By John W. Karth, M.D.
Recent advances in surgical instrumentation have allowed safer and more effective treatment of complex surgical diseases. Vitrectomy surgery is used for many retinal problems, including diabetic retinopathy, tractional retinal detachments and proliferative vitreo-retinopathy.
Some of the most challenging cases are severe tractional detachments due to diabetic retinopathy. This occurs when there are abnormal blood vessels growing into the center of the eye ball from the retina. These abnormal blood vessels are prone to bleeding and can cause pulling on the retina, which detaches the retina if it is severe enough. A retinal detachment is when the retina (the light sensitive layer on the inside of the back of the eye) pulls away from the back of the eye, causing loss of vision.
When a retinal detachment occurs due to pulling by abnormal blood vessels and scar tissue caused by diabetes, it can be very difficult to separate the abnormal tissue from the retina. Indeed, the attachment between the abnormal vessels and associated scar tissue can be stronger than the retina itself, which is the consistency of wet toilet paper.
We have been using the 27-gauge vitrectomy instruments for about a year now, and find it extremely useful for challenging cases, especially for diabetic tractional detachments. The 27-gauge systems use a significantly smaller shaft, only 0.4mm (0.016 inches) in diameter.
This smaller shaft of the 27-gauge instrument allows for safer and faster separations of the membranes that are pulling on the retina. This can help reduce the risk of retinal damage when removing these membranes and reduce the bleeding encountered during the procedure. The small spaces where these instruments will fit allow efficient segmentation of the membranes that are pulling on the retina. Even if it is not possible to remove the entire membrane, if the scarring can be reduced to a single point of attachment it will not be able to pull on the retinal further.
We have found that by using the smaller 27-gauge vitrectomy cutter with a slightly larger incision, we can continue to use a broad array of instruments for these complex cases. Valves at the incision prevent most of the fluid from leaking around the shaft, and we use this configuration routinely.
The improvements in the care we provide for our patients with this system are very worthwhile. We will likely be doing a broader array of cases with the 27-gauge system in the future.