descemet-on versus descemet-off donor cornea for deep anterior lamellar keratoplasty

purpose: to determine the effect of retained donor descemet membranes (dms) on visual outcomes following deep anterior lamellar keratoplasty (dalk). methods: in this retrospective comparative study, keratoconic eyes undergoing dalk using the big-bubble technique were enrolled. a bared dm was achieved in all cases. a donor cornea without (group 1; 48 eyes) or with (group 2; 22 eyes) dm was sutured to the recipient bed. the 2 groups were compared in terms of best spectacle-corrected visual acuity, keratometric astigmatism, refractive error, contrast sensitivity (cs), higher-order aberrations (hoas), and central graft thickness at least 3 months after complete suture removal. results: the mean follow-up duration was 23.2±6.9 months in group 1 and 26.5±6.5 months in group 2 (p = 0.61). the postoperative best spectacle-corrected visual acuity was 0.18±0.08 logmar and 0.24±0.30 logmar, respectively (p = 0.36). the 2 groups had comparable postoperative keratometric astigmatism, spherical equivalent refraction, and hoas. in terms of cs, however, group 1 demonstrated better results at a low spatial frequency. the mean postoperative central graft thickness was greater in group 2 (589.8±34.5 mm) than in group 1 (523.6±63.0 mm; p< 0.001). conclusion: dalk using the big-bubble technique for keratoconus may give better results in terms of cs if a donor cornea without dm is transplanted.