A Sandwich-Type Double-Layer Amniotic Membrane Graft for Repairing Myopic Macular Hole-Related Retinal Detachment in a Child with Knobloch Syndrome.

This case report describes a surgical technique using double-layer human amniotic membrane (hAM) grafting to repair a high myopic macular hole (MH)-related chronic retinal detachment (RD) with subretinal bands in a child with Knobloch syndrome. A 4-year-old boy diagnosed with Knobloch syndrome presented with macular atrophy in the right eye and chronic total RD with subretinal bands associated with a myopic MH in the left eye. The surgery involved an encircling band, pars plana vitrectomy, and subretinal band extraction through a retinotomy. The retinotomy and MH were sealed using hAM with a 5000 centistoke (cS) silicone oil (SO) tamponade. RD recurred two weeks postoperatively due to hAM contracture, leading to MH reopening. A second intervention included replacing the contracted graft with two larger hAM grafts; the first positioned under the MH and the second over the MH in a sandwich configuration, with 5000 cS SO tamponade. Eighteen months after SO removal, a flat retina, closed MH, and ambulatory vision were achieved. In conclusion, double-layer hAM grafting provides a strong seal for MH in high myopia-associated RD where conventional techniques fail.