Trends in Indications and Techniques of Corneal Transplantation from 1999 through 2015 at a Tertiary Referral Center in Athens, Greece

Abstract

Introduction: During the past decade, novel techniques of corneal transplantation allowing faster and better restoration of vision have emerged. The present cohort study describes a shift of indications and techniques that has occurred in the field of corneal transplantation over a 17-year period in Greece.

Methods: All patients undergoing keratoplasty between January 1999 and December 2015 at an academic tertiary referral center in Athens, Greece, were retrospectively reviewed. The annual incidence of keratoplasty indications and techniques was recorded and analyzed.

Results: A total of 1382 keratoplasty procedures were included. Leading indications were bullous keratopathy (BK) (37.5%), followed by allograft rejection (17.7%), corneal scar (12%), keratoconus (KC) (10.3%), and Fuchs endothelial dystrophy (FED) (8.8%). A decreasing trend was observed for KC (P=0.009) and an increasing trend for BK (P=0.003) and FED (P=0.001). In 2015, the incidence of penetrating keratoplasty (PK) had decreased from 100% (1999 to 2009) to 21.4%; for cases with isolated pathology of the corneal endothelium, DSAEK was the preferred technique (59.8%), while the respective rate of DMEK was 18.8%.

Conclusion: Herein, we observed an increasing trend of endothelial pathology among keratoplasty indications as well as a major shift in preferred techniques due to a wide adoption of the new EK procedures.

Figure 1

Chart depicting distribution of recipient age (a) and gender distribution (b) per calendar year. (a) Recipient age shows a statistically significant increase (P < 0.001, r²=0.79, univariate linear regression). (b) In addition, a switch from male to female predominance is noted in 2009, the year of EK implementation. This also may be explained by the increase Fuchs endothelial dystrophy that affects mainly women.

Figure 2

Chart depicting recipient age (a) and gender distribution (b) per indication. (a) The lowest age is observed in keratoconus while the highest in Fuchs endothelial dystrophy patients. (b) Significant predominance of men is noted in keratoconus (65.5%) and corneal scar (67.5%) whereas of women in Fuchs endothelial dystrophy patients (65.6%).

Figure 3

The pie chart illustrates the incidence of all keratoplasty indications from 1999 to 2015. Top 3 indications were bullous keratopathy (37.5%), regraft (17.7%), and corneal scar (12%). Each diagnosis is represented by the same color as in the bar chart in Figure 2.

Figure 4

Scatter plot depicting the annual incidence of each keratoplasty indication. A significant trend was found for bullous keratopathy (BK; r²=0.47, P=0.003), corneal scar (r²=0.72, P < 0.001), keratoconus (KC; r²=0.38, P=0.009), and Fuchs endothelial dystrophy (FED; r²=0.55, P=0.001). All others were found not significant (univariate linear regression analysis).

Figure 5

Column chart depicting the absolute number of keratoplasty procedures performed in each calendar year from 1999 to 2015. Penetrating keratoplasty (gray columns) was the only technique applied until DSAEK (green columns) and DMEK (red columns) were implemented (2009 and 2013, resp.). In the last year, PK was only performed in 21.4%. Significant fluctuations in the annual number of surgeries were caused by fluctuations in the number of operating surgeons as well as by graft shortage periods.

Figure 6

Column chart depicting keratoplasty techniques applied for endothelial pathology, that is, BK (a), FED (b), and regrafts (c). Note that, in the last 3–6 years of the observation period, PK has been replaced to a variable extent by endothelial keratoplasty, that is, DSAEK and DMEK.