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Form. They Are Probably Caused the Plasmodium. the Choroid, Ciliary

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Form. They Are Probably Caused the Plasmodium. the Choroid, Ciliary is thoroughly established, quinin may be discontinued packed together and contain no pigment. The lam- and tinctura cinchona? compound given instead. ina vitrea forms the inner coat of the choroid; it is Continued fevers, that are not typhoid, are often also devoid of pigment cells. The framework uniting encountered in malarial districts, over which quinin the vessels of the choroid is composed of delicate con- seems to exercise no influence. They can not be clas- nective tissue. sified as "irregular" malarial fevers for this reason, The arterial vessels entering into the formation of and because an examination of the blood does reveal the choroid are the short posterior ciliary arteries. the plasmodium, either in its regular or irregular These are about twenty in number and are derived (sestivo-autumnal) form. They are probably caused from the ophthalmic artery. They pass through the by an organism different from but closely related to sclera in a whorl or circle, close to the optic nerve, the plasmodium. dividing into branches and passing forward for some For the enlarged spleen but little can be done by little distance, where they change their course medication. Time will help the matter somewhat. obliquely inward, terminating in the capillary layer. For chronic malarial poisoning a change of resi- The venous system lies on the outside of the arteries dence, either temporary or permanent, to a colder and is arranged in curves (vasa vorticosa). They climate is demanded. unite, forming four or five principal trunks, which pass through the sclera about half way between the corneo-scleral and the nerve. INFLAMMATION OF THE UVEAL margin optic TRACT, The nerves of the choroid are branches of the cili- CONSIDERED IN ITS ANATOMIC ary, about fifteen in number. These are derived from RELATIONS. the ciliary ganglion and the nasal branch of the oph- Read before the McLean County Medical Society, May 5, 1898. thalmic division of the fifth nerve. They pass BY J. WHITEFIELD SMITH, M.D. through the sclera near the optic nerve entrance, pass- Ex superintendent of the Illinois Asylum for Feeble-minded Children; ing forward between the choroid and sclera, lying in Member of the American Medical Association, Brainard District immediate contact with the former, and partly im- Medical Society and McLean County Medical Society. bedded in grooves, on the inner surface of the latter. BLOOMINGTON, ILL. They send branches into the choroid, in which they The choroid, ciliary body and iris, taken together, form a gangliated plexus. form the middle tunic of the eye, and is called the The continuation of the uveal tract from the uvea or uveal tract. This may be considered embry- ora serrata to the peripheral or attached border of ologically and histologically, as forming a continuous the iris is known as the ciliary body and consists membrane. If we remove the conjunctiva, sclera and of two portions, the ciliary muscle and the ciliary cornea from the globe of the eye, and evacuate its processes. The ciliary muscle is composed of two contents\p=m-\the aqueous humor, lens, lens capsule, vit- kinds of fibers, which accordingly divides it into reous humor, and detach the retina from the choroid\p=m-\ two portions, the longitudinal or meridional fibers we shall have left, depending upon the optic nerve, (Brucke's portion) and the circular fibers (Mul- the uvea. It gets its name from its fancied resem- ler's portion). The ciliary processes consist of dupli- blance to a grape hanging upon a vine (uva). The cations or folds of the choroid. There are about microscopic anatomy presents a striking similarity seventy in number, arising near the ora serrata and throughout its entire structure. There are, however, extending forward to near the equator of the lens. some variations, which may be noticed before consid- They are arranged parallel with the meridians of the ering the inflammation in its respsctive portions. eye. The framework of the ciliary processes is of Beginning with the choroid in situ, we find that it connective tissue. The ciliary processes are the most of comprises the posterior section the uvea, extending vascular part of the eye. They are covered on their from the aperture of the optic nerve to the ora ser- inner surface by three layers—the hyaline lamella; rata. At the optic aperture its termination is marked a layer of pigmented cells, the pigmented epithelium; by a delicate ring of cellular and elastic fibers sur- and a row of non-pigmented cylindrical cells. The rounding the nerve and firmly adhering to the sclera. last two rows of cells are a continuation from the Also, a few fibers are sent to the neurilemma of the retina and are called pars