GOOD RESULTS

Newer small-gauge vitrectomy instruments can facilitate the dissection of all types of proliferative tissue in eyes with proliferative diabetic retinopathy, said Borja Corcostegui MD at the 13th EURETINA Congress in Hamburg. “Good results can be achieved with any size of instrument, and it is up to the surgeon's preference which gauge to use. However, 23-gauge or new 25-gauge with a variable duty cycle seems to be the more acceptable size of instrument to use today, said Dr Corcostegui, Institut de Microcirurgia Ocular (IMO) Barcelona, Spain.

The advantages of small-gauge instruments include a small port that is closer to the distal end of the probe, and a better duty cycle than the older cutters. Furthermore, the shape of the port of vitreous cutters enables a more efficient removal of proliferative tissue from the macula, Dr Corcostegui noted. “25-gauge or 27-gauge instruments can be very useful in removing proliferative tissue over the retina especially over the main veins. It is also a good idea to use valved micro-cannulas to avoid having a low pressure during the operation and bleeding inside of the eye,” he added.

He noted that, prior to surgery, it is essential to perform fundus examination in order to determine the extent and location of the vitreoretinal attachments and the amount of proliferative tissue present. In many cases a B scan will be necessary because of an opaque vitreous. The goal of surgery in eyes with proliferative diabetic retinopathy is to remove the maximum amount of proliferations while avoiding damage to the main retinal vessels and the creation of retinal breaks and controlling retinal bleeding during the operation, Dr Corcostegui said.

Surgical strategies

Dr Corcostegui noted that he uses three different surgical strategies depending on the place of the proliferation and the extent of the proliferation. In the simpler cases he will simply remove the proliferative tissue over the retina using only the new 23-gauge and 25-gauge vitreous cutters with a onehanded technique.

In the more complex cases with much more proliferative tissue and where the space between the proliferation and the retina cannot be visualised, he uses a bimanual method with a forceps and a 23-gauge or 25-gauge vitreous cutter. Using a light irrigation system and infusion, he teases the proliferative tissue to one side with a forceps to find the attachments points, which he then slowly removes with controlled pressure. At the end of the operation he removes all the proliferation over the macula.

Avoid surgical bleeding

He also uses a bimanual approach in eyes with proliferative diabetic retinopathy that have retinal detachment, using a forceps with one hand and the slightly curved scissors to remove the proliferative tissue. “For me, using only three good sclerotomies with a light irrigation system makes it possible to remove every type of proliferative tissue. You can avoid surgical bleeding by working fast and maintaining high-pressure during the dissection. Scleral buckle is still useful in some cases with retinal detachment, but silicone oil is rarely needed,” Dr Corcostegui said.