Articles about Eye Health and Disease 2002
 

Outcomes of Lasik Following Flap Complications

(From Pallikaris IG et al., Ophthalmology 2002;109:57.)

The Lasik procedure for the surgical correction of refractive errors (nearsightedness, farsightedness, and astigmatism) has certain risks, including complications arising during the creation of the lasik flap with the microkeratome. With ongoing improvements in design and safety, microkeratomes are now more reliable than in the past. However, complications can still occur, and most surgeons today will abort the procedure if there is a flap complication.

This study looked at cases where the surgery was completed in spite of a complication, specifically to determine if there was a loss in best corrected vision after the surgery. A loss in best corrected vision would indicate corneal scarring or irregularities from the surgery that lead to an uncorrectable loss in vision. In this study from Greece, 334 consecutive myopic lasik procedures were performed by the same surgeon using the same microkeratome from 1997 to 1998. The average range of correction was -3.5 diopters to -14.5 diopters of nearsightedness.

If a complication occurred during the creation of the flap by the microkeratome (48 eyes, or 15% of cases), the surgery was completed in 77% of the cases.  In the remaining cases, the surgery was aborted.  If a buttonhole developed in the flap, the bed of the flap was cleaned of debris and then treated with the laser.  If a free cap occurred (no hinge in the flap), the laser treatment was applied and the flap was repositioned.  If an incomplete flap was created, manual dissection was used to complete the flap.

One year after surgery, 24% of the eyes had lost 1 line of best corrected vision when the surgery was completed in spite of a complication.  13% of eyes maintained their preoperative vision.  2.7% of eyes lost more than one line of vision.  In cases where the surgery was aborted after a complication, 10% of eyes lost one line of vision, but none lost more than a line.  The largest loss of vision was found in cases with irregular flaps, buttonhole flaps, ultra-thin flaps, and incomplete flaps.  None of the eyes with a free cap lost best corrected vision.

It was concluded that microkeratome-related complications are an important source of loss of best corrected vision, even in cases where the surgery is aborted.  Cases with irregular, incomplete, and buttonholed flaps are especially at risk for vision loss, and these cases should generally be aborted and not treated with laser.

 

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