Lattice corneal dystrophy Type I (LCD1) is characterized by amyloid deposition in the corneal stroma, however its impact on Descemet's membrane adhesion remains poorly understood. This study reports a rare case of Descemet's membrane detachment (DMD) during cataract surgery in a patient with LCD1 and investigates the potential role of posterior corneal amyloid deposits in this complication. A 68-year-old male presented with LCD1 was admitted for cataract surgery for the left eye. DMD appeared during the irrigation and aspiration (I/A) phase after intraocular lens (IOL) implantation. After intraoperative partial removal of DM, persistent Descemet's membrane folds and corneal stromal edema developed the day after surgery. These complications did not improve over time, necessitating penetrating keratoplasty eight months later. Following the keratoplasty, the patient's vision improved to 0.5 LogMAR with an uneventful postoperative course. Pathological examination of the excised corneal tissue demonstrated the presence of Congo red stain-positive amyloid deposits in the posterior segment of the cornea, localized between the layers of Descemet's membrane and the corneal stroma. While it is established that amyloid deposition in the anterior segment of the cornea induces alterations in epithelial adhesion, leading to corneal erosions, the effects of deposits on DM adhesion in the posterior segment are yet to be fully understood. Our case's pathological findings suggested that these deposits may contribute to DMD. Therefore, careful monitoring of DM is crucial during cataract surgical interventions in patients diagnosed with LCD1.