By Laird Harrison
—Macular buckling together with pars plana vitrectromy works better than pars plana vitrectomy alone for retinal detachment in high myopia, a researcher says.
“The surgery is not so complex,” said Carlos Mateo, MD, of the Instituto de Microcirugía Ocular, in Barcelona, Spain, who presented the technique at the European Society of Retina Specialists 15th EURETINA Congress.
Retinal detachment often occurs in patients with high myopia, he said, noting that these eyes frequently suffer from vitreous schisis, atrophy of the retinal pigment epithelium (RPE) and staphyloma.
When confronted with these cases, said Dr. Mateo, “the community of vitreal surgeons is divided into two groups.”
Most perform pars plana vitrectomy alone, in many cases including a silicon oil tamponade. The weakness of this approach, according to Dr. Mateo, is that it doesn’t address some of the causes of retinal stretching, such as vascular traction and posterior staphyloma. As a result, macular holes may not close.
So an old technique, macular buckling, is making a comeback. It has the potential to counter the pulling of the posterior staphyloma and change the concavity of the posterior part of the eye into a flatter, or even convex shape, decreasing tractions, according to Dr. Mateo.
In 9 studies on the two approaches, Dr. Mateo said, plars plana vitrectomy closed macular holes in 26% to 86% of cases, and reattached retinas in 54% to 95%. By contrast, the rate of macular hole closure in macular buckling ranged from 83% to 93%, and the rate of retina reattachment ranged from 93% to 100%.
The use of a silicon oil tamponade in these studies appeared to produce worse results, he said.
Given these findings, the goals of the procedure should be retinal reattachment, closure of the macular hole and avoiding the use of a silicon oil tamponade, he said.
Dr. Mateo advocates combining the two approaches. This technique is most effective in patients who have not previously been treated with pars plan vitrectomy, he said.
In a Greafe’s Archives paper (Graefes Arch Clin Exp Ophthalmol (2014) 252:572-581 http://www.ncbi.nlm.nih.gov/pubmed/24158373
), Dr. Mateo and his colleagues reported on 42 eyes with retinal detachment due to macular holes that were treated with the combination surgery. Twenty-one of these had previously been treated with pars plana vitrectomy.
A year after the combination surgery, the macular holes had closed in 81% of the treatment naïve eyes and 57% of the previously treated eyes. The retina was reattached in all of the treatment naïve eyes, and 90.5% of the previously treated eyes.
Silicon oil was used in only 1 of the treatment naïve eyes, but 7 of the previously treated eyes.
The greatest improvement was seen at 3 months. But the greatest difference between the two group in clinically significant visual gain (-0.19 log units) was seen at 12 months.
The visual outcome was better when the retinal detachment was confined to the area of the staphyloma, Dr. Mateo said.
“Perhaps you think is this only a mirage in the desert,” he said. He then displayed a slide showing post-operative best-corrected visual acuity in 10 cases where the combination surgery was used in treatment naïve eyes. The logMAR results ranged from 0.1 to 0.9, with most of the results clustered around 0.2
In the macular buckling procedure, the surgeon exposes the superotemporal quadrant and places a suture pointing to the foveal area.
Dr. Mateo prefers to perform a pars plana vitrectomy. He removes all tractions from the posterior hyaloid and internal limiting membrane.
When staining the interior limiting membrane, Dr. Mateo recommends mixing the dye with viscoelastic “to avoid the dye going through the break and into the subretinal space.”
When inserting the buckle, Dr. Mateo said, he uses an optic fibre to check the position. It is important to avoid damaging the optic nerve.
“At the end when we see this is right, then we put additional sutures to maintain the buckle in place,” he said.
At times, subretinal fluid takes a long time to reabsorb. If that happens, Dr. Mateo said, “don’t worry.” He cited the example of a patient whose vision continued to improve over the course of five months while his subretinal fluid slowly subsided.
More serious are retinal pigment epithelium disturbances in the central macula, he said. However his team his running into these less and less frequently.
He concluded that the combination procedure offers high rates of reattachment and macula hole closure, while avoiding the need for laser photocoagulation around the macular hole and the use of silicone oil as a temporary tamponade.
For the future, he is hoping to develop better control over the buckling effect and easier removal of the buckle when necessary.