8.4Surgery

Surgery for PVR varies from performing conventional operations to retinectomy of the inferior retina.

8.4.1Mild PVR

(Approximately C1–C2) Perform a non-drain procedure or

PPV with additional surgical steps: Insert heavy liquids.

Stain membranes with trypan blue. Peel PVR membranes.

Use long-acting tamponade.

When dealing with PVR from C1 to C2, if the retinal breaks are far away from the PVR, for example, you have a superior horseshoe break with inferior CP2 PVR, often all that is required is to close the break, for example, a plombage can be placed on the tear. The normal physiological mechanisms will overcome the shortening to the retina from the PVR.

If the PVR is any more than this, however, you will have to perform a vitrectomy and attempt to peel any retinal membrane from the surface of the retina to allow the retina to open up and reattach itself to the back of the eye.

Table 8.2 Difficulty rating for surgery for mild PVR

Surgical Pearl of Wisdom

On the empirical use of silicone oil when no breaks are found:

Silicone oil that floats may be more effective at displacing aqueous from the upper fundus and heavy silicone oil that sinks may be better at tamponading inferior retinal breaks. But a slight under fill with either will lead to large area of retina unsupported. There is no such thing as a total tamponade. Successful reattachment depends on identification of all retinal breaks, relief of traction and application of retinopexy. Use of silicone oil empirically (without identification of retinal breaks) invariably leads to recurrence of retinal detachment with oil in situ or upon its removal.

David Wong, Eye Institute, University of Hong Kong, Hong Kong, China

Note: Insert heavy liquids onto the posterior retina to stabilise the retina and act as countertraction as you pull on the membranes.

Use trypan blue dye to visualise the membranes and grasp with serrated forceps. Unfortunately, early membranes are often friable and difficult to remove. In this case, stretch and open out the contraction from the membranes using heavy liquid. The eye is primed to produce scar tissue, and the surgical intervention may induce further PVR formation; therefore, perfluoropropane gas or even silicone oil may be required.

8.4.2 Moderate PVR

(Diffuse grade B, C3–C5)

PPV with additional surgical steps: Insert heavy liquids.

Stain with trypan blue. Peel PVR membranes. Use silicone oil.

With levels of PVR C3–C5, peeling the membrane on its own may often be enough. Stabilise the retina with a heavy liquid, for example, perfluoro-n-octane (Han et al. 1994). This acts as a counterweight when pulling on the membranes; otherwise, the retina will be pulled with the membrane, and there is a risk of tearing. Use trypan blue stain to see the membrane more easily, and use either serrated forceps or forceps with a sharp tip to elevate the membrane. It is often easiest to engage the membrane in the centre of a star fold. Thereafter, deal with any breaks and fill the eye with silicone oil to allow reattachment of the retina. Leave the oil in until the proliferative process has had a chance to stop usually a few months. Superior holes can be treated with silicone oil. The management of inferior breaks is controversial. The placement of an inferior indention in a silicone eye may prevent adequate inferior silicone oil fill and may create a space behind the indent where shortening of the retina can easily form. I now do not use inferior buckles with moderate PVR and rely on the silicone oil fill on its own. Surprisingly, the inferior holes can flatten in this situation allowing silicone oil removal. This is despite the lack of inferior tamponade on the breaks from the oil (see sphere within a sphere in Appendix). If the inferior retina does not flatten, proceed to retinectomy.

Table 8.3 Difficulty rating for surgery for moderate PVR

B

Fig. 8.23 Adding an inferior indent to try to close inferior breaks in a patient with moderate PVR often results in more shortened retina and elevated inferior breaks probably because the oil bubble cannot fill the inferior vitreous cavity at B. It is better to allow the oil to fill the eye after stretching or removing the PVR. Surprisingly, the breaks often close, most likely from reduced fluid currents inferiorly

b

Heay liquid

Fig. 8.24 Indentation under an area of contraction from PVR membrane (shown in green) here can be used to aid attachment of the retina at that site. However, the system only works if the PVR is on the apex of the indent point A. If the PVR is also present at point B, the indent will cause lifting of the retina

Remove the silicone oil at 3–4 months, to avoid long-term oil-induced complications.

Fig. 8.25 In patients with funnel RRD from PVR (a) heavies are useful in patients with PVR to stabilise the posterior retina (b). Oil can be inserted on top of the heavies (c) whilst draining through the retinal break. As the oil bubble increases, the heavy liquid is compressed by the oil which pushes the peripheral retina flat. The SRF can drained from the meniscus between the oil and heavy liquids