1. Pachymetry-Assisted Lamellar Keratoplasty Versus Penetrating Keratoplasty in Keratoconus
Martha Jaimes Gutierrez M.D
Alexandra Abdala Figuerola M.D.
Alejandro Navas M.D., M.Sc.
Arturo Ramirez-Miranda M.D.
Enrique O. Graue-Hernandez M.D., M.Sc.
Department of Cornea, Refractive Surgery
Instituto de Ophthalmologia
“Fundacion Conde de Valenciana”
Mexico City, Mexico
Dr. Ramirez-Miranda and Dr. Navas are consultants for Carl Zeiss Meditec (Jena, Germany).
Dr. Ramirez-Miranda is a speaker of Thea Laboratoires. 
The remaining authors have no financial or proprietary interest in the materials presented herein.

2. Introduction
Keratoconus is a non inflammatory and progressive condition that causes significant visual loss
Corneal transplantation is performed in advanced cases in order to improve visual acuity
New techniques are available for the management of keratoconus, but penetrating keratoplasty is still the gold standard for treatment
Pachymetry-assisted lamellar keratoplasty uses the excimer laser technology in order to achieve a smooth stromal bed to preserve the receptor endothelium

3. Purpose
To compare the visual outcomes of keratoconus patients treated with penetrating keratoplasty (PK) vs. patients treated with pachymetry assisted lamellar keratoplasty (PALK)
Colagenasa
Tripsina
Pepsina
Papaína

4. Materials and methods Prospective case series 28 eyes treated
14 patients underwent PK
14 patients PALK
PK was performed conventionally with a trephine diameter of 7.75/8 mm in all patients
PALK was performed with an excimer laser ablation of the host corneal stroma, leaving 100 mm of residual stromal bed. Donor cornea was secured with 16 interrupted 10-0 nylon sutures
The outcome was the UDVA, CDVA, keratometric power and astigmatism

5. Results
28 eyes: PALK (n=14) and PK (n=14), with keratoconus stage II – IV (Amsler Krumeich) years old
Group
Age
Preoperative UDVA
Preoperative CDVA PK
29.5 (18-53)
1.49±0.4
0.87±0.33
PALK
26,7(18-40)
1.67±0.6
0.92±0.46
p value
0.43
0.38
0.74

7. logMar UDVA Preop 1 week 1 mo 3 mo 6 mo PALK 1.67±0.6 1.4±0.45
1.16±0.4
1±0.4
0.9±0.3 PK
1.49±0.4
0.93±0.26
0.87±0.24
0.78±0.26
0.67±0.3 p
0.38
0.003
<0.001
0.1
0.07

8. logMar CDVA Preop 1 w 1 mo 3 mo 6 mo PALK 0.92±0.46 0.95±0.24 0.7±0.32
0.61±0.3
0.56±0.33 PK
0.8 ±0.33
0.55±0.21
0.42±0.2
0.42±0.16
0.34±0.13 p
0.74
<0.001
0.01
0.07
0.05

9. Topography (Mean K)

10. Astigmatism

11. Conclusions
PALK and PK are safe and effective techniques for treating keratoconus patients
In a short-term follow-up, PK and PALK results showed similar visual outcomes with no difference in postoperative astigmatism between groups
Longer follow-up will be performed for further analysis

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