Corticosteroids for the treatment of diabetic macular edema with massive hard exudates: An evidence-based update.

Diabetic macular edema (DME) often presents with scattered punctate or massive hard exudates (HE), which can lead to visual acuity impairment. Plaque-like HE, a special type of massive HE, are even an independent risk factor for subfoveal fibrosis. Therefore, the elimination of HE is necessary for the treatment of DME. Triamcinolone acetonide (TA) and dexamethasone (DEX) implant are the most commonly used corticosteroids in the management of DME with HE, which can reduce HE through many pathways. Their pharmacokinetics differ in non-vitrectomized and vitrectomized eyes. We analyze the effectiveness and safety of TA and DEX implant in the treatment of DME with HE in non-vitrectomized eyes and vitrectomized eyes, with emphasis on plaque-like HE. Many studies based on HE-related biomarkers have shown that both TA and DEX implant are effective in promoting scattered punctate and plaque-like HE resorption in non-vitrectomized eyes and vitrectomized eyes, but DEX implant are preservative-free and have more stable drug concentration than TA in vitrectomized eyes. Complications should also be monitored, including ocular hypertension, cataracts, sterile endophthalmitis, retinal toxicity, ocular hypotony and migration into the anterior chamber. Combining vitrectomy with corticosteroids targets various pathophysiological mechanisms and may be an attractive alternative for DME with massive HE.