The role of amniotic membrane extract eye drop (AMEED) in in vivo cultivation of limbal stem cells

IntroductionLimbal stem cell transplantation (LSCT) is the definitive treatment for total limbal stem cell deficiency (LSCD). This study evaluates the anatomical and visual outcomes of a surgical technique supplemented by amniotic membrane extract eye drop (AMEED) for in vivo cultivation of limbal stem cells (LSCs).MethodsOne small limbal block (2×1 mm) harvested from contralateral healthy eye was transferred to the diseased eye, which had been already covered by cryopreserved amniotic membrane (N=20). The patients were categorized into case and control groups. AMEED was administered postoperatively only for patients in the case group (N=14). Sequential penetrating keratoplasty (PKP) was performed in 4 eyes of case group for optical clarity. Visual acuity, epithelial healing, corneal clarity and regression of conjunctivalization/vascularization were evaluated after surgery. The corneal buttons of post-PKP eyes were evaluated for LSC markers.ResultsIn case group, the mean corrected distance visual acuity (CDVA) was 20/400 before surgery which improved to 20/40 and 20/50 at the last follow up in eyes with and without PKP, respectively. Epithelial defect healed in all eyes of case group during 2 weeks after surgery. Corneal conjunctivalization/vascularization regressed dramatically in all patients of case group 2-3 months after surgery. In PKP cases, all transplanted corneas were clear at the last follow up. LSC markers were expressed on the surface of all trephined corneal buttons. All eyes in control group developed persistent epithelial defect.ConclusionThis study suggests that amniotic membrane extract may be helpful for in vivo cultivation of limbal stem cells

Keywords:

Amniotic membrane , Amniotic membrane extract , In vivo cultivation , Limbal stem cell , Limbal stem cell deficiency , Limbal stem cell transplantation