54.3.3 Prognosis

When employed as the initial surgery, both SB and PPV yield a ~80% permanent retinal reattachment rate.33 In the unsuccessful eyes, the culprit is either PVR (~2/3 of the eyes) or a retinal break.34 If proliferation is the cause of failure, PPV is the natural choice for reoperation (see Chap. 53). If a retinal break is at fault, either option may be selected.

54.4Scleral Buckling35

54.4.1 Preoperatively

¥Examine the sclera for any area of structural thinning (see Fig. 21.3a). In the presence of such thinning, SB is contraindicated,36 even if the buckle were to be placed elsewhere.

¥Perform a careful, detailed examination to determine the strength and range of VR traction and the location of the retinal break/s.

ÐSlit lamp with a 90 D lens and/or 3-mirror contact lens.

ÐIBO with scleral indentation.37

¥Make a drawing, and indicate all major Þndings.38

¥Decide what kind of buckle you want to use and how many of them (see

Table 54.7).

¥If the RD is bullous, discuss with the patient that for a day or two he stays in bed preoperatively, with both eyes patched, so that the height of the detachment is decreased (see above).

33This is a very rough number. Many factors have signiÞcant impact on whether the retina remains permanently attached after the operation (e.g., the duration of the RD, experience of the surgeon).

34Commonly referred to as Ònew or previously unrecognized.Ó The distinction is academic because you can never determine whether the identiÞed break is one or the other, and it has no inßuence on the treatment.

35See Sect. 26.2 for a reminder of some important anatomic facts.

36Especially in case of a systemic disease that lasts a lifetime (see planning, Sect. 3.1).

37This allows a dynamic evaluation of the VR traction, especially on the edges of the retinal breaks. The magniÞcation is rather small, and the patient may experience pain.

38It is not a piece of artwork that is required, simply a document that shows the area or the detachment and the crucial retinal and VR pathologies.

*Only the main variants are listed here.

aSome surgeons use a sponge that is split in half. This requires an entirely different technique to make it work: while the band is stretched after the sutures were put in place, the sponge needs to be stretched each time before the suture is tied. The band will cause an evenly distributed indentation; in case of the sponge the indentation will differ per stretching between two sutures (the indentation is also inßuenced by other factors such as bite width, see below).

bThe tire comes in various shapes and sizes. cThe sponge comes in various shapes and sizes.

dSome surgeons prefer using multiple radial buckles if there are multiple breaks in different locations. eThe grooved element comes in various shapes and sizes.

Pearl

There is no better empirical evidence to show the importance of VR traction than the behavior of the RD when the patientÕs eyes and head are immobile: the retina almost always reattaches, usually rapidly.

54.4.2 Intraoperatively39

54.4.2.1 Initial Steps

¥Make sure that if local anesthesia is used, the analgesia is full; the operation, especially manipulations involving the extraocular muscles, can be very painful.40

¥Open the conjunctiva at the limbus and then make radial incisions.

39The order of certain steps may be different with some surgeons. Most commonly, the buckle is placed prior to drainage; I do not prefer this because, especially if the detachment was high, the Þnal resting point of the retinal break may be at a location different from the expected. The main reason why to employ the buckle-Þrst-then-drain sequence is the fear of hypotony after the drainage. I restore the IOP using an intravitreal BSS injection; see below.

40This is one of the reasons why patients prefer PPV to SB.

ÐIf a segmental buckle is planned, make sure that the opening is wide enough to expose at least 2 extraocular muscles. If an encircling band41 is to be used, the entire conjunctiva needs to be incised at the limbus. In either case, two radial cuts of ~10 mm in length are needed.

ÐBluntly dissect the conjunctiva to have good direct visualization of the naked sclera and unhindered access to all the exposed rectus muscles in the entire operative Þeld.

¥Using a fenestrated muscle hook,42 introduce a retraction suture43 under each exposed muscle.44

ÐClamp a hemostat onto each suture; this makes manipulations of the eye much easier.

¥Localize the retinal break/s and mark each one on the sclera with a sterile pen.

ÐIf the break is large or radially oriented, mark the posterior edge: the buckle will have to extend beyond this point (see Fig. 54.5). The reason why it is best to avoid having to deal with a bullous RD45 is that the break appears more posterior that it really is.

ÐIn case of a giant tear or dialysis, mark both ends as well as the central edge in the middle of the break. If the dialysis is narrow, as shown above, there is no need to mark its central extension.

41Called ÒcerclageÓ in many countries.

42With a hole at its tip to loop a suture through it.

43Such as 2-0 silk; it should be black for easy identiÞcation.

