VI. SURGICAL FAILURES IN RETINAL DETACHMENT

Dr. Hirose and his associates have special expertise in reattaching a retina following surgical failure. The most common cause of treatment failure of retinal detachment is proliferative vitreoretinopathy or PVR. It is caused by cells that migrate, (move), adhere and multiply on both surfaces of the retina (front and back) and on the back surface of the vitreous (the gel inside the eye). By forming membranes on the surface of the detached vitreous and on both surfaces of the retina, these cells contract both the vitreous and the retina. They also distort and tear the retina. If the pulling force is strong, the retina redetaches by traction even after a successful operation. Once closed retinal breaks are pulled open, the retinal detachment quickly becomes total. Under the retina is a single layer of pigment cells called retinal pigment epithelium (RPE). When the retina tears and detaches, the RPE is no longer in contact with the retina and its cells start to move into the vitreous and the surrounding tissues, where they multiply. The result is PVR. Mechanical manipulation of the globe by a surgical procedure stimulates PVR. Factors that increase the risk of developing PVR are large retinal tears (giant tears), multiple tears, intraocular bleeding, surgical treatment, particularly cryoapplication, and a soft eye.

In order to prevent PVR, we, at the SRA Foundation take special precautions. We avoid softening of the eye, minimize surgical insults and use cold irrigating solution in vitrectomy to cool the eye. We also prevent intraocular hemorrhage, avoid lengthy surgical time, and use anti-inflammatory agents such as steroids. Anti-metabolite drugs such as are used in cancer therapy are tried to prevent cellular proliferation. But as of today, no very effective means of PVR prevention is known. Once the cells are liberated into the intraocular space and start to multiply, there is little that can be done to control the process of PVR. In an attempt to prevent this, at the SRA Foundation, Dr. Hirose is surgically removing the RPE that is not covered by retina in eyes with large retinal tears. In such cases, the RPE is left exposed to the vitreous cavity. The procedure prevents the RPE from moving over the retinal surface and into the vitreous. The RPE removal is done by gentle scraping of the exposed RPE cells with a soft tipped probe. Another method is to inactivate the RPE cells by laser treatment.

Case Report. A woman reported with a 360 degree giant tear considered inoperable elsewhere, because the retinal detachment was associated with severe PVR (Fig. 9). Her best corrected vision was perception of light, and the other eye had been blind for many years. A vitrectomy was performed, the new formed membranes attached to the retina were peeled away, the exposed RPE was removed, air and long-lasting gas were injected to keep the retina reattached postoperatively. Endolaser was also used. Postoperatively her retina was reattached (Fig. 10). Silicone oil, which is commonly used by other surgeons, was not used in her operation. Her postoperative vision was 20/100 with correction. Eight years after the last surgery, her retina remained reattached, her vision was stable and there was no sign of complication.