Purpose:
To evaluate the efficacy of a novel instrument in the treatment of recurrent corneal erosions (RCEs). Current treatment of RCEs includes conservative management as well as mechanical techniques, including epithelial debridement and anterior stromal puncture. These methods can induce significant scarring via injury to Bowman’s membrane and disruption of laminar stromal architecture. A microfabricated glass-based corneal instrument was designed and tested ex vivo to investigate a new technique for anterior stromal puncture that provides reproducible penetration into the corneal stroma with minimal visually significant scarring.
Methods:
Experiments were performed using a microfabricated glass corneal instrument providing a 3-dimensional array of designable spikes on a hand-held platform. The spikes measure 60-70µm in length with a pitch of 120µm. Soft contact lenses and porcine corneas were used, divided into multiple sections and indented using the corneal punch. Mechanical disruption of the substrate and India ink served as identifying markers for imaging.
Results:
The India ink and mechanical patterns in the lens and corneal sections revealed regular penetration of the array into the anterior corneal stroma. Coating the spikes with India ink showed reliable and reproducible stromal deposition of the dye from the matrix array.
Conclusions:
The microfabricated corneal instrument reliably penetrated corneal stroma in several trials on porcine corneas and soft contact lenses with excellent reproducibility. The benefit of the corneal punch is a patterned matrix that provides an attachment point for basal epithelial cells by inducing microscopic scars at each point. The regular spacing and small width of the spikes creates focal defects and avoids unnecessary damage and potential visual loss via visual, refractive, or anatomical complications seen with other forms of anterior stromal puncture. The instrument may also serve as a novel delivery system for medications targeted to corneal stroma and those unable to penetrate intact corneal epithelium.
Keywords: cornea: clinical science • cornea: epithelium • cornea: stroma and keratocytes