Comparison of Early Anatomical, Functional and Safety Results of 3 Anterior Lamellar Keratoplasty Te

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Comparison of Early Anatomical, Functional and
Safety Results of 3 Anterior Lamellar
Keratoplasty Techniques

• Ramón Naranjo-Tackman,MD
• Ilka E. De Obaldía-Faruggia,MD
• Cornea and Refractive Surgery Department
• Assn. To Prevent Blindness in Mexico
• Mexico

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OBJECTIVES

• To stablish the potential advantages of 3
  different techniques for Anterior Lamellar
  Keratoplasty(ALK)
• Microkeratome assisted ALK,
• Femtosecond Laser Assisted ALK and
• Predescemet big bubble technique,
• In terms of anatomical integrity, visual results
  and endothelial survival.

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MATERIAL AND METHODS

• Patients diagnosed with Keratoconus.
• Patients were divided in 3 groups, to determine
  the differences between 3 different ALK
  techniques.
• Inclusion criteria were
• corneas had to be thinner than 450µ, and
  thicker than 350µ, with contact lens intolerance
• and were assigned to three different groups
  
• 1 Microkeratome assisted ALK, an Amadeus(Ziemer
  ophthalmics, Switzerland) microkeratome and
  artificial anterior chamber, using a 200 or 250µ
  cutting plate.
• 2 Femtosecond laser assisted ALK, an Intralase
  (AMO-Intralase, California)30KHz FSL was used.
• 3Big bubble pre-Descemet's technique.UCVA,BSCVA,
  K readings, were measured at PreOp. and Mo. 1 and
  3. Corneal imaging was done using a Visante OCT
  (C. Zeiss, Germany), for contrast sensitivity a
  CSV-1000 screen was used, and for endothelial
  evaluation a Topcon specular non contact
  microscope was used.All surgeries were done by
  the same surgeon (RNT)

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MATERIAL AND METHODS

• Methods
• UCVA,BSCVA,K readings, were measured at PreOp.
  and Mo. 1 and 3.
• Corneal imaging was done using a Visante OCT (C.
  Zeiss, Germany),
• Contrast sensitivity a CSV-1000 screen was used
• For endothelial evaluation a Topcon specular non
  contact microscope was used.
• All surgeries were done by the same surgeon (RNT)

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RESULTS

• A total of 18 eyes were included, and divided in
  the 3 groups in equal numbers.
• The Mean PreOperative values for all cases
  were
• UCVA20/400, BSCVA 20/70, K53.2D,
• Thickness 412µ,
• Contrast sensitivity at 3,6,12,18 were 3,4,4,4
  Respectively.
• Endothelial cell density was2456.At Mo. 3, Mean
  postoperative values were G 1UCVA20/80,BSCVA
  20/50, Ks 51.2D, Thickness 510 µ, CV 3,3,2,3,
  Endotelial cells 2107 283.Mean donor thickness
  250 µG 2UCVA20/80,BSCVA 20/50, Ks 49.62D,
  Thickness 573 µ, CV 2,3,2,3, Endothelial cells
  1902 417. Mean donor thickness 370µG
  3UCVA20/70,BSCVA 20/40, Ks 50.7D, Thickness
  540 µ, CV 3,3,3,3, Endotelial cells 1862 459.
  OCT Images disclosed a more anatomical
  resemblance of the anterior surface of the cornea
  in group 1.

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LAMELAR CON BURBUJA

• Big bubble technique
• Best case of improvement of contrast
  sensitivity

Pre and postOp Keratometric maps in this case
Confocal image of the posterior donor estroma,
showing microfolds. Although the contrast
sensitivity imoproved extremelly well, this case
is the exception, not the rule.
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DISCUSION

• Anterior lamellar keratoplasty, has certain well
  defined advantages over PK,
• Microkeratome lamellar keratoplasties, were the
  ones that achieved the best anatomical results,
  in terms of curvature and shape, and less
  reduction of endothelial cells, no improvement in
  contrast sensitivity was observed.
• Femtosecond assisted lamellar keratoplasty became
  the most repeteable, and kept a very good
  endothelial cell count, there was no improve in
  contrast sensitivy
• The 3rd. Group showed only one case with an
  impressive improvement in contrast sensitivity,
  but more decrease in the endothelial cell count.

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CONCLUSIONS

• Anterior lamellar keratoplasty, has certain well
  defined advantages over PK, but has been
  criticized about the lack of visual quality, and
  poor contrast sensitivity.
• This series, although rather short, tries to
  define if there are anatomical, functional or
  safety issues that may have to be considered when
  deciding an specific technique.
• We think that the main factor to consider, is to
  evaluate endothelial manipulation in the
  pre-descemet techniques, that may pose a risk for
  long term graft survival.
• Definetively, until we improve the interface that
  is not natural, and we are creating, this will
  the factor not allowing us to improve visual
  quality after the graft.