Brit. J. Ophthal. (I976) 6o, I 63 Br J Ophthalmol: first published as 10.1136/bjo.60.3.163 on 1 March 1976. Downloaded from Scleritis and episcleritis PETER G. WATSON* AND SOHAN SINGH HAYREHt From Moorfields Eye Hospital, City Road, London*, and Addenbrooke's Hospital, Cambridge*, and the Department of Ophthalmology, University of Iowa Hospitals and Clinics, Iowa City, USAt From the earliest available descriptions of episcleritis Leigh, I965), subconjunctival phlegma or simple (Slade, 1838; Rognetta, i844; Desmarres, 1847) or phlegmatous conjunctivitis by Mackenzie (I830), a confusion has existed between scleritis and and episcleritis periodica fugax by Fuchs (I895). episcleritis. This has led to contradictory views Duke-Elder and Leigh (I965) distinguished be- on the relative severity and prognosis of these tween nodular episcleritis and rheumatic episcleritis, conditions, and the erroneous belief that episcleritis but such a differentiation appears to be unjustified is accompanied by serious complications (Viswaling- as rheumatoid arthritis can be associated with ham, 1936; Wood, 1936; Mann and Markson, I950; either condition. We have classified episcleritis Clavel and Teulieres, 1958). While Slade (I838), into two types: Rognetta (i844), and Desmarres (I847), thought i. Simple episcleritis that episcleritis was both common and severe, 2. Nodular episcleritis. Mackenzie (i830) considered it to be neither and gave copyright. at the same time a vivid and accurate description SCLERITIS of scleritis. This confusion still persists today. In an attempt to clarify the position we have Many classifications of scleral disease have been been studying patients with scleritis and episcleritis proposed (Holthouse, I893; van der Hoeve, in a special clinic at Moorfields Eye Hospital 1934; Franceschetti and Bischler, I950; Duke- during the past io years. Of these, 207 patients Elder and Leigh, I965; Sevel, I967) which have (30I eyes) with episcleritis and 159 patients (2I7 been based on a mixture of clinical and pathological eyes) with scleritis were analysed in depth.§ The observations. Although we tried to adopt these, http://bjo.bmj.com/ results reported below have led us to conclude from the clinical point of view they have all been that scleritis and episcleritis are clinically distinct, unsatisfactory. We eventually adopted the following with a different symptomatology and prognosis classification because, although there is some slight and requiring different management. overlap between the groups, clinically we have The incidence of these conditions is not known, observed several distinct patterns. This classifica- but Williamson (1974) suggested that it was about tion has proved to be satisfactory and has enabled us to assign almost all the patients to a particular o-o8 per cent of hospital new patient referrals. Our on September 26, 2021 by guest. Protected series is from highly selected patients, all being category at the initial examination. referred from elsewhere, often where there was (a) Anterior scleritis difficulty in diagnosis, and with unusual problems. i. Diffuse scleritis This is reflected in the fact that go per cent of the 2. Nodular scleritis patients who had rheumatoid arthritis were seen 3. Necrotizing scleritis within a year of the start of the special clinic. a. with inflammation b. without inflammation (scleromalacia per- forans) Classification (b) Posterior scleritis. EPISCLERITIS Episcleritis has been recognized for over a century, Material although-,called by many different names, such as Using the above classification, patients were subconj4ctivitis by von Graefe (Duke-Elder and distributed as in Table I. §Mr B. Augier and Mrs B. Phillips of the Institute of Ophthal- mology. London, used the University of London computer to analyse the findings Normal anatomy Before Address for reprints: 22 Parkside, Cambridge, England*, or considering the criteria by which the University of Iowa, Iowa City, Iowa 52242, USAt differential diagnosis is reached it is necessary to. 164 British Journal of Ophthalmology Br J Ophthalmol: first published as 10.1136/bjo.60.3.163 on 1 March 1976. Downloaded from understand the normal vascular anatomy of the 3. Scleral (deep episcleral) plexus (Fig. I) outer coats of the eye. The blood vessels of the This plexus consists of a rete (criss-cross) of episclera are not easily seen in the uninflamed eye, vessels lying within the visceral layer of Tenon's but as soon as the eye becomes congested three capsule, closely applied to the sclera. At the limbus quite separate vascular plexuses become readily the superficial and deep episcleral plexuses merge visible. into one another and terminate in the superficial marginal plexuses of the cornea. When congested i. Bulbar conjunctival