Anatomy.- The ciliary body is that part of the uveal tract extending from the periphery of the iris to the choroid, and consists the ciliary processes and ciliary muscle.
The Ciliary Processes, some seventy or eighty in number, are composed of a connective tissue stroma, continuous with that of the iris and ligamentum pectinatum, of blood-vessels arranged in convolutions or folds, and overlaying these folds is a densely pigmented layer. The tips of the ciliary processes lay a little in front of the edge of the lens, but are not in contact with it. From the posterior surface of the processes extends a transparent structure called the zonule of Zinn or suspensory ligament of the lens. This is derived from the hyaline layer on the inner surface of the ciliary body, and, as if passes to the border of the lens, it splits up to go each surface of the lens, leaving a small triangular space called the canal of Petit. Through this structure transfusion from the vitreous to the aqueous humor takes place. The ciliary processes, while not erectile, enlarge or shrink with variations of blood pressure.
The Ciliary Muscle is composed of three sets of unstriped fibres: The meridional, running parallel to the sclerotic; the circular, forming a ring parallel to the cornea; and the radiating fibres. Iwanoff has shown that in certain myopic eyes, the circular fibres may be entirely lacking, and, on the contrary, in hyperopic eyes are so highly developed that they form one-third of the ciliary muscle.
As to the action of this muscle Heinrich Muller ascribes a different action to each set of fibres:
1. ” The circular fibres of the ciliary muscle exert a pressure upon the edge of the lens, by means of which the latter becomes thicker.”
2. ” The longitudinal fibres of the muscle cause an increase in tension the vision humor, on account of which the posterior surface of the lens is prevented from shifting and the action of the peripheral pressure is chiefly confined to the anterior surface,” and also, that, ” The arching forward of the centre of the anterior surface of the lens is rendered possible and favored by the recession of the peripheral portion of the iris, which is accompanied by a contraction of the deeper (circular) layer of the ciliary muscle and the iris.” Thus we see that the circular fibres of the ciliary muscle are the ones by which the act of accommodation is chiefly caused, and, further, the these circular fibres are especially developed in hyperopic eyes.
The vessels supplying the ciliary body are the posterior and anterior ciliary. The nerves are from the ciliary, forming a network in which are multi-polar ganglion cells containing sensitive, motor and sympathetic filaments. From this plexus fibres pass to supply the ciliary body, iris and the cornea.
Cyclitis.- Inflammation of the ciliary body is very rarely found uncomplicated with other diseases and usually, except when caused by wounds, is an extension of a choroiditis, or iritis, and when the inflammation commences in the ciliary body it usually extends to these parts, and in fact the iris is always more or less involved. The recognition of cyclitis is essential on account of the danger to vision it threatens. The distinction between cyclitis and iritis is not an easy one, and it is necessary, therefore, to search carefully for the characteristic signs, which are the extreme sensitiveness to touch, cloudiness of the vitreous and the change in the tension, which is first increased and later decreased. Cyclitis may occur as either a plastic, serous or purulent inflammation.
Cyclitis Plastica.- PATHOLOGY.- The pathological changes are the same as those found in plastic inflammation of the iris, wandering cells and an exudation of an amorphous mass, especially on the inner surface of the ciliary body. The exudation may extend forward upon the posterior chamber. It may be deposited on the posterior surface of the cornea, floating about in the aqueous, or be found in the iritic angle. There is also an exudation into the vitreous, especially in its anterior portion, causing it to become hazy, which, as it gradually absorbs, leaves opacities floating in the vitreous that may become membranous. If the disease goes on, the retina and choroid become affected and the retina detached from the contractions of the pathological membrane and filled with a sero-albuminous fluid. In the late stages the ciliary processes may become detached from the sclera. The exudation is the same, only more extensive than in iritis.
