Recession-lengthening of Medial Recti for Convergent Squint*

TEXT-BOOK examples ot strabismus fixus and of the retraction syndrome are not commonly encountered. Abnormal medial recti, however, showing some tendency towards the fibrosis or muscular thickening characteristic of such conditions, not uncommonly appear when ordinary squints are operated upon. Abnormal medial recti are usually found in congenital convergent squint. In most such cases there is limited abduction, suggesting paresis of one or both lateral recti, but, when qperation is performed, it is usually so difficult to abduct the eyes by pulling with forceps that it becomes obvious that not even a normal lateral rectus could overcome the resistance of the abnormal medial recti. On severing the medial recti from their scleral insertions it is common to observe a divergence, proving activity of the lateral recti which had been presumed to be paretic, or under-developed. Bilateral recession of these thick, inextensible medial recti does not give sufficient correction. Resection-advancement of the lateral recti can help, but really good surgical results are not always to be expected in congenital convergent squint when these well-established operations are performed. Better results in such cases have been obtained since adopting the operation of medial rectus recession-lengthening. This operation was designed to weaken the over-strong medial recti so that they matched, more or less, the weaker lateral recti; at the same time the fibrous contracture was to be mitigated, thereby giving the weak lateral recti a chance to contract effectively. I first tried this operation 4 years ago and it is now my intention to give a preliminary account of the operation and (in geneial terms) of the results obtained during the last 4 years. Satisfactory results were obtained from this operation, no lateral rectus advancement or resection being required as a rule in cases of congenital convergent squint. Encouraged by these successes, the same operation was applied to other squints where the medial recti were found to be thickened or fibrosed, and good results have usually been obtained. The operation can succeed in most cases where the medial recti are relatively much too strong or active compared with the lateral redti, with or without fibrous contracture.