RESUMO
PURPOSE: To analyze the results of very deep lamellar keratoplasty using dissection with air and a viscoelastic substance. METHODS: This was a prospective monocentric noncomparative study. Candidates for lamellar keratoplasty were enrolled between November 1998 and July 2000. Deep lamellar dissection was performed following air injection into the cornea to create a white emphysema of the stroma. The dissection was performed to the Descemet membrane. Whenever a large bulla was present in the recipient bed, the dissection of the deepest stromal lamellae was performed by injecting a viscoelastic substance into the bulla. A full-thickness allogenic corneal button was sutured to the recipient bed. RESULTS: Fifteen eyes of 14 patients (mean age, 39.3 years) underwent deep lamellar keratoplasty: keratoconus (11 eyes), atopic keratoconjunctivitis (1 eye), herpes zoster keratitis (1 eye), corneal scar after pterygium surgery (1 eye), and rosacea keratitis (1 eye). Excluded from the analysis of the refractive outcome were patients who underwent intraoperative perforation (n = 3) and the patients with postoperative complications affecting the central visual axis: (n = 2 [hemorrhage in the interface and herpetic simplex keratitis]). The mean preoperative visual acuity was 0.10 (range, 0.05 to 0.3). After a 3.8-month-follow-up, the mean best corrected visual acuity was 0.21 (range, 0.1 to 0.6). The visual results were better in patients with keratoconus (mean best corrected visual acuity: 0.22; range, 0.1 to 0.6). The mean postoperative astigmatism was 4.15 diopters (range, 0 to 8). CONCLUSION: Intrastromal air and viscoelastic substance injection appeared to be very useful for performing a very deep lamellar keratoplasty. The results of the refractive outcome were encouraging. Deep lamellar keratoplasty is an interesting alternative to penetrating keratoplasty, because it cannot induce progressive primary graft failure and allogenic endothelial graft rejection and it obviates the need to perform a lamellar dissection of the donor button.