III. WHAT IS A DETACHED RETINA?

The thin retina is stuck to the inside wall of the eye by a single-cell layer of pigment cells, called the retinal pigment epithelium (RPE). The cavity inside the more or less spherical retina is filled with a clear jelly, called the vitreous body. This body adheres to the retina. A detached retina occurs when the retina is no longer in contact with the RPE. This often occurs when the vitreous body shrinks somewhat and pulls the retina off the RPE. When the shrinkage of the vitreous body is uneven, traction on the retina becomes greater in one area. This may cause a tear or rip in the retina. The retinal tear opens an area of contact between the water expressed out of the shrinking vitreous body, and the RPE. This water tends to unglue the retina off the RPE, thus producing a retinal detachment. The detachment of the retina deprives it from nourishment. This causes blindness. To restore vision, it is necessary to reattach the retina.

How To Reattach The Retina

In 1922, Professor Jules Gonin, from Switzerland, demonstrated that to reattach the retina, it is essential to close the tears in the retina. This was done by making a localized burn on the external wall of the eye, in the area corresponding to the location of the retinal tear. The method was later popularized and was successful in restoring vision in about 50% of the cases.

About 50 years ago, Dr. Charles Schepens revolutionized the surgery for retinal detachment and improved the percentage of surgical success from approximately 50% to over 90%. He made two key advances. One was the capability of seeing even minute tears in all areas of the retina with a new type of ophthalmoscope. (This is an instrument to examine a patient’s retina through his pupil). The other was the reduction of internal traction by the vitreous on the retina, through the performance of a scleral buckling.

The purposes of the surgery for a detached retina is to find all the tears in the retina, create an adhesion between the retina and the wall of the eye around the tears, reapproximate the retina to the wall of the eye and keep the structures in place.

At the SRA Foundation, we maintain the strict standards of preoperative retinal examination that have been the hallmark of our practice over the past 50 years. A mapping of the retina is made that extends to its anterior border. Locating breaks is enhanced by recording pertinent blood vessel patterns and other landmarks such as sites of retinal pigment and scars. Signs of internal traction by the vitreous are also recorded. From this examination, a general prognosis for surgical success can be estimated and a plan for surgery devised. The surgery is performed at the Massachusetts Eye and Ear Infirmary with an experienced and qualified post-graduate ophthalmologist as the surgical assistant in a facility that has the modern equipment available and plentiful back-up instrumentation.

Outlook for good vision after surgery depends on several factors, one being the status of the macula (Fig. 1). This is the small central area of the retina that gives one sharp, color vision. In addition to the integrity of the macula, one factor widely considered is whether or not the macula is flat or elevated from the RPE. Having the retina flat at the time of retinal surgery is ideal. However it is also important to know that the visual outlook is minimally affected adversely if it is elevated for only a few days. Too often retina surgery is done as an "emergency "when the better course would be to transfer the patient to a retina center where experienced specialists have a greater chance of success. There, a thorough preoperative mapping of the retina could be performed under optimal conditions prior to surgery. This detailed mapping is necessary to make sure that all retinal tears, even the smallest ones, have been detected. Then, surgery in a sophisticated operating theater leads to a greater chance for optimal long-term postoperative vision. It is ironic that some patients are sent thousands of miles away for successful retina surgery while others from less than one hundred miles away are operated upon by the initial observer (often not a fully trained retina specialist), because the patient has been told that surgery must done as an "emergency". It remains important to have timely surgery, compatible with a thorough preoperative evaluation, followed by surgery performed in a facility with access to all the latest sophisticated instrumentation, and a fully trained staff.

Fig. 1 Cut-away of the human eye showing its essential parts. In back is macula, the small central area of the retina that gives one sharp, color vision.