SYMPTOMS.- There is ciliary injection and often chemosis. The iris may be discolored and the pupil contracted, but there are no synechiae, unless the iris is involved. The veins of the iris are engorged, owing to the swelling of the ciliary body preventing a return of the blood from the iris. Pain is usually a prominent symptom; it is generally quite severe in and around the eye and often extending into the head-in fact, about the same as that in iritis. The most characteristic symptoms is the extreme sensitiveness of the eye to touch. There may or may not be haziness of the aqueous, but the haziness of the vitreous is almost invariably present in the early stages, appearing on weak illumination like fine dust floating in the anterior part of the vitreous. The anterior chamber may be deepened in the earlier stages and later it may be shallow from fluid or exudation behind the iris or lens pressing it forward. There is a rapid loss of vision and the accommodation is impaired. The tension may be either increased, decreased, or normal.
Cyclitis Serosa.- In this we have the same pathological changes as in serous iritis and it is always invariably accompanied by serous infiltration of other parts of the uveal tract. The symptoms are the same as just described, but less severe. The tension, however, in serous cyclitis is apt to be increased and the pupil is usually dilated. (See Choroiditis Serosa).
Cyclitis Purulenta – In this there is a very marked lymphoid infiltration. The pus will extend into the aqueous humor, forming an hypopyon, which in purulent cyclitis may come and go very quickly. The disease, as a rule, passes over into panophthalmitis, in which there is a suppuration of the whole eyeball with subsequent atrophy. In sub-acute cases we may find a diminished tension, but there us generally increased tension. All the symptoms of the plastic form are present in this, and even of a higher degree.
CAUSES.- Cyclitis, when not dependent upon other inflammations, most frequently results from some form of injury, as in contusions of the eye or penetrating wounds in the ciliary region; after cataract operations where the incision was far back in the sclera: from dislocation or swelling of the lens from rupture of its capsule. It may occur form a prolapse of the vitreous through a scleral wound, or from a contraction of scars in the ciliary region. It may, however, be spontaneous so far as any direct cause can be determined, and is often from sympathetic inflammation. It chiefly occurs as secondary to inflammations of the iris or choroid.
PROGNOSIS is most unfavorable in the purulent form, as it generally leads to suppuration of the entire eye. In the plastic form the prognosis is also unfavorable, because from its pathological changes, the vitreous loses its nutrition, becomes fluid, the retina detached, lens cataractous and the eyeball becomes fluid, the retina detached, lens cataractous and the eyeball becomes atrophied.
TREATMENT should first be directed to the cause. If dependent upon a foreign body, it may be removed by the magnet; if due to a dislocation or swelling of the lens, remove it; if there is a wound with a prolapse of the iris, it should be drawn out and cut off and a compress bandage applied.
The treatment of inflammation in this portion of the uveal tract will depend almost exclusively upon internal medication. The eye must be kept warm, as in iritis, and Atropine may be necessary, as the iris is liable to become involved, but must be used with caution from the danger of increased tension. Special indications for remedies are to be found under Iritis, page 296.
Injuries Implicating the Ciliary Region are not only dangerous on account of inflammatory complications, but as a cause of sympathetic ophthalmia. Simple incised wounds may readily unite by keeping the eye at rest, or it may be necessary to use a fine suture, which should be inserted from within outward in both edges of the wound. Extensive injuries in this region will usually necessitate enucleation, though under certain circumstances the eye may be preserved, providing the patient is intelligent and will attend to the first unfavorable symptoms which may arise. Foreign bodies must be removed, if it is possible, without too much injury to the tissues, or the eye must be sacrificed. Nettleship has called the region of about 5 mm. around the cornea the “dangerous zone,” because an injury of this zone is almost certain to implicate the ciliary body.
Professor of Ophthalmology in the College of the New York Ophthalmic Hospital; Surgeon to the New York Ophthalmic Hospital. Visiting Oculist to the Laura Franklin Free Hospital for Children; Ex-President American Homoeopathic Ophthalmological, Otological and Laryngological Society. First Vice-President American Institute of Homoeopathy : President Homoeopathic Medical Society of the State of New York ; Editor Homoeopathic Eye. Ear and Throat Journal : Associate Editor. Department of Ophthalmology, North American Journal of Homoeopathy, etc.