Secondary IOL implantation for an aphakic patient with congenital cataract living in Bonin Islands; follow-up study

Introduction: We previously reported a case of a patient with bilateral congenital cataract identified in the Ogasawara village, Bonin Islands, Japan, on a visit by an ophthalmologist and describe its course over 17 years from initial surgery. Here, we report on a secondary intraocular lens (IOL) implantation that was subsequently performed at 22 years and 5 months of age. Methods: After cataract surgery at 7 months, the aphakic patient began amblyopia treatment using extended-wear soft contact lenses (SCLs). After 10 years of age, SCLs were chosen to achieve crossed monovision considering the cosmetic appearance when facing other people. At 22 years of age, a secondary IOL implantation was performed. Secondary implant in the patient considered appearance and postoperative vision without glasses, we selected the crossed monovision method using a monofocal IOL. The postoperative targeted refraction for the right (non-dominant eye) and left eyes (dominant eye) planed − 0.33D and − 2.25D, respectively. Results: At 3 months after surgery, the corrected distance visual acuity (CDVA) with IOLs for the right and left eyes was 20/16 and 20/60, respectively, and the binocular visual acuity was 20/16 for distant vision and 20/25 for near vision. The CDVA for the right eye was: 20/13 × IOL = sph−0.25D and that for the left eye was: 20/13 × IOL = sph −1.75D D/cyl −0.50D/Ax170°. Although the exotropia was complicated by dissociated horizontal deviation and dissociated vertical deviation, there were no significant changes in ocular position before and after surgery. The patient was satisfied with achieving independence from spectacles and SCLs. Conclusion: The use of the crossed monovision method with monofocal IOLs in this patient and defective binocular function created a visual environment with no inconvenience in everyday life after secondary IOL implantation. In terms of secondary implant after amblyopia treatment, the IOL type or postoperative targeted refraction must be chosen to maintain or improve the visual environment obtained with the amblyopia treatment.