To report a case of decreased endothelial cell density 7 years after posterior chamber phakic intraocular lens implantation.

A 45-year-old man with high myopia combined with astigmatism was treated with Toric implantable Collamer Lens (ICL) implantation. The patient's best corrected visual acuity was 0.7 in both eyes before the operation. After the treatment, his uncorrected visual acuity was 0.9 and corrected visual acuity was 1.0 in both eyes, indicating an improvement in visual function. Preoperative endothelial cell density measured 3,063 cells/mm² in the right eye and 3,126 cells/mm² in the left eye. At 5 years postoperatively, measurements were 2,897 cells/mm² in the right eye and 2,974 cells/mm² in the left, showing little change. However, a 6-year postoperative measurement of 2,198 cells/mm² in the right eye and 2,803 cells/mm² in the left showed a slight decrease in endothelial cell density in the right eye, and a follow-up measurement one year later displayed a rapid decline to 1,272 cells/mm² in the right eye and 2,852 cells/mm² in the left eye. The Toric ICL lens was removed from the right eye and phacoemulsification and posterior chamber intraocular lens implantation was performed. Two-month postoperative endothelial cell density was 1,257 cells/mm² and endothelial cell damage from the operation itself was minimal.

ICL implantation may cause complications related to corneal endothelial cells as well as glaucoma. Patients should receive regular follow-up examinations for endothelial cell density.