Mobility of hydroxyapatite orbital implant covered with autologous sclera

PURPOSE: To evaluate the mobility of a hydroxyapatite implant covered with autologous sclera from the enucleated globes of patients with severe atrophy of the eyeball or eyelid retraction. METHODS: This implant was used in seven patients with phthisis bulbi. We measured the movement of the implant by photographic analysis of the anterior orbit and by using a strain gauge. RESULTS: At 1-3 years after surgery, neither infection nor prolapse of the implant had occurred in any of the patients. The implant remained stable in the orbit; the extraocular muscles sutured to the sclera of the implant were functioning satisfactorily, and the implants showed great conjugate mobility to the ocular movement of the healthy eye. On photographic analysis of the anterior orbit, the adducting efficiency of the implant was 92.6 +/- 3.3%; the abducting efficiency was 85.9 +/- 5.4%; the supraducting efficiency was 84.9 +/- 5.6%, and the infraducting efficiency was 90.9 +/- 3.9%. The mean tugging weight, as determined using a strain gauge, was 344.2 +/- 29.2 g for adduction, and 327.6 +/- 33.4 g for abduction. These values corresponded to 90.4 +/- 4.4% and 89.5 +/- 5.3% of the respective movements of the healthy eye. CONCLUSIONS: Fitting an artificial eye to the peg of this implant did not greatly impair the movement of the implant, and its mobility was greater than that of the artificial eye of the controls in which a semi-integrated magnetic implant, previously available, had been used. This new technique makes it possible to wear an artificial eye earlier than with other prosthetic procedures.