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 …