We thank Hong and associates for their interest in our article. In our study, there was a slow recovery of visual acuity in cases with keratoconus compared with the other diseases, and we suspected that this result was the result of the greater refractive shifts after surgery in those with keratoconus. This view originated from our preliminary observation that the patients with keratoconus demonstrated greater fluctuation in refraction after surgery. Unfortunately, there were some missing data in our sample, and we were unable to perform a valid statistical analysis. We are now in the process of examining the postoperative refractive outcome after deep anterior lamellar keratoplasty (DALK) using a larger sample, and we will report the data elsewhere.
Stromal air injection was attempted more frequently in patients with bacterial keratitis and moderate keratoconus because it was difficult to expose the Descemet membrane. However, we thought original diagnoses might have nothing to do with less endothelial cell density (ECD) in our study. Indeed, severe bacterial keratitis could lead to endothelial cell loss, because it usually involved endothelium. In this case, it was adaptive to perform penetrating keratoplasty instead of DALK. Only patients with normal endothelium examined by slit-lamp microscope before surgery were enrolled in our study. That was why we believed the effect of original diagnoses on ECD could be excluded and that the air injection attempts may be relative to the loss of ECD. In our opinion, the most important factor leading to the loss of ECD in our patients was chemical burns, instead of bacterial keratitis. Patients with chemical burns had the second highest incidence of Descemet membrane exposure (73.3%) and experienced no more obvious loss of ECD than other groups after surgery. Our study indicated that patients who received more attempts of air injection during DALK were more likely to have lower ECD. We also explained this phenomenon in the review process. Additionally, Hong and associates indicated that postoperative ECD was higher in DALK groups than in penetrating keratoplasty groups. We thought it was another topic.
Finally, we agree that for patients with herpetic stromal keratitis, it is worthwhile to administer systemic and topic prophylactic antiviral agents to prevent herpes recurrence.