|Year : 1972 | Volume
| Issue : 1 | Page : 1-3
Attempt to isolate trachoma agent from lacrimal-sac tissue
NA Vali, AP Goswami, UC Gupta
Dept. of Virolagy, Trachoma Research Centre, Aligarh, India
N A Vali
Dept. of Virolagy, Trachoma Research Centre, Aligarh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Vali N A, Goswami A P, Gupta U C. Attempt to isolate trachoma agent from lacrimal-sac tissue. Indian J Ophthalmol 1972;20:1-3
Trachoma is a chronic communicable disease of the eye caused by a specific agent belonging to the Psittacosis-lympho-granulomatrachoma group. Invariably, the eye will be the reservoir of infection. Atleast in the acute stages of the disease, the material from the infected eyes yield the agent on culture, but we are not sure of the same during the chronic stages. The sac is one of the regions of the eye which is involved, either primarily or as a secondary manifestation of trachoma infection which is initiated in the conjunctiva or the canaliculi. This entity has been known since Weber  reported it for the first time in 1861. Much later, Cange  described the obstruction of the naso-lacrymal duct due to trachoma infection According to Girgis  about 50% of the sacs examined by him were in the cases which had been infected by trachoma. Thus the relationship between trachoma and sac involvement is highly presumptive. According to Duke-Elder  , primary trachomatous dacryocystitis is a rare occurrence but secondary involvement of the sac, after the primary involvement of the conjunctiva and canaliculi and the inflammatory reaction there from is not a rarity. Mac Callan  had reported that the inflammation of lacrymal sac is more common in countries where trachoma infection is more prevalent and therefore concluded that trachoma is a contributory factor for the dacryocystitis.
Papolezy  confirms the existence of trachoma as stated by Mac Callan', and other workers in the field. This confirmation is based on the demonstraction of follicles in the wall of the sac and also of the inclusion bodies in the epithelial cells.
Postic  on the other hand observed follicles regularly in non-trachomatous and trachomatous cases, there being hardly any difference between the two in this respect. Even the rupture of folliccles into the lumen was seen in non-specific dacryocystitis similar to that seen in trachoma. He states that the principal difference seems in plasma cells which are more abundant in tracho.matous sacs, and the rarity of cicatrices. He concludes that the sequalae of dacryocystitis in many instances of trachoma infection is not due to the specific agent.
The lacrymal sac with its crypts and folds can give easy access to the infective agent. We have to try and find out whether the agent may get access to the region in the acute stage, can find lodgement in it and remain in a latent state or not. It has been shown that in chronic and healing stages of the infection, it is difficult to demonstrate the organisms in the infected exudate or in the epithelial cells from the conjunctiva and cornea. It has also been the experience of clinicians, that the organisms do reappear on acute exacerbation or on experimental activation. These observations have led us to imagine that they may be fcund in areas which may have the same environmental features as the conjunctival cells and are easily accessible to them.
It was reported by Attiah  (1963) that lacrymal gland may probably act as a latent habital of the trachoma virus. It was also important that the virus itself, has never been observed in or isolated from the gland excretions. This prompted Attiah and his associates to attempt to isolate the agent from the gland tissues from children showing active disease in stages I and II and also from adults in the chronic stages as III with a few follicles and from cases with scars. In both the latter group of cases there was absence of the virus in the epithelial layers. In their attempt, they were successful to isolate TRIC agent from the lacrymal gland tissue from children in Stages I and II. These findings and earlier observations wich have been enumerated above have encouraged us to try to isolate the specific agent from the lacrymal sac tissue by the routine isolation techniques.
| Material and Methods|| |
Selection of Cases
Seven cases of dacrycyatitis with chronic trachoma in Stage III and two cases in Stage IV were selected from the indoor department of our hospital. Details of the cases are given in [Table - 1] with the results.
In all the cases dacryocystectomy was performed and part of the tissue so removed was studied.
Method of Culture
A piece of lacrymal sac tissue measuring about 3 mm cube was cut with a sharp scalpel into small bits of one mm cubes. These pieces were transferred to a mortar and ground in 1 ml of our standard pre serving fluid (Vali)  . The standard fluid contained streptomycin in concentration of 20 mg. per ml. to supress the contaminating bacteria. The ground suspension of the tissue was transferred to a 15 ml centrifuge tube and centrifuged at 800 r.p.m. for about ten minutes. This step sedimented the coarse tissue particles and the fibrous portion which could not be ground. The supernatent was collected and used as an inoculum. Half a ml of this supernatent was inoculated into the yolk sac of each of two embryonated chicken eggs aged about seven days in the routine way. The inoculated eggs were incubated. at 35˚C in a humidified egg incubator as a routine. and the viability of the embryos were watched. In the absence of any lethal effect on the eggs one of them was allowed to incubate and hatch out and the other egg was opened on the seventh cr eighth day post-inoculation (15th or 16th day of embiyonation) for further studies. Changes in the consistency of the yolk and the difference in the transparency and brittleness of the yolk sac membrance were studied critically as compared to those in the embryonated normal eggs of the same age.
Part of the yolk sac tissue was ground and the emulsion was passed into fresh batch of embryonated egg of the same age as in previous passage. These passages were made irrespective of the positive or negative findings of the presence or absence of the viral particles in order to increase the possibility of isolating the agent after the second or third such blind passage.
| Results|| |
None of the inoculated embroys died after incubation for seven to eight days post-inoculation.
One egg from each of the groups was opened. The examination of the yolk sac revealed nothing abnormal. The transparency due to the thickness of the yolk sac membrane was in no way different from those of normal eggs embroynated the same period.
Further there was no increase in the brittleness of the yolk sacmembrane which is one of the effects of the growth of the agent in the yolk sac. The consistency of the yolk was not different from that of the normal embryonated egg.
The stained smears from the embryonated yolk sac on microscopic examination did not reveal any particles resembling the trachoma agent.
| Conclusions|| |
In our studies of the locrimal sac tissue from nine cases which were removed during dacryocystectomy, we did not find evidence of presence of trachoma agent, though the cases were of trachoma clinically proved to be in Stages III and IV. It is probable that the presence of the agent in the late stages of the disease is doubtful as is generally the case, even in conjuctival smear examination for the presence of inclusions.
To make the study more representative and statistically sound a larger series should be studied. Until it is proved otherwise we like to concur with the views of Postic  that dacryocystitis can not be a sequela to trachoma infection.
| References|| |
Attiah, M. A. (1963) : J., Egypt. Med. Assoc. 46:74. (1963).
Cange, A. ((1928) : Am. J. Oph. 11: 169 (Arch. d'Ophthal. 44:465 (1927).
Duke-Elder (1952): Text book of Ophthal., Vol. V. p. 5222. Pub. Kimpton (Lond.).
Girgis, A. M. (1954): Abst. Oph. Literature 8:2140.
Mac Callan. A. F. (1936): in Trachoma - Pub. Butterworth, Lond. p 36.
Papolezy. V. F. (1934): Quoted by Garfin (1942). A. M. A. Arch. Ophthai. 27:180.
Postic, S. (1957): Arch, d'Ophth. 17: 749. Abstracted in Am. J. Oph. 46:779 (1958).
Vali, N. A. (1968): Am. J. Ophthal. 66:110.
[Table - 1]