Fellow Eye Comparison of Nerve Fiber Regeneration After SMILE and Femtosecond Laser-assisted LASIK: A Confocal Microscopy Study.
OBJECTIVE
To compare postoperative corneal nerve fiber regeneration after small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (FS-LASIK).


METHODS
The medical records of patients who underwent SMILE were retrospectively reviewed. Patients with SMILE in one eye (the SMILE group) and FS-LASIK in the fellow eye (the FS-LASIK group) and who had undergone a confocal microscopy study were retrospectively identified. Subbasal nerve fiber density was measured and compared between the groups preoperatively and at 1 week and 1, 3, and 6 months postoperatively.


RESULTS
Thirty eyes of 15 patients were included in the study. Preoperative characteristics of the eyes were similar between the groups. However, there was a statistically significant difference in subbasal nerve fiber density between the groups at 1 month (SMILE group: 1,505 ± 627 µm/mm(2) [range: 625 to 2,540 µm/mm(2)], FS-LASIK group: 1,107 ± 509 µm/mm(2) [range: 595 to 2,313 µm/mm(2)], P = .003) and 3 months (SMILE group: 1,534 ± 503 µm/mm(2) [range: 650 to 2,255 µm/mm(2)], FS-LASIK group: 1,194 ± 485 µm/mm(2) [range: 530 to 1,695 µm/mm(2)], P = .004) postoperatively. No statistically significant difference was detected at 1 week and 6 months postoperatively.


CONCLUSIONS
Eyes treated with SMILE have a higher density of subbasal nerve fibers than eyes treated with FS-LASIK in the early postoperative period (1 week to 3 months) but the two procedures are equivalent by 6 months postoperatively.
Alper
A
Agca
Kadir I
KI
Cankaya
Ihsan
I
Yilmaz
Yusuf
Y
Yildirim
Dilek
D
Yasa
Onur
O
Olcucu
Ali
A
Demircan
Ahmet
A
Demirok
Omer F
OF
Yilmaz
D000328:Adult; D003315:Cornea / Q000294:innervation*; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000601:surgery*; D048988:Corneal Surgery, Laser; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D009412:Nerve Fibers / Q000502:physiology*; D009416:Nerve Regeneration / Q000502:physiology*; D011184:Postoperative Period; D012189:Retrospective Studies; D013524:Surgical Flaps; D014276:Trigeminal Nerve / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult