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The electron microscopic characteristics of the trachomatous conjunctiva and the trachoma agents and their evolution cycle are examined in a study on seven patients with Stage II trachoma, as classified by MacCallan, who had received no treatment. All the cellular epithelial structures remain intact despite the presence of pathological agents whose developmental cycle is entirely comparable to that observed "in vitro" in strain cultures. An imortant fact is the demonstration of macrophages in the sub-epithelial layers and of free pathological agents in the tarsal zone. The necrosis of the former may be responsible for the presence of the latter. A new hypothesis on the dynamics of trachoma infection is proposed together with its consequences in relationship to the forms of trachoma therapy.

A new simplified grading system for trachoma, which is based on the presence or absence of five selected key signs, has been assessed. The level of inter-observer variation and of variation for individual observers (intra-observer variation) showed that the system had good reproducibility following a training period that included interactive clinical teaching. The grading scheme was quickly learned by experienced ophthalmologists and auxiliary health personnel (ophthalmic nurses). The scheme should therefore be suitable for widespread application in field surveys of trachoma.

Ocular infection with Chlamydia trachomatis, whether of genital or endemic trachoma origin, usually produces diffuse infiltration and swelling of the scleral limbus, grey infiltrates of the corneal limbus, and superficial extension of vessels onto the corneal limbus. In genitally transmitted C. trachomatis infections, subepithelial infiltrates have been reported as well. In classic endemic trachoma, limbal changes also include limbal follicles which resolve, leaving Herbert's peripheral pits, and an extensive vascular pannus. To evaluate the limbal changes in trachoma, follow-up studies were done in 1986-1987 in a group of 213 children originally seen between 1969-1972. Pannus formation occurred at a much earlier age than conjunctival scar formation and was an excellent predictor of later severe conjunctival scarring. The evidence from this study suggests that the mechanisms for corneal pannus formation from the limbus are quite different from those for scarring of the conjunctiva.

A blind volunteer was inoculated in one eye with an isolate of Chlamydia trachomatis in 1961 and followed for 20 years. During this time, many observations were made of his clinical responses to the first inoculation and several subsequent inoculations with the same and other strains, chlamydial shedding, and antibody and cell-mediated immune responses. Evidence is presented that partial resistance to chlamydial eye infection developed during repeated infections and that antibodies, cell-mediated immune reactions, and specific antigen in conjunctival cells persisted for many years after the last infection. The antibody response was directed mainly against the original infecting immunotype, regardless of whether the response was restimulated by infection with the same immunotype or with other immunotypes. The lymphocyte stimulation response appeared to be species specific.

Serum C1q, C3, C4, and C5 components of complement levels were measured in 56 healthy subjects and 98 patients with trachoma. Serum C1q and C3 levels were found to be significantly low in stages II and III. There was no change in serum C4 and C5 levels in any of the stages. The levels of C1q and C3 complement components in serum in stages II and III returned to normal as the disease resolved following the medical treatment.

Trachoma remains the major infectious cause of blindness in many developing areas, especially where hygiene is poor. The practices and behaviors associated with an increased risk of trachoma were studied in central Tanzania, where a stratified random cluster sample of 8409 people was examined. Data were collected on family and individual characteristics and behaviors and on trachoma status. Overall, 60% of the children aged 1 to 7 years had active inflammatory trachoma, and 10% of those aged 60 years or older had trichiasis. Regression analysis showed that active inflammatory trachoma in children was associated with the characteristics of the more traditional families and several measures of poor personal hygiene. Two important risk factors for severe inflammatory trachoma were poor facial cleanliness in children (odds ratio of 1.7 [1.17, 2.50]) and household fly density (odds ratio of 1.63 [1.17, 2.29]). Both factors are potentially amenable to intervention. These data suggest that an intervention strategy aimed at these hygiene measures would provide an effective method of controlling trachoma in this region, and a similar approach may be useful in other areas.

In two villages in southern Tunisia where trachoma was endemic 7 per cent and 14 per cent of adults respectively had visual acuity of 20/400 or less. In both villages active trachoma affected most children under the age of two, reached a peak in two- to five-year-olds, then declined to age 15. The chronic inflammatory disease in childhood appeared to produce irreversible scarring of the eyelids, and loss of vision occurred in adult life due to corneal scarring caused by inturned eye lashes and loss of tears (dry-eyed syndrome). Economic development in one village was associated with a decline in active, infectious disease. In the second village, whose traditional economy was unchanged, there was the same prevalence of active disease over a three-year period. Unless economic development or public health control programmes reduce the prevalence of severe and moderate trachoma children now affected will develop the same blinding lesions as their parents. With the increasing numbers of children who survive there will probably be a dramatic increase in the numbers of the blind from trachoma in 10 to 20 years. Since active inflammatory trachoma in childhood responds to tetracyclines, erythromycin, and sulphonamides the disease should be attacked in those undeveloped rural areas where it continues to lead to blindness.

