Clinical Outcome of Zig-Zag Penetrating Keratoplasty Post Microwave System Thermal Keratoplasty for Treatment of Keratoconus
To examine the postoperative results of eyes that underwent ziz-zag penetrating keratoplasty (z-PKP) by femtosecond laser post reshaping of the central cornea by microwave-system thermal keratoplasty for the treatment of keratoconus.
This study involved 8 eyes of 8 keratoconus patients which underwent z-PKP by femtosecond laser (IntraLase iFS; Abbot Medical Optics) at 1-month post thermal keratoplasty by use of the Keraflex Microwave System (Avedro, Inc.) to reshape and solidify the central part of the cornea to relieve the prominence (MW group). Those eyes were compared with 7 eyes of 7 keratoconus patients which underwent z-PKP without thermal keratoplasty during the same period (control group). In all operated eyes, corneal shape, power [diopters (D)], and the surface regularity index (SRI) were evaluated by use of a topographic modeling system (TMS-4; Tomey Corporation).
At 3-months postoperative, uncorrected visual acuity (VA) (LogMAR), best-corrected VA (BCVA) (LogMAR), corneal power (D), and SRI of the MW group and the control group were 0.57±0.47, 0.12±0.14, 42.9±2.6D, and 1.34±0.45 and 0.92±0.46, 0.37±0.31, 44.1±5.2D, and 1.43±0.31, respectively. BCVA in the MW group tended to be better than that in the control group (P = 0.07).
Treatment by microwave-system thermal keratoplasty prior to femtosecond z-PKP was found to be effective for the improvement of postoperative outcomes in patients with keratoconus.