Transactions 29th European Strabismological Association Meeting – de Faber (ed) © 2005 European Strabismological Association, ISBN 04 1537 211 9

Hiper maximum lateral rectus recession operation of adults with large angle exotropia

M.D. Basak Yılmaz, Birsen Gökyig˘it, Serpil Akar & Ömer Faruk Yılmaz

Beyog˘lu Kuledibi Eye Education and Research Hospital, Istanbu, Turkey

ABSTRACT:

Purpose: To introduce and evaluate the effect of a new adjustable suture technique in hiper maximum lateral rectus recession operation added to medial rectus resection in adults with large angle exotropia.

Materials and Method: This study was done in 8 adult patients who had very large angle exotropia. Six of the patients were female and 2 were male. Their ages ranged between 21 and 64. These patients only one eye was operated which included medial rectus resection and new technique hyper maximum lateral rectus recession. In new technique we use 2 scleral passes, one of which is passed through insertion. The muscle was released 12 mm behind insertion. The operation continued as usual. Mean follow-up was 6 months.

Findings: While the patient’s pre-operative deviations were between 60 and 90 prism diopter (PD), their post-operative deviations were between 2 and 12 PD. Only one patient needed adjustment for over correction. None of the patients had limitation of ocular motility.

Conclusion: 8 mm behind the insertion adjustable suture technique is a practical method which gives patients recession up to 12 mm.

1INTRODUCTION

Strabismus surgery with adjustable suture technique which is first described by Mc Mullen was popularized in early 1970’s by Jampolsky. Adjustable sutures were introduced as an adjunct to traditional surgery to allow the surgeon to place the eyes in the desired alignment in the immediate postoperative period (within 24– 48 hours ), with the goal of promoting the best possible long-term alignment once postoperative drift, if any, occured. Especially the cases in which we can not predict amount of deviation correction with conventional surgery due to contracture or scarring of extraocular muscles are the most important advantages of this technique. (Howard, C.W. 1986) Other indications are reoperations, large angle deviations, thyroid ophthalmopathy, blow out fracture, paralytic strabismus, combined horizontal and vertical muscle surgery. (Jampolsky, A.J. 1975, Jampolsky, A.J. 1979, Franklin, S.R. 1989) In this study we aimed to investigate the efficiacy and effectiveness of the hypermaximum lateral rectus muscle recession surgery with the adjustable suture technique in the large angle exotropia patients.

2MATERIAL AND METHODS

10 (Ten) patients who were operated with adjustable suture hipermaximum lateral rectus recession technique in addition to medial rectus resection of one eye and followed in the strabismus department of the Beyog˘lu Eye Education Hospital between 20.02.2003–29.03.2004 were included in our study. Mean follow up time was 6,80 3,55 month and preoperative deviations were 60 PD (Prism Diopter) or bigger in 4 (four) of the our patients at near and distance as seen in table 1. In table 1

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Table 1. Near and distance deviation measurements of all patients.

DD: Distance deviation (Prism deviation)

ND: Near deviation (Prism deviation)

Patient No

Figure 1. Change in prism deviation at near after adjustable surgery.

Patient No

Figure 2. Change in prism deviation at distances after adjustable surgery.

our patient’s preoperative and postoperative prism deviation measurements have been shown. We made complete ophthalmological and orthoptic examinations to all the patients. Distance vision examination with Snellen chart; anterior segment examination with biomicroscopy and then posterior segment examination with indirect ophtalmoscopy were made to all the patients. Their deviations at near and distance were measured with alternan cover test, cover test, prism cover test. The prism deviations of the patients with low vision were measured with Krimsky test. Ocular ductions and versions were evaluated.

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Table 2. Average deviations and correction rate of prism deviations.

Complete orthoptic and ophthalmological examinations were made preoperatively, first day after adjustment, postoperative 1st–2nd week, postoperative 4–6th Week, postoperative 3rd–4th month, postoperative 6th month.

We evaluated the operation as successful if the postoperative prism deviation value was 10 PD (Prism Diopter) or less during at least 2 months postoperative follow up examinations. In our study Wilcoxon Signed Ranks test was used statistically.

3SURGICAL TECHNIQUE

After standart limbal conjunctival peritomy, lateral rectus muscle is hooked and released from peripheral attachments. After placing the pole suture by passing through muscles recessed with double armed 6-0 vicryl, the both ends of the suture are tied at the two edges of the muscle and the muscle separated from its original insertion. First vicryl suture passed through the sclera that is 6–8 mm behind muscle insertion; then after, with the condition of the muscle being 10 mm behind, one needle passed through musle insertion site and near half of the muscle shaft in the form of the Z shape. Same procedure is repeated with other needle. The suture is tied as knot first and then tied as bowknot. Conjunctiva is sutured with the 8-0 vicryl suture.

