|Year : 1990 | Volume
| Issue : 4 | Page : 166-168
Postural variation of exophthalmometry in Graves' ophthalmopathy
Rajvardhan Asad, HK Tewari, MMS Ahuja, A Mithal
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, A.I.I.M.S., Ansari Nagar, New Delhi-110 029, India
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, A.I.I.M.S., Ansari Nagar, New Delhi-110 029
Source of Support: None, Conflict of Interest: None
30 patients with Graves' ophthalmopathy were subjected to exophthalmometry in the upright and supine positions to determine if the difference in exophthalmometer readings in these two situations are significantly different and would help in distinguishing the early and late Graves' ophthalmopathy patients. The cases were divided into two groups (of 15 patients each) of early Graves' ophthalmopathy (Grades 0,1,2) and late Graves' ophthalmopathy (Grades 3,4,5) according to the American Thyroid Association classification. In addition, 15 age and sex matched normal individuals who served as controls, also underwent similar investigation. Contrary to earlier observations, the results showed statistically insignificant increase in exophthalmometer readings when going from the erect to the supine position. It was concluded that postural change in exophthalmometer readings neither helps in distinguishing normal subjects from patients of Graves' ophthalmopathy nor can it differentiate between various grades of Graves ophthalmopathy.
|How to cite this article:|
Asad R, Tewari H K, Ahuja M, Mithal A. Postural variation of exophthalmometry in Graves' ophthalmopathy. Indian J Ophthalmol 1990;38:166-8
|How to cite this URL:|
Asad R, Tewari H K, Ahuja M, Mithal A. Postural variation of exophthalmometry in Graves' ophthalmopathy. Indian J Ophthalmol [serial online] 1990 [cited 2020 Jan 20];38:166-8. Available from: http://www.ijo.in/text.asp?1990/38/4/166/25508
| Introduction|| |
The ocular changes in thyroid disease are well known. Analysis of these changes reveal a rapid progression, lack of modalities or methodologies of early diagnosis and non responsiveness to therapy in late stages. Of the various methodologies ,,, positional exophthal mometric change has been mentioned as one of the diagnostic tests in cases of Graves' ophthalmopathy (with and without extra ocular muscle involvement). According to Hauer, who is one of the proponents of this test, the normal subjects and patients of Graves' disease without extra ocular muscle involvement can be distinguished from patients of Graves' disease with extra ocular muscle involvement on the basis of 1 to 3 mm decrease in exophthalmometer readings on going from the erect to supine position.  However later, contrary results were observed by Frueh et al in 1985, which were neither significant nor diagnostic of Graves' ophthalmopathy. In view of the conflicting opinion in the literature, we undertook this study to find out the factual position of this test and its relevance in the Indian population by using a study design similar to that of Frueh et al. 
| Materials and methods|| |
30 patients, 15 each with early and late Graves' ophthalmopathy were included in the study. Cases of early Graves' ophthalmopathy fell into the class 0, 1, 2 of ATA classification. In addition, 15 age and sex matched normal subjects served as controls. All the patients were subjected to systemic investigation which included T3, T4, TSH, RAIU after 2 hours and 24 hrs and TRH test (in cases of euthyroid Graves' ophthalmopathy). Ophthalmological investigations included exophthalmometry using Hertel's exophthalmometer in the erect and supine positions and orthoptic check up; Hess charting and diplopia charting were done to reveal any extraocular muscle imbalance.
| Results|| |
The mean exophthalmometric readings in the erect and supine position, their mean differences, S.E. of difference of Means and p value for normal and Graves' ophthalmopathy patients are given in [Table - 1]. The difference in exophthalmometry readings in the erect and supine positions recorded in normals were 0.6(S.E = 0.83) and 0.4 (S.E. = 1.01) for OD & OS respectively and these values were statistically insignificant (p=N.S.) The differential values obtained in Graves' ophthalmopathy (G.O) group were 0.26 (S.E = 0.39) and +0.14 (S.E. = 1.01) of OD & OS respectively but their p values were not significant. [Table - 2] shows comparison of positional exophthalmometry change between early and late Graves' disease, the mean difference in early Graves' disease was 0.4 (S.E. = 1.52) for OD and -0.2(S.E. = 1.27) for OS. The mean difference in late Graves' disease was 0.1 (S.E. = 1.27) for OD and 0.1 (S.E. = 1.58) for OS respectively. However neither of these difference were statistically significant.
