To report cases of intraocular pressure that was normalized, after removing the capsule that had incarcerated into the valve after Ahmed valve implantation.

A 34-month-old boy visited our clinic for elevated intraocular pressure of the right eye. The patient had received Ahmed valve implantation 1 year earlier. At the first ophthalmological examination in our hospital, intraocular pressure of the right eye measured by Perkins tonometer was 28 mm Hg using Cosopt® and Iopidine®, and 26 mm Hg after additional digital massage; the authors decided to remove the capsule with surgery. The fibrotic tissue was removed after finding the tissue incarcerated into the valve during the operation. One day after the surgery, without using any glaucoma medication, intraocular pressure of the right eye measured by Perkins tonometer was 15 mm Hg. Three months after surgery, using topical intraocular pressure lowering agents, intraocular pressure of the right eye was 18 mm Hg. Because the intraocular pressure of other patients after Ahmed valve implantation was not regulated well, surgery was performed, and the fibrotic tissue was removed after finding the tissue incarcerated in the valve during the operation.