44Alternatively, a needle equipped with the suture may also be used, but reverse it Ð advance under the muscle the suture with its blunt (suture-) end forward.

45Bedrest with bilateral patching (see above) or drainage (see below).

Q&A

Q What is the optimal viewing technique for SB?

AThe operating microscope offers the best view, increasing control and thus safety. The alternative is to use the IBO for the internal structures (break localization etc.) and either the naked eye or, preferably a loupe, for the external procedures (suturing etc.).

54.4.2.2 Creating a Chorioretinal Adhesion

The surgeon may use cryopexy (see Sect. 29.2) or laser (see Sect. 30.3.4). Laser is generally preferred since it reduces the risk of PVR development; however, the retina must be attached Þrst (see below). The surgeon may want to drain the subretinal ßuid Þrst and apply the laser afterward.

Conversely, cryopexy may be used even if the retina is detached and even if the indentation actually reaches only as deep as the RPE. The effect, however, is more difÞcult to monitor, making this a less preferable option (see Table 29.1).

54.4.2.3 Drainage of the Subretinal Fluid

Some surgeons always, others never drain; most decide on a case-by-case basis.

¥Locate the area with the highest elevation of the RD.

¥Use a diathermy needle, if one is available, to penetrate as posterior as possible the sclera and choroid directly while applying cautery.

ÐIf there is no diathermy needle at hand, create a radial sclerotomy of 1Ð2 mm in length, diathermize the choroid, and then use a small needle or blade to penetrate the choroid.46

¥Use a cotton-tip applicator or a muscle hook/scleral depressor to press the subretinal ßuid from further-away areas toward the incision site.

¥When the drainage is complete,47 either suture the sclerotomy or leave it open.48

¥As the ßuid egresses, the IOP drops. An intravitreal BSS injection may be needed to reduce the risk of intraocular bleeding and the difÞculty of suturing the sclera in the soft eye (see Sect. 63.5).

An alternative drainage technique involves the oblique insertion of a needle (25Ð27 g)49 directly into the subretinal space. It requires constant monitoring via the IBO of the needle tip to withdraw it as the retina is ßattening. This technique also leaves the occurrence of a choroidal bleeding up to chance (see Sect. 3.2), and if the subretinal ßuid is very thick, it may clog the needle.

46Remember, the choroid is elastic. If the opening is small, it may spontaneously close even when there still would be subretinal ßuid ÒwillingÓ to drain (see Fig. 21.10).

47The retina is completely attached or the remaining subretinal ßuid is too posterior to drain.

48It can be left unsutured if it is small and will be right underneath the buckle.

49For easy handling, the needle is connected to a syringe whose plunger is removed: the drainage is passive.

54.4.2.4 Selecting and Placing the Buckle50

The goal is to place the buckle so that the retinal break is on its ridge or slightly anterior to it. If the buckle is misplaced, the break remains open, the intravitreal ßuid is still able to access the subretinal space, chorioretinal adhesion will not form, and the RD persists.

It is possible to do buckle placement and suturing without additional helping hands Ð but the surgeon is much better off if he has a trained nurse to assist, especially during suturing.

Pearl

To counter the traction, the indentationÕs height is more important than the width. To provide a solid mechanical foundation for the break, the buckleÕs width is crucial: the surgeon must make sure that the entire break (i.e., the area of the naked RPE) is supported.

¥If an encircling band is employed, have two anatomic forceps51 to place the band. One forceps is used to advance the forceps under the muscle; the other one is to pull it out/through from the other side.

ÐMake sure that the band is not twisted.

ÐThe two ends of the band must meet in the quadrant the surgeon selects. You can choose the one that offers the easiest access to it (e.g., inferotemporal) or the one that has the retinal break.

ÐInsert the two ends of the band into a sleeve of proper size.52 Once the sutures have been placed (see below) and the band properly stretched, cut the superßuous endings with a ~1 mm overhang.

¥If a segmental sponge is employed, you have two options: keep the order as described above or place the sutures Þrst and then insert the sponge under the muscle, the sutures, and then the other muscle.

Pearl

Make sure the muscle moves freely over a sponge. If a very thick sponge is used, it must be buried rather deep (i.e., the indentation should be high).

¥If a radial sponge is employed, it will have no contact with the muscle; place the sutures Þrst.

Buckles that are Òhigh and broadÓ are associated with severe complications (see below).

50Again, this is one possible option; other surgeons may use very different techniques.

51Preferably with a bent tip to ease maneuvering (e.g., Jameson muscle forceps or KelmanÐ McPherson tying forceps).

52The sleeve forceps has reversed action.