If the patient has no complaint and diplopia, and if deviation measured with prism cover test is appropriate for our target success criteria during the examination which is made 24 hours after operation; by using topical anesthesia (Benoxinate, Alcaine) bowknot is opened and is tied as second knot. Depending on the results, suture is either tightened to reduce the amount of recession, or slackened to increase it. The latter is done by fixing the globe by means of the Vicryl handle, and asking the patient to look in the direction of action of the muscle. The process is repeated until the optimum cosmetic and functional alignment is achieved, following which a permanent knot is made, and the trimmed ends tucked under the edge of conjunctival flap.

4FINDINGS

Ten eyes of 10 patients ranging in age from 21 to 72 years underwent adjustable lateral rectus recession. Prism deviation measurements at near and distance were 60 PD (Prism Diopter) or bigger in 4 (Four) of the 10 (ten) patients. 6 (six) of the patients were female and 4 of the patients were male in our study. Mean age was 46,5 15,69 years (21–72). Mean follow up time was 6,80 3,55 month. In our study 90% of all adjustable suture lateral rectus recession operations we made were primary, other 10% of operations we made was reoperation.

Table 1 shows the preoperative and postoperative deviation values measured (PD). Considering surgical alignment to be “successful”, when there is less than 10 prism diopters (PD) deviation. (Metz, H.S. 1988, Lee, J. 1992, Gunton, K.B. 2002). We had success rates of 70% for surgery of adjustable lateral rectus recession according to this criteria in our study.

Overall correction rate of prism deviation after operation with adjustable suture technique was 79% as seen in table 2. In our study Wilcoxon Signed Ranks test was used statistically. Difference

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Figure 3. Change of average deviations at near and distance after adjustable surgery.

between postoperative and preoperative prism deviations for both near and distance fixation was statistically significant. (p 0,005 for near deviation and p 0,005 for distance deviation).

5CONCLUSIONS

Adjustable suture modifications to traditional strabismus surgery were introduced to increase the rate of surgical successes and to reduce the frequency of reoperations by eliminating undesirable early postoperative under or over corrections. (Agnello, R. 1986, Fells, P. 1987, Keech, R.V. 1987, Franklin, S.R. 1989, Lee, J. 1992, Currie, Z.I. 2003)

This procedure permits the surgeon to enhance or diminish the amount of muscle recession on the evening after surgery or the first postoperative day if cover testing indicates an inapropriate amount of under correction or over correction so these advantages increase success of surgery and decrease the need for reoperation in early postoperative period.

Preoperative evaluation including measurement of the deviation, forced ductions, rotations, and active force generated and variables such as the age of patient and cause of strabismus are all included in the process of deciding on the amount of surgery.

It is generally accepted that adjustable suture surgery requires cooperation and is very difficult under the age of 14. (Fells, P. 1988, Guyton, D.L. 1988, Gunton, K.B. 2002) Our youngest patient was 21 years old.

Surgery of horizontal muscle deviation was considered successful by most authors if there was less than 10 prism deviation. (Lee, J. 1992, Gunton, K.B. 2002, Metz, H.S. 1988). Some authors reported success rate as 67–91,7% in horizontal muscle surgery with adjustable suture procedure; (Smith, A.G. 1986, Fells, P. 1988, Pratt-Johnson, J.A. 1988), some other authors suggested that rate as 80–85% after primary surgery. (Jampolsky, A.J. 1975, Rosenbaum, 1977, Rosenbaum, 1978). The frequency of need for reoperation was proposed as 4–11% in most studies. (Jampolsky, A.J. 1975, Fells, P. 1988, Metz, H.S. 1988, Morris, R.J. 1992). Kraft recorded this rate as 5% (Jampolsky, A.J. 1975), in our study one of ten patients needed reoperation (10%).

There are different ideas about suture adjustment time, adjustment must be done 5–24 hours after surgery according to some authors (Jampolsky, A.J. 1975, Smith, A.G. 1986,) maximum in 2 weeks after surgery according to Cleve. (Guyton, D.L. 1988) Haward and Simith suggested adjustment 3–4 day after operation. (Guyton, D.L. 1988) In our study we preferred making adjustment 24 hours after operation because we think that if we wait much more time, the risk of hemorrhage and suture break increases.In our study there was no postoperative complication such as suture granulma or conjunctival reaction seen especially in Cinch method.

In large angle exotropia successful alignment was achieved in 71–76% of cases with conventional lateral rectus recession and/or medial rectus resection operation according to various studies. (Kraft, S. 1991) Successful alignment was reported in average 77% of cases with adjustable suture technique lateral rectus recession operation in various studies. (Scott, W.E. 1977). In our

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study successful alignment was achieved in 70% of cases with large angle exotropia. As a result lateral rectus recession operation with adjustable suture procedure gives satisfactory results with one operation, so is effective and efficient technique for large angle exotropia.

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