Ординатура / Офтальмология / Английские материалы / Strabismus Surgery and Its Complications_Coats, Olitsky_2007

Fig. 13.11a–c. Jensen procedure for lateral rectus paralysis. a The superior and inferior and lateral rectus muscles are split longitudinally into two equal halves. Note that one anterior ciliary vessel has been left undisturbed in the nasal half of each of the vertical rectus muscles.

muscle hook is used to split each muscle longitudinally into two equal halves (>Fig. 13.11a). The surgeon should attempt to leave at least one anterior ciliary artery undisturbed in the portion of each of the vertical rectus muscles not being transposed. The course of the anterior ciliary vessels can be complex and irregular and the surgeon should carefully review their course along the orbital surface of the muscle before proceeding. Nonabsorbable suture, such as 5.0 Mersilene, is then looped around adjacent rectus muscle segments and gently tied to bring adjacent muscle halves in contact approximately 12 mm posterior to the limbus (>Fig. 13.11b). The transposed muscle segments should not be crushed during this process, as excessive tension on the suture can result in rupture or damage to the rectus muscles. The medial rectus muscle is then recessed if needed and adjustable sutures can be used if desired on the

b Adjacent muscle halves are gently brought into contact approximately 12 mm from the limbus with a nonabsorbable suture. c The medial rectus muscle is recessed, if needed

medial rectus muscle. (>Fig. 13.11c). Simultaneous recession of the medial rectus muscle increases the risk of anterior segment ischemia. Botulinum toxin injection is sometimes used instead of medial rectus muscle recession.

13.2.7.1Vessel-Sparing Modification of the Jensen Procedure

Coats [18] described a modification of the Jensen procedure that allows the surgeon to spare all of the anterior ciliary vessels. Instead of looping the suture around the entire rectus muscle segments to be transposed, the suture is passed beneath the anterior ciliary vessels on the orbital surface of each muscle

Fig. 13.12. Vessel-sparing modification of the Jensen procedure. To avoid crushing the anterior ciliary vessels, the suture is passed under the anterior ciliary vessels on the orbital surface of the rectus muscles. The procedure is otherwise identical to a standard Jensen procedure

segment (>Fig. 13.12). The procedure is otherwise unchanged from the previous description.

13.2.8Technique for Superior Oblique Tendon Transposition

Superior oblique tendon transposition was first reported by Peter in 1934 [19]. Indications for the procedure are infrequent. Superior oblique tendon transposition can be used to improve ocular alignment in patients with complete or near-complete third cranial nerve palsy, and is most useful as an adjunct to other, more effective, procedures. As a stand-alone procedure,

Fig. 13.13a–c. Superior oblique tendon transposition. a The superior oblique tendon is isolated nasally and cut near the superior rectus muscle. b The tendon is sutured to the sclera above the medial rectus

muscle insertion under tension with nonabsorbable suture. c The protruding anterior portion of the tendon is excised

superior oblique tendon transposition is minimally effective and a large primary position deviation always persists.

The procedure can be carried out through a fornix or a limbal incision. If a fornix incision is used, it should be placed in the superonasal quadrant. The superior oblique tendon is isolated on the globe along its nasal aspect and transected near the superior rectus muscle (>Fig. 13.13a). The assistant surgeon rotates the eye nasally and superiorly well beyond the primary position. The tendon is sutured to the sclera above the medial rectus muscle insertion under tension, using nonabsorbable suture such as 5.0 or 6.0 Mercilene (>Fig. 13.13b). The protruding anterior portion of the superior oblique tendon is excised and discarded (>Fig. 13.13c).

Some surgeons prefer to fracture the trochlea, believing that this step will enhance the effect of the transposition, though this claim is debatable. Prior to suturing the tendon to the sclera, a hemostat is placed in the superonasal orbit until it is engaged in the trochlea. The hemostat is moved temporally to fracture the trochlea (>Fig. 13.14). While technically simple to perform, this step can result in bleeding and/or damage to the superior oblique tendon. The procedure is otherwise unchanged.

