Comparative study between big-bubble technique and manual dissection in deep anterior lamellar keratoplasty

Abstract

Purpose The aim of this study was to compare the big-bubble technique and the manual dissection technique as regards visual outcome in patients with corneal stromal opacities. Patients and methods A prospective interventional comparative study was conducted on 30 eyes of 30 patients attending the outpatient's clinic in Kasr El Aini Hospital, Cairo University, who met the inclusion criteria. Inclusion criteria were as follows: best-corrected visual acuity (BCVA) less than 6/36 and an intact endothelium/descemet membrane complex on ultrasound biomicroscopy. Exclusion criteria were as follows: full-thickness corneal pathology involving descemet membrane, endothelial dysfunction, intraocular pathology, ectatic corneal conditions, previous intraocular surgeries, lid abnormalities, active keratitis, or dry eye. The patients were divided into two groups: group A included 16 patients with successful achievement of the big-bubble technique, and group B included 14 patients operated upon manually layer by layer (predescematic deep anterior lamellar keratoplasty) due to failure to create a big bubble. Postoperative follow-up with group masking was carried out as regards the following outcome measurements: BCVA, presence of interstitial haze, contrast sensitivity using the functional acuity contrast test contrast sensitivity chart, intraocular pressure, ultrasound biomicroscopic assessment of graft thickness, and residual stroma. Results All patients completed 12 months of follow-up. The significance level was set at P value of 0.05 or less. In the big-bubble group, the mean BCVA was significantly better (P = 0.006), whereas the mean residual stroma was significantly lower (P = 0.0001) and the interface haze was significantly less (P = 0.018) than that found in the predescematic deep anterior lamellar keratoplasty group. Other variables showed a statistically insignificant difference between the two groups. Conclusion The big-bubble technique is superior to manual predescematic dissection as regards BCVA and mean residual stroma.