|Year : 1984 | Volume
| Issue : 6 | Page : 491-493
A study on adjustable rectus muscle surgery
Dept. of Paediatric Ophthalmology, Aravind Eye Hospital, Madurai, India
Dept. of Paediatric Ophthalmology Aravind Eye Hospital Madurai
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Vijayalakshmi P. A study on adjustable rectus muscle surgery. Indian J Ophthalmol 1984;32:491-3
The use of adjustable sutures, allowing the surgeon to increase or decrease the effect of a rectus muscle recession in the immediate post operative period was described by Jampolsky . A follow up study by Rosenbaum et al showed that stable results were obtained in the majority of cases, with little change from the angle measured at the time of adjustment to the angle measured at follow up. Adjustable sutures can be used on any rectus muscle and the procedure can be combined with surgery on other muscles, for example recession of the medial rectus combined with resection of the lateral rectus in esotropia.
| Material and methods|| |
16 patients have been operated on using an adjustable suture procedure, comprising 11 patients with exotropia, 3 patients with esotropia and 2 with vertical strabismus. All were co-operative adults. The follow up period ranged from one to twelve months, with a mean of 7 months.
In nearly all cases surgery was performed under local anaesthesia, using 2% Xylocaine mixed with appropriate doses of adrenaline and hyalase as a muscle block. The injection was given first around the limbus then on either side of the muscle exactly over the subconjunctival space, A routine limbal incision was made and the muscle freed. A double armed 5`O' Vicryl suture was passed through the centre of the muscle and brought out through its superior and inferior borders where it was locked. The muscle was then severed from its insertion and allowed to retract leaving a small stump at the insertion site. The two needles were passed slightly obliquely to the insertion and the sutures were brought out through the muscle stump. The sutures were then pulled back and forth several times to form a scleral tract, thus enhancing the sliding quality of the suture. The previously determined amount of recession was measured with a caliper and the suture was tied over the caliper using a loose bow knot. [Figure - 1]
The conjunctiva was sutured on either side of the muscle stump leaving the knot exposed to give easy access to the suture during adjustment. The suture ends were well buried under the fornices. Finally a fixation suture was applied at the limbus to fix the globe during adjustment. Except in one case resection of the lateral or medial rectus was then carried out as indicated.
Adjustment of Sutures
Adjustment of the sutures is made approximately 24 hours post-operatively. The patient, who must be fully alert, is seated in the examination room and the angle of deviation measured using a prime cover test for near and distance. Alternatively a Maddox rod can be used for measurement in functional cases. 3 measurements are taken at half hour intervals. After the third measurement a local anaesthetic is instilled, the bow knot is loosened and the adjustment is done either by pulling the muscle anteriorly in overcorrections or pushing the muscle back in under-corrections. In practice, it is easier to pull the muscle anteriorly rather than pushing it posteriorly. The prism cover lest is repeated and further adjustment made if indicated. If necessary the procedure can be repeated several times until the desired eye position is obtained. When the final adjustment is made the suture is tied and the ends are trimmed. [Figure - 2][Figure - 3].
| Observations|| |
1. Esotropia (11 cases)
The adjustable suture was applied to the recessed lateral rectus. Post operatively the deviation ranged from under-correction of 8∆ to an over-correction of 12∆, 3 patients were over-corrected and 5 were under corrected whilst no adjustment was needed in 3 cases. After adjustment orthophoria was obtained in 5 cases and a slight overcorrection ranging from 2∆ to 6∆ was obtained in the remaining cases. The amount of adjustment achieved ranged from 4∆ to 22∆. 6 of the 11 patients had unilateral aphakia with a favourable prognosis for a functional result.
2. Esotropia (3 cases)
The adjustable suture was applied to the medial rectus. Postoperatively two patients were slightly overcorrected by 2∆ and 6∆ respectively, the third patient was under corrected by 20∆. All cases were made orthophoric after adjustment.
3. Hypertropia 2 cases
Both patients were slightly under-corrected and were made orthophoric by adjustment.
During the follow-up period the change in deviation averaged 5∆ indicating little change from the final adjustment.
| Discussion|| |
Adjustable sutures can only be used on selected co-operative patients with a minimum age of 15 years. They are unsuitable for use on children. The patient must be alert and in an upright position when the sutures are adjusted. The use of local anaestbesia for muscle surgery ensures an alert state. Vicryl sutures facilitate adjustment by their superior slipping power. Post operatively it is easier to pull on the suture to bring the muscle forward then it is to loosen it to make the muscle slide back, therefore an over-correction is easier to adjust than under-correction. The small change in angle at followup suggests that the angle remains stable and that adjustment is not premature as has been suggested. Optimum results are obtained when there is potential fusion resulting in BSV post operatively.
Adjustable sutures allow the surgeon to perform less conservative surgery in the knowledge that over-correction can be quite easily overcome. In this way further muscle surgery can be avoided. The use of adjustable sutures is especially indicated when binocular single vision is expected, for example in recent onset strabismus, intermittent strabismus and paralytic strabismus.
| Summary|| |
A rectus muscle recession on an adjustable suture enhances the chance of a satisfactory postoperative result, both functionally and cosmetically. The surgical and adjustment techniques are described and the results of adjustable muscle surgery on 16 cases are given. The most satisfactory results occur in patients who are over-corrected immediately postoperatively and in those whose ability to maintain binocular single vision can further stabilize the post adjustment position of the visual axes.
| References|| |
Jampolsky A., 1975, Trans. Am. Acad. Ophthalmol and Otolaryngol 79 : 704-717.
Rosenbaum Al., Metz H. S. Carlson M. Jampolsky AJ., 1977, Arch. Ophthalmol 95 :817-820
[Figure - 1], [Figure - 2], [Figure - 3]