Purpose:
To evaluate intra-op complications during epithelial laser-assisted in situ keratomileusis (Epi-lasik), and to correlate complications with pre-op findings.
Methods:
290 eyes of 145 US Army soldiers, age 21 or over underwent Epi-lasik for myopia or myopic astigmatism using the Amadeus II epikeratome and LADARVision 6000 excimer laser. Epikeratome parameters were set per manufacturer recommendation. If there was a complication in the first eye (right) a new epithelial separator was used for the second eye. The epithelial flap was retained after laser ablation whenever possible. Pre-op data included: Age, gender, manifest spherical equivalent (MSE), refractive cylinder (CYL), keratometry (K), and central corneal thickness (CCT). Statistical analysis was performed using SPSS software version 15. Odds ratios (OR) were used to determine likelihood of flap complications. Pearson Chi square was performed to determine statistical significance between patients with and without flap complications. P-value <0.05 was considered significant.
Results:
Mean age was 34 years old with 62.8% males. Mean pre-op MSE was 2.97+ 1.19D (range -1D to -6.25D), mean CYL was -0.56 +0.51D, K steep was 44.36 +1.46D, K flat was 43.55 +1.44D, and mean CCT was 540 +34µm. Intra-op flap complications are listed in Table 1. Overall there was a 35% chance of some form of flap complication, with a 23% chance of losing the flap. There was a relative increase in rate of complications for age ≤40 (OR=2.05, P=0.022), CCT <500µm (OR=1.227, P=0.590), right eye (OR=1.53, P= 0.085), K CYL >1 (OR=1.33, P=0.288), K flat <42 (OR=1.21, P=0.568). There is a decreased OR for K steep >46 (OR=0.568, P=0.160).
Conclusions:
Epi-lasik was associated with a high rate of epithelial flap abnormality or loss during surgery. Careful patient selection may allow this technique to be a useful surgical tool, but Epi-lasik should not be relied upon as a sole means of modifying surface ablations to mitigate against late complications such as corneal haze.
Clinical Trial:
www.clinicaltrials.gov NCT00413517
Keywords: refractive surgery: complications • refractive surgery: other technologies