Purpose:
To evaluate the efficacy of Arcuate Keratotomies (AK) performed with femtosecond laser for the correction of high astigmatism after Penetrating Keratoplasty (PKP).
Methods:
18 eyes of 16 patients, (11M, 5F; mean age: 49yrs ± 16.50SD, min 30yrs max 77yrs), with high astigmatism after successful PKP were submitted to AK assisted by a 60 kHz femtosecond laser (IntraLase, AMO, Irvine, CA, USA). Mean preoperative topographic cylinder was 7.85D ± 3.74SD; mean preoperative refractive error in (SE) spherical equivalent was -3.37D ± 5.47SD; mean preoperative refractive cylinder was -4.19D ± 6.89SD (range from -12D to +9D). Average preoperative K was 45.21D ± 3.79SD. Mean preoperative Surface Asymmetry Index (SAI) was 3.15 ± 1.47SD. Mean preoperative UCVA was 0.11 ± 0.07SD and mean preoperative BSCVA was 0.62 ± 0.23SD.
Results:
Twelve months postoperatively, mean topographic astigmatism was 3.29D ± 2.93SD; mean refractive error in SE was -2.03D ± 3.46SD; mean refractive cylinder was -2,44D ± 3,26SD (Range: from -7D to +3D). That showed a surgical correction of 58% of the topographic cylinder and of 42% of the refractive cylinder. Average postoperative K was 45.84D ± 4.45SD. Mean postoperative SAI was 2.92 ± 1.36SD, showing a 15%reduction of the preoperative values.Mean postoperative UCVA was 0.18 ± 0.18SD and mean postoperative BSCVA was 0.70 ± 0.21SD.
Conclusions:
The reduction of more than 50% of the preoperative topographical astigmatism showed the effectiveness of femtosecond laser assisted AK to correct astigmatic errors after successful Penetrating Keratoplasty. The better results in postoperative BSCVA was probably related to the slight reduction of corneal asymmetry (SAI reduction of 15%).
Keywords: refractive surgery: other technologies • astigmatism • transplantation