Early onset ectasia following laser in situ keratomileusus: case report and literature review.
OBJECTIVE
Laser in situ keratomileusis (LASIK) has been associated with the development of postoperative corneal ectasia. We present a case of early onset ectasia after LASIK, review known risk factors in development, and discuss possible strategies for prevention.


METHODS
A 39-year-old man underwent bilateral LASIK for moderate myopia. Preoperative cycloplegic refractions were -9.00 + 0.25 x 140 degrees OD and -7.75 sphere OS. Corneal topography demonstrated mild inferior steepening bilaterally although definite evidence of keratoconus by either the Klyce/Maeda and Smolek/Klyce keratoconus screening tests was not present. Following the creation of flaps with 160-microm plates, ablations of 93 microm OD and 80 microm OS were performed, estimated to leave residual stromal beds of at least 314 microm OD and 330 microm OS.


RESULTS
On the first postoperative day, uncorrected visual acuities were 20/400 OD and 20/40 OS. On the fifth postoperative day, the patient's uncorrected visual acuity was 20/400 OD, and 20/300 OS. Corneal topography of the right eye showed profound inferior steepening with an apical corneal power in excess of 57 D; topography of the left eye showed mild inferior steepening. Eighteen months after surgery best corrected visual acuity was 20/40 OD and 20/30 OS with rigid gas permeable contact lenses.


CONCLUSIONS
This case highlights the need for a high index of suspicion when one notes an asymmetric bow-tie pattern on preoperative LASIK corneal topography, despite seemingly safe estimates of residual stromal bed thickness.
Rao
Sanjay N
SN
Cornea Service, Department of Ophthalmology, Rush Medical College of Rush University, Chicago, IL, USA.
Epstein
Randy J
RJ
D000328:Adult; D003316:Corneal Diseases / Q000209:etiology*; D019781:Corneal Topography; D004108:Dilatation, Pathologic / Q000209:etiology; D006801:Humans; D007049:Iatrogenic Disease; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects*; D008297:Male; D009216:Myopia / Q000601:surgery; D012029:Refraction, Ocular; D012307:Risk Factors; D014792:Visual Acuity