A 31-year-old man presented to our clinic to discuss refractive surgery to correct his myopia in order to pass aviation screenings for the U.S. Air Force Academy. He had a 15-year history of contact lens wear and no known history of ocular infections or trauma. His medical history was negative for collagen vascular diseases, obstructive sleep apnea, allergies, and eye rubbing. His family history was negative for complications with refractive surgery or ectasia.
Upon examination, the patient’s BCVA was 20/20 OU. Pupils were reactive from 4 mm to 2 mm bilaterally with no relative afferent pupillary defects detected. IOPs were 14 mm Hg and 13 mm Hg. Confrontation visual fields were within normal limits.
The patient’s spectacles prescription was:
OD: –5.75 –0.75 x 90
OS: –5.50 –0.25 x 115
Manifest refraction:
OD: –6.00 –0.50 x 85
OS: –5.75 –0.25 x 180
Cycloplegic refraction:
OD: –6.25 –0.25 x 80
OS: –6.00 –0.25 x 175
Pachymetry showed thin corneas (518 µm OD; 524 µm OS). Keratometry readings were approximately 41 for each eye with less than a half diopter of cylinder.
After discussing several surgery options—PRK, LASIK, SMILE, and ICL—the patient chose SMILE.
The Surgery
The patient was taken to the laser suite, and the VisuMax femtosecond laser (Carl Zeiss Meditec) was used to create the SMILE lenticule and incision. The lenticule was dissected and removed from the right eye without complication. When attempting to dock the left eye, an irregularity was noted in the patient interface (Figure 1). The patient interface was cleaned with a Weck cell and was redocked. During creation of the lenticule in the left eye, a slight irregularity was noted in the lenticule cut at the same inferonasal area where the patient interface irregularity had been previously. When attempting to dissect the posterior aspect of the lenticule, the surgeon found that the inferonasal area was not free. The decision was made to try to circumferentially tear the lenticule, which resulted in removal of about 85% of the lenticule. The 15% of retained lenticule was crescent-shaped inferonasally and could not be removed from the eye. At this point, the eye was irrigated and the surgery was concluded.
Figure 1. Intraoperative patient interface abnormality and irregular lenticule creation.
Postoperative Follow-up
On postoperative day 2, an attempt was made to remove the retained portion of the lenticule. Because the surgeon was unable to dissect to the posterior plane, a false plane was created, and once this was realized, the decision was made to abort the attempted dissection.
At the 1-month postoperative visit, manifest refraction in the left eye was +0.75 –1.00 x 83. Slit-lamp examination of the left eye revealed significant stromal irregularity and scarring from 5 o’clock to 8 o’clock (Figure 2).
Figure 2. Pentacam of left eye at postoperative month 1.
At postoperative month 6, the patient’s visual acuity was 20/15 OU, and he went on to pass his aviation examination.
Key Learning Points
This case demonstrates several learning points. First, while SMILE complications such as a partially retained lenticule are rare, they are important to discuss with patients preoperatively. This patient was fortunate to not have symptomatic complaints after surgery, but he could have needed further intervention, such as topography-guided PRK or further dissection of the partial lenticule.
Second, any irregularity of the patient interface is important to note during LASIK and is even more vital to note during SMILE, because of the precision of lenticule creation. In hindsight, this patient could have benefited from an exchange of the patient interface, and we would recommend, “When in doubt, switch it out.”
Finally, more intervention is not always better. As an experienced surgeon advised, when having a complication, “Don’t just do something. Stand there!” In this case “standing there” and deciding to employ watchful waiting yielded the desired result for this patient, who is highly reliant on excellent vision.
