|Year : 1979 | Volume
| Issue : 4 | Page : 14-16
Experimental lens induced uveitis in rabbits
RN Misra, AHS Rahi
3/4, New Flat, MLN Medical College Campus, Allahabad, India
R N Misra
3/4, New Flat, MLN Medical College Campus, Allahabad
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Misra R N, Rahi A. Experimental lens induced uveitis in rabbits. Indian J Ophthalmol 1979;27:14-6
Lens induced uveitis on toxic pathogenesis was first time described in detail by Straub. Verhoeff and Lemoine encouraged by the original work of Uhlenhuth, described it on the basis of,allergy and gave the term phakoanaphylactic endophthalmitis. Since then a good number of investigators (Burky, Scobee & Slaugheter, Geodner, Ahuja et al,) and others failed in experimental animals to demonstrate the granulomatous inflammatory reaction to the injured lens similar to that observed in the typical human phakoanaphylactic endophthalmitis. However, Marak, reported in few of his rats typical human like lens induced granulomatous uveitis. In all these previous studies, a due consideration was given to B cells (anti bodies) but T cell activities were seen only by delayed cutaneous hypersensitivity test, which is less reliable test in comparison to sophisticated test like lymphocyte transformation test.
We reviewed the study of experimental lens induced uveitis in rabbits, guineapigs and rats. The study of guineapig and rats will be reported elsewhere. In the present study we will discuss the experimentally lens induced uveitis in rabbits. The immunological aspect of this study has already been published. Rahi et al 7, Misra et al 6,. Since now it is well known that anaphylactic reaction is IGE mediated so we will use the term Phakoallergic endophthalmitis instead of term like Phakoanaphylactic endophthalmitis.
| Material and method|| |
The study was performed on New Zealand adult albino rabbits using littermates where possible in Institute of Ophthalmology, London. Heterologous lens protein from guineapig lens, homologous lens protein rabbit lens and autologous lens protein from same rabbit in saline with or without incomplete and complete Freunds adjuvant were given intramuscularly at different sites at ten days interval in different groups of rabbits. The animals were bled on the first day of immunisation and also at the time of subsequent injection. The antibodies were tested by gel diffusion, immunoelectrophoresis, immunofluorescence, immuno per oxidase and by passive haemagglutination test. After the final injection, the animals were skin tested and injection site was biopsied 48 hours later. They were anaesthetised and discission of the right lens was performed with Ziegler's knife. They were killed a week later and. blood was collected from the heart in preservative-free heparinised container for lymphocyte transformation test The aqueous was collected for the study of aqueous antilens antibody and aqueous prostaglandins. Both eyes were enucleated for histological examination. In the animals where autologous lens was injected, in few of the animals intravitreal challenge was made by autologous lens.
The rabbits were divided in following groups on the basis of systemic immunisation schedule:
Group I. Heterologous lens with saline, incomplete or complete Freund adjuvant.
II. Homologous lens with saline, incomplete or complete Freund adjuvant.
III. Autologous lens with complete Freunds adjuvant.
IV. Saline, incomplete or complete Freund adjuvant were injected intramuscularly without lens and intravitreal injection was given in few animals without prior systemic immunisation.
The changes in the skin in immunised rabbit after lens injection were minimal and showed a mixture of polymorphonuclear and lymphocyte infiltration. The lymphocyte transformation index was in between nil to 2.5 in different animals. Clinicaliy, the inflammation persisted for only a few days and histological examination a week later showed little evidence of granulomatous phakoallergic endophthalmitis. The needled lens showed only mild cellular infiltration, consisting mainly of macrophages, and the iris appeared haemorrhagic and congested.
Skin biopsies from immunised rabbits following homologous lens injection showed a non-granulomatous reaction which consisted of lymphocytes polymorphs, eosinophil and macrophages. The inflammation was more marked when injection was given with complete rather than incomplete adjuvant. The lymphocyte transformation index was 2.5 to 3.5. The needled eyes showed evidence of nongranulomatous inflammation. The lens was infiltrated with polymorphs, eosinophils, macrophages and occasional lymphocyte and plasma cells. Similar inflammatory exudates were present in the vitreous and also in the chamber. Epithelial hyperplasia of the lens with subcapsular fibrosis was a common feature of all eyes.
