Bioengineering endothelialized neo-corneas using donor-derived corneal endothelial cells and decellularized corneal stroma.

Corneal transplantation is a common transplant procedure performed to improve visual acuity by replacing the opaque or distorted host tissue by clear healthy donor tissue. However, its clinical utility is limited due to a lack of high quality donor corneas. Bioengineered neo-corneas, created using an expandable population of human donor-derived corneal endothelial cells (HCEC), could address this current shortage. The objectives of this study were to establish HCEC isolation and culture protocols and to investigate the feasibility of bioengineering corneal tissue constructs by seeding the cells on decellularized human corneal stroma. HCECs were removed from the discarded corneas of eye donors by enzymatic digestion. Cells were expanded and evaluated for their expression of Na(+)/K(+)-ATPase and zona occludens-1 (ZO-1). Donor corneal stromas were cut to 120-200 microm thickness slices using a microtome and then decellularized. Extracellular matrix components and mechanical properties of the scaffolds were measured after decellularization. To engineer neo-corneas, 130 HCEC/mm(2) were seeded on decellularized human corneal stromas. The resulting constructs were placed in growth medium for 14 days and then analyzed using scanning electron microscopy (SEM), histology, and immunocytochemistry. Seeded cells retain expression of the functional markers Na(+)/K(+)-ATPase and ZO-1 and constructs have biomechanical properties similar to those of normal corneas. These results indicate that construction of neo-corneas, using HCECs derived from discarded donor corneas and decellularized thin-layer corneal stromas, may create a new source of high quality corneal tissue for transplantation.

Photodynamic therapy with verteporfin for subretinal neovascularization secondary to bilateral idiopathic acquired juxtafoveolar telangiectasis.

The clinical course of a patient treated with multiple sessions of photodynamic therapy (PDT) with verteporfin for subretinal neovascularization secondary to bilateral idiopathic acquired juxtafoveolar telangiectasis is described. The patient presented with subfoveal subretinal neovascularization in one eye secondary to bilateral idiopathic acquired juxtafoveolar telangiectasis. The visual acuity improved from 5/40 to 20/60 and fluorescein angiography documented near-complete closure of the subretinal neovascularization within 2 weeks following the initial session of PDT. The visual acuity decreased to 20/200 and fluorescein angiography documented reperfusion of the neovascular membrane 6 weeks later. Four additional sessions of PDT were administered during the next 13 months with similar results. This case indicates that PDT for subretinal neovascularization due to bilateral idiopathic acquired juxtafoveolar telangiectasis may achieve partial short-term neovascular membrane closure and improvement in visual acuity.