outcomes of deep lamellar keratoplasty by big bubble method with using shifting bubble sign in patients with keratoconus or corneal opacity

purpose: to investigate the results of deep lamellar keratoplasty (dlk) by big bubble method with using shifting bubble sign in patients suffering from keratoconus or corneal opacity methods: in this prospective interventional clinical trial, 20 eyes of 18 patients (10 males and 8 females) who underwent dlk by big bubble method using shifting bubble sign were investigated. mean age of cases were 26.94 years old (19 to 66 years). keratoplasty was done as a treatment of keratoconus in 18 cases (90%) and corneal opacity due to trachoma in 2 cases (10%). results: in this study, 20 eyes of 18 patients who underwent dlk by big bubble method using shifting bubble sign were investigated. best corrected visual acuity (bcva) of 14 cases (70%) were equal or lower than 20/200 and in 6 cases (30%) were between 20/200 and 20/50. mean uncorrected visual acuity of all cases in the first, third, sixth and twelfth months of follow-ups were 20/160, 20/120, 20/120 and 20/80 respectively. mean of bcva of cases after one year was 20/35 (20/20 to 20/120). micro perforation occurred in 3 cases (15%) during the procedure, but dlk were not converted to penetrating keratoplasty (pk) in any of the cases. vascularization and corneal opacity was occurred in 2 cases (10%) at the junction of donor and recipient cornea. conclusion: dlk by big bubble method is an effective way to treat the keratoconus or corneal opacity and using shifting bubble sign will confirm formation of the big bubble. the results of this study are comparable with similar previous studies on the same subject.    iranian journal of ophthalmology 200921(2):41-45 © 2009 by the iranian society of ophthalmology