Corrective measures
Scotcher et al (p 1031) report a personal series of 21 consecutive patients managed with recession of the inferior rectus muscle. The aetiology was contralateral superior oblique underaction in 62%, thyroid orbitopathy in 9.5%, following retinal detachment surgery in 9.5%, and in the remaining 19%, associated with childhood strabismus. The surgical technique is not reported in detail, but is described as ‘standard’. Adjustable sutures were used whenever possible in a total of 18 cases (86%).
Their results are enviably good. Only two patients (9.5%) developed an overcorrection, and both could be ascribed to the development of a previously masked contralateral superior oblique paresis, as originally described by Hermann.1
The authors cite several references on late progressive overcorrection after inferior rectus recession surgery. It would be no exaggeration to state that this particular surgical misadventure has afflicted most ophthalmologists who profess an interest in ocular motility, and not a few whose interest lies elsewhere, but who have been persuaded to weaken an obviously overacting inferior rectus, especially in the context of a symptomatic contralateral superior oblique paresis.
The usual story is that the alignment is adequate immediately after surgery, but by the first postoperative visit the eye is hypertropic with limited depression and diplopia on downgaze. At this point, panic usually sets in, and ignoring Cooper’s principle,2(‘undoing what was done before is not always the best treatment’) the offending muscle is replaced where it started from. This rarely helps much, as the ipsilateral superior rectus has by that time developed some degree of contracture. The definitive surgical treatment seems to be a combination of ipsilateral inferior rectus strengthening, ipsilateral superior rectus weakening, and contralateral inferior oblique weakening, all muscles on adjustable sutures. Understandably, once one has managed a few such cases enthusiasm for inferior rectus surgery, except when strictly necessary, tends to wane.
In the restrictive ophthalmopathies such as dysthyroid eye disease, ocular restriction after retinal or orbital surgery, or orbital trauma there may be no alternative to inferior rectus weakening surgery, but where the aim is to compensate a relative underaction of a superior oblique muscle, I have personally become much more inclined either to simply weaken the ipsilateral inferior oblique or to tuck the underacting superior oblique.
Scotcher et al are to be congratulated and envied for their excellent results. They have no need to attach a question mark to their title. I exhort them to continue to collect their data on this frequently disappointing operation, to paraphrase Voltaire, ‘pour encourager les autres’.3
