|Year : 1958 | Volume
| Issue : 2 | Page : 30-34
Difficulties in the field diagnosis of trachoma
Satnam Singh, AD Grover
Muslim University Institute of Ophthalmology and Gandhi Eye Hospital, Aligarh, India
|Date of Web Publication||8-May-2008|
Muslim University Institute of Ophthalmology and Gandhi Eye Hospital, Aligarh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Singh S, Grover A D. Difficulties in the field diagnosis of trachoma. Indian J Ophthalmol 1958;6:30-4
Trachoma where endemic, is more or less a monopoly of the rural masses; their illiteracy, poorer standards of personal hygiene and environmental sanitation, combined with lack of adequate medical facilities are some of the factors responsible. In all future trachoma control programmes, it is envisaged that almost all the clinical work will have to be done in the villages. Often, a medical officer with his diagnostic kit comprising of no more than a light source, a binocular loupe (X 2.1), a uniocular loupe(X 10) and a Desmarre's lid retractor will be required to pay house to house visits. In our considered opinion an understanding of the limitations in the field diagnosis of trachoma in various stages, will keep diagnostic errors down to a negligible level.
In a clinic where facilities for the bio-microscopic examination are available, the diagnosis of trachoma presents hardly a problem Thygeson (1957) Even, the demonstration of H. P. inclusion bodies in the conjunctival scrapings is rarely called for.
However, in a small number of cases, a short follow-up is necessary to remove certain doubts in the diagnosis. For workers in the rural areas, ideal facilities may not always be available, or if some are made available, the working conditions are such that it is not always possible to make use of them.
| Working Facilities|| |
The authors for some time have been working in the rural areas of Aligarh District, almost under ideal conditions i.e. with a portable slit-lamp (Zeiss model), laboratory facilities and opportunity to study a fixed untreated rural population every month over a period of one year. This longitudinal study which in certain respects is a definite advantage over a cross sectional study, has helped to understand certain limitations of working, without the above mentioned facilities.
| Diagnostic Criteria|| |
The criteria of diagnosis adopted were as stated in the WHO Technical Report Series No.106 of May 1956 which are as follows:
In making the clinical diagnosis of trachoma two at least of the following should be present :-
(i) Follicles (conjunctival or limbal).
(ii) Epithelial keratitis most marked in the upper part of cornea.
(iii) Pannus in the upper part of cornea.
(iv) Typical scars.
However, in infants and children it was not always possible to examine the upper limbus and the diagnosis of TR. I and TR. II. was often made by the findings in the upper tarsal conjunctiva of uniformly distributed pre-follicles or follicles interspersed amidst varying degrees ol papillary hypertrophy.[Figure - 1]
| Difficulties in the Field of Diagnosis|| |
The following factors singly or combined may often make the field diagnosis of trachoma in various stages difficult :-
1. Associated Acute or Sub-Acute Bacterial Conjunctivitis.
In the prevailing rural environmental conditions, infants and children, especially in the summer months suffer from repeated attacks of acute or sub-acute bacterial conjunctivitis. Kock-weeks, pneumococcus. Morax Axenfield and others in this order of frequency. As the age of onset of trachoma lies in the same age group, the oedema and injection of the associated conjunctivitis often marks an important early sign of trachoma (TR. I) which consists of uniformly distributed light yellow coloured pre-follicles in the tarsal conjunctiva [Figure - 2]. The importance of this sign, in view of frequent inability to examine the upper limbus in this age group, has already been mentioned.
In an ophthalmic clinic the diagnosis in a case of the above difficulty may be settled by the use of one or more of the following procedures :-
A child of about 3 years of age, will often permit the examination of the everted upper lid by the slit-lamp, and even though cedema and injection is intense the yellow hemispherical prefollicles may be seen buried in the thickened conjunctiva. With the uniocular or binocular loupe, the prefollicles may either not be seen or appear doubtful.
Secondly, one or more conjunctival scrapings may be taken from the tarsal conjunctiva and the upper fornix, to look for the typical cytology and presence of H. P. inclusion bodies. Absence of the latter do not negative the diagnosis, for in the region around Aligarh, where the disease pattern and incidence of trachoma is comparable with that prevailing in the Western States of Uttar Pradesh, Punjab and Rajasthan - Radovanovic (1956 a, b) only about a third of TR. I cases, (with only one scraping taken from the upper tarsal conjunctiva) are positive for H. P. inclusion bodies.
