Does surgery improve outcomes in patients with severe diabetic macular edema?

This study looked at the treatment of severe diabetic macular edema (DME). It compared eyes treated with surgery to eyes treated with injections.  It showed that surgical treatment leads to a better resolution of DME compared to injections.

Diabetic eye disease affects the retina, which is the layer of specialized cells at the back of the eye where light is turned into images. The center of the retina is called the macula, and this is where most of the detailed vision takes place. 

Diabetes leads to the formation of leaky blood vessels within the eye. When these vessels leak into the macula the condition is called diabetic macular edema (DME). DME is a major cause of sight loss in diabetic patients. DME is usually treated with a course of injections into the eye. Severe DME leads to the formation of fat deposits in the macula called hard exudates. This form of DME is very difficult to treat. Treatment options include injections, laser treatment, and surgery. However, it is not clear which option is best.

40 eyes with DME were included in this study. 21 eyes were treated with surgery, while 19 eyes were treated medically. The eyes treated surgically had an operation to remove the vitreous jelly from the eye and peel the inner layer of the retina. This procedure is called vitrectomy with ILM peel. The group treated medically had a course of injections with bevacizumab (Avastin) or ranibizumab (Lucentis). Both groups have followed for an average of 20.2 months. Eyes were monitored for signs of resolution of DME. These signs include improvement in vision, decreased thickness of the macula, and shrinking of hard exudates.

Eyes treated with surgery had a better vision at 6 months, 12 months, and at the final visit than eyes treated with injections. The group treated with surgery also had a reduced thickness of the macula compared to the other group. Also, the surgery group had a greater shrinking of hard exudates than the injection group. In the surgery group, 62% of the eyes treated did not need further injections into the eye after surgery.

This study showed surgery may lead to a better resolution of DME in patients with severe DME with hard exudates.

This study is based on medical records, more studies are needed. Also, the number of patients was small.