The patient is automatically moved head first into the CT gantry, and the x-ray tomogram is acquired. Now the patient is automatically moved through the PET gantry, which is mounted in parallel with the CT gantry, and the PET slices are acquired. The patient may now leave the device, and the PET-CT software starts reconstructing and aligning the PET and CT images.
Diagnostic Procedures. Three common diagnostic procedures, tonometry, visual field tests, and ophthalmoscopy, enable ophthalmologists to screen patients for glaucoma. To make a definitive diagnosis, ophthalmologists often use all 3 procedures as part of an overall eye examination. The procedures are simple, relatively quick, and virtually painless.
Tube-Shunt Surgery for Glaucoma. Guide. Tube-shunt surgery (seton glaucoma surgery) involves placing a flexible plastic tube with an attached silicone drainage pouch in the eye to help drain fluid (aqueous humor) from the eye. This type of surgery is usually done after a trabeculectomy that failed.ate complications of tube-shunt surgery include: 1  Scar tissue forming around the device. 2  Softening of the eyeball due to fluid loss (hypotony), leading to clouding of the lens (cataract). 3  Infection in the eye. 4  Blood in the eye (hyphema). 5  Eye muscle imbalance, resulting in double vision.