The last and often the most satisfactory method which can be adopted in a clinic is to treat the associated conjunctivitis and to re-examine the tarsal conjunctiva on the second or the third day, when, with the diminished conjunctival oedema, the presence or- absence of the pre-follicles can be ascertained.
Majority of the adolescent and adult subjects are in TR. stage IV with mild or moderate degrees of conjunctival scarring and without any entropion or trichiasis. During the height of the seasonal peaks (in summer months) of bacterial conjunctivitis some of these cases get conjunctivitis. Although, in the majority of cases this superadded bacterial infection is easy to differentiate clinically, some present the signs nearly simulating a reactivation of the trachomatous process i.e. TR. IV going back to TR. III - reinfection or relapse. In the upper third of the cornea of these cases the attenuated blood vessels of healed pannus get filled up with blood. Further the upper tarsal conjunctiva, may show mild papillary hypertrophy. This combined picture though very suggestive of TR. III on the first examination restitutes to initial TR. IV. within about a fortnight even if untreated if it is a secondary infection on TR IV, whereas actual reactivation of the trachomatous process takes months to settle down.
2. Differentiation of Mild TR. IV From TR. 0 Cases.
Trachoma uncomplicated by secondary infection is a mildly contagious disease with a tendency to spontaneous cure in a good number of cases. This is so in individuals having the benefit of relatively better personal hygiene. In this class, seasonal attacks of conjunctivitis which aggravate and prolong the course of trachoma, are fewer and less severe. The result of all this being that in an average village primary school, only the first two or three classes may show some cases of TR. III and out of the remaining school children, barring the few with Tr. 0, all of them show signs of mild or moderate degrees of healed trachoma (TR. IV). It is while differentiating some of the cases of mild Tr. IV from normal eyes, that a field worker misses his slit-lamp and corneal microscope.
Ordinarily, to label a case as Tr. IV, the conjunctival and limbal signs are depended upon. In a mild case, the thin superficial and scattered conjunctival scarring may be so fine, as not to be visible under ordinary magnifications and recourse to the slit-lamp especially with a broad beam of light is essential. Many such tarsal conjunctivae, under ordinary magnifications, show loss of transparency often associated with change of the vascular pattern - Radovanovich (1957) which consists in the increased number of blood vessels with irregular branching.
Also, there are cases which after having had a very mild course of trachoma [Figure - 2] present normal conjunctivae (restituto ad integrum). In such a group, biomicroscopic picture of the upper limbus is of help in the diagnosis. Fortunately, the high incidence of Herbert Pits (mostly arranged at the upper limbus), - Satnam Singh and Grover (1957) that is met with, in the region where observations have been made, makes the diagnosis simpler, for these tell-tale scars of once limbal follicles are pathognomonic of trachoma - Thygeson (1957). Ocampo (1955) - and their presence can always be detected with ordinary magnifications [Figure - 3]. Where the Herbert Pits are not well developed a regular festooning of the corneal edge of the upper limbus is very suggestive.
A limbus with no pits and looking apparently normal cannot always be dismissed as non-trachomatous in a heavily endemic area as ours (70 to 80% being the total incidence of trachoma) - Singh and Grover (1957). When such cases are examined with a biomicroscope, in light reflected from the iris (retroillumination) a surprisingly large number of them show thin attenuated blood vessels extending up to one to two m.m. on to the clear upper cornea. The lower limbus may also show such involvement but always less than that of the upper - Thygeson (1957). In such a group of cases, under ordinary magnifications the normally translucent limbus opacity may appear dense though with an uninterrupted smooth corneal edge. The final confirmation however must always come from the slit-lamp examination.
3.'Kajjal' Scarring of the Conjunctiva.
`Kajjal' which is lamp-black with Zinc Oxide and with other vegetable and mineral matters grinded into it, is a popular salve with the villagers for almost all eye ailments. Most of the infants and children get it religiously applied at least once a day. It is, where the Kajjal ritual is continued in the children suffering from acute mucopurulent or purulent ophthalmias, that the after-effects interest us. Kajjal particles get locked up either in the pseudo-membranes or in the various recesses of the inflamed and doubled-up conjunctival fornices. When the conjunctivitis abates after a few weeks, depending on the quantity and the arrangements of the Kajjal deposits, fine or moderate degrees of conjunctival scarring is laid around these particles. In most of these cases even by ordinary magnifications, the Kajjal scarring can be distinguished from the genuine trachomatous scarring by its colour, shape and position. In a few cases where the finely scattered Kajjal deposits get covered up with light scarring, the biomicroscopic examination alone can show deeply embedded fine black particles which reveal the nature of the conjunctival scarring. Often in some such cases the trachomatous and the Kajjal conjunctival scarrings are so intimately mixed up that one mainly relies on the degree of limbal involvement to understand the past course of trachoma.
