A practical treatise on diseases of the eye / by Robert Brudenell Carter.

  • Robert Brudenell Carter
Date:
1875
Catalogue details

Licence: Public Domain Mark

Credit: A practical treatise on diseases of the eye / by Robert Brudenell Carter. Source: Wellcome Collection.

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    (Vv, ri. directed from before backwards, and situated posteriorly to the equator, about the junction of the middle with the posterior third of the eyeball. The inner vascular layer of the choroid, often called the chorio-capillaris, contains fine or capillary vessels only, and is separated from the retina by a smooth and homogeneous basement membrane. A short distance in front of the equator, and of the anterior boundaries of the ven£e vorticosce, the choroid no longer remains in contact with the sclerotic, but begins to be elevated from it into a regular circle of plaits or folds, usually seventy in number, and known as the ciliary processes (Pc, PI. I. and PC, Fig. 1, Plate II.). These processes are arranged radially around the posterior aspect of the margin of the iris; and, as shown in the Plates, they increase in size from behind forwards, and terminate anteriorly in rounded extremities. Each process is covered, and also the sulcus between each two processes, by the choroid, but the mass of each process is formed by the ciliary nmscle. The processes, taken collectively, constitute the ciliary body; and the part of the eye in which they are situated, and in which the several tunics are united more intimately than elsewhere, is called the ciliary region. This region is very abundantly supplied with nerves and blood-vessels, and, as will be seen hereafter, is one of great surgical importance. The ciliary muscle, muscle of accommodation, or tensor of the choroid,* consists of unstriped fibres, of which the anterior (mc, Fig. 1, PI. II.) are arranged in a circle, while the posterior, or meridional, radiate in the direction of the processes them- selves. These meridional fibres (Mf, Fig. 1, PI. II.) have their origin in a circular tendon, situated at the corneo-scleral junc- tion, immediately on the inner side of Schlemm's canal, and separated from Descemet's membrane by a little- connective tissue. The external fibres pursue a course parallel to the inner surface of the sclera, and lose themselves in the choroid, forming connections with the muscular tissue which is dis- persed through its stroma. The internal meridional fibres turn somewhat away from the sclerotic towards the axis of the eyeball, and form an intricate network, which fills up much of each process. The circular fibres, seen in section at Mc, Fig. 1, PI. II., pass through and occupy the anterior rounded
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