Does Preoperative or Postoperative Graft Thickness Influence Postoperative Visual Acuity in Descemet Stripping Automated Endothelial Keratoplasty for Advanced Pseudophakic Bullous Keratopathy?

Purpose: To describe the evolution of best spectacle-corrected visual acuity (BSCVA) after Descemet stripping automated endothelial keratoplasty (DSAEK) for very advanced pseudophakic bullous keratopathy (PBK) and to determine whether the thickness of corneal grafts in DSAEK surgery for advanced PBK correlates with BSCVA 6 months postoperatively.
Methods: In a prospective, single-center, observational study, 141 eyes treated with DSAEK surgery were studied, from patients requiring posterior lamellar transplantation for advanced PBK. Graft thickness was measured during the surgery and in vivo 6 months later. The primary end point was BSCVA in LogMAR at 6 months.
Results: BSCVA 6 months after surgery was slightly correlated with 6 months graft thickness (r = 0.24, P = 0.01), but not with preoperative graft thickness (r = 0.01, P = 0.93). After adjusting for preoperative BSCVA, a better 6 months BSCVA was best associated with thinner grafts at 6 months (P < 0.01), but not with preoperative graft thickness (P = 0.80).
Conclusions: BSCVA after DSAEK was significantly related to graft thickness measured 6 months after surgery, suggesting that better BSCVA after DSAEK is related to a decrease in graft thickness after surgery and not to the use of a thinner graft during surgery. This decrease may be because of the good health of the endothelium, but this result may be biased because of the intrastromal scars inherent in severe PBK. This study shows that DSAEK is a good option for advanced PBK but has low visual acuity potential recovery because of stromal scarring. Therefore, a penetrating keratoplasty may be indicated to obtain maximal recovery of visual acuity or for monocular patients.