Lasik flap problem

New England Eye CenterGrand Rounds

Anil U. Swami, M.D. March 29, 2001


CASE PRESENTATION:

• A 61 year old Caucasian female was referred to Ophthalmic Consultants of Boston 2 days following Laser in situ keratomileusis (LASIK) complaining of pain and decreased vision in her right eye.

• Two days prior to presentation, the patient underwent LASIK

in both eyes at an outside institution. Her second eye (OD) was complicated by a “free flap” at the time of surgery.

New England Eye Center Grand Rounds

• On the day of surgery, treatment was performed and LASIK flap was replaced with a contact lens placed over the eye. On postoperative day 1, the contact lens was removed and the flap was non adherent. A single 10-0 nylon suture was placed at the 12 o’clock position and a BSCL was a placed

• The patient was seen the following day. Despite the single suture the flap remained non-adherent and the patient was refereed for further evaluation and treatment


• The patient was complaining of blurry vision and pain OD.

• The patient was happy with her vision in left eye and had no discomfort OS

• She had no other significant PMH or POH• The patient was currently on fluromethalone

(FML) to both eyes 4x a day, and Ocuflox to both eyes 4x aday


• The patient’s visual acuity was CF at 5 feet OD, 20/25 OS.

• SLE: See Figure 1

• The left eye showed a normal nasal hinged LASIK flap with no striae.


Figure 1


Figure 2


• The LASIK flap showed only minimal epithelium along the anterior surface and multiple nests of epithelium on the undersurface of the flap. The flap was felt to have its true epithelial surface facing the LASIK bed.

• The flaps was then inverted and sewn into place with 4 10-0 nylon sutures. Care was taken to avoid any tension on the wound to prevent any induced astigmatism. The epithelium was removed from the undersurface of the LASIK bed and the anterior surface before the tissue was flipped to its proper orientation.


Figure 3a &b


• 1 month following the surgery the patient was 20/30 OU uncorrected. The patients epithelium was completely healed and the 4-10 nylon sutured were removed. One week following suture removal the patient, uncorrected visual acuity remained unchanged and the following topography was taken.

• The patient returned to her referring ophthalmologist for all further postoperative care.


Figure 4


• Figure 5a&5b


DISCUSSION:• Microkeratome related complications are rare during

LASIK but do occasionally occur. Among the most common are “free flaps”, “button holes” and “incomplete flaps”

• “Free flaps” may be seen with in patients with a flat cornea (K less than 40), in patients with loss of suction, and in patients in which the flap is amputated while lifting up on the dermatome (if a back pass is not made).


• In most cases, when a free flap occurs, the operating surgeon can continue the laser treatment of the patient. The flap should be kept sterile and removed from the microkeatome. The flap should be placed on the treated bed. Marking are done before the keratome pass and used to center the flap following treatment if a free flap occurs. If only a single vertical mark is placed the tissue may become inverted.

• The flap is allowed to dry and adhere to the undersurface. Most physicians place a contact lens over the flap to secure it.


• Once the epithelium grows in over the “gutters” of the flap it is secure and the BSCL is removed. If the flap remains non-adherent, it may be sutured but this often leads to irregular astigmatism.

• Patients with very steep corneas are at increased risk for “button-holes.” If a button hole occurs, no treatment should be performed and the LASIK flap placed back. Treatment may be performed with a keratome with a deeper depth to recut approximately 3-6 months following the original surgery. A similar approach should be followed for incomplete flaps.


References:

• Holland SP, Srivannaboon S, Reinstein Avoiding serious complications of laser in situ keratomileusis and photorefractive keratectomy. Ophthalmology 2000 107:640-52

• Tham VM, Maloney RK Microkeratome complications of laser in situ keratomileusis. Ophthalmology 2000:26:650-659

• Leung AT Rao SK Lam DS Flap complications associated with lamellar refractive surgery. Am J Ophthalmology. 2000. 130:258-259

• Rao SK, Padmanabhan P, Sitalakshmi G, Rajagopal R, Lam DS Timing of retreatment after a partial flap during laser in situ keratomileusis. J cataract Refract Surg 1999. 11:1424-5


• References (cont)• Pulaski JP Etiology of button hole flaps J Cataract Refract

Surg. 2000 26:1270-1271.

• Lan DS et al. Management of severe flap wrinkling or dilodgement after laser in situ keratomileusis J cataract Refract Surg. 1999 25:1441-1447

Art & Photos

Lasik flap problem