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Special Articles

EYE SIGNS IN GRAVES’ DISEASE

THE eye signs which accompany Graves’ disease are socharacteristic of the condition that it would be a greatconvenience if there was some form of standardisednomenclature with which to describe them. Eponyms likeStellwag, von Graefe, and a host of others only addconfusion and are often used to describe signs which theiroriginators never intended. The occasion of the FourthInternational Goitre Conference, held in London in July,provided a unique opportunity for a group of peopleinterested in eye signs to sit round a table and try to reachsome agreement on classification.

Sir Russell Brain took the chair, and the following werepresent:Dr. Brown M. Dobyns (Cleveland, Ohio), Prof. Russell

Fraser (London), Mr. Keith Lyle (London), Prof. JamesHoward Means (Boston), Dr. Rulon W. Rawson (New York),Mr. Selwyn Taylor (London), and Dr. Sidney C. Werner(New York). Dr. Nigel Oakley (London) acted as recorder.

EXOPHTHALMOS, PROPTOSIS, OR EYE SIGNS

The word exophthalmos stems from the Greek andimplies that the eye is out. Proptosis is also Greek in

origin and means that the eye is pulled forwards.Ophthalmic surgeons have in the past used the wordexophthalmos to imply an active protrusion and proptosisa passive one; the latter being due to an increase in theretrobulbar mass. This is not a satisfactory distinction,nor is there a scientific basis for it.

Exophthalmos (measured in millimetres of protrusion)appears to be the most satisfactory term which can be usedto describe the disorder of the orbital contents in Graves’disease; but other changes, such as lid retraction, are notnecessarily implied by it. Exophthalmos is not, therefore,considered a completely satisfactory descriptive term. Itwas agreed that the term " protrusio bulbx " was super-fluous.The possible alternative to using the above terms would

be to refer to this phenomenon as " eye signs of Graves’disease ". It must, however, be recognised that eye signssimilar to those seen in Graves’ disease may be seen inpatients with Cushing’s syndrome or even in patients withkidney disease, and one member made a strong plea forthe term " endocrine ophthalmopathy ". However, sincethe whole clinical picture may not be a single physiologicalentity, it seems best to adopt a purely descriptive nomen-clature.

PROGRESSIVE CHANGES

On turning to the natural history of exophthalmos itwas considered that one of the important reasons for

trying to document eye signs accurately was to predictfuture changes, even though this might be very difficult.There was fairly general agreement on a number ofspecific points, among which were the following:Loss of visual acuity in Graves’ disease rarely occurs without

some degree of exophthalmos and never without increasedretrobulbar pressure. This loss falls into two separate cate-gories : (a) due to corneal ulceration and resulting cornealopacity; and (b) due to defects in the visual fields includingparacentral or central scotomata, and these are due to pressureon the optic nerve or, possibly, circulatory disturbances.True lid-lag is virtually specific to hyperthyroidism and

usually disappears on return to a euthyroid condition. Itmay be due to increased tension in the levator palpebrssuperioris.

Even the most severe orbital lesions may show completeregression.Permanent impairment of function in the orbital contents

is usually related to the duration and severity of the changes.CLASSIFICATION

When it comes to the classification of eye signs therewere almost as many different classifications as there were

people present. However, there was general agreementthat " malignant exophthalmos " (though a misleadingterm) referred to those cases in which protrusion continuedto progress so that visual acuity was impaired and cornealulceration or even loss of the eye appeared likely. It was

pointed out that lid retraction may, in some instances, bedue to increased tension in the levator palpebrm superiorisrather than to contraction of the unstriped muscle in theupper eyelid. Such a mechanism should be carefullydistinguished from the mechanical effect of mere pro-trusion of the eyeball on the upper lid.

RECORDING OF EYE SIGNS

There was general agreement that eye signs should becarefully recorded and measured as far as possible; andone list, which most members took least objection to, hadeight items as follows:

1. Eyeball protrusion-measured from the lateral rim of thebony orbit.

2. Lid retraction-measured at rest from the upper irismargin with the eyes looking horizontally forward.

3. Lid-lag.4. Bulge of upper lid.5. Bulge of lower lid.6. Chemosis and peripheral conjunctival congestion-

grades 1-4.7. Decreased resiliency of the eyeball estimated by pressure

upon the closed eyelids.8. Impairment of ocular movements.When the abnormality cannot be directly measured it

is useful to define different grades of severity, and a

simple way of so doing is to give a number of plus signs,from + to + + + +. It is then desirable that the samedoctor always makes the assessment. Better than this isto measure, where possible, as in 1 and 8.

For eyeball protrusion different workers attach impor-tance to a variety of methods. The Hertel exophthalmo-meter was considered by most to be a valuable aid inmeasuring the degree of protrusion, but again it wasstressed that the same observer must use the identicalinstrument when measuring progress in any one patient.Accurate lateral photographs were also considered of valuein assessing progress; and reference was made to anapparatus which fitted over the head and carried a mirrorat the angle of the orbit together with a millimetre scaleso that the eyes could be photographed showing the degreeof protrusion and thus provide a permanent record. TheCopper orbitonometer was generally regarded as a mostuseful research tool, but is not suitable for general clinicalapplication. It does not appear to have yielded importantinformation.

CONCLUSION

Since we remain ignorant of the aetiology of Graves’disease it is not surprising that general agreement onnomenclature was not reached. Some preferred the " eyesigns of Graves’ disease "; others were unwilling to drop" exophthalmos " while appreciating its limitations; onemember preferred " endocrine ophthalmopathy ". How-ever, all agreed that the careful recording and grading ofthe eye changes, as described above, was of real value.

SELWYN TAYLOR.