Treatment of Diabetic Retinopathy
The treatment options currently available are effective in halting or delaying further vision loss but will not reverse changes. The approach to the treatment of diabetic retinopathy depends on the stage of retinopathy, presence and extent of clinically significant macular edema, type of diabetes, general condition of the patient, and status of the opposite eye.
The treatment options for diabetic retinopathy include :
- surgical management (laser surgery, vitrectomy)
- medical treatment (drug)
The specific treatment for diabetic retinopathy should not be seen as a means of undoing the effects of prolonged and poorly controlled diabetes mellitus (sugar diabetes). Proper management of diabetes through medication, diet and lifestyles are essential.
Surgical Management for Diabetic Retinopathy
Laser surgery or laser photocoagulation is the standard treatment approach for diabetic retinopathy that aims to slow the disease progression. Laser photocoagulation is a noninvasive treatment with a high success rate and low complication rate. A highly focused laser beam is directed at the target tissue to produce a coagulation response. Focal photocoagulation is recommended for nonproliferative diabetic retinopathy while panretinal photocoagulation is considered for proliferative diabetic retinopathy.
Vitrectomy is another surgical option available for diabetic retinopathy. The surgery involves the removal of vitreous humor, usually under local anesthesia. Vitrectomy is usually required in long standing vitreous hemorrhage (unresolved for more than 6 months) and retinal detachment. The surgery aims to repair or prevent retinal detachment and to remove the blood in the vitreous hemorrhage.
Cryotherapy may be occasionally used to treat retinopathy in presence of cataract or vitreous hemorrhage.
Medication for Diabetic Retinopathy
The treatment of diabetic retinopathy with medication has limited use if good glucose control is not undertaken. Intravitreal injections (injecting the drug into the vitreous humor) of triamcinolone (corticosteroid) is used for the treatment of diabetic macular edema but focal photocoagulation (mentioned above) is still a more effective option in the long term. The effect of single injection of triamcinolone lasts for only about 3 months and repeated injections are necessary to sustain the beneficial effects.
Intravitreal bevacizumab and ranibizumab are anti-VEGF agents which are used for macular edema, vitreous hemorrhage, and neovascularization. These medications have shown encouraging results. A combined approach with focal laser therapy and anti-VEGF drugs may yield better results. Other drugs under evaluation for diabetic retinopathy include ruboxistaurin for delaying progression of proliferative diabetic retinopathy and ovine hyaluronidase for the clearance of a vitreous hemorrhage.
Complications of Diabetic Retinopathy Treatment
Laser photocoagulation may result in a loss of some peripheral vision and some reduction in color vision and nocturnal vision. This is of less consequence when the benefits are weighed against the long term impact of diabetic retinopathy. Other complications may include decreased central vision, areas of reduced vision (scotoma), neovascularization in choroid and an occasional increase in macular edema.
Intravitreal injections of triamcinolone can result in cataract, glaucoma, and serious eye infections (like endophthalimitis).