Technique uses dye to find retinal breaks

LISBON, Portugal — A novel technique for identifying retinal breaks following rhegmatogenous retinal detachment using trypan blue was introduced here at the Euretina meeting.

Upon occasion, the surgeon may be unable to locate a patient’s retinal break, said G. William Aylward, MD. When that occurs, the surgeon must “cover all of our options by doing an encircling buckle or 360· laser,” which is not an ideal solution, he said.

In such cases, “subretinal dye has a useful but occasional role in identifying missing retinal breaks during vitrectomy,” Dr. Aylward said.

In his technique, trypan blue is injected into the subretinal space through a 40-gauge cannula.

“In our early cases we used small volumes of dye, but we have found that larger volumes — up to 1 mL — give better staining, particularly in bullous detachments,” Dr. Aylward said. After the dye is initially injected, it forms “a kind of thumbs-up sign,” and Dr. Aylward said he knows he will have a good result from there.

The surgeons must be patient and allow time for the dye to diffuse through the subretinal space, he said. He injects perfluorocarbon liquid to fill the eye and force the fluid peripherally.

The dye will then form “what looks like an arrowhead,” revealing the location of the break, he said.

“More important, it shows where the breaks are not,” Dr. Aylward said

In a small case series of five patients, only the first patient’s retinal break remained unidentified with the modified technique, and Dr. Aylward said the small amount of trypan blue used did not affect the outcome.

Toxicity is not a factor, Dr. Aylward said, because a low concentration (0.15%) is used. The dye is in the eye for a short time and is washed out after identifying the break, he said.