Does femtosecond laser assisted penetrating keratoplasty lead to less astigmatism in keratoconus patients, compared with conventional penetrating keratoplasy?

Purpose Visual impairing including high irregular astigmatism is a well‐known problem after penetrating keratoplasty ( PK ). The femtosecond ( FS ) laser technique allows completely new trephination methods such as the zig‐zag, top hat or the mushroom cutting profiles, which result in a more rapid and stable wound healing. In the present study we compare conventional PK and FS laser PK concerning astigmatism and visual outcome in keratoconus patients 2 years postoperatively Methods A total of 67 patients were operated with PK between September 2013 and June 2015 at Oslo University Hospital, Norway. All patients were examined 2 years after surgery. Ten keratoconus patients who were operated with FS laser‐assisted PK ( FS group) were included, using Alcon Wavelight FS 200 Femtosecond Laser, and compared with a control group who underwent conventional PK (n = 20). Controls were matched for diagnosis, age, gender and time of operation. Postoperative results regarding astigmatism and visual outcome were compared. Results At the 2 years follow‐up, the mean log MAR BCVA was 0.17 ± 0.14 in the FS ‐group and 0.16 ± 0.19 in the control group (p = 0.89). The mean spherical equivalent was ‐1.91 ± 4.58 in the FS ‐group, and ‐3.08 ± 2.81 in the control group (p = 0.39). The mean subjective and corneal cylinder was ‐6.08 ± 2.50 and 7.71 ± 3.78 in the FS ‐group, compared to ‐4.89 ± 2.57 (p = 0.24) and 5.73 ± 3.84 in the control group (p = 0.21), respectively. K‐mean was 44.00 D ± 3.99 in the FS ‐group and 44.98 D ± 1.63 in the control group (p = 0.50). ECD was 1456 cells/mm²± 325 in the FS ‐group, and 1679 cells/mm²± 475 in the control group (p = 0.22). Conclusions Even though the study included relatively few eyes, the findings confirm previous studies. No significant difference in astigmatism or visual outcome was found between the two groups 2 years postoperatively.