THE THREE TUNICS OF THE EYE, THE HYALOID AND ITS ATTACHMENTS
This dissection is a rather difficult one to make, and requires patience.
Fig. 61—Cutting through the iris.
Prepare an eye by placing it in a 5 per cent. solution of formaldehyde for about ten days to two weeks. Remove all the outside tissues. Cut away the cornea, as in the dissection for the choroid or the retina. Loosen, as far back as possible, the sclerotic from the choroid. Remove the sclerotic for about 10 mm. back of the equator of the eye. With the tweezers pick up the pupillary edge of the iris. Using the small pointed scissors, cut through the iris. ([Fig. 61].) Lift either one of the cut edges of the iris, and, with the sharp edge of the scalpel, gently scrape the processus zonuloe free from the ciliary processes, cutting through the ciliary ring as the ciliary processes are detached from the hyaloid (processus zonuloe). ([Fig. 62].)
Fig. 62—Scraping the ciliary processes free. Showing, also, the choroid cut around the ciliary ring.
Great care must be taken not to thrust the point of the scissors into the hyaloid, suspensory ligament, or vitreous, else the lens may become detached.
After the iris with the processes has been removed, pinch up with the tweezers a fold in the choroid. Make an incision with the fine-pointed scissors, and begin removing the choroid to within about 5 mm. of the cut end of the sclerotic. ([Fig. 63].) Care must be taken not to penetrate the underlying retina while making this part of the dissection.
