Indian Journal of Ophthalmology

ORIGINAL ARTICLE
Year
: 1982  |  Volume : 30  |  Issue : 3  |  Page : 139--141

Tear lysozyme level in patients with trachoma


DK Sen, GS Sarin 
 Department of Ophthalmology, Maulana Azad Medical College, and Guru Nanak Eye Centre, New Delhi, India

Correspondence Address:
D K Sen
Guru Nnak eye centre, New Delhi-110 002
India




How to cite this article:
Sen D K, Sarin G S. Tear lysozyme level in patients with trachoma.Indian J Ophthalmol 1982;30:139-141


How to cite this URL:
Sen D K, Sarin G S. Tear lysozyme level in patients with trachoma. Indian J Ophthalmol [serial online] 1982 [cited 2020 Apr 1 ];30:139-141
Available from: http://www.ijo.in/text.asp?1982/30/3/139/28193


Full Text

Our preliminary observation showed lyso­zyme level in tears in persons with active trac­homa to be lower as compared to normal per­sons[1]. It has been observed that the level of lysozyme in tears in keratoconjunctivitis sicca tended to decrease with the severity of disease[2]. Minton observed some patients with healed trachoma showing absolutely no tear lyso­zyme[3] However, there is no comprehensive study on the subject available in the literature The purpose of this study was to find out the tear lysozyme level in different stages of trac­homa including healed trachoma and evaluate the results statistically.

 MATERIALS AND METHODS



Seventy three patients with trachoma with their age ranging between 16 and 45 years were consecutively chosen from the Outpatient De­partment of Guru Nanak Eye Centre, New Delhi. Seventy five healthy persons with similar age and sex distribution were also cho­sen to serve as control. The diagnosis of trac­homa was made by clinical examination includ­ing slit-lamp biomicroscopy and the stages were determined in accordance with MacCal­lan's classification as modified by W.H.O.[4],[5]

Tear Samples were collected as described previously and stored at-20° until assayed.[6] Tear lysozyme was quantified by employing a single radial immunodiffusion technique. Monospecific rabbit antihuman lysozyme serum and reference standard were obtained from Behring Institute, West Germany.

 OBSERVATIONS



Lysozyme was found in all the tear samples in measurable quantity. The tear lysozyme levels in the different stages of trachoma and in the healthy subjects are shown in [Table 1].

Before attempting a comparison between the healthy subjects and the trachoma patients, it is essential to ensure that the trachoma patients, suffering from different stages of the disease, are not a heterogenous group. For this it is useful to compare the lysozyme level among patients at different stages of trachoma. For this purpose an analysis of variance was carried out and the results are given in [Table 2].

It is clear that the patients in various stages of trachoma do not differ significantly from each other in so far as the lysozyme level is concerned (P>0.05) although on a cursory inspection there appears to be a suggestion that the tear lysozyme level progressively de­creases. It is therefore in order to combine them for a comparison with the healthy group of persons. When the mean lysozyme level among trachoma patients (0.99 mg/ml) is com­pared with that (1.41 mg/ml) among the normal persons the difference was found to be statisti­cally significant (P>0.001).

 DISCUSSION



At present the most commonly employed method for the estimation of lysozyme is the lysoplate method introduced by Bonavida and Sapse[7]. However, Johansson and Malmquist[8] observed that the bacteriolytic lysozyme deter­mination is not a specific enzyme assay and is probably influenced to some extent by factors other than the lysozyme activity. The immu­noassay of lysozyme employed by us is less sensitive to disturbances and thus is expected to provide more accurate information about the true lysozyme level in biological fluids. The mean level of lysozyme in healthy subjects by the immunoassay method was 1.41 mg/ml, which is lower than the level (27 mg/ml) reported by Bonavida and Sapse[7] in normal human tears. This supports the contention of Johansson and Malmquist[8] that the bacteriolytic lysozyme level determination is not a specific enzyme assay.

In this study we found lysozyme in tears in all stages of trachoma although its level was significantly lower than that in healthy sub­jects. However, there was no significant diffe­rence in tear lysozyme level between the diffe­rent stages of trachoma.

It is not clear whether the low level of lyso­zyme in tears in subjects suffering from trachoma was inherent, making them prone to infection by the trachoma agents or was the result of trachoma infection that caused structural changes in the lacrimal gland and tubules and interfered with the local production of the enzyme. However, it is interesting to note that even in the earlier stages of the disease the lysozyme level was significantly low.

 SUMMARY



Tear lysozyme levels have been measured in 75 healthy subjects and in 73 patients with different stages of trachoma by employing a single radical immunodiffusion technique. The lysozyme was found in all the tear samples in measurable quantity. In healthy subjects, the mean tear lysozyme level was 1.41 mg/ml. In trachoma patients, the mean tear lysozyme level was 0.99 mg/ml, which was significantly low as compared to that in healthy subjects, However, there was no significant difference in the lysozyme level between the different stages of trachoma.

 ACKNOWLEDGEMENTS



Mr. G.P. Mathur, statistician, New Delhi Tuberculosis Centre, New Delhi, has done the statistical analysis of the data.

References

1Sen, D.K. and Sarin, G.S., 1980, Amer. J Ophthalmol. 90:715.
2Mayer, K., 1948, (Ed.) Sorsby, A. Modern Trends in Ophthalmology. London, Butterworth, Vol. 2, p. 71.
3Minton, L.R., 1965, Amer. J. Ophthalmol. 60 532.
4MacCallan, A.F., 1913, Trachoma and its com plications in Egypt, p. 5 London, Cambridge Univer­sity Press.
5World Health Organization, 1962, Expert Com­mittee on Trachoma Third Report. W.H.O. Tech. Report No. 234, p.9.
6Sen, D.K., Sarin, G.S., Mani, K. and Saha, K., 1976, Brit. J. Ophthalmol. 60 : 302.
7Bonavida, B. and Sapse, A.T., 1968, Amer J. Ophthalmol. 66 :70.
8Johansson, B.G, and Malmquist, J., 1971, Scand J, Clin. & Lab. Invest. 27 : 255.