References

1.Miller JM, Demer JL, Rosenbaum AL (1993) Effect of transposition surgery on rectus muscle paths by magnetic resonance imaging. Ophthalmology 100:475–487

2.Paysse EA, Brady McCreery KM, Ross A, Coats DK (2002) Use of augmented rectus muscle transposition surgery for complex strabismus. Ophthalmology 109:1309–1314

3.Foster RS (1997) Vertical muscle transposition augmented with lateral fixation. J AAPOS 1:20–30

4.Clark RA, Demer JL (2002) Rectus extraocular muscle pulley displacement after surgical transposition and posterior fixation for treatment of paralytic strabismus. Am J Ophthalmol 133:119–128

5.Buckley EG (2004) Paralytic strabismus. In: Plager DA (ed) Strabismus surgery. Basic and advanced strategies. Oxford University Press, New York, pp 88–89

6.Brooks SE, Olitsky SE, de BRG (2000) Augmented Hummelsheim procedure for paralytic strabismus. J Pediatr Ophthalmol Strabismus 37:189–195; quiz 226–227

7.Hummelsheim E (1908–1909) Weitere erfahrungen mit partieller sehnenuberpflanzung an den augenmuskeln. Arch Augenheilkd 62:71

8.O’Conner R (1921) Transplantation of ocular muscles. Am J Ophthalmol 4:838

9.Wiener M, Scheie HG (1952) Surgery of the eye, 3rd edn. Grune and Stratton, New York

10.Schillinger RJ (1959) A new type of tendon transplant operation for abducens paralysis. J Int Coll Surg 31:593

11.Knapp P (1969) The surgical treatment of double-elevator paralysis. Trans Am Ophthalmol Soc 67:304

12.Fishman PH, Repka MX, Green WR, D’Anna SA, Guyton DL (1990) A primate model of anterior segment ischemia after strabismus surgery. The role of the conjunctival circulation. Ophthalmology 97:456–461

13.McKeown CA, Lambert HM, Shore JW (1989) Preservation of the anterior ciliary vessels during extraocular muscle surgery. Ophthalmology 96:498–506

14.Coats DK, Brady-McCreery KM, Paysse EA (2001) Split rectus muscle modified Foster procedure for paralytic strabismus: a report of 5 cases. Binocul Vis Strabismus Q 16:281–284

15.Jensen CD (1964) Rectus muscle union: a new operation for paralysis of the rectus muscles. Trans Pac Coast Otoophthalmol Soc Annu Meet 45:359–387

16.Bleik JH, Cherfan GM (1995) Anterior segment ischemia after the Jensen procedure in a 10-year-old patient. Am J Ophthalmol 119:524–525

17.von Noorden GK (1976) Anterior segment ischemia following the Jensen procedure. Arch Ophthalmol 94:845–847

Chapter 13

18.Kushner BJ, Coats DK, Kodsi SR et al (2002) Grand rounds #68: a case of consecutive exotropia after recession of all four horizontal rectus muscles for the treatment of nystagmus. Binocul Vis Strabismus Q 17:304–311

19.Peter (1934) Am J Ophthalmol 17:297

Adjustable suture use in strabismus surgery affords the surgeon the opportunity to inspect the ocular alignment achieved after surgery in an alert patient and allows adjustment of the final position of one or more extraocular muscles without the need to return to the operating room. Surgeons who use adjustable sutures believe that their use, particularly in patients with complex strabismus, results in superior outcomes. Many adjustable suture techniques have been described, some allowing wide latitude in the further recessing or advancing of a muscle, and others allowing more limited adjustment potential. Some adjustable procedures are designed to require no postoperative manipulation if the alignment is satisfactory, while other techniques require additional manipulation of all patients postoperatively to secure the final position of the muscle. Though adjustable sutures are primarily utilized for rectus muscle recession and resections, they can also be used during rectus muscle transposition surgery [1] and during surgery on the oblique muscles [2, 3] (Chap. 12). The use of adjustable sutures for rectus muscle recession and resection surgery is described in this chapter. Small modifications are required when using adjustable sutures during other procedures. The decision to use adjustable sutures depends both on the complexity of the surgery and on surgeon preference. Some surgeons strongly believe that adjustable sutures offer a distinct advantage while other surgeons do not see a significant enough benefit to justify their use. There are no definitive studies in the literature that prove either belief.

Adjustable sutures can be used in one form or another on patients of any age, though most surgeons typically offer adjustable strabismus surgery techniques only to adult patients. Surgeons who are willing to utilize adjustable sutures on younger patients usually use one of several techniques. Some surgeons examine children in the recovery room and re-administer sedatives or general anesthesia to facilitate adjustment. Others depend on preoperative patient selection, with consideration for adjustable sutures limited to cooperative children and parents who have a good rapport with the surgeon [4]. Releasable adjustable suture techniques that require minimal postoperative manipulation have been described and are useful for pediatric strabismus surgery [5, 6].