4. Non-Trachomatous Follicular Conditions.
In chronic follicular conjunctivitis or in folliculosis, with superadded mild secondary bacterial conjunctivitis it may sometimes be difficult in the field to differentiate them from mild early trachoma. This is so when the follicles on the upper tarsal conjunctiva instead of being uniformly distributed are localised more near its upper border and the angles [Figure - 4], (Thygeson (1957) considers this as one of the early signs in TR. I) the limbus at the same time appearing almost normal or doubtful on a naked-eye examination. In such cases though the distribution and the prominence of the follicles in the upper fornix as compared to the lower, may point to the diagnosis of trachoma, the confirmation has to come from the biomicroscopic examination of the upper limbus, which is not always possible in the field.
A genuine difficulty which even a worker in a clinic has sometimes to face is, when a case of trachoma after having a prolonged course of treatment, presents himself with a healed pannus but still with stray follicles in the fornices. To decide if these remaining follicles are those of incompletely regressed trachoma or the non-trachomatous follicles unaffected by the treatment, help can be obtained from follicular expression and by a follow-up. Due to degenerative changes, the follicles of trachoma are soft, easily expressible and contain numerous macrophages or Leber cells, and fragmented cells with bare nuclei - Thygeson (1955). Then again trachoma follicles take weeks to disappear; those of chronic follicular conjunctivitis months and of folliculosis years. Use of local cortico-steroids as tried by various workers, - Freyche, Roger, Maurin, Delon (1953), to reactivate trachoma needs further confirmation thus making its present use unreliable in the above group of cases. Though chronic follicular conjunctivitis and folliculosis are commonly seen in urban children, their incidence among the rural population fortunately is relatively low.
5. Children Suffering From Severe Anemia.
Severely anaemic children are not uncommonly met with in the rural areas. The conjunctiva assumes a pale white appearance bolishing all colour contrast between the papillary hypertrophy and the follicles. For the same reason the conjuctival scarring, unless it is dense enough cannot be easily distinguished.
In such cases, the presence of varying degrees of the papillary hypertrophy, follicies and the mild scarring of the conjuctiva, can be assessed with confidence only when aided by a biomicroscope
| Summary|| |
For the field diagnosis of trachoma cases, the benefits of biomicroscopy, examination of the conjunctival scrapings and follicular expressions and the follow-up facilities may not always be available. A field worker, who mainly relies on a portable light source, a binocular loupe (X 2½), a uniocular loupe (X 10) and a Desmarre's lid retractor, for making the diagnosis, may experience difficulty in the following situations :-
(a) In children where the conjunctival signs of early trachoma are masked with associate subacute or acute bacterial conjunctivitis.
(b) To differentiate mild TR. IV cases with no typical limbal signs from normal cases (TR. 0).
(c) To differentiate fine trachomatous scarring from that caused by fine deposit of Kajjal
(d) To differentiate certain non-trachomatous follicular conjunctivitis from mild trachoma.
(e) In severely anaemic children.
We are thankful to the Indian Council of Medical Research in providing facilities for field work and to Dr.M.Radovanovic,Senior WHO Officer, who has guided us on many occasions.
| References|| |
Freyche, M. J., Roger, N., Maurin, J., Delon. P. (1953), WHO/Trach.135.
Ocampo, G. de (1953), WHO/Trach./42.
Radovanovic, M., (1956), SEA/Trach/2 - WHO Document for Internal Working.
Radovanovic, M. (1956), SEA/Trach./2, Part II, (Rajasthan State) - WHO Document for Internal Working.
Radovanovic, M. (1957), Personal Communication.
Singh, S., Grover, A. D., (1957), Proc. All India Oph. Soc. - XVIII Conference.
Thygeson, P. (1957), Proc. All India Oph. Soc. - XVIII Conference.
Thygeson, P. (1955), WHO/Trach./52.
W.H.O. Expert Committee on Trachoma. (1955), WHO/Trachoma/67.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4]