ciliaris retina?. The blood to optic nerve and the lamina cribrosa. At the ora vessels of the ciliary processes are derived principally serrata the choroid is continued into the ciliary body. from the anterior arteries, five or six in num- The termination ciliary of the choroid proper at this point, ber. These arteries are supplied from the muscular is marked by the limiting denticulated border of the and branches of the retina lachrymal ophthalmic artery. which underlies it. Perforating the sclera near the sclero-corneal margin, The choroid is situated between the sclera and the they divide into branches supplying the ciliary body, retina, and is essentially a vascular body. It is com- and assist in forming the circulus arteriosus iridis posed of four layers: The suprachoroid or lamina major. is suprachoroidea the outer layer and forms the attach- The venous system is in connection with the vasa ment to the sclera. It is a non-vascular membrane, vorticosa. The nerves of the ciliary body are derived containing pigment and lymphoid cells. The next from the ciliary nerves, which form a dense in is the of plexus layer layer large vessels, consisting princi- the ciliary muscle; some fibers from the trigeminus pally of veins which communicate freely with each also supply the ciliary body. other. The spaces between the veins contain pig- The portion of the uvea remaining to be considered* ment cells of a brown color. The arteries lie on the is the iris. This from the anterior surface of inner side of springs the veins. The layer of medium sized the ciliary body. The stroma composing the iris con- vessels forms the next layer and it is but slightly pig- sists of a connective tissue or cellular mesh mented. work, The small blood vessels or the layer of containing numerous vessels and some pigment cells. capillaries (tunica Ruyschiana) constitutes the next Near the pupillary border of the iris on its posterior vascular layer of the choroid. These are closely surface is a narrow circular band of muscular tissue Downloaded From: http://jama.jamanetwork.com/ by a Penn State Milton S Hershey Med Ctr User on 05/22/2015 (sphinter pupilhe) whose function is to close the in many cases, panophthalmitis with subsequent pupil. Also close to the posterior surface, beginning shrinking of the globe (phthisis bulbi). Again, an at the ciliary margin, the dilator fibers are found inflammation originating in the anterior portion of (dilator papillse). The anterior surface of the iris is the uvea—the iris (iritis), is not so likely to be trans- lined with an endothelium. This is a continuation of mitted to the choroid, for the same reason. The the endothelium of Descemet's membrane. The blood supply to the iris is almost independent of that posterior surface of the iris is lined with a layer of of the choroid. pigment epithelium (pars iridica retinae) and is con- An inflammation of the iris may be confined entirely tinuous with the retinal pigmentary layer. The blood to the structures of which the iris is composed. It is, supply of the iris is derived mainly from the long however, very frequently accompanied by an inflam- posterior ciliary arteries, two in number. These mation of the ciliary body (irido-cyclitis). This may arteries enter the eye near the optic nerve entrance, be accounted for by the fact that the blood supply of passing forward betwegn the sclera and choroid. the two portions of the uvea, is in part, from a com- Each artery divides into an upper and lower branch mon source. The blood passing through the two just behind the peripheral border of the iris. The long posterior ciliary arteries is distributed almost branches run concentrically with the margin of the entirely to the iris. It is true that the circulus arte- cornea, uniting with the branches on the opposite riosus iridis major is in connection with the anasto- side, forming the large arterial circle (circulus arteri- mosing branches of the anterior ciliary arteries, and osus iridis major). Near the pupillary margin they that the major circle sends some branches to the eili- form by anastomosis the small circle (circulus arte- ary muscle, and in this way there is a connection riosus iridis minor). The long posterior ciliary between the iris and ciliary body in their blood sup- arteries are branches from the ophthalmic. The ply, as well as in their anatomic elements. An inflam- venous system of the iris has a corresponding arrange- mation beginning in the iris is less liable to be ment with the arteries. There is a communication extended to the ciliary body than one originating in between the canal of Schlemm and the veins of the the ciliary body, is to be transmitted to the iris. This iris. The nerves of the iris are the ciliary. They is probably due to the comjilexity existing in the follow the course of the blood vessels and send off blood supply to the respective parts.
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