Anterior lamellar keratoplasty is a surgical procedure in which a maximum of diseased corneal stroma is replaced by donor tissue. Commonly, the anterior stroma is incised with a trephine that can be set to a depth not exceeding the corneal thickness, and several stromal layers may be dissected until the desired depth of the recipient bed is obtained. Lamellar dissections, for example in lamellar keratoplasty, are generally made by removing stromal tissue layer for layer, while the depth of the dissection is judged by the changing tissue structure with deeper stromal beds.

Compared to a penetrating keratoplasty, a lamellar procedure has the advantage of avoiding most complications associated with open sky surgery, easier postoperative management, and less risk of allograft rejection and other long-term complications. Despite these benefits, surgeons commonly perform a penetrating keratoplasty for anterior corneal disorders, because the latter technique is easier to perform, and lamellar transplants often show decreased best corrected visual acuity due to irregular astigmatism and/or scarring at the donor-to-recipient interface. Less scarring may occur with deeper, i.e. smoother keratectomies, and techniques such as air injection in, and hydrodelamination or photoablation of the posterior stroma have been advocated to obtain a deep recipient stromal bed.

With all of these techniques, the stromal dissection depth relative to the corneal thickness cannot be optically visualized. The posterior corneal surface is invisible through an operating microscope, due to the small difference in the refractive index between corneal tissue and aqueous. Lamellar dissection techniques therefore bear the risk of inadvertent perforation, when deeper dissections are intended. If perforation occurs, completion of the stromal dissection can be difficult, so that the donor button may have to be sutured into an imperfectly prepared recipient bed. When conversion of the procedure into a penetrating keratoplasty is required, donor tissue with good quality endothelium may not be available.

Anterior lamellar keratoplasty may become a more feasible and less complicated surgical procedure, if a stromal dissection could be made at a visually controlled depth during surgery, and the dissection could be completed in the event of a micro-perforation, or aborted until a planned penetrating keratoplasty can be performed.