63.5Suturing the Sclera

The natural wound-closing process starts immediately after the injury, and within hours it results in a surprisingly Þrm closure Ð unless uveal tissue or vitreous has been incarcerated (Fig. 63.6). In such cases the wound never truly heals, and the sclera may get macerated by the oozing aqueous.

The sclera is a hard tissue, with rather signiÞcant resistance against the needle the surgeon uses to suture it. This provides excellent tactile feedback, informing the surgeon whether, when introducing a transconjunctival suture, he indeed engaged the sclera or just the conjunctiva. However, when the eye is soft, this feedback completely disappears: the surgeon should restore the normal IOP4 before he can take advantage of this feedback (see also Sect. 54.4.2.3).

Proper suturing achieves proper healing and reduces the risk of PVR by preventing primary incarceration (see below). Table 63.4 provides an overview of the most important rules in scleral wound closure.5

Fig. 63.6 Unsutured scleral wound. A 4-week-old injury. There is obvious uveal prolapse, yet the patientÕs original ophthalmologist decided not to explore the eye and suture the wound. The IOP is normal since the wound is not open, but neither has it healed. During closure, the iris had to be excised because it was overgrown by epithelium and it was scarred to the sclera. Large bites were used with the vicryl suture to prevent cheesewiring in the macerated tissue

4Injecting BSS into the vitreous cavity with a 27 g needle.

5Especially if the wound is posterior to the muscle insertions, it should be the VR surgeon who closes the wound: he understands best the consequences of improper closure and not performing timely vitrectomy.

aRunning a Þnger carefully over the anesthetized conjunctiva, the surgeon feels a little bump if one edge of the scleral wound is not in level with the other edge.

bHigher because the prolapsing tissue tamponades the wound and the intraocular hemorrhage is not stopped immediately; lower because the ciliary body may have shut down.

cThe border between ÒanteriorÓ and ÒposteriorÓ is not well deÞned, but the equator is a good approximation.

dOrbital fat outside the eyeball; the vitreous, retina, and choroid as intraocular tissues. eSuch as a spatula.

fIt is a braided suture, which may occasionally result in an entanglement of the thread. It is absorbable, but, contrary to earlier concerns, this does not represent any risk for wound reopening: by the time the suture starts to degrade, the wound will have healed.

WLO

Fig. 63.7 The close-as-you-go technique to suture a posterior scleral wound. (a) The conjunctiva is opened anteriorly to expose the part of the scleral wound that is fairly anterior and relatively easy to access. (b) Once the initial 4 sutures are placed, the conjunctiva is dissected in a larger (more posterior) area, and sutures #5 and #6 are placed. The rest of the scleral wound is too posterior for safe closure and is thus left open. L limbus, CD conjunctival dissection, SW scleral wound, EOM extraocular muscle, S suture, WLO wound left open. The numbers represent the order of suture placement

a

C

SPA

b

c

Fig. 63.8 Sequential placement of a scleral suture. (a) In most cases, a blunt instrument such as a spatula is sufÞcient to hold the prolapsing tissue back, and the needle can be introduced with a single motion, into both wound edges, as shown by the arrows. (b) If tissue prolapses despite the effort to hold it back, the needle is Þrst inserted into one wound edge and then pulled out through the wound. (c) The needle is then reinserted into the opposing wound edge, thereby avoiding direct incarceration of the prolapsing tissue (the latter and the spatula, which still needs to be used, are not shown here and on (b) for simplicity). S sclera, SPA spatula, C choroid