The indications for adjustable suture use vary markedly depending upon individual surgeon training, experience, and

preference. Some surgeons utilize adjustable suture techniques widely while others use them far more selectively, or not at all. One common, generally agreed indication is for rectus muscle surgery in the treatment of incomitant strabismus, such as a rectus muscle paresis or restriction. Thyroid-related ophthalmopathy is a good example. While many variations of adjustable surgery have been described, this chapter will concentrate primarily on a few selected techniques that can be applied universally. Adjustable suture techniques can be performed through a limbal or a fornix incision, depending upon the procedure planned and surgeon preference.

There is no universal agreement on the optimal time to assess ocular alignment and perform the final manipulation of the muscle(s) after surgery. There are advantages and disadvantages to each recommendation, and the approach chosen depends upon the training and experience of the individual surgeon. Some surgeons prefer to make final adjustments in the operating room after performing surgery with sedation and topical anesthesia [7] (Chap. 6). Others carry out adjustment in the recovery room or in the office an hour or more after surgery [8], while still others prefer to routinely make adjustments one or more days following surgery [9]. In our experience, the longer the duration from surgery to adjustment, the more difficult the adjustment tends to be because of one or more of the following reasons including patient discomfort, conjunctival edema, bleeding with tissue manipulation, and adherence of the muscle to the sclera. Surgeons who prefer to make adjustments several days to a week after surgery may choose to place viscoelastic or antimetabolites on the surgical site intraoperatively to reduce the initial degree of adherence of the muscle to the sclera before adjustment [5, 10].

14.1Modifications of the Surgical Site for Adjustable Sutures

Modifications of the surgical site are helpful to simplify the process of postoperative adjustment and to improve patient comfort. Adjustable sutures can be used with either a fornix or a limbal conjunctival incision. The modifications described below are applicable to any adjustable suture technique.

14.1.1Surgical Site Modifications for Adjustable Sutures Through a Limbal Incision

Two techniques are commonly used to facilitate adjustable strabismus surgery through a limbal incision. First, the conjunctiva may be recessed to the level of the original insertion to allow ready access to the adjustable suture (>Fig. 14.1a). Alternatively, the surgeon may leave one corner of the limbal incision open, deferring suture closure of this corner until after the adjustment has been made (>Fig. 14.1b).

14.1.2Surgical Site Modifications for Adjustable Sutures Through a Fornix Incision

A retraction suture can be placed near the distal edge of the muscle insertion prior to the end of the procedure (>Fig. 14.2a). Gentle traction on this suture postoperatively will expose the surgicalsite,simplifyingtheprocessofadjustment(>Fig. 14.2b). The traction suture is removed after adjustment.

Alternatively, adjustment can take place on the conjunctival surface. The needle on one end of the muscle suture is removed. The muscle suture ends are then tied together and

are passed through the conjunctiva using the remaining needle (>Fig. 14.3a). Adjustment can then be done without manipulating the conjunctiva. Upon completion of the adjustment procedure, the suture knot should be made to retract into the opening in the conjunctiva (>Fig. 14.3b, c). The suture tends to cause significant patient discomfort if it remains externalized.

14.1.3Bucket Handle Globe Manipulation Suture

Manipulation of the globe during muscle adjustment can be uncomfortable for patients, regardless of the surgical approach utilized. The patient may be unwilling or unable to move and/ or hold his/her eyes in the direction requested by the surgeon during the adjustment process because of pain and discomfort, making adjustment complex. The use of a bucket handle suture on the sclera anterior to the muscle insertion can greatly facilitate both the process of adjustment and patient comfort. To place a bucket handle suture, an absorbable suture is passed into the sclera anterior to the muscle stump and is tied into a loop (>Fig. 14.4a). The suture loop can be grasped with forceps by the assistant surgeon to manipulate the globe during the adjustment process after surgery (>Fig. 14.4b). The bucket handle suture is removed upon completion of the adjustment procedure.

