Published online by Cambridge University Press: 02 December 2009
Ophthalmological uses
Introduction
Botulinum toxin targets the cholinergic neuromuscular complex with exquisite precision producing dose dependent muscle weakness. The concept of using this property therapeutically was an ingenious and bold one, and it came from a thoughtful and innovative ophthalmologist over 30 years ago. Working at the time on extraocular muscle electromyography (EMG) Alan Scott of the Smith Kettlewell Eye Research Foundation was exploring the treatment potential of the ability to locate a needle tip at or near the motor point of extraocular muscles. Using an EMG guided injection technique could enable focal delivery of a drug – for example local anaesthetic – to modify muscle function. The ideal drug would need to remain localized at the injection point and have an effect on muscle function only, without inducing inflammation or scarring, either temporarily enhancing or more probably reducing function, over a predictable time frame. Full recovery of extraocular muscle function would be necessary to restore normal eye movement. During the period of induced muscle underactivity it was hypothesized that the balance between two opposing extraocular muscles (agonist: antagonist balance) would be altered in such a way that a permanent change in the relative position of the two eyes would be achieved after the effect of the drug had worn off. This created the possibility of treating misalignment of the eyes (strabismus or squint) by non-surgical means.
To save this book to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.