plexus (Fig. i) this layer looks bluish-red in colour and is immobile. This is the most superficial plexus of fine hair-like interlacing vessels freely moveable over the under- Clinical examination lying structures. Overlying the episclera the Careful examination will determine the depth of conjunctival arteries are derived from two sources the inflammation, so that it is almost always possible the anterior ciliary arteries at the limbus, and the to decide when the patient is first seen whether palpebral branches of the ophthalmic and lacrimal scleritis or episcleritis is present. This depends on arteries. When they are inflamed the colour is accurate observation of the relationship of one bright red. layer of vessels to the other and to the underlying sclera. 2. Episcleral plexus (Fig. i) HISTORY The vessels, which are straight and radially arranged, lie in the superficial episclera (parietal A detailed clinical history is taken of the patient's layer of Tenon's capsule) at a depth of about one- ocular and systemic disorders, including family quarter to one-third of the distance between the history. Any contact with chemical irritants and surface of the conjunctiva and sclera (Graves, solvents is noted, as is any history of allergic 1937). The visible vessels are mainly veins, accept- conditions, rheumatic, connective-tissue or skincopyright. ing the aqueous veins at intervals around the globe. disease, gout, venereal disease, tuberculosis, or These vessels are moveable over the deep layers, sarcoidosis. The site, distribution, and nature of although not so easily as the conjunctival vessels. any ocular pain and disturbances of vision are In the anterior episcleral plexus (anterior to the important in deciding the type of inflammation equator and over the muscle) the vessels belong to present. the anterior ciliary system; while in the posterior EXAMINATION OF THE EYE episcleral arterial plexus (posterior to the equator) http://bjo.bmj.com/ they are derived from the arteries of the oblique After the visual acuity has been recorded, the muscles, the posterior ciliary arteries, and the vessels following routine of examination is used: of the optic nerve sheaths (Hayreh and Baines, 1972). When inflamed, these radially arranged vessels I. External examination of the eye in daylight can easily be seen, giving the eye a salmon pink It is essential to examine a case of episcleritis in colour. daylight as this is often the only way of distin- on September 26, 2021 by guest. Protected FIG. i Normal vascular networks of episclera. There are three layers- the-deepest is almost invisible in the uninflamed eye Scleritis and episcleritis I65 Br J Ophthalmol: first published as 10.1136/bjo.60.3.163 on 1 March 1976. Downloaded from guishing episcleritis from the much more serious dary retinal detachment, and optic neuritis. Prop- scleral disease. In episcleritis the colour is salmon tosis and limitation of movement of the extraocular pink; in deep scleral disease the colour has a muscles are also looked for as evidence of an much deeper purple hue. These colour changes involvement of posterior sclera. are difficult to distinguish in tungsten or fluorescent light. After recurrent attacks of scleral inflammation SYSTEMIC EXAMINATION the sclera may become more transparent and is sometimes thinner, and as a consequence the grey As scleritis is frequently a manifestation, and choroid may be seen through the sclera. Some- sometimes the first manifestation, of systemic times these areas are black and well defined, but disease, a thorough physical examination is impera- more often they give a faint grey tinge to the sclera. tive, special attention being paid to the joints and This is a particularly important observation in the cardiovascular system to eliminate a vasculitis.* scleromalacia perforans, in which there is no sur- rounding inflammation. Time and again it is Special investigations possible to see areas of scleral thinning in daylight which were invisible with the slit-lamp or by ROUTINE STUDIES CARRIED OUT IN ALL PATIENTS illumination with tungsten or fluorescent light. i. Full blood count This included haemoglobin estimation, white blood examination cell count and differential white cell count, and 2. Slit-lamp microscopic erythrocyte sedimentation rate. Of the greatest assistance in distinguishing epi- scleritis from scleritis is the relationship of one 2. Rheumatoid arthritis latex agglutination test vascular network with another and the changes within them. The of this examination is to The Rose-Waaler sheep-cell agglutination test was object copyright. confirm the macroscopic findings. In scleritis, the used as a confirmatory test for rheumatoid factor. examination is directed to detecting scleral oedema and the involvement