According to several publications, Descemet-endothelial keratoplasty (DEK or DMEK) has a faster and better visual recovery than with other keratoplasty techniques with endothelium transplantation such as penetrating (PK) and endothelial lamellar (ELK or DSAEK), with best-corrected visual acuity (BCVA) greater than 0.5 in 95% of the cases 6 months after the intervention¹ (Table 1).

DESCEMET-ENDOTHELIAL KERATOPLASTY COMPARED WITH PENETRATING KERATOPLASTY

In comparison with PK, DEK (DMEK) presents a superior final BCVA and the intervention does not induce significant refractive changes^2,3. In addition, the risk of rejection associated with DEK is significantly lower, around 1%⁴. This allows to reduce the use of corticosteroids in the postoperative period or to switch earlier to those with little intraocular penetration. The endothelium is maintained in figures equal to or better than with PK^5,6.

DESCEMET-ENDOTHELIAL KERATOPLASTY COMPARED WITH ENDOTHELIAL LAMELLAR KERATOPLASTY

While ELK (DSAEK) includes a lamella of donor's posterior stroma, DEK (DMEK) comprises only Descemet’s membrane and endothelium. Consequently, there is no stromal interface, which would explain the better results of visual acuity and quality than in the former (Table 2)⁷. The percentage of patients with BCVA greater than or equal to 0.5 is 60%-80% in ELK and 80%-95% in DEK. In addition, it has been observed in the latter BCVA greater than or equal to 1.0 decimal between 25% to 40% of cases, a lower degree of high order corneal aberrations and better optical quality⁸. While DEK does not induce any refractive changes, it is common to observe an induced hyperopia of 1 to 3 diopters with ELK and even astigmatism in some cases^9-11. The risk of immunological rejection also decreases in order and magnitude. As we can see in table 2, the rejection rates after ELK vary between 1% and 18%, while in DEK they are of the order of 1% or less (table 1) (see also chapter 7.5.4).

ELK, on ​​the other hand, is superior to DEK in some factors among which are included: (1) lower learning curve due to easier manipulation of the graft, (2) lower rate of dislocations (ELK between 1% and 35% against DEK between 1% and 60%)^12-14, (3) lower incidence of air/gas reinjections and reinterventions. However, it should be noted that in many cases dislocations in DEK do not affect the transparency of the cornea and it is not always necessary to perform any additional maneuvers. The percentages of primary failure of the graft are similar in both techniques, between 1% and 8% (tables 1 and 2)^15,16.

On the other hand, variations have been developed in ELK, such as the «ultrathin» (ut-DSAEK), with refractive and visual results comparable to DEK and greater ease in graft manipulation¹⁷. There are also hybrid techniques that include a central disc of Descemet-endothelium and a peripheral zone with a portion of posterior stroma, with the objective of maintaining the refractive advantages of DEK together with the easier manipulation of the tissue of ELK.

All these data show that DEK has many advantages compared to the rest of endothelial transplant modalities. It is, however, a relatively recent technique, which is why many of its aspects are in evolution, whether preoperatively – e.g. tissue preparation in the eye bank – intraoperative maneuvers and associated technologies – injectors and other surgical materials, etc. – or postoperative, and should continue to be analyzed until a most refined technique is defined, which produces greater reproducibility, better results and fewer complications.