Bilateral simultaneous cataract surgery and intraocular lens implantation in an adult female chimpanzee (Pan troglodytes) inducing monovision

Background: Cataract is the major cause of visual impairment in humans. Phacoemulsification with intraocular lens (IOL) implantation is the standard technique for cataract treatment with a high success rate. In a few cases, the surgical cataract procedure and lens implantation have been applied in non-human primates. Case Description: A +/− 40-year-old female chimpanzee (Pan troglodytes) in captivity was diagnosed with mature cataract optical density (OD) and posterior subcapsular cataract combined with cortical opacities OS after ophthalmic examination. To restore vision and facilitate far- and near sight, phacoemulsification OU with +22.5 diopter (D) IOL implantation OD and + 24 D OS were performed. Despite complicated surgery OD due to posterior capsular rupture, the outcome was successful during 1-year follow-up. The chimpanzee regained adequate vision, normal behavior, and was successfully re-introduced to her group of chimpanzees. Conclusion: This is the first case report of a simultaneous bilateral cataract surgery with IOL implantations in both eyes, targeting emmetropia OS and near vision OD resulting in monovision, in a chimpanzee. Vision was restored without postoperative complications.