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Clinical experience in the intra-ocular use of acetylcholine.

1967; BMJ; Volume: 51; Issue: 3 Linguagem: Inglês

10.1136/bjo.51.3.183

1468-2079

G. V. Catford, Elisabeth AW Millis,

Drug-Induced Ocular Toxicity

ACETYLCHOLINE is not a new substance, having been first synthesized by Baeyer (1867).Dale (1914) showed its pharmacological importance and Loewi (1921a, b; 1924a, b, c) and Loewi and Navratil (1924a, b) demonstrated its role as the chemical mediator of the nerve impulse.One of the first references to the use of acetylcholine in ophthalmic surgery was that of Amsler and Verrey (1949), who stated that a rapid and intense miosis was produced after its injection into the anterior chamber.Barraquer (1964) concluded that a 1: 100 dilution was the most effective and reliable.Harley and Mishler (1964) stated that the miosis was effective but must be augmented by a longer-acting miotic, dilutions of 1: 200 and 1: 100 being the most effective.Our own experience indicates that the advances in intra-ocular surgery have made operative techniques more numerous and complicated; it has been found that in anterior segment surgery greater control of the pupil size can best be achieved by using the naturally occurring miotic acetylcholine.It has been the custom in cataract surgery to instill pilocarpine (2 per cent.) as the last zonular attachments were broken or where the anterior vitreous face was seen to be bulging after the use of alpha-chymotrypsin.The miotic produced a small pupil and disaster was often averted.However, in the course of post-operative manage- ment, eyes treated in this way tended to develop irritation and iritis, which settled down in I to 2 weeks but did prolong convalescence.This adverse effect might be attributed to the preservative or to the pilocarpine itself.As acetylcholine has been shown to be superior to other miotics in anterior segment surgery, it was decided to investigate whether it also showed a tendency to produce an irritable eye or iritis post-operatively.A series of intracapsular extractions was therefore carried out using acetylcholine, and the present paper outlines the results of this clinical experience. MedicationMiochol, the preparation used, is a sterile, stable lyophilized acetylcholine chloride in powder form which, in its two-chamber vial, allows the solution to be made up and drawn at the moment when it is required during the operation.The 1: 100 solution of acetyl- choline is in a sterile 5 per cent.mannitol solution.