The eyes from immunised rabbit showed lymphocyte and plasma cells in the ciliary body and choroid. There was evidence of subcapsular fibrosis in the lens remnants which were surrounded by lens protein containing macrophages.
The skin hypersensitivity test was negative. The animals did not show lymphoblastic changes when challenged in vitro with lens antigens. The eye showed very minimal reaction after needling of lens.
| Discussion|| |
In group I, the degree of phakoallergic endophthalmitis was very mild. This is in keeping with the concept that heterologous antibodies are less pathogenetic than auto antibodies. It is known that the insoluble albuminoid is more potent than soluble, lens crystalline, in inducing 'T' cell sensitisation and therefore tissue allergy (Manski), it was speculated that since in this group only soluble lens proteins were used, it is likely that rabbits were not sufficiently sensitised to manifest granulomatous reaction. This was further supported by the fact that the animals in the present series did not show marked lymphoblastic changes when challenged in vitro with lens antigens.
In group II, where homologous lens was used as a whole followed by discission of lens, did not lead to granulomatous phako-allergic endophthalmitis. The lenses, however, were infiltrated by polymorphs, eosinophils, lymphocytes, and plasma cells suggesting an arthus type reaction.
In group III, where systemic immunisation with autologous lens protein did not lead to a granulomatous inflammatory reaction either in the uvea or in and around the lens remnants, intravitreal injection of autologous lens proteins in pre-immunised animals led to marked polymorphonuclear infiltration suggesting an arthus type reaction.
The fact that a granulomatous reaction was not present inspite of marked delayed hypersensitivity as evidenced by a strongly positive lymphocyte transformation test and good titre of antibodies suggests that rabbits are not suitable experimental model for lens induced granulomatous uveitis. In a study using heterologous and homologous lens antigens, we have found that guineapigs and rats show a greater preponsity to develop phakoallergic endophthalmitis. These studies will be reported in detail elswhere.
| Summary|| |
The rabbits were immunised by hetero, homo and autologous lenses with and without incomplete and complete Freunds adjuvant. The complete immunological study was conducted at regular intervals. The antibodies were demonstrated by various immunological techniques. The skin hypersensitivity test against lens was seen. The lens was needled and after one week the animals were killed and lymphocyte transformation test was done. The eyes were enucleated and sections were examined under microscope.
The main type of reaction was an arthus type of reaction. In none of our animals, the typical human like granulomatous endophthalmitis was seen, inspite of high titre of antilens antibody and positive lymphocyte transformation test, a new term, 'Phakoallergic endophthalmitis' is also being suggested,
| Discussion|| |
Dr. L.P. Agarwal commenting on the paper remarked that rabbit is not the ideal animal for studies of lens induced uveitis.
| References|| |
Ahuja, 0 P., Kothalkar M.S., and Shukla, B.R., 1972, Ind. J. Ophthal., 70.
Burky, E.L., 1934, Archives Ophthal , 12, (new series), 536.
Goodner, E.K., 1964, Immunopathology of Uveitts, 233 Ed, by A.E. Maumnee and A.M. Silverstein, Baltimore, Williams & Wilkins.
Manski, W., 1973, The Human Lens, Ciba Symposium, 19. (New Series), Amsterdam, Excerpta Medica.
Marak, G.E. Font, R.L. and Alepa, F.P.. 1976, Modern Problems in Ophthal., 16, 75.
M isra, R.N., Rahi, A.H.S., and .v; organ, G., 1977, Brit. J. Ophthal., 61, 205.
Misra, R.N., Rahi, A.H.S., and Bhattacharjee, 1977, Brit. J. Ophthal., (in Fress).
Rahi. A.H.S., Misra R.N., and Morgan, G., 1977, Brit. J. Ophthal., 61, 164.
Rahi, A.H.S., Misra R.N., and vorgan, G., 1977, Brit. J. Ophthal., 61, 371.
Scobee, R.G., and Slaughter, H.C. 1944, Amer. J. Ophthal., 27, 491.
Straub. M., 1919, On inflammation of the Eye caused by Resorption of Crystalline Lens Matter in Eye Lymph (in Dutch). Ed. J. H. de Bussy. Amsterdam.
Unlenhuth, P.T., 1903, Festschrift zum Sechzigsten Guberstage von Robert Koch, 49. Fischer, Jena.
Verhoeff, F.H., and Lemoine, A.N., 1922, Amer. J. of Ophthal., 5, 737.