Medical Care
Uveitis/inflammation
Steroids are considered an effective treatment to uveitis, administered in 3 different ways: topical, oral, and injectable. [3]
Topical steroids and nonsteroidal anti-inflammatory agents have been used in the treatment of cystoid macular edema (CME), especially when associated with uveitis. Most studies have evaluated the efficacy of these drugs in the presence of pseudophakic CME after cataract surgery. [11] However, the effect of these medications in stabilizing the blood-retinal barrier may aid in the treatment of other forms of CME.
Oral steroids also are a commonly used modality of stabilizing the blood-retinal barrier for the treatment of inflammation and CME in patients with intermediate or posterior uveitis. Oral steroids should be avoided unless necessary because of the associated complications of systemic use (eg, aseptic necrosis of the femoral head).
Injections of long-acting depot steroids (eg, triamcinolone) into the sub-Tenon space usually are more effective and commonly are used in the treatment of noninfectious uveitis. Peribulbar injections have a greater risk of intraocular injection than a subconjunctival approach; however, the drug delivery to the retina is superior when administered into the posterior sub-Tenon space. These implants allow sustained release of the steroid, maximizing drug efficiency and minimizing toxicity. Three potential candidates are undergoing clinical trials: dexamethasone implant (Posurdex), triamcinolone acetonide implant (I-vation TA), and fluocinolone acetonide implant (Retisert, which is FDA approved).
Intraocular triamcinolone acetonide has been found to effectively, but temporarily, reverse CME in eyes with many conditions, including pseudophakic CME, retinal vein occlusions, diabetic macular edema, uveitis, and juxtafoveal telangiectasis. Clinical trials are underway to study the long-term benefit and safety of this treatment approach.
Many other causes of CME are treated by addressing the underlying condition. CME associated with CMV retinitis is treated by managing the retinitis with antiviral agents (eg, ganciclovir, foscarnet, cidofovir).
CME associated with immune recovery in patients with inactive CMV retinitis and a stronger immune system are also treated with steroids, either oral or posterior sub-Tenon injection of long-acting depot steroids.
Orbital pseudotumor is treated effectively with oral steroids, and, in the case reported to be associated with CME, the macular edema resolved with treatment of the orbital pseudotumor.
Diabetic maculopathy
As stated, intraocular triamcinolone acetonide is an effective treatment for diabetic macular edema.
Research implicates VEGF as an important mediator of vascular permeability and CME. Therefore, clinical trials are being conducted to evaluate the benefit of VEGF inhibitors in treating CME associated with different conditions, such as diabetic macular edema, retinal vein occlusions, and age-related macular degeneration. [12] Anti-VEGF treatments also stunt neovascularization.
When CME is associated with diabetic macular edema, focal laser photocoagulation according to the guidelines of the Early Treatment of Diabetic Retinopathy Study (ETDRS) should be followed (see Diabetic Macular Edema). However, CME in the setting of diabetic macular edema often suggests chronicity of the condition and will not respond adequately to laser treatment. Some physicians advocate the use of posterior sub-Tenon or intraocular injection of triamcinolone with or without macular laser photocoagulation to treat diabetic macular edema associated with CME. A randomized, sham-controlled trial testing the efficacy and safety of a dexamethasone intravitreal implant showed that it was safe and efficacious in correcting best corrected visual acuity. [13]
A 5-year randomized controlled trial showed that eyes receiving ranibizumab with prompt or deferred laser treatment had better long-term vision improvements than eyes managed with laser or triamcinolone with laser follow by deferred ranibizumab. [14]
Age-related macular degeneration
CME associated with choroidal neovascularization in ARMD is a secondary response to the presence of subretinal neovascularization. [4, 5] It is present most commonly in eyes with significant subsensory fluid in the macula and a poor prognosis for central vision. Fortunately, current treatments of exudative ARMD reduce the incidence of disciform scarring and associated CME.
FDA-approved treatments for ARMD include the following:
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Ranibizumab (Lucentis)
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Aflibercept (Eylea)
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Pegaptanib sodium (Macugen)
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Verteporfin (Visudyne)
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Implantable telescope
Retinal vein occlusions
Intraocular triamcinolone acetonide and VEGF inhibitors have been found to reverse CME in eyes with retinal vein occlusions. [15]
Currently, anti-VEGF agents are the primary treatment for retinal vein occlusion, specifically ranibizumab. Alongside, the Posurdex Study is evaluating the benefit of an injectable dexamethasone implant for the treatment of macular edema in retinal vein occlusions.
