PURPOSE: Recent advances aimed at preventing and treating complications after keratoprosthesis
surgery have improved prognosis, but it has been suspected that various preoperative diagnoses may carry substantially different postoperative outcomes. This article attempts to clarify the
ranking of
prognostic categories for patients undergoing keratoprosthesis
surgery. METHODS: A retrospective review of the outcome in a recent series of 63 patient
eyes operated at the Massachusetts
Eye and
Ear Infirmary between 1990 and 1997 and followed up for a minimum of 21 months.
Anatomic retention of the device and the
loss of vision caused by complications were recorded. The patients were divided into four categories according to preoperative cause. RESULTS:
Anatomically, one keratoprosthesis
extruded spontaneously. Another 10 were permanently removed because of complications. Of the 63
eyes, 10 never achieved a
visual acuity of at least 20/200 vision because of preexisting
retinal or
optic nerve damage. The remaining 53 had a
visual acuity of 20/200 to 20/20 as follows:
Stevens-Johnson syndrome (n = 7), after 2 years: 33%, after 5 years: 0%;
chemical burn (n = 17), after 2 years: 64%, after 5 years: 25%; ocular
cicatricial pemphigoid (n = 20), after 2 years: 72%, after 5 years: 43%;
graft failure in noncicatrizing conditions (dystrophies, degenerations, or
bacterial or
viral infections) when a repeat
graft was expected to have a poor prognosis (n = 19), after 2 years: 83%, after 5 years: 68%. The difference in outcome between the
Stevens-Johnson syndrome outcome group and the
graft failure group or the ocular
cicatricial pemphigoid group was
statistically significant. In the group of 53
eyes,
visual acuity was restored to 20/200 to 20/20 for a cumulative total of 138 years. CONCLUSION: Outcome of the keratoprosthesis
surgery varied markedly with preoperative diagnosis. Most favorable was
graft failures in non-cicatrizing conditions, whereas
Stevens-Johnson syndrome was the worst. Ocular
cicatricial pemphigoid and
chemical burns occupied a middle ground. The difference between the groups seemed to
correlate with the degree of past preoperative
inflammation.
