Clinically, we obtained an average ECD loss of 46.3% at month 6 and 49.1% at month 12, which was similar (or slightly higher) than other cases found in the literature. For instance, the ECD loss reported after 12 months from UT-DSAEK surgery was 49% by Feng et al.,
43 38.9% by Graffi et al.,
44 and 35.6% by Busin et al.
8 For DSAEK, van Cleynenbreugel et al.
45 reported a 40.2% loss after 6 months, Guerra et al.
46 a 34.9% loss after 12 months, and Javadi et al.
47 a 42.8% at 2 years of follow-up. We observed that our cohort showed a large variability on ECD loss at the different time intervals, without a clear pattern (
Fig. 10). Indeed, some patients showed a deceleration on ECD loss over time with an almost nonexistent progression within the last 6 months, whereas others depicted a small acceleration on ECD loss at that time. Regarding CV and HEX, barely any postkeratoplasty study includes them in their analysis because of the lack of reliability (up to now) in automatic methods. In our case, we estimated from the manual assessments a CV of 26.1 ± 5.7% and a HEX of 58.1 ± 7.1% at month 12. Existing literature in various ethnic groups indicates that the average CV is 26 ± 4%
48,49 and HEX is within 58% to 74%
50 in healthy population, and it is widely accepted that a CV of less than 30% and a HEX of greater than 60% is usually a sign of a healthy, stable endothelium. Hence, our post-transplant cohort showed an overall good outcome in terms of CV and HEX. Furthermore, we have shown that (1) our automatic method provides a high accuracy in CV and HEX (
Table), (2) the existence of an evolution pattern after UT-DSAEK surgery (decrease of CV, increase of HEX;
Fig. 9), particularly significant for the cases with the largest loss in ECD, and (3) a correlation between some of the parameters’ evolution (stronger between CV and HEX), which might be an indication of good healing and cell loss stabilization. Indeed, the transplants that suffered a larger ECD loss in the first month had a better improvement in CV and HEX later. These two parameters can tell us something about the distress of the cells, but this is merely an extrapolation from biological science lacking proper confirmation from clinical trials. In contrast, ECD as a clinical parameter to evaluate the functionality of the cornea in terms of total thickness and clarity has been studied extensively, both in the natural state and after corneal transplantation. As we have developed a better method to analyze CV and HEX, it would be interesting to study these two parameters, for example in future follow-up studies of corneal grafting.