Purchase this article with an account.
G. S. Figueiredo, E. Loo, M. S. Figueiredo, F. C. Figueiredo; Long-Term Outcomes Following Penetrating Keratoplasty and Deep Anterior Lamellar Keratoplasty for Keratoconus. Invest. Ophthalmol. Vis. Sci. 2009;50(13):2209.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To determine and evaluate the long-term clinical outcomes in a cohort of patients with keratoconus, who had either penetrating keratoplasty (PKP) or a deep anterior lamellar keratoplasty (DALK).
Data from 76 operated eyes (67 patients) was extracted from the Newcastle Corneal Transplant Registry (NCTR), an 11-year prospective, single-centre, noncomparative, interventional case series of 529 consecutive corneal transplants. Preoperative recipient information and postoperative data were analysed including changes in visual acuity (VA), K-values and complications, eg. Urrets-Zavalia Syndrome (UZS). Kaplan-Meier survival analysis was used to estimate the long-term probability of graft survival. Student’s t-test was used to analyse differences between PKP and DALK in terms of K-values, endothelial cell density (ECD) and percentage of hexagonal corneal endothelial cells.
There were 69 PKPs and 7 DALKs, mean follow-up was 68 months (range 6-132). Preoperative VA was 6/24 or worse in 70% of patients and 6/18 or better in 29%. Postoperatively, 4% of patients had a best corrected VA of 6/24 or worse, and 96% had 6/18 or better. Twelve eyes (16%) developed UZS, which were associated with raised intraocular pressure within 24 hours post-graft when compared with unaffected grafts (p=0.02). Kaplan-Meier survival analysis predicted an overall graft survival rate at 10 years of 81% (95%CI 31-96). Thirteen eyes (17%) had rejection episodes, of which 3 (23%) were in atopic patients. There were no DALK rejections; whilst mean time to rejection for PKPs was 24 months (SD±22, range 3-96). Postoperative average K-values for PKP and DALK were 45.4 and 47.8 respectively (p=0.14). Average ECD at the end of follow-up for PKP and DALK were 1071 cells/mm² (SD±598) and 2265 cells/mm² (SD±398) respectively (p=0.004).
This study shows a long-term improvement in best corrected VA in patients who have had PKP or DALK. Projected survival rates show the majority of grafts survive to 10 years, with rejections in PKPs commonly appearing within 24 months despite a lower rejection rate than previously reported. Postoperative K-values were steeper for DALK compared with PKP, with DALK having a significantly higher ECD on specular microscopy. The NCTR offers a unique opportunity to analyse the long-term outcomes of corneal transplantation for keratoconus in an ophthalmic unit in the UK and to guide clinical practice.
This PDF is available to Subscribers Only