Confocal microscopy findings in deep anterior lamellar keratoplasty performed after Descemet's stripping automated endothelial keratoplasty

Abstract

Audrey Pang,1,2 Karim Mohamed-Noriega,1 Anita S Chan,1,3–5 Jodbhir S Mehta1,3 1Singapore National Eye Centre, 2Department of Ophthalmology, Tan Tock Seng Hospital, 3Singapore Eye Research Institute, 4Department of Histopathology, Pathology, Singapore General Hospital, 5Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore Background: This study describes the in vivo confocal microscopy findings in two patients who had deep anterior lamellar keratoplasty (DALK) following Descemet's stripping automated endothelial keratoplasty (DSAEK). Methods: The study reviewed the cases of two patients who first underwent DSAEK followed by DALK when their vision failed to improve due to residual stromal scarring. In the first case, a DSAEK was performed for a patient with pseudophakic bullous keratopathy. After surgery, the patient's vision failed to improve satisfactorily due to residual anterior stromal opacity and irregularity. Subsequently, the patient underwent a DALK. The same two consecutive operations were performed for a second patient with keratoconus whose previous penetrating keratoplasty had failed and had secondary graft ectasia. In vivo confocal microscopy was performed 2 months after the DALK surgery in both cases. Results: At 3 months after DALK, the best-corrected visual acuity was 6/30 in case 1 and 6/24 in case 2. In vivo confocal microscopy in both cases revealed the presence of quiescent keratocytes in the stroma layers of the DSAEK and DALK grafts, which was similar in the central and peripheral cornea. There was no activated keratocytes or haze noted in the interface between the grafts. Conclusion: Our short-term results show that performing a DALK after a DSAEK is an effective way of restoring cornea clarity in patients with residual anterior stromal opacity. In vivo confocal microscopy showed that there were no activated keratocytes seen in the interface of the grafts, which suggests that optimal visual acuity may be obtained with minimal interface haze. Keywords: cornea, transplant, keratocytes, histology