Diabetic Tractional Retinal Detachment
Tractional retinal detachment (TRD) occurs when the hyaloid contracts but fronds of neovascular ingrowth prevent it from separating from the retinal interface. The tractional forces are transmitted to full-thickness retina and, in the absence of a retinal break, cause schisis and/or detachment of the underlying retina from its corresponding RPE (Fig 20-6). Vitrectomy is indicated when progression of a TRD threatens or involves the macula. In certain complex cases, spontaneous breaks can also occur in an atrophic retina under traction, resulting in combined traction and rhegmatogenous detachments; this variety of TRD is also a strong indication for earlier surgical intervention. Although panretinal photocoagulation should precede vitrectomy whenever possible, it can be more difficult to accomplish in the presence of vitreous hemorrhage. A preoperative adjunctive intravitreal injection of an anti-VEGF agent may induce regression of neovascularization, facilitating dissection and minimizing intraoperative bleeding.
Figure 20-6 Color fundus photograph montages of diabetic tractional retinal detachment. A, Fibrovascular proliferation and a contracted posterior hyaloid along the retinal arcade vessels and over the macula cause elevation and distortion of the retinal surface at the arcade vessels and in the temporal macula. B, After surgery, the macula and vessels are flattened.
(Courtesy of Colin A. McCannel, MD.)
Vitrectomy for TRD is performed to relieve vitreoretinal traction that interferes with retinal reattachment. In this procedure, the cortical vitreous and posterior hyaloid are removed from the retinal surface, particularly in areas of retinal neovascularization. Point adhesions of cortical vitreous to surface retinal neovascularization can be relieved by unimanual or bimanual techniques using various instruments, including scissors or the vitrectomy cutter. Surgical approaches to fibrovascular tissue include segmentation and delamination. In segmentation, bands of fibrovascular tissue causing traction are cut, but the epiretinal proliferations are not completely removed. In delamination, the epiretinal proliferations are completely, or nearly completely, dissected off the retinal surface to relieve the traction.
After tractional membranes are removed, diathermy may be used to treat fibrovascular tufts and achieve hemostasis, and supplementary laser treatment may be used in the periphery to reduce ischemia.
Brunner S, Binder S. Surgery for proliferative diabetic retinopathy. In: Schachat AP, Wilkinson CP, Hinton DR, Sadda SR, Wiedemann P, eds. Ryan’s Retina. Vol 3. 6th ed. Philadelphia: Elsevier/Saunders; 2018.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.