Incisional surgeries such as trabeculectomy reduce the resistance of the eye to trauma. Trabeculectomy is often performed together with mitomycin C, and late onset hypotony is already an expected complication in these eyes. This case report presents a patient who developed dehiscence of the scleral flap and hypotony maculopathy after Valsalva maneuver after 5.5 years of trabeculectomy. In a 6-month period, the patient's hypotonic maculopathy became evident, and vision was affected after this period. Thereupon, the wound site was explored, and dehiscence of the scleral flap at the temporal wound site and increased aqueous outflow were detected. Repair was done with sterile pericardium patch. Post-operative vision, intraocular pressure, and hypotony maculopathy recovered very quickly. After incisional surgeries, patients should be warned against both external trauma and minor traumas such as eye rubbing and Valsalva maneuver.