Big bubble formation in deep anterior lamellar keratoplasty may be more successful in early keratoconus eyes

The recent publication by Lucchino et al reports on preoperative predictive factors for big bubble (BB) formation during deep anterior lamellar keratoplasty (DALK) in keratoconus eyes.1 In a total of 140 eyes of 140 patients, the authors observed successful pneumatic dissection in 98 eyes (70.0%), with 94 type 1 BB (67.1%) and 4 type 2 BB (2.9%). The study provides topographic evidence for a higher BB success rate among earlier stages of keratoconus, as characterised by lower K-max, lower K-mean, higher corneal thickness at the thinnest point and lower difference in peripheral-minimal corneal thickness. Moreover, the anterior segment-optical coherence tomography (AS-OCT) classification2 was found to be the only factor that predicted BB formation, with mild to moderate keratoconus eyes, particularly those with no posterior stromal scars, demonstrating a greater likelihood of undergoing successful BB creation. DALK is widely accepted as a preferred type of keratoplasty for anterior stromal pathologies such as keratoconus or scars.3 4 While achieving similar visual recovery …