CLINICAL SCOPE 33 



equator beneath the capsule (see arrows in Fig. 1), meet and unite 

 along " suture lines " radiating from the axis of the lens. Near 

 the central, embryonic region of the lens these suture-lines are 

 very simple, as in lower animals ; but nearer the capsule of the 

 lens where, for a given area, there are more fibres to unite, the 

 suture lines become more extensive by dichotomous branching 

 of the limbs of what, deeper in nearer the centre, is only in the 

 form of a simple Y. The different levels of the substance of 

 the lens, both anteriorly and posteriorly, corresponding with the 

 period of their development are distinguishable in their precise 

 localization by slit-lamp microscopy ; the clinical importance 

 of the exact localisation of pathological features seen within the 

 lens is thus obvious. 



The vitreous fluid, V, normally contains a tenuous gossamer-like 

 fibrillar optical meshwork, except in the " retrolental gap," R, 

 immediately behind the lens. Pathological processes may occur here 

 and may call for minute inspection, e.g., a neuroblastoma growing 

 from the posterior part of the interior of the eye of a child may be 

 revealed for the first time from its having pushed the retina, which 

 it may have detached, up against the back of the lens ; the " cat's 

 eye " reflex which this creates is not always easily distinguished 

 from a rather similar appearance caused by the much less serious 

 condition of " pseudoglioma " due to organised inflammatory 

 exudate secreted behind the lens by the ciliary body, C. When the 

 object seen behind the lens is a detached retina, its arteries will run 

 from the centre towards the periphery of the lens ; when it is a 

 cyclitic membrane, its arteries will run from near the periphery, 

 i.e., from the ciliary body, towards the centre. Microscopy of the 

 vessels, revealing the direction of flow of the contained corpuscles, 

 will afford distinction between these two conditions. These few 

 examples will serve to indicate something of the clinical importance 

 of minute inspection and precise localisation of features within 

 the transparent and translucent media of the eye. 



For practical clinical purposes. Microscopy of the Living Eye 

 is concerned with roughly the anterior half of the eye, i.e., lids 

 and conjunctiva, cornea, anterior chamber, iris, lens and that part 

 of the vitreous just behind the lens. The subject of microscopy 



R.A.31. 2 