[Table - 3] shows the sensitivity and specificity of applying a positional exophthalmometry test to distinguish early and late Graves' eye disease. Using the criteria of at least 1 mm increase in exophthalmometry readings from erect to supine position a specificity of 73% for OD and 80% for OS with a very poor sensitivity was observed.
| Discussion|| |
The Graves' disease is defined as a multisystem disorder of unknown etiology characterised by one or more of three clinical entities as mentioned below. 
1. Hyperthyroidism (associated- with diffuse hyperplasia of thyroid gland)
2. Infiltrative ophthalmopathy
3. Infiltrative dermopathy (Localised pre-tibial oedema)
It has been observed that about 33% of patients of Thyroid disease present with ocular symptoms and signs. The ocular features also exist even in the absence of any clinically evident thyroid dysfunction. The natural history of eye changes in majority of these cases shows a tendency towards a chronic, insidous progression. 
The clinical course runs through an early congestive phase followed by a fibrotic phase which may remain stationary or eventually get burnt out. Early diagnosis of the condition is of importance to keep the patient relatively comfortable by instituting various modes of therapy. The various methodologies adopted for the early diagnosis are positional intraocular pressure changes ultrasonographic assessment of extra ocular muscle thickness  and also the postural changes in exophthalmometery readings. 
Earlier studies have indicated that exophthalmometer readings show a definite decrease when going from upright to supine position in normal subjects and cases of early Graves' ophthalmopathy with no extra ocular muscle restriction. The postural increase in exophthalmometer readings has been attributed to displacement of fat and fluid content of the orbit in normal subjects and patients of early Graves' ophthalmopathy. However late Graves' ophthalmopathy with extraocular muscle involvement show very little change in exophthalmometer readings.  In the present study we did not observe a decrease in exophthalmometer readings in erect to supine postures in normals and in cases of early Graves' ophthalmopathy. Instead we got an increase in exophthalmometer reading in these two group of cases. Similarly the late Graves' ophthalmopathy cases also showed a reversed phenomenon. However none of these values were statistically significant, hence we cannot give any credence to the change in exophthalmometer readings in erect and supine positions as has been given by earlier workers. Therefore we agree with the observation of Frueh et al, who obtained nearly similar results as ours.
Hence we conclude that the postural exophthalmometer readings neither help to distinguish between normal subjects and patients of Graves' ophthalmopathy with or without extra ocular muscle involvement nor detect subclinical cases of Graves' ophthalmopathy. Thus our results also negate the hypothesis put forward to explain a decrease in exophthalmometer readings in two situations, nevertheless the practice of routine exophthal mometry in subclinical and clinical Graves' cannot be denied especially in the presence of the classical signs of lid retraction and lid lag which are by no means universal but are virtually pathognomic.
Therefore we suggest that mild degree of proptosis may be a more important diagnostic parameter and not the positional variation in exophthalmometer readings.
However, it is imperative to emphasise here that the importance of diagnosing subclinical involvement is always essential for which a rise in intraocular pressure of more than 3 mm on attempted upgaze ,, or thickening of ocular muscle on ultrasonography or CAT scan mar be one of the more important diagnostic parameters . ,
| References|| |
Hauer J : Clinical observations in endocrine exophthalmos: Br. J. Ophthalmol. 40:533-557. 1957.
Frueh BR. Garber F, Grill R, Musch DC : Positional effect on exophthalmometer readings in Graves' eye disease. Arch Uphthalmol 103, 13551356,1985.
Azad Rajvardhan, Gupta A.K. Sharma S.K. & Tewari H.K. : Increased intraocular pressure on upgaze : A test for early diagnosis of Graves' ophthalmopathy. Proceedings of VII Congress of European Society of Ophthalmologists, Helsinki P-526: 1985.
Werner SC, Coleman DJ, and Franzen LA. USG evidence of consistent orbital involvement in Graves' disease. New Engl. J. Med. 290: 1447-1450 1974.
Feldon SE, Clinical significance of extraocular muscle volume in Graves' ophthalmopathy; quantitative tomography study. Arch. Ophthalmol 100:1266-69,1982,
Lawton NF, Diagnosis of dysthyroid eye disease. Recent advances in Ophthalmology Page. 96-104,1983,
Sergott RC, Graves' ophthalmopathy: A clinical and immunological review surv ophthalmol 26:1-21. 1981.
Gamblin GT, Harper DG, Galentine P, Buck DR, Chernow B, Eil C, Prevalence of frequent subclinical ophthalmopathy. New Engl. J. Med. 308(8): 420-424, 1983.
[Table - 1], [Table - 2], [Table - 3]
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