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.

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

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

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

Results 28 eyes: PALK (n=14) and PK (n=14), with keratoconus stage II – IV (Amsler Krumeich) 18-53 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

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

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

Topography (Mean K)

Astigmatism

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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