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Comparison between manual trephination versus femtosecond laser-assisted deep anterior lamellar keratoplasty for keratoconus
  1. Ramin Salouti1,2,
  2. Mohammad Zamani2,
  3. Maryam Ghoreyshi2,3,
  4. Isabel Dapena4,
  5. Gerrit R.J. Melles4,
  6. Mohammad Hossein Nowroozzadeh1
  1. 1 Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
  2. 2 Salouti Cornea Research Center, Salouti Eye Clinic, Shiraz, Iran
  3. 3 Health Policy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
  4. 4 The Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands
  1. Correspondence to Dr Mohammad Hossein Nowroozzadeh, Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran; nowroozzadeh{at}


Background/aims To compare the outcomes of femtosecond laser-assisted deep anterior lamellar keratoplasty (F-DALK) versus manual trephination DALK (M-DALK) in patients with keratoconus.

Methods In this retrospective, comparative, clinical study, medical charts of 860 patients with keratoconus who underwent F-DALK (n=391) or M-DALK (n=469) with the Melles’s technique, and had at least a 12-month follow-up record were reviewed. The main outcome measures comprised best spectacle-corrected visual acuity (BSCVA), manifest refraction and keratometric indices. The postsurgical measurements were recorded for all patients at 12 months (suture-in condition), and a subset of patients with complete data at 24 months (suture-out condition; 111 F-DALK and 282 M-DALK cases).

Results Both procedures had comparable mean (±SD) logMAR BSCVA at 12 months (0.18±0.12 for M-DALK and 0.17±0.12 for F-DALK; p=0.224) and 24 months (0.11±0.10 vs 0.09±0.09, respectively; p=0.166) examinations. M-DALK was associated with a significant more residual myopia at 12 months (−3.85±3.27 vs -1.94±2.86 D; p<0.001), and a milder similar trend at 24 months follow-up (−2.94±2.72 vs −2.38±2.65 D, p=0.064). The mean keratometry (12 months: 46.15±1.88 vs 44.39±1.72, p<0.001; 24 months: 45.33±2.37 vs 44.14±1.68, p<0.001) and apical keratometry values (12 months: 50.92±5.00 vs 47.13±2.38, p<0.001; 24 months: 50.29±4.25 vs 48.12±3.81) were significantly greater for M-DALK than F-DALK, while the keratometric astigmatism was similar (12 months: 2.62±1.58 vs 2.53±1.33, p=0.364; 24 months: 3.21±1.83 vs 3.34±1.88, p=0.529).

Conclusions F-DALK for advanced keratoconus performs as well as M-DALK in terms of BSCVA and keratometric astigmatism in both suture-in (12 months) and suture-out (24 months) conditions. It might have advantages over M-DALK for residual myopia and restoring corneal anatomy.

  • femtosecond
  • deep anterior lamellar keratoplasty
  • keratoconus
  • laser-assisted
  • Manual-trephination

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  • Contributors Research design: RS, ID and MHN. Data acquisition and statistical analysis: MZ, MG, GM and MHN. Writing of the manuscript: all authors. Revising and Final approval of manuscript: all authors.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Obtained.

  • Ethics approval The ethics committee at Shiraz University of Medical Sciences approved the study protocol.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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