|Year : 1982 | Volume
| 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
D K Sen
Guru Nnak eye centre, New Delhi-110 002
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Sen D K, Sarin G S. Tear lysozyme level in patients with trachoma. Indian J Ophthalmol 1982;30:139-41
Our preliminary observation showed lysozyme level in tears in persons with active trachoma to be lower as compared to normal persons. It has been observed that the level of lysozyme in tears in keratoconjunctivitis sicca tended to decrease with the severity of disease. Minton observed some patients with healed trachoma showing absolutely no tear lysozyme 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.,
Tear Samples were collected as described previously and stored at-20° until assayed. 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. However, Johansson and Malmquist 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 in normal human tears. This supports the contention of Johansson and Malmquist 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|| |
Sen, D.K. and Sarin, G.S., 1980, Amer. J Ophthalmol. 90:715.
Mayer, K., 1948, (Ed.) Sorsby, A. Modern Trends in Ophthalmology. London, Butterworth, Vol. 2, p. 71.
Minton, L.R., 1965, Amer. J. Ophthalmol. 60 532.
MacCallan, A.F., 1913, Trachoma and its com plications in Egypt, p. 5 London, Cambridge University Press.
World Health Organization, 1962, Expert Committee on Trachoma Third Report. W.H.O. Tech. Report No. 234, p.9.
Sen, D.K., Sarin, G.S., Mani, K. and Saha, K., 1976, Brit. J. Ophthalmol. 60 : 302.
Bonavida, B. and Sapse, A.T., 1968, Amer J. Ophthalmol. 66 :70.
Johansson, B.G, and Malmquist, J., 1971, Scand J, Clin. & Lab. Invest. 27 : 255.
[Table - 1], [Table - 2]