TABLE 1.
Details of the reviewed studies.
| References | Intervention | Outcomes | Setting | Patients (eyes) | Keratome/laser type(s) (flap creation) | Laser type(s) (stromal ablation) | Flap/hinge technical characteristic | Tests used | Follow-up intervals |
| Lee et al. (95) | Hinge position | RR and DES | South Korea, same center | 30 (50) | • Hansatome (Bausch & Lomb Surgical) or the M2 (Moria): superior hinge (25) • SCMD (New United Development Corp.) or the Summit Krumeich-Barraquer (SKBM, Alcon Surgical): nasal hinge (25) |
Star S2 excimer laser (VISX) |
• Flap thickness: • 160 μm • Flap diameter: • 8.5 mm |
• BUT • ST (without anesthesia) |
2 months |
| Donenfeld et al. (96) | Hinge position | CS and DES | USA, same center, same surgeon | 52 (104) | • Hansatome microkeratome (Bausch & Lomb, Rochester, NY, USA): superior hinge • Amadeus microkeratome (Allergan Pharmaceuticals, Irvine, CA, USA): nasal hinge |
VISX Star II excimer laser (VISX, Inc., Santa Clara, CA, USA) | • Flap thickness: • 160 μm • Flap diameter: • 9.5 mm |
• Masked Cochet–Bonnet esthesiometry • LGS (corneal and conjunctival) • ST (with anesthesia) • TBUT • Subjective evaluation of DE sensation |
1 week 1 month 3 months 6 months |
| Donenfeld et al. (74) | Hinge width | CS and DES | USA, same center, same surgeon | 54 (108) | • Amadeus microkeratome: nasal hinge (horizontal flap) | VISX Star 3 excimer laser | • Flap thickness: • 160 μm • Flap diameter: • 9.5 mm • Hinge widths: • 0.6 mm vs. 1.2 mm |
• Cochet-Bonnet esthesiometry • LGS (corneal and conjunctival) • ST (with anesthesia) • TBUT |
1 week 1 month 3 months 6 months |
| Nassaralla et al.(97) | Hinge position and flap thickness | CS | Brazil, Same center, Same surgeon, 1 (right) eye of each patient | 40 (40) | • Hansatome microkeratome: superior hinge • ACS microkeratome: nasal hinge |
Technolas 217-C Excimer laser (Bausch & Lomb, Rochester, NY, USA) | • Flap thickness: 160 and 180 μm (Sup. H) 130 and 160 μm (Nasal H) (four groups of eyes) • Flap diameter: 8.5 mm |
• Cochet-Bonnet esthesiometry | Q1 month until full recovery |
| Ghoreishi et al. (99) | Hinge position | DES | Iran, same center, same surgeon | 106 (212) | • Hansatome zero compression • Microkeratome (Bausch & Lomb, Rochester, NY, USA): both hinges |
Technolas 217 z excimer laser (Bausch & Lomb) | • Flap thickness: • 160 or 180 μm • Flap diameter: • 8.5 or 9.5 mm ü All are determined by the surgeon (based on each individual) but the same in both eyes |
• Visual acuity • Fluorescein tear-film breakup time • ST (with anesthesia) • OSDI questionnaire (subjective) |
1 week (except OSDI) 1 month 3 months 6 months |
| Vrom an et al. (90) | Hinge position | CS and DES | USA, same center | 47 (94) | • Hansatome microkeratome (Bausch & Lomb): superior hinge • Amadeus microkeratome: nasal hinge |
VISX S3 laser | • Flap thickness: 180 μm in SH Flap 160 μm in NH Flap • Flap diameter: • 8.5 mm • Hinge width: • 5.0 mm |
• Visual acuity • Contrast sensitivity • CS (Cochet-Bonnet corneal esthesiometer) • Basic secretion test • TBUT • OSS (conjunctival and corneal) • OSDI questionnaire (subjective) |
1 week 1 month 3 months 6 months |
| De Paiva et al. (99) | Hinge position | CS, DES, visual acuity, and ocular surface parameters | USA, same center, three surgeons for surgeries but one surgeon for follow-up, bilateral LASIK and same flap in both eyes of each patient | 35 (70) | • Hansatome microkeratome (Bausch and Lomb, Rochester, NY, USA): superior hinge • Amadeus microkeratome (Advanced Medical Optics, Irvine, CA, USA): nasal hinge |
VISX Star IV excimer laser (VISX Inc, Santa Clara, CA, USA) | • Flap thickness: • 160 μm • Flap diameter: • 9.5 mm |
• Corneal surface evaluation • Optical aberrometer • Snellen visual Acuity measurement • TBUT • CFS • Belmonte modified noncontact gas esthesiometry (for corneal sensitivity) • ST |
1 week 1 month 3 months 6 months |
| Mianet al. (91) | Hinge position | CS and DES | USA, same center, university-based academic practice | 33 (66) | • 30 KHz IntraLase Femtosecond Laser (IntraLase Corp.): both hinges | Technolas 217 excimer laser (Bausch & Lomb) | • Flap thickness: • 130 μm • Flap diameter: • 9.0 mm • Hinge angle: • 45 degrees |
• Central cochet-bonnet esthesiometry • OSDI questionnaire (subjective) • ST (with anesthesia) • TBUT • CFS • Conjunctival LGS (with a modified Oxford scale) |
1 week 1 month 3 months 6 months 12 months |
| Mian et al. (94) | Hinge position, hinge angle and flap thickness | CS and DES | USA, same center, university-based academic practice | 95 (190) | • 30 or 60 KHz IntraLase FS laser (IntraLase Corp.): both hinges | Technolas 217 excimer laser (Bausch & Lomb) | • Flap thickness: • 100 or 130 μm • Flap diameter: • 9.0 mm • Hinge angle: • 45 or 90 degrees |
• Central cochet-bonnet esthesiometry • OSDI questionnaire (subjective) • ST (with anesthesia) • TBUT • CFS • Conjunctival LGS (with a modified Oxford scale) |
1 week 1 month 3 months 6 months 12 months |
| Huang et al. (100) | Hinge position | CS and DES | N/A | 43 (86) | • Femtosecond laser | N/A | • superior- versus nasal-hinged flaps | • Corneal esthesiometry • BST • TBUT • OSS • OSDI questionnaire (subjective) |
1 week 1 month 3 months 6 months |
RR, refractive results; DES, dry eye syndrome; SCMD, standard cubic meters per day; TBUT, tear break-up time; ST, Schirmer test; CS, corneal sensation; LGS, lissamine green staining; DE, dry eye; ACS, automated corneal shaper; OSID, ocular surface disease index; OSS, ocular surface staining; CFS, corneal fluorescein staining; BST, Schirmer basic tear secretion test.