Fig. 14.3a–c. (continued) Fornix incision modifications for adjustment on the conjunctival surface. b Appearance at end of the procedure,

prior to adjustment. c After adjustment, a permanent knot is tied and made to retract into the episcleral space

14.2 Adjustable Suture Techniques

14.2.1Technique for Bow-Type Adjustable Sutures

The bow-type technique can be applied to a recessed or resected rectus muscle. In both cases, the muscle sutures are passed back through the original insertion. If a recession is performed, a hang-back technique is used (Chap. 9). After the muscle is placed in the desired position, the suture ends are tied into a half bow (>Fig. 14.5a). If adjustment is required, the bow is untied, the muscle position adjusted, and the bow retied (>Fig. 14.5b). This procedure is repeated until ocular alignment is satisfactory. The bow is then converted into a permanent knot (>Fig. 14.5c). Some surgeons tuck the sutures under the conjunctiva and externalize them postoperatively only if adjustment is needed [11]. If the sutures have been covered with conjunctiva and the alignment is satisfactory, no further manipulation is necessary, as the bow is secure enough to hold the muscle in position during healing.

The surgeon must understand the construction of the bow to prevent premature conversion to a permanent knot, which makes further adjustment very difficult. Pulling on the loose end of the bow loop suture will open the bow (>Fig. 14.6a), while pulling on the suture loop itself will convert it to a permanent knot (>Fig. 14.6b).

14.2.2Technique for Cinch Knot Adjustable Sutures

The cinch knot technique is preferred by some surgeons, especially by those who perform adjustable suture techniques through a fornix incision. The sutures from a bow-type closure tend to become tangled and can be difficult to work with when trying to use the bow technique with a fornix incision and the use of the cinch knot technique avoids this problem. The muscle sutures are passed through the muscle stump whether performing a resection or a recession. For a recession, a hangback technique is used (Chap. 9). The sutures can be placed close together in the center of the muscle stump or spread out along the muscle stump (>Fig. 14.7a). If the latter approach is used, it is helpful to make the scleral tunnel exits of the two suture passes as close together as possible. After placement of the sutures, the needles are removed and the muscle is pulled anteriorly until it makes contact with the muscle stump. While the surgical assistant holds the muscle in this position, a second absorbable suture is tied around the muscle sutures. If a recession is planned, the cinch suture is placed around the muscle suture anterior to the muscle stump to produce an adjustable hang-back muscle recession (>Fig. 14.7b). If a resection has been performed, the cinch suture is placed against the muscle stump.

Prior to the conclusion of surgery, it is advisable to place a conjunctival traction suture on the edge of the muscle stump distal to the fornix incision as described above, a step that greatly simplifies postoperative adjustment (>Fig. 14.2a). At the conclusion of the case, the conjunctiva is re-approximated and three key sutures should extend out of the conjunctival incision including the conjunctiva traction suture (not shown in this example), cinch knot suture, and the muscle suture (>Fig. 14.7c). Gentle traction on the conjunctiva traction suture postoperatively will result in excellent exposure of the surgical site.

Adjustment is later accomplished by sliding the cinch suture in an anterior or posterior direction, as needed (>Fig. 14.7d). When the desired position of the muscle has been achieved, the muscle sutures are then tied securely over the cinch knot (>Fig. 14.7e). Both absorbable and nonabsorbable sutures can be used for the cinch knot. In general, we favor absorbable sutures having seen nonabsorbable sutures migrate through the conjunctiva postoperatively weeks to months after surgery in several patients.

14.2.3Technique for Traction Knot Adjustable Sutures

Saunders and O’Neil [12] described a technique utilizing friction created in the scleral tunnel passes by placing knots along the muscle sutures to hold the muscle in position postoperatively (>Fig. 14.8a). The free ends of the sutures are allowed to extend from the wound following this procedure. If ocular alignment is satisfactory following surgery, the free ends of the muscle sutures are cut anterior to the knots and no further manipulation is needed (>Fig. 14.8b). The knots provide sufficient friction to prevent the muscle from retracting further posteriorly. If alignment is not satisfactory, the muscle can be advanced by pulling it anteriorly and tying a knot in the muscle sutures (>Fig. 14.8c). If further recession is needed, the knots can be easily pulled through the sclera suture tunnels by grasping the sutures posteriorly (>Fig. 14.8d). A permanent knot is tied when optimal alignment has been achieved after adjustment.

14.2.4Technique for Ripcord Adjustable Sutures

Coats [5] described an adjustable suture technique that allows for a one-time, single-step programmed recession of a recessed or resected muscle. The procedure is recommended for patients in whom adjustment potential is deemed desirable, but in whom standard adjustable suture techniques are not considered feasible. The rationale for this approach is that the majority of adjustments performed do not exceed 2–3 mm [9]. There is enough flexibility in the ocular motor fusion system that approaching optimal alignment, rather than achieving optimal alignment, is usually sufficient in most patients. The procedure can be used for a recession or a resection.