Pterygium; its nature and a new line of treatment.

MANY theories are put forward and discussed in the literature regarding the nature of pterygium, and many papers were written on the subject, fewof which tried in a precise way to describe exactly how the pterygium is formed. The aim of this paper is to report the results of a six years' investigation of the subject iii a locality full of cases of pterygia. It discusses a new theory of its development, and a. new line of treatment, based upon this theory, which was practised on more than 600 cases with complete success. A true pterygium is a pathological encroachment of part of the bulbar conjunctiva exposed in the palpebral fissure over the cornea. This encroachment' is in the form of a fold of the conjunctiva, triangular in shape, with the apex, called the head, on the cornea, the base merging imperceptibly in the caruncle region, or theregion of the outer canthus, and the sides formed of two folds 'of the conjunctiva, an upper and a lower. This shape is not pathognomonic because if you pull the conjunctiva towards the cornea from any point near the limbus, it forms a triangular fold quite identical with a pterygium. The clinical appearance of the pterygium differs according to the stage in which it is seen and according to the degree of activity of the process that leads to its formation. Thus in its active and progressive stage, the fold is hyperaemic witlx dilated and congested radially disposed blood vessels, usually two or three in number, and the fold looks thickened, opaque and less translucent than the surrounding conjunctiva. In the meantime, surrounding the advancing head over the cornea, a halo of. greyish white opacity is. seen, with its convexity towards the centre of the cornea. This halo of opacity is denser near the head of the pterygium and fades away towards the centre of the cornea. It is quite superficial being present in the (pithelium and Bowman's membrane, and is; composed Of greyish white dots mostly aggregated at the points where the ciliary nerves pierce Bowman's membrane. This appearance of the clinical aspect of progressive active pterygia differs according to the amount of the activity of the case. But it is always noticed that the more the hyperaemia and congestion of the conjunctival vessels, the denser is the halo of opacity in the cornea and the..