Modified big-bubble for deep anterior lamellar keratoplasty.

A new technique of air injection is described for big-bubble deep anterior lamellar keratoplasty (DALK) in eyes with keratoconus, along with a comparative analysis of the original technique. Fifty eyes were analyzed in each group. The mean steep keratometry and anterior chamber depth distribution were comparable between the 2 groups. The mean size of type 1 bubble achieved with single air injection (Group 1) was 7.8 ± 0.4 mm (range 6.5 to 8.5 mm), and with sequential air injection (Group 2) was 8.5 ± 0.3 (range 8 to 9 mm) (P < .001). Intraoperative complications of spontaneous bursting of bubble in 1 eye (2%) and peripheral microperforation in 3 eyes (6%) occurred only in Group 1. The modified technique of big-bubble DALK using sequential air injection aided by paracentesis to lower intraocular pressure allowed enlargement of a type 1 bubble in a safe and controlled manner with minimal risk for complications.