Preoperative lens status does not influence DMEK outcomes

The authors studied how surgical indication and preoperative lens status affects Descemet membrane endothelial keratoplasty (DMEK) outcomes.

Study design

This retrospective study assessed the 6-month clinical outcomes of 1,000 eyes undergoing DMEK performed at a single institute. The authors sought to determine if outcomes were influenced by the surgical indications of Fuchs endothelial corneal dystrophy (FECD) versus bullous keratopathy (BK) as well as by preoperative lens status in FECD eyes.

Outcomes

At 6 months following DMEK, comparison of best corrected visual acuity (BCVA) of eyes treated for FECD and BK as well as phakic and pseudophakic FECD eyes showed similar outcomes. Endothelial cell loss at 6 months was higher for BK eyes than for FECD eyes but comparable between phakic and pseudophakic FECD eyes.

Overall, graft detachment rate did not differ between any of the study groups. However, BK eyes had a higher re-bubbling rate than FECD eyes. Re-transplantation rate for persistent graft detachment occurred in only 2% of cases and did not differ between groups.

Limitations

In this study cohort, 85.3% of patients underwent DMEK for underlying FECD while only 10.5% of cases underwent DMEK for BK (the remaining patients had underlying graft failure or other corneal pathologies). The disparity between the numbers of patients with each underlying condition is a limitation but can likely be attributed to the fact that FECD is a more common indication for DMEK surgery compared with BK. In addition, patients with BK often have more complex pathology and multiple prior surgeries, rendering them poor candidates for DMEK. Postoperative data was limited to 6 months. Longer term follow-up in future studies can provide additional information and evidence for surgeons.

Clinical significance

Several studies have sought to determine if DMEK outcomes are affected by surgical indication and preoperative lens status. This study, comprised of a large cohort of eyes, showed that 6-month BCVA, overall graft detachment rates and re-transplantation rates were not statistically different between FECD and BK eyes as well as phakic and pseudophakic FECD eyes. However, BK eyes experienced higher rates of postoperative endothelial cell loss as well as graft re-bubbling.

These results indicate DMEK can be a favorable treatment option for patients with both FECD and BK. Given the comparable results between phakic and pseudophakic FECD patients, the natural crystalline lens can often be preserved at the time of DMEK surgery in phakic FECD patients with good visual outcomes and deferment of cataract surgery until a later time. These results can help surgeons better plan their surgical procedure and counsel their patients on surgical outcomes.