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

The functional outcome of very late surgery in infantile strabismus

E.Ch. Schwarz, K.S. Kunert, G. Wunsch & H. Zappe

CharitéUniversity School of Medicine Berlin, Campus Virchow Klinikum,

Clinic of Ophthalmology, Germany

1INTRODUCTION

The number of adult squint patients being operated is rising (Figure 1). An important question to answer is: How often do we restore binocular vision in these patients?

The prospective multi-centre clinical trial “Early versus Late Infantile Strabismus Surgery Study” (EOLISS) conducted in 11 European countries showed that binocular vision (striated glasses of Bagolini positive) is significantly better in the early treatment group (age at surgery 6–24 months) than in the late treatment group (age at surgery 32–60 months), but there was no difference beyond Housefly positive between both groups. Therefore we were interested to learn, what degree of binocular vision can be obtained in patients with infantile convergent strabismus having with their first surgery as an adult.

2MATERIALS AND METHODS

All adult patients with infantile convergent strabismus beginning in the first or second year of life who underwent first strabismus surgery after age 18 in our eye-clinic were collected consecutively. These patients had a permanent great angle and had not received any orthoptic training or prism correction in the past. All patients were examined preand postoperatively receiving a full orthoptic status especially tests for binocularity including Bagolini and Titmus tests.

Figure 1. Squint operations at the Charité.

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3RESULTS

We collected 258 patients who were operated between the years of 1975 to 2002 at age 18 up to 80 years with a mean age of 33, 3 years. Seventy seven percent were female and 23% were male. The median of preoperative squint angle was 17° convergent with a range of 6° to 30° convergence. Forty three percent of the patients had no amblyopia, 35% showed had mild ( 0,3–0,8), 20% a moderate ( 0, 1–0, 3) and only 2% a severe ( 0,1) amblyopia. We found a lack of correspondence in the after image test in 49% of our patients, an anomalous retinal correspondence in 46% and a normal retinal correspondence in 2%. The drop out rate was 3%. In the prism adaptation test done preoperatively, 57% of the patients were Bagolini positive, 41% Bagolini negative and 2% Housefly positive. Ninety five percent of these patients received a combined operation (medial rectus recession combined with resection of the opponent lateral rectus on the same eye). Only 5% got a bilateral recession of the medial rectus muscle. The postoperative angle ranged from 0° to 5° convergence and the median was 0°. Sixty five (25%) of our adult patients with infantile convergent strabismus with very late first squint surgery showed postoperatively binocular vision in the form of Bagolini positive and 5 patients had a positive Housefly or Titmus circle up to 140’’ (Figure 2).

6% 2%

92%

Bagolini + Housefly + Titmus rings 140''

Figure 2. Tests of binocularity in patients with postoperative binocular vision (25%).

Figure 3. Binocular vision after very late squint surgery.

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4CONCLUSIONS

The functional outcome in very late strabismus surgery in adult patients is not as good as in late or early surgery during childhood, but an improvement of simple binocular vision is possible in 23% and in some cases with stereopsis (Figure 3), if there is a postoperative microtropia. The good functional outcome was preoperatively predictable in 57% of the patients with the prism test. The restored binocular vision is very useful for the patients. If preoperatively no signs of diplopia are found, squint surgery in adults is recommendable, can be successful and should be done.

5LITERATURE

Unnebrink K, Bauer C, Kolling GH, Simonsz HJ. The early versus late infantile strabismus surgery study: first results (EOLISS). Transactions 28th meeting European Strabismological Association, de Faber (ed.) 2004.

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