Pneumatic Retinopexy (PR)

• Patient selection

In RD, there is a causative retinal tear, through which fluid seeps underneath the retina leading to detachment of the retina causing vision loss. Sometimes there can be multiple retinal tears. Not all types of retinal detachments can be treated by PR. PR is useful in relatively fresh RDs and only when the retinal break/breaks is/are superior in location.

The injected gas bubble tends to move against gravity due to buoyant force. The gas bubble expands initially and opposes the retinal break.

• Procedure

The procedure can be performed under topical or under local anesthesia. In the topical variant, anesthetic eye drops are used whereas in the other injection of local anesthetic agents is given surrounding the eyes. Since after injection of gas bubble pressure within the eyeball tends to rise, pressure-lowering agents are given before the procedure. Intravenous mannitol is usually given 20 to 30 minutes before the procedure mostly.

During the surgery, the eye is cleaned with betadine (aseptic agent) and draped.

The pressure of the eyeball is assessed. Sometimes the surgeon performs paracentesis ( a technique in which some fluid is removed from the eyes with a plunger less syringe).

 After considerable reduction of eye-pressure, gas bubble is injected with a syringe into the eye. After injection, the surgeon checks the opposition of the gas bubble with the help of indirect ophthalmoscope (an instrument used in visualization of the retina). Once the apposition is confirmed, cryotherapy (with a freezing device) is given externally to the site of the retinal break. By providing high cold energy, permanent adhesion of the break can be achieved.

• Postoperative care and restrictions

The patient might not feel pain during the procedure due to the anesthesia. After the procedure, the patient’s eye will be patched. The patch can be opened after 4-6 hours. Eye drops will be prescribed and should be used accordingly. The most important part is the positioning. The patient will be advised to be in a specific position for the initial 2 weeks to 1 month. The types of positions include: prone (face down), sitting, face tilted (left or right). The type of position depends on the location of breaks which may vary in individual patients. Positioning helps in better opposition of the retinal break by the air bubble and therefore improves the success rate of the procedure.

The gas bubble tends to expand in the initial 24 hours. Hence the eye pressure tends to rise. The patient will be asked to report the next day for a checkup. Pressure lowering agents (drops and oral) may be required accordingly.

One of the two types of gases can be used: C3F8 or SF6. Based on the type of gas injected, the bubble tends to stay for 3 weeks to 8 weeks. Since these are expansile gases, they tend to expand based on surrounding atmospheric air pressure. So air travel is strictly prohibited. High altitude travel (to hill areas) and deep-sea diving are also to be avoided until the gas bubble present.

• Conclusion

Though pneumatic retinopexy is a safe and quick procedure for treating retinal detachment, the success rate is relatively less and the procedure can be used only for selective patients. The advantages are lesser side effects and faster postoperative recovery.

Written by: Dr. Dheepak Sundar – Consultant Ophthalmologist, Velachery