Top Hat Keratoplasty For Keratoglobus - A Unique Solution For A Challenging Situation

To describe a new technique utilizing femto-laser assisted penetrating keratoplasty for the surgical management of keratoglobus.

The Cornea Unit in a single tertiary hospital- Rabin Medical Center

The first case involves a 38-year-old male with a 20-year history of keratoglobus, who previously underwent PKP in both eyes. Keratoglobus re-occurred in his left eye with significant corneal distortion, extreme thinning at the periphery and visual acuity of counting fingers. To address the challenge of keratoplasty on an extremely thin cornea, femtolaser-assisted top hat configuration was exclusively performed on the donor cornea, facilitating the augmentation of the peripheral cornea and safe placement of corneal sutures in this case. Two years after surgery, the graft is stable and best corrected visual acuity improved to 6/10 in his left eye.

In the second case, a 41-year-old male with keratoglobus experienced recurrent corneal ulcers and hydrops in his left eye. Following the resolution of edema, once again a femtolaser-assisted top hat configuration of the donor cornea was performed and sutured safely to the host’s trephined cornea without any complications. Best corrected visual acuity improved from 1/60 prior to operation to 6/9 three months after surgery.

Top-Hat configuration keratoplasty on the donor cornea only may be a a unique surgical solution in keratoglobus eyes, providing good visual outcomes as well as structural integrity. Longer follow up is mandatory.