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. 2014:8:35-42.
doi: 10.2147/OPTH.S53370. Epub 2013 Dec 10.

Rate of ectasia and incidence of irregular topography in patients with unidentified preoperative risk factors undergoing femtosecond laser-assisted LASIK

Majid Moshirfar  1 , Jared G Smedley  2 , Valliammai Muthappan  1 , Allison Jarsted  3 , Erik M Ostler  1
Affiliations

Rate of ectasia and incidence of irregular topography in patients with unidentified preoperative risk factors undergoing femtosecond laser-assisted LASIK

Majid Moshirfar et al. Clin Ophthalmol. 2014.

Abstract

Purpose: To report the rate of postoperative ectasia after laser-assisted in situ keratomileusis (LASIK) with femtosecond laser-assisted flap creation, in a population of patients with no identified preoperative risk factors.

Methods: A retrospective case review of 1,992 eyes (1,364 patients) treated between March 2007 and January 2009 was conducted, with a follow up of over 4 years. After identifying cases of ectasia, all the patient charts were examined retrospectively for preoperative findings suggestive of forme fruste keratoconus (FFKC).

Results: Five eyes of four patients with post-LASIK ectasia were identified. All eyes passed preoperative screening and received bilateral LASIK. One of the five patients developed ectasia in both eyes. Three patients retrospectively revealed preoperative topography suggestive of FFKC, while one patient had no identifiable preoperative risk factors. Upon review of all the charts, a total 69 eyes, including four of the five eyes with ectasia, were retrospectively found to have topographies suggestive of FFKC.

Conclusion: We identified four cases of post-LASIK ectasia that had risk factors for FFKC on reexamination of the chart and one case of post-LASIK ectasia with no identifiable preoperative risk factors. The most conservative screening recommendations would not have precluded this patient from LASIK. The rate of purely iatrogenic post-LASIK ectasia at our center was 0.05% (1/1,992), and the total rate of post-LASIK ectasia for our entire study was 0.25% (1/398). The rate of eyes with unrecognized preoperative FFKC that developed post-LASIK ectasia was 5.8% (1/17).

Keywords: LASIK; ectasia; forme fruste keratoconus; topography; visual acuity.

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Figures

Figure 1
Figure 1
Orbscan® (Bausch and Lomb, Inc, Rochester, NY, USA) image of patient 1, showing inferior ectasia in the right eye 21 months postoperatively.
Figure 2
Figure 2
Preoperative Atlas™ (Carl Zeiss Meditec Inc, Jena, Germany) topography of patient 1, demonstrating inferior steepening of right eye.
Figure 3
Figure 3
Orbscan® (Bausch and Lomb, Inc, Rochester, NY, USA) image demonstrating inferior ectasia in the right eye at postoperative month 44 in patient 2.
Figure 4
Figure 4
Atlas™ (Carl Zeiss Meditec Inc, Jena, Germany) topography demonstrating right eye inferior steepening preoperatively in patient 2.
Figure 5
Figure 5
Orbscan® (Bausch and Lomb, Inc, Rochester, NY, USA) image demonstrating inferior steepening of the left eye at 12 months postoperatively in patient 3.
Figure 6
Figure 6
Orbscan® (Bausch and Lomb, Inc, Rochester, NY, USA) demonstrating inferior ectasia in the right eye at 32 months postoperatively in patient 3.
Figure 7
Figure 7
Orbscan® (Bausch and Lomb, Inc, Rochester, NY, USA) showing inferior steepening preoperatively in the left eye of patient 3.
Figure 8
Figure 8
Atlas™ (Carl Zeiss Meditec Inc, Jena, Germany) topography showing inferior steepening preoperatively in the right eye of patient 3.
Figure 9
Figure 9
Inferior ectasia seen in patient 4′s left eye 22 months postoperatively, by Atlas™ (Carl Zeiss Meditec Inc, Jena, Germany) topography scan.
Figure 10
Figure 10
Normal preoperative topography of patient 4′s left eye as seen on Atlas™ (Carl Zeiss Meditec Inc, Jena, Germany) topography scan.
See this image and copyright information in PMC

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