Abstract
Purpose: :
Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) is an alternative to penetrating keratoplasty (PK) for the surgical treatment of pathologically altered corneal endothelium. We here present our experimental and first clinical results using the Carriazo-Pendular-Microkeratome and a newly designed artificial anterior chamber for DSAEK.
Methods: :
Porcine corneoscleral discs were fixed in the anterior chamber under 100 or 200 mbar of pressure. Groups of 5 corneas were cut using the 300, 350 and 400µm microkeratome heads. The thickness of the uncut cornea, the resulting corneal flap and corneal bed were measured using an ultrasound pachymeter. So far we performed DSAEK in 12 eyes of 12 patients. Best spectacle corrected visual acuity, pachymetry, endothelial cell density, objective refraction and intraocular pressure were measured just before as well as 1, 2 and 6 weeks and 3 and 6 months after DSAEK.
Results: :
In the porcine model lamellae of 300±7 (324±10), 370±27 (398±11) and 437±50 (486±11) µm were cut using the 300, 350 and 400 µm microkeratome heads at 100 (200) mbar. During DSAEK the microkeratome produced anterior lamellar free caps with peripheral flap irregularities in 3 cases. However all posterior lamellar donor buttons were deemed to be suitable for DSAEK. In the 12 patients the visual acuity increased from 1.1±0.6 before to 0.2±0.2 logMAR 6 months after DSAEK. Meanwhile the central corneal thickness decreased from 724±113 to 574±113 µm. The grafts endothelial cell density decreased from 2270±204 to 1940±240 cells/mm² equalling a total cell loss of 14.5% at 6 months after DSAEK. No case of graft rejection or failure was observed. After 6 months a mean surgically induced astigmatism of 1.9 dpt was measured. Intraocular pressure increased from 13.2±2.2 to 16.0±6.7 mmHg.
Conclusions: :
Thickness and standard deviation of the cut lamellae depend mainly on the pressure applied to the artificial anterior chamber. DSAEK can be performed safely using the Carriazo-Pendular-Microkeratome and the newly designed artificial anterior chamber leading to satisfactory visual results. However the cutting process should be improved to avoid peripheral irregularities of the free anterior lamellar flap.
Keywords: cornea: endothelium • cornea: clinical science • anterior segment