|Year : 1983 | Volume
| Issue : 4 | Page : 405-407
'Morphology of fungal corneal ulcers'-influence of immunosuppression
R Gogi, Renu Hajela, K Nath
A.M.U. Institute of Ophthalmology, Aligarh, India
A.M.U. Institute of Ophthalmology, Aligarh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Gogi R, Hajela R, Nath K. 'Morphology of fungal corneal ulcers'-influence of immunosuppression. Indian J Ophthalmol 1983;31:405-7
|How to cite this URL:|
Gogi R, Hajela R, Nath K. 'Morphology of fungal corneal ulcers'-influence of immunosuppression. Indian J Ophthalmol [serial online] 1983 [cited 2020 Jul 6];31:405-7. Available from: http://www.ijo.in/text.asp?1983/31/4/405/27566
In our previous paper we have reportec that immuno-stimulation can cut short the course of fungal corneal ulcer in experimenta animals'. In the present work an attemp has been made to produce B-lymphocyt( suppression by systemic use of cyclophospha. mide and a local immuno-suppression b) Dexamethasone sodium.
| Material and method|| |
This study was carried out on twenty foul rabbits divided into the following groups.
Group A (8 rabbits)
This group underwent systemic B-lymphocyte suppression.
Method of Systemic Immunosuppression:
Rabbits were treated with an intraperil toneal injection of cyclophosphamide, (200 mg/kg body weight). In both eyes ulcer were produced on the third day.
In both eyes of the animal, corneal ulcer was produced as described in our previous communication and was painted twice daily with Candida albicans suspension (containing 1 million yeast particles/ml) for two days.
Both eyes were clinically examined every day. Two eyes (one rabbit) were enucleated after every twenty four hours till eighth day. These eyes were histopatholgically examined.
Group B (8 rabbits)
This group underwent local immunosuppression.
Method of Local Immunosuppression:
In all 8 rabbits (16 eyes) subconjunctival injections of Dexamethasone sodium (0.5 mg) were given for four days. Ulcer was produced on the third day.
The method of ulcer production and rest of the procedure was same as for group A.
Group C (8 rabbits):
This group served as control where no systemic or local immunosuppression was produced. Rest of the procedure was same as in other groups.
| Observations|| |
In cyclophosphamide treated animals there was intense inflammatory reaction during the first four days which subsided very quickly during the next four days. Complete healing could be observed on the 7th day.
Corneal stroma and perilimbal area was densly populated by large number of lymphocytes and polymorphonuclear cells [Figure - 1]. However, there was a marked fall in the leucocytic concentration after four to five days. Presence of fungus at the site of the ulcer could be seen during the first three days.
In dexamethasone treated eyes the inflammatory reaction declined sharply from second day onward. Healing could not take place even with antifungal treatment till the end of 8th day.
Histopathological examination showed the presence of fungus in the stroma and leucocytic infiltration [Figure - 2]. Intensity of inflammatory cells was more during first 24 hours and started subsiding afterwards.
In the control group inflammatory reaction was of mild to moderate intensity which subsided gradually and ulcers were completely healed by sixth day. Intensity of this reaction was much milder is eyes where antifungal treatment was given.
Microscopic cytology consisted of lesser number of fungi and mild polymorphs and lymphocytic infilteration.
| Discussion|| |
The inflammatory reaction in cyclophosphamide treated animals was very severe during the first three days and declined very sharply during the next four to five days. Whenever a tissue is exposed to an antigen `T' lymphocytes are stimulated in the local lymph nodes (fornix and perilimbal lymph nodes in case of eye). The soluble antigen at the same time is released to stimulate B lymphocytes. These stimulated B lymphocytes have suppressive action on the T-lymphocytes. This modulating effect can be removed completely by treatment with cyclophosphamide, therefore permitting the T lymphocytes to undergo proliferation. In the present experiment suppression of B lymphocytes was induced, this resulted in stimulation of T-cells that brought in rapid control of inflammatory reaction. It is, therefore, suggested that direct or indirect stimulation of `T' lymphocytes can help in the rapid healing of the corneal ulcer.
Local suppression by corticosteroids affects both T and B lymphocytes as seen in this experiment which gave rise to delayed healing. Appropriate concentration of inflammatory cells at the site of inflammatory reaction is very essential for quick recovery.
| Summary|| |
1. Immunosuppressants like cyclophosphamide produce B-cell depression and therefore T-cell proliferation.
2. T-cell proliferation has favourable effect on the healing of fungal corneal ulcer.
3. Local corticosteroids (Dexamethasone) lead to suppression of both types of lymphocytes, checks the inflammatory reaction and subsequent delayed healing.
| References|| |
Gogi, R., Hajela, R., Nath, K. and Maheshwari, R., 1982, Proc. All Ind. Ophth. Soc. (In pressi).
Turk, J.L., Parker, D. and Poulter, L.W., 1972 Immunology, 23: 493.
[Figure - 1], [Figure - 2]