ANSWERS

From questions on page 1445

1. LIST THE DIFFERENT TECHNIQUES SHOWN IN FIG 1A–E WHICH CAN BE USED TO MANAGE INTRACTABLE DIPLOPIA

Various methods are employed in the treatment of intractable diplopia. Each method shares a common end-point, namely ocular occlusion.

Patching or occlusive spectacles have a useful role but do not usually provide an acceptable long-term cosmetic solution (fig 1A,B). Physiological patching can be achieved by inducing a “Botox” ptosis, but this requires repeated injections and for some patients simply substitutes one unacceptable appearance for another (fig 1C). An alternative is the use of an occlusive contact lens, which is cosmetically superior. However, intolerance to contact lenses may develop (fig 1E). More permanent techniques include corneal tattooing in which the central cornea is stained black or implantation of an opaque intraocular lens (fig 1D).

2. HOW IS CORNEAL TATTOOING PERFORMED?

Two different methods are commonly described. Chemical dyeing with metal salts (gold chloride, silver nitrate, platinum chloride) and impregnation of the cornea with insoluble pigments (Indian ink, iron oxide, titanium dioxide).1

This case describes the more popular method of chemical dyeing which is easier and quicker to perform but fades more rapidly than …