Intravitreal triamcinolone has been reported to be effective in reversing CME in branch retinal vein occlusion and nonischemic central retinal vein occlusion. [16, 17] The Standard Care vs Corticosteroid for Retinal Vein Occlusion (SCORE) Study, a clinical trial sponsored by the National Institutes of Health (NIH), is evaluating the benefit of preservative-free intraocular triamcinolone acetonide in retinal vein occlusions.
Macular edema is a common cause of visual loss in eyes with branch retinal vein occlusion or central retinal vein occlusion. CME also can be associated with this form of macular edema. Macular laser photocoagulation has been shown to be effective in improving vision in patients with branch retinal vein occlusion for greater than 4 months’ duration and a visual acuity of 20/40 or worse. However, the Central Vein Occlusion Study (CVOS) did not show any visual benefit from laser photocoagulation in eyes with central retinal vein occlusion and macular edema, although it did reduce the macular edema.
Choroidal melanoma
When malignant intraocular tumors are associated with CME, the priority is to treat the tumor. Systemic malignancies, such as multiple myeloma, have been observed to be associated with CME. Systemic treatment of the myeloma is the priority and usually addresses the CME. However, sub-Tenon injection of steroid may enhance resolution of the CME in such cases. Depending on the nature of the disease, CME associated with intraocular tumors requires treatment of the tumor (eg, laser photocoagulation, cryotherapy, radiation, thermotherapy, enucleation).
Juxtafoveal macular telangiectasis
Treatment of CME associated with juxtafoveal telangiectasis has been undergoing preliminary trials with steroids, VEGF antibodies, and laser photocoagulation. Results show that intraocular triamcinolone acetonide temporarily lessens CME, but it recurs less than 6 months after treatment. Both bevacizumab and ranibizumab are being tested to reduce CME. Results show success in improving vision and CME for up to 12 months. [18]
CME secondary to juxtafoveal telangiectasis in Coats disease has been shown to respond to laser photocoagulation, with resolution of the edema and improvement in visual acuity, and remains the prevalent form of treatment.
Drug-induced and postoperative CME
Macular edema secondary to radiation retinopathy is often treated with laser photocoagulation.
CME after surgical interventions such as retinal reattachment surgery, corneal relaxing incisions, and keratoplasty usually resolve with time.
In drug-induced cases, such as CME associated with latanoprost, echothiophate iodide, or nicotinic acid, discontinuation of the drug usually causes reversal of CME.
Genetic disorders
Other forms of CME have been reported to respond to treatment with acetazolamide. CME after scleral buckling procedures, CME in some forms of uveitis, and CME associated with RP may respond to acetazolamide therapy. [15]
Complications
Complications associated with the treatment of CME are infrequent. When a posterior sub-Tenon injection of triamcinolone is given, patients can occasionally experience a transient ptosis or subconjunctival hemorrhage. Retinal arterial occlusion after sub-Tenon steroid injections has been reported due to intravascular injection of the drug.
Intravitreal triamcinolone has been associated with ocular hypertension, cataract progression, retinal tear or detachment, infectious and noninfectious endophthalmitis, and lens damage.
Long-Term Monitoring
Typically, patients with cystoid macular edema (CME) are evaluated 1-3 months after intervention to evaluate the efficacy of treatment.
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Fundus photograph of left eye with branch retinal vein occlusion and cystoid macular edema. Visual acuity was 20/50, and the patient was treated with a modified grid laser photocoagulation and posterior sub-Tenon injection of triamcinolone.
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Fundus photograph of nonproliferative diabetic retinopathy with clinically significant macular edema and cystoid macular edema.
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Fluorescein angiogram of same eye as in the image above, revealing both cystoid macular edema and leakage from microaneurysms associated with diabetic retinopathy.
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Ocular coherence tomographic image of cystoid macular edema in a patient with uveitis.
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Cystoid macular edema in patient with diabetic retinopathy.
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Eye in previous image with diabetic CME after injection with 4 mg of intravitreal triamcinolone.
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Ocular coherence tomographic image of cystoid macular edema in an eye with nonproliferative diabetic retinopathy.
