Inadequate results for microkeratome-assisted additive stromal keratoplasty for management of keratoconus

To evaluate a new automated technique--microkeratome-assisted additive stromal keratoplasty (MASK)--for the management of keratoconus in eyes scheduled for surgery with clear cornea associated with total contact lens intolerance.

This non-comparative, interventional case series included four eyes of four patients with stage I and II keratoconus associated with total contact lens intolerance. The first step of the surgical procedure consisted of performing a nasal-hinged flap on the host cornea with a microkeratome. The second step consisted of extracting a stromal piano-powered disk from the donor's cornea using an artificial chamber. The 80-microm thick lamellar graft was punched with a 7.5-mm circular trephine and positioned beneath the flap. Corneal refractive surgery was scheduled for the end of the sixth postoperative month.

No corneal refractive surgery was performed after 6 months of follow-up. Only one eye gained five lines of best spectacle-corrected visual acuity (BSCVA). Among the other three eyes, two had unchanged BSCVA and one lost one line of BSCVA. At the end of surgery, mean corneal thickness was increased by 148.75 microm.

Microkeratome-assisted additive stromal keratoplasty appears to be a safe and straightforward surgical technique that preserves the host endothelium and avoids the need of an open-sky procedure. However, in our study, MASK is not considered as an alternative to penetrating or deep lamellar keratoplasty in the management of keratoconus with clear cornea because of imprecise anatomic and refractive outcomes.