Abstract
Purpose::
In eyes with trauma that is so severe that standard corneal transplantation carries a poor prognosis, a keratoprosthesis (KPro) may provide functional visual acuity when successful. The purpose of this study is to determine the outcome of the Boston KPro in the rehabilitation of severe ocular trauma.
Methods::
This is a retrospective study of 29 eyes with severe ocular trauma, which underwent a Boston KPro implantation. Six patients had mechanical trauma, 20 patients had chemical burns, and 3 had thermal burns. The measures used in this review are fivefold. Pre-operative and post-operative visual acuity; Anatomic success is defined as the number of KPro devices remaining in the eye without extrusion or need for replacement; the number of postoperative repair procedures performed; the number of eyes with concomitant preoperative retinal or optic nerve damage prior to KPro surgery; incidence of post-operative complications such as endophthalmitis, retinal detachment or end-stage glaucoma.
Results::
Preoperative visual acuity ranged from Count Finger to Light Perception (Median Hand Motion). Best corrected post-operative visual acuity ranged from 20/20 to Light Perception (Median 20/80). Anatomic success was achieved in 5 out of 6 mechanical traumas (the sixth was followed elsewhere), 9 out of 20 chemical burns (3 were followed elsewhere), and 3 out of 3 thermal burns. Repair procedures were done in 7 of the 20 chemically burned eyes. None of the eyes in either the mechanical trauma group or the thermal group required repair. The number of eyes with concomitant preoperative ocular disease was 2 out of 6 in the mechanical trauma group, 10 out of 20 in the chemical burn group (most frequently advanced glaucoma), and 1 out of 3 in the thermal burn group. The incidence of post-operative complications was 1 out of 6 in the mechanical trauma group (endophthalmitis), 5 out of 20 in the chemical burn group (glaucoma, retinal detachment, expulsive hemorrhage, endophthalmitis), 2 out of 3 in the thermal burn group (endophthalmitis, retinal detachment)
Conclusions::
The Boston KPro had good visual outcome and anatomic retention rate in these severely traumatized eyes. The overwhelming danger in severe chemical burns is glaucoma progression despite a functioning tube implant and normal intraocular pressures. In mechanical trauma, KPros have few complications but the ocular structures are often too damaged to allow good vision. Finally, in ocular phthisis, macular edema reduces the potential benefit of a well-positioned KPro.
Keywords: keratoprostheses • trauma • cornea: clinical science