Sir,

The principle of muscle recession in squint surgery is to detach the muscle from the globe, then to reattach it at the pre-determined distance from the limbus with or without postoperative manipulation. In order to avoid excessive fibrosis and contracture of the muscle and adjacent tissues, this should be achieved with minimal trauma to the muscle and surrounding tissues. We describe a novel method of primary muscle recession that is used in our routine clinical practice.

Method

The conjunctiva and Tenon's capsule are raised as a flap and the muscle tendon is exposed at its insertion (Figure 1a). Light cautery is applied to the blood vessels at the insertion of the muscle tendon (Figure 1b). At 1 mm behind the insertion, one-third of the muscle tendon is secured (Vicryl 7-0, Ethicon, Spreintenbach, Switzerland) using a locking suture (clove hitch knot, which consists of two half hitches made in opposite directions) (Figures 1c and 2a). Two-thirds of the width of the tendon is then detached from the globe, while the other third remains untouched (Figure 1d). Calipers are using to mark the desired amount of recession and the cut part of the tendon is reattached to the sclera. A spatulated quarter circle 6.O needle is used to reattach the muscle by spreading the tendon through a 1.5–2-mm scleral passage (Figure 2b). The second part of the muscle is then recessed in a like manner (Figure 1e and f). The conjunctiva is then sutured with the 8-0 vicryl.

Figure 1
figure 1

Surgical technique. (a) Firstly, a limbal conjunctival flap is created. (b) The blood vessels are identified at the muscle insertion (arrow) and cauterised. (c) One half of the muscle tendon is secured with the suture. (d) Two-thirds of the tendon is detached from the globe, while the other third remains untouched. The tendon is reattached at the desired distance. The other third of the tendon is secured with the suture (arrow) (e), detached and reattached at the desired distance (f).

Full size image
Figure 2
figure 2

Illustration of stepped recession muscle (a). The muscle is identified and one-third of the tendon is secured with the suture. Two-thirds of the tendon is detached from the globe, while the other third remains untouched. The tendon is reattached at the desired distance. The tendon is secured using a clove hitch knot, which consists of two half hitches made in opposite directions (b).

Full size image

Discussion

Today, the most common technique of squint surgery is based on that of Helveston.1 The squint hook is used to help recognise and stabilise the muscle, before it is detached from the globe. In our experience, during primary muscle surgery, fine-toothed forceps are all that is necessary to identify and secure the muscle tendon, without the need for a squint hook.

Our method has been used successfully for over 10 years. The maximum recession from this method is 6 mm. The main advantage is it minimises manipulation of the tissues and thus minimises fibrosis and scarring. In addition, it has fewer steps, is rapid to perform, and is easy to learn. The use of cautery, prior to any manipulation of the muscle, prevents bleeding and ensures good visibility throughout the procedure. The muscle is not at any time fully detached from the globe and thus averts the rare but significant complication of a lost muscle during the procedure. Finally, the time taken for each muscle is 10 min or less, and with two surgeons working in tandem on two eyes, we have significantly increased our surgical throughput.