Refractive outcome of keratoconus treated by big-bubble deep anterior lamellar keratoplasty in pediatric patients: two-year follow-up comparison between mechanical trephine and femtosecond laser assisted techniques.

BACKGROUND

To evaluate refractive outcome 24 months after Deep Anterior Lamellar Keratoplasty (DALK) in pediatric patients by comparing results achieved using mechanical trephine and femtosecond laser.

METHODS

Twenty eyes of 20 patients affected by keratoconus were evaluated. To perform big-bubble DALK, 10 eyes (Group 1; mean age 11.2 ± 2.2 years) were subjected to the Hessburg-Barron mechanical trephine and the remaining 10 eyes (Group 2; mean age 11.3 ± 3.1 years) to a 150 kHz femtosecond laser that performed mushroom incisions. Preoperative thinnest point in the corneal thickness map and K readings were measured by the Sirius Scheimpflug camera. We also evaluated corrected distance visual acuity (CDVA) as logMAR value using spectacles, spherical equivalent and refractive astigmatism.

RESULTS

Mean preoperative thinnest point and pre- and post-operative K readings did not show significant difference ( > 0.05) between the two groups. CDVA, spherical equivalent and refractive astigmatism were respectively, 0.14 ± 0.08 logMAR and 0.13 ± 0.10 logMAR ( = 0.8), - 4.2 ± 1.1 D and - 2.8 ± 1.2 D ( = 0.03), 4.4 ± 2.0 D and 3.6 ± 1.2 D ( = 0.4) in Groups 1 and 2. All DALK procedures were uneventful.

CONCLUSION

Our findings suggest that femtosecond laser compared to mechanical trephine could significantly reduce the spherical equivalent amount in pediatric big-bubble DALK.