a chance of flap dislocation.
5- Patients with large pupil will have high order aberrations like halos and glare after lasik. To prevent these high order aberrations, the size of ablation zone should be larger than the pupil size but in lasik the size of ablation zone has limits to preserve corneal tissue and so they are not good candidate for lasik but they can undergo lasek or Epi-lasik because with them the size of the ablation zone can be made larger than the pupil size.
6- Patients with dry eye are at high risk to develop severe dry eye post lasik than after lasek or Epi-lasik because the lasik flap will cut through corneal nerves which play a role in tears secretion.
7- Patient with glaucoma can be at high risk in lasik due to high intra-ocular pressure that is created with suction ring which can add more pressure on optic nerve and can cause further damage.
Although lasek and epilasik have some advantages over lasik but still lasik has some advantages over them.
With lasik there will be less postoperative pain, the recovery period is faster in lasik. Visual stabilization with lasik is faster and the incidence of corneal haziness is extremely low after lasik.
Due to extensive use of steroid in Lasek and Epi-Lasik, there will be a risk of inducing glaucoma after those two procedure but still the incidence can be reduced by which can be prevented by continuous monitoring of intraocular pressure and by using weak steroid.