Deep Anterior Lamellar Keratoplasty with Femtosecond Laser Zig-Zag Incisions: Initial Results Roger F. Steinert MD and Marjan Farid MD

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Deep Anterior Lamellar Keratoplasty with
Femtosecond Laser Zig-Zag Incisions Initial
ResultsRoger F. Steinert MD and Marjan Farid MD
Dr. Steinert is a consultant to Abbott Medical
Optics
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Purpose

• To evaluate visual recovery and astigmatism in
  eyes with stromal corneal pathology and ecstatic
  disease that underwent deep anterior lamellar
  keratoplasty (DALK) with femtosecond laser zigzag
  incisions

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Methods

• Retrospective Chart Review
• Patient selection
• Consecutive patients who underwent femtosecond
  laser assisted DALK over a 1 year period
• Exclusion Cystic blebs, severe peripheral
  opacity or NV

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Main Outcome Measures

1. Astigmatism (by Orbscan or Pentacam)
2. BSCVA

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Surgical Technique 1

• Femtosecond laser zig-zag incision The
  femtosecond laser is used to create matching
  zig-zag (posterior angled cut, lamellar ring cut
  at 300um depth and anterior angled cut) incisions
  in the host and donor corneas. Based on the
  thinnest area of the patients peripheral cornea,
  the laser is set to leave 70 microns of posterior
  uncut tissue.
• DALK The zig-zag incision is bluntly dissected.
  A 30-gauge needle on an air-filled syringe is
  inserted along the lamellar ring cut or just
  above the 70 micron uncut tissue. Air is injected
  at this level to bare Descemets membrane with
  the big-bubble technique as described by Anwar.

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Surgical Technique 2

• If successful, the remainder of the posterior
  stromal cut is excised, leaving bare Descemets
  membrane. The endothelium is wiped off the donor
  cornea and the donor is sutured to the patients
  corneal rim.
• If a Descemets membrane perforation occurs, the
  surgeon converts to a standard femtosecond laser
  assisted PKP. In that case, the donor corneal
  endothelium is left intact before suturing it to
  the corneal rim.

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Results
Sex Age Eye Dx Preop BCVA BCVA 1 m BCVA 3m BCVA 6m BCVA 9m ? K 1m ?K 3m ?K 6m ?K 9m
1 M 29 R KC 20/400 20/25 20/30 20/30 N/A 3.3 3.7 1.9 1.8
2 M 34 R KC 20/40 20/20 20/30 2.2 2.8
3 M 25 R KC 20/400 20/30 20/400 20/25 20/20 3.3
4 F 34 L ectasia CF 20/60 20/40 2.7
5 M 25 L KC 20/80 20/20 20/25 3.7 4.2
6 M 78 L KC 20/50 20/100 20/50 20/30 0.6 1.2 1.6
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Results

• Average BSCVA by month 3 was 20/32 (logMar 0.2)
• In 4 out of 6 patients who had topography
  performed at that visit
• Average astigmatism by month 1 was 2.45 diopters
  (1.26 SD)
• Average astigmatism by month 3 was 2.7 diopters
  (1.22 SD)

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Results

• Patient 4 had recurring epithelial breakdown due
  to HSV keratitis
• Approximately 30 of our initial big bubble
  attempts resulted in Descemets perforations
  which required conversion to full thickness PKP
• Visante OCT showed good Descemets membrane
  apposition to the donor cornea and the zig-zag
  wound healing reaction in all eyescses.

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Conclusions

1. Femtosecond zigzag DALK results in a
   biomechanically stable wound and excellent
   apposition of Descemets membrane.
2. Early results demonstrate excellent recovery of
   BSCVA and astigmatism which are comparable to
   full thickness femtosecond laser keratoplasty.
3. There is an early surgical learning curve for
   achieving successful baring of Descemets membrane