Staining of the internal limiting membrane with intravitreal triamcinolone acetonide

Purpose: To evaluate the use of triamcinolone acetonide to stain the internal limiting membrane (ILM) during vitreoretinal surgery. Methods: A prospective clinical interventional case series study was performed, including 16 patients who underwent pars plana vitrectomy. Seven patients had proliferative diabetic retinopathy with macular edema. Seven patients had epiretinal membranes. One patient had a retinal detachment with a cystoid macular edema and proliferative vitreoretinopathy. One patient had a pseudophakic cystoid macular edema. After vitrectomy, 2 mL triamcinolone acetonide suspension was injected into the vitreous cavity. The ILM was peeled, as it was evidenced by the particles of triamcinolone that adhered to its surface. The ultrastructure of tissue harvested during surgery was analyzed using transmission electron microscopy in selected cases to confirm the presence or absence of ILM. Results: After the injection of triamcinolone, the visualization of the vitreous base and hyaloid was excellent in all patients. The particles of triamcinolone deposited on the retinal surface enabled the ILM to be stained. Once removed, the ILM was clearly distinguishable, floating in the vitreous cavity with particles of triamcinolone adhering to its surface. Ultrastructural analysis of tissue collected during vitrectomy confirmed that the removed tissue represented ILM. Conclusion: We observed that triamcinolone acetonide can be useful in staining the internal limiting membrane, thus greatly facilitating the retinal ILM peeling. The absence of particles of triamcinolone on the underlying retina enables the area where the ILM has already been removed to be identified. The peeling of the internal limiting membrane (ILM) has been recommended as an effective means of reducing tangential traction on the retinal surface, particularly in macular hole surgery.1,4 The removal of this very thin membrane can be difficult even if indirect signs, such as a mild whitening of the retinal surface, can be observed on the peeled retina. Small retinal hemorrhages may also indicate that the ILM has been removed. Nevertheless, this should be considered a complication, even if it barely affects functional outcome. For these reasons, an incomplete peeling might occur because of poor visualization. It has recently been shown that indocyanine green (ICG) stains the ILM, thus enhancing the visibility of this structure and greatly facilitating its identification and removal.5–9 It has also been demonstrated that ICG can enable the vitreous cortex to be distinguished from the ILM.10 Triamcinolone acetonide is a corticosteroid suspension. The intravitreal injection of triamcinolone acetonide was first proposed in an experimental study by Tano.11 Today, many authors suggest the use of triamcinolone to treat vitreoretinal diseases such as cystoid macula edema, diabetic retinopathy, proliferative vitreoretinopathy, and exudative macular degeneration.12–24 In 2000, Peyman proposed the use of triamcinolone acetonide to visualize the vitreous and the posterior hyaloid during pars plana vitrectomy.25 In addition, Burk et al then adapted this idea to visualize the vitreous loss during complicated anterior segment surgery.26 Recent studies have shown the possibility to stain and remove the ILM using the intravitreal triamcinolone acetonide.27,28 This study was performed to confirm the possibility of using triamcinolone to visualize the internal limiting membrane durin