Placement of a scleral lens has also demonstrated efficacy for healing PED. When using this technique, lenses of at least 17.5 mm diameter should be chosen since the smaller diameter, mini-scleral lenses do not completely vault over the cornea.
The larger-diameter scleral lenses are available from a variety of manufacturers or as the custom-manufactured PROSE (Prosthetic Replacement of the Ocular Surface Ecosystem, Boston Foundation for Sight).
Modalities under investigation for treatment of PED include thymosin beta 4 and a connexin43 antisense gel (Nexagon, CoDa Therapeutics)—both of which have shown promise in compassionate-use cases.
Thymosin beta 4 is a synthetically produced copy of a 43-amino acid peptide that is found in most tissues and has been shown to promote corneal wound re-epitheliailziation, decrease inflammation, and inhibit apoptosis.
The connexin43 antisense agent decreases the upregulation of connexin proteins that mediate bystander cell death (apoptosis induced by dying epithelial cells).
Mesenchymal stem cells—which are autologous adipose-derived multipotent cells—and a variety of products derived from whole blood are also being investigated for promoting epithelial healing.
1. Katzman LR, Jeng BH. Management strategies for persistent epithelial defects of the cornea. Saudi J Ophthlamol. 2014;28:168-172.