|Year : 1983 | Volume
| Issue : 4 | Page : 409-411
'Morphology of fungal corneal ulcers'-influence of immunostimulation
R Gogi, Renu Hajela, K Nath, R Maheshwari
A.M.U. Institute of Ophthalmology, Aligarh, India
A.M.U. Institute of Ophthalmology, Aligarh (U.P.)
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Gogi R, Hajela R, Nath K, Maheshwari R. 'Morphology of fungal corneal ulcers'-influence of immunostimulation. Indian J Ophthalmol 1983;31:409-11
|How to cite this URL:|
Gogi R, Hajela R, Nath K, Maheshwari R. 'Morphology of fungal corneal ulcers'-influence of immunostimulation. Indian J Ophthalmol [serial online] 1983 [cited 2020 Aug 5];31:409-11. Available from: http://www.ijo.in/text.asp?1983/31/4/409/27567
The possibility of fungal invasion of the cornea in a study of corneal ulcer has been reported to be as high as 20%. This could be due to indiscriminate use of corticosteroidh or due to the lowering of host resistance as a result of acute or chronic systemic ailments or systemic steroid therapy. There is a great possibility that if immune status of the host be increased the course of such corneal ulcers could be different.
In the present study 'T' lymphocyte stimulation was induced in raqbits with D.N.C.B. (2-4, Dinitrochlorobenzene). In these primed animals fungal corneal ulcer was produced and morphological changes were studied.
| Material and methods|| |
Twenty four adult rabbits were divided into two groups :
Group A (16 rabbits)
In this group immunostimulation was carried out.
Method of Immunostimulation
In all the 16 rabbits T lymphocyte stimulation was induced by an epicutaneous application of 2 mg of DNCB. After a period of two weeks the same dose was repeated. One week later corneal ulcers were produced in both eyes.
In all the animals (32 eyes) ulcer was produced by cutting out 0.3 mm deep corneal button with a 5 mm; trephine. A normal concentration of candida albicans suspension (containing I million yeast particles/ml) was painted on the ulcer with the help of a spatula twice daily for two days. On the third day conjunctival smear was prepared and stained to confirm the presence of fungi at the site of the ulcer. The ulcer in right eye was treated with antifungal ointment (Nystatin 10,000 per gm). Left eye remained untreated.
The experimental eyes were clinically examined every day for the presence of inflammatory signs. Four eyes (2 animals) were enucleated at 24 hours interval till the end of 8 days. These eyes were fixed in formal saline, paraffin blocks were prepared, 5-6 micron thick sections were cut and stained with haematoxylin and eosin and PAS stain.
Group B (8 rabbits)
This group served as control. No immunostimulation was carried out and rest of the procedure was same as in group A.
| Observation|| |
In DNCB primed animals there was severe inflammatory reaction during the first three days which started subsiding thereafter [Figure - 1][Figure - 2]. Healing of the corneal ulcer was observed as early as third day and after 6 days none of the cornea had corneal ulcer. The course of clinical findings in Nystatin treated eyes was similar to that of untreated eyes.
There was intense inflammatory reaction in the perilimbal area in the form of lymphocytic infilteration. In the area of corneal ulcer, apart from the presence of fungi, there was polymorphonuclear and lymphocytic infilteration during the early part of the corneal ulcer. With the passage of time the polymorphonuclear cells started decreasing, however, degeneratee polymorphs could be seen even at the end of the fourth day. In nystatin treated eyes there was early disappearance of fungi from corneal stroma and rest of the course was same as in untreated eyes.
There was a mild inflammatory reaction that persisted during the first five days. In some of the eyes although the corneal ulcer was present, yet there was mild or practically no inflammatory response [Figure - 1][Figure - 2]. Complete healing of the cornea was observed from sixth day onward. There was no difference in the course of clinical findings in Nystatin treated and untreated eyes.
There was mild perilimbal reaction in the form of lymphocytes during the first two days in both eyes. In the area of corneal ulcer polymorphonuclear infilteration and presence of fungus in corneal stroma was seen.
| Discussion|| |
Increased intensity of inflammatory reaction in DNCB primed animals was the highlight of this experiment. The reaction was recorded at the macroscopic and microscopic level. This is in contrast to the control group where inflammatory reaction was mild. Increase in intensity of inflammatory reaction in fungal corneal ulcer is a favourable finding as it brings in active defence mechanism and early healing of the corneal ulcer. The present experimental model emphasizes that a weak immune mechanism in fungal corneal ulcers requires some kind of stimulation to promote early and better healing of the corneal ulcer. This was possible by selective `T' lymphocyte stimulation with DNCB. This hapten has been used for immunostimulation, in cases of immune paralysis associated with systemic carcinomas, by other workers. It is, therefore, suggested that the advantage of DNCB should also be utilized in fungal corneal ulcer.
Treatment of fungal corneal ulcer with specific antifungal drugs can only help in the early disappearance of fungus from the corneal stroma. It, however, did not shorten the course of the ulcer. Therefore, the use of specific antifungal therapy in conjunction with immunostimulation may prove the ideal treatment.
| Summary|| |
Immunostimulators such as Dinitrochlorobenzene induce `T' lymphocyte proliferation which in turn helps in shortening of the course of fungal corneal ulcer in experimental animals.
| References|| |
Prasad, S. and Nema, H.V., 1982, Ind. J. Ophthalmol. 30:81.
[Figure - 1], [Figure - 2]