Baseball orbital implants: a review of 39 patients.

Thirty-five secondary and six primary 'baseball' implants--acrylic balls in envelopes of donor sclera--were followed up for a minimum of 24 months. 97.1% secondary and 50% primary implants were retained. Volume replacement was satisfactory in 83.8% with a single operation, and motility of the artificial eye was at least 14 degrees of horizontal gaze in 86%, at least 7 degrees of upgaze in 95%, and at least 14 degrees of downgaze in 62.6%. Ptosis associated with the procedure occurred in 22%, and 12.2% developed a shallow fornix with instability of the artificial eye.