Computer–Assisted Planning for High–Precision Rotational Corneal Autograft

Abstract

Abstract: : Purpose: To evaluate the use of computer digital imaging and manipulation for the pre–operative planning in rotational corneal autografts. Methods: Four eyes of four patients with dense central corneal scars were operated by one surgeon (M.A.M). One had central scarring secondary to post–traumatic corneal ulcer, two eyes had corneal scarring secondary to recurrent, chronic herpes stromal keratitis and one eye had scarring secondary to pseudomonas keratitis following PRK. Each patient had photos of the affected eye taken with a standard 35 mm camera, which were scanned into the Adobe Photoshop© program and numerous models of corneal graft rotation were constructed. The size of trephination, location of the trephination and degree of trephination were based on the outcome of the surgical model. Each patient underwent rotational autograft without complication. One patient had an associated cataract and had an open sky cataract extraction and intra–ocular lens placement at the time of rotational autograft. Results: Two of the three patients had significant visual improvement from 20/200 to 20/40 in patient one and from 20/200 to 20/40 in patient two. Patient three experienced improvement from 20/100 to 20/40. Patient four, who had vision of 6 feet/200, underwent cataract extraction with placement of an intra–ocular lens and had persistent corneal edema post–operatively. She went on to have a corneal allograft with eventual vision of 20/40. Conclusions: We provide a rationale for using advanced imaging software in the planning of rotational allografts in patients with visually significant corneal scarring. This modality also aids in the ability to predict and comfortably select patients in whom corneal autograft is preferable to allograft. Three patients had successful outcomes and one patient required an allograft to achieve acceptable visual results. The latter patient illustrates that a failed rotational autograft is amenable to subsequent allograft with good visual results. This case also suggests that corneal endothelial count may be important in appropriate patient selection. We recommend the use of commercially available imaging software to aid in the surgical planning for rotational autografts.

Keywords: cornea: basic science • transplantation • computational modeling