For a smaller recessions, under the superior rectus muscle, the usual approach with one big opening is used. If larger recessions are indicated, the total opening size can be drastically reduced by using two cuts, one at the site where the tendon has to be desinserted and one where it will be reinserted. A limbal traction suture is applied to expose the superior quadrant of the eye globe. A 4 mm radial cut is performed over the insertion of the superior oblique muscle and a smaller radial cut of approximately 2 mm where the muscle will be reattached (Fig. 6.15a). The reinsertion place is found using a measure caliper. With blunt Wescott scissors, the superior oblique insertion is separated from the surrounding tissue. Now, a single, nonresorbable suture is applied to the anterior third of the muscle tendon close to the insertion (Fig. 6.15b). Usually, it is only necessary to reinsert the anterior border to the sclera, and, therefore, no second posterior suture is needed. Afterwards, a blunt 20G sub-TenonÕs anesthesia cannula is passed through the reinsertion site opening and advanced under the superior rectus muscle to come out through the second opening. The needle is gently inserted in the cannula until it is Þxed (Fig. 6.15c). Now, the cannula is retracted and the tendon is completely detached at its insertion (Fig. 6.15d). Then, the scleral Þxation is performed (Fig. 6.15e). After having checked that all posterior Þbers of the superior oblique insertion have been properly cut, the surgical procedure is completed by applying single sutures to each of the two small cuts (Fig. 6.15f). This approach allows, a MISS superior rectus muscle recession or plication using the same two cuts to be performed.

6.5.4MISS Superior Oblique Muscle Plication

(Fig. 6.15i). The same procedure is performed at the posterior tendon border. Both sutures are passed through the insertion of the muscle. After placing a spatulum, the plication is performed by tying both sutures (Fig. 6.15j). The spatulum is retracted (Fig. 6.15k). The surgical procedure is completed by applying single sutures to the small cut (Fig. 6.15l).

6.5.5Boergen’s Modified Harada-Ito Operation

Acquired fourth nerve palsy is characterized by horizontal V-pattern, vertical, and cyclotorsional deviation. Boergen described a modiÞcation of the HaradaIto procedure for excyclotropia correction, which is less invasive and seems to induce less postoperative BrownÕs syndrome [2]. After applying a traction suture and the superior oblique tendon has been visualized through a temporal approach (Fig. 6.16a), the tendon is split over a distance of 8Ð10 mm starting at the insertion (Fig. 6.16b). This can be performed through a small keyhole opening. Without detaching the insertion, the anterior part is displaced 3Ð6 mm temporal to the lateral insertion of the superior rectus muscle using a nonresorbable suture (Fig. 6.16c). Thus, the anterior half of the tendon will form a loop. The procedure corrects excyclotorsion. However, as the anterior and posterior parts of the tendon are still joined, this will also decrease the V-pattern incomitance and vertical deviation to a certain degree. For unilateral cases with more than 5¡ of vertical deviation, it will be necessary to also tuck the posterior half of the tendon. This will require a larger conjunctival opening.

Superior oblique muscle plications are indicated for superior oblique palsies. The use of a microscope is recommended. A limbal traction suture is applied to expose the superior quadrant of the eye globe. Direct contact of the traction suture with the cornea has to be avoided. An L-shaped cut is placed over the insertion of the superior oblique muscle (Fig. 6.15g). The tendon is hooked while another hook pulls the lateral rectus muscle border medially (Fig. 6.15h). After measuring the amount of plication, a single, non-resorbable suture is passed at that location through the anterior third of the tendon

6.5.6Mühlendyck’s Partial Posterior Superior Oblique Tenectomy for Congenital Brown’s Syndrome

Many cases of congenital BrownÕs syndrome are caused by an inelastic thickening of the posterior part of the superior oblique tendon [15]. MŸhlendyck described this anomaly in a large case series and proposed a minimally invasive approach to treat the condition. After applying a traction suture, a temporal approach to the superior oblique is chosen. By elevating the tendon at

Fig. 6.16 Schematic representation of the surgical steps for BoergenÕs modiÞed Harada-Ito operation. (a) The superior oblique tendon is visualized through a temporal approach, (b) the tendon is split over a distance of 8-10mm, (c) the anterior part is displaced in order to form a loop. Schematic representation of the surgical steps for MŸhlendyckÕs partial posterior

superior oblique tenectomy for congenital BrownÕs syndrome. (d) After choosing a temporal approach, the posterior inelastic part of the tendon is exposed, with a spatula (e) the anterior, normal part is separated from the posterior, inelastic part, (f) as much of the posterior part as possible is resected

the insertion site using a small spatula while a hook is displacing the lateral border of the rectus muscle medially, the posterior inelastic part can be easily visualized (Fig. 6.15d). The anterior, normal part and the posterior scar are separated using a second, small hook (Fig. 6.15e). The enlarged, inelastic posterior part of the

tendon is resected as far as possible medially, starting at the insertion site (Fig. 6.15f). Now, forced elevation in adduction of the eye should again be possible. During the Þrst postoperative days, it is important that scarring between the remaining tendon and sclera is prevented. This can be achieved by occluding the opposite eye and

Fig. 6.15 Schematic representation of the surgical steps for MISS superior oblique recession: (a) A radial cut is performed over the insertion of the superior oblique muscle and where the muscle will be reattached, (b) with blunt Wescott scissors, the superior oblique insertion is separated from the surrounding tissue, and a single, nonresorbable suture is applied to the anterior third of the muscle tendon, (c) afterwards, a cannula is passed through the reinsertion site opening and advanced till it reappears at the second opening, and the needle is gently inserted in the cannula until it is Þxed, (d) now, the cannula is retracted, and the tendon is completely detached at its insertion, (e) the scleral Þxation is performed, (f) after having checked that all posterior

Þbers of the superior oblique insertion have been properly cut, the conjunctival cuts are sutured. Schematic representation of the surgical steps for MISS superior oblique plication: (g) L-shaped opening over the insertion of the superior oblique insertion, (h) the tendon is hooked while another hook pulls the lateral rectus muscle border medially, (i) after measuring the amount of plication, a single, non-resorbable suture is passed at that location through the anterior and another suture through the posterior-third of the tendon, (j) the sutures are passed through the insertion of the muscle and after placing a spatulum, the plication is performed, (k) the spatulum is retracted, (l) conjunctival closure