Ultrastructural and histochemical studies were performed on conjunctival concretions (yellow spots in the tarsal conjunctiva) from two patients who had associated atopic keratoconjunctivitis and posttrachomatous degeneration. By electron microscopy, these concretions were composed of finely granular material and membranous debris accumulating in the conjunctival subepithelium. Histochemically, concretions stained strongly positive for phospholipid and elastin, weakly positive for neutral polysaccharides and lipid, and were negative for amyloid, collagen, glycogen, iron, mucopolysaccharides, RNA, and DNA. In view of the absence of both calcium and phosphate in the accumulated material, the use of the term "lithiasis" is misleading and should be avoided. These findings support a hypothesis that concretions that follow chronic conjunctivitis represent products of cellular degeneration.

We performed lacrimal sac biopsies in 35 patients who underwent dacryocystohinostomies in Saudi Arabia. The nasolacrimal duct obstructions were presumably secondary to trachoma in 22 cases and unknown in the remaining 13 cases. Lacrimal sac specimens were submitted for routine histopathologic examination and the direct-smear fluorescent antibody test. All specimens were negative for chlamydia. Possible reasons for the low detection rate of chlamydia in the trachomatous group were the frequent finding of clinically inactive disease, common canalicular obstruction, and loss of the epithelial lining in the lacrimal sac.

Phlyctenular keratoconjunctivitis is now a rare clinical entity. Histologic staging has been updated by infection-immunological findings: phlyctenules have been identified as delayed-type cellmediated immune responses involving bacterial, mycobacterial, chlamydial, fungal or parasitic pathogens. Establishment of a correct diagnosis should include conjunctival and systemic work-ups for pathogenic agents. Case reports of three patients are presented.

To study chlamydial conjunctivitis, conjunctival autografts subcutaneously implanted in pockets on the abdomens of rhesus (Macaca mulatta) and pig-tailed (M. nemestrina) monkeys were inoculated percutaneously (4-10 X 10(4) inclusion-forming units per pocket) with trachoma strains of Chlamydia trachomatis (serovars B & C). These conjunctival pockets were removed on days 2, 3, 4, 5, 6, 7, 8, 10, 14 and 16 post-inoculation (pi). Tissues (at least two samples at each time interval) were prepared either for reisolation of the organisms by cell culture or histologic examination by light and electron microscopy. Control tissue, inoculated with either HeLa cell material or UV-inactivated organisms, were prepared in parallel. Bloods were drawn and tear strips taken at weekly intervals for 8 weeks. A total of 221 bulbar and 99 palpebral conjunctival pockets were established over time with the success rate of 75% and 88%, respectively, in six rhesus and ten pig-tailed monkeys. Histological examination revealed widespread infiltration of mixed polymorphonuclear and mononuclear cells on days 2 and 3 pi. By day 5 pi, lymphocytes had migrated into the thinned epithelial layer. Patches of inflammatory infiltrate similar to trachoma follicles were observed, although distinct germinal centers were absent. Surface morphologies of normal and infected pocket conjunctiva were examined by scanning electron microscopy. Normal tissue was characterized by a regular mosaic pattern of closely packed epithelial cells containing numerous microvilli. Infected tissue was edematous, and the continuity of the mucosal surface had been altered. Chlamydiae were reisolated from the pockets on days 2, 3, 6, 8 and 10 pi.(ABSTRACT TRUNCATED AT 250 WORDS)

The course of primary ocular infection with guinea-pig inclusion conjunctivitis agent was followed in 2 groups of animals. One group of fully grown animals was repeatedly scraped; the other of small animals was used on 1 occasion only and scraped after clinical examination. The intensity of conjunctival inflammation was measured, conjunctival scrapings were taken, and the numbers of polymorphonuclear cells, mononuclear cells, and epithelial cells containing chlamydial inclusions were counted, and the level of antibodies in serum was measured. It was found that inflammation of the conjunctiva lasted for about 30 to 40 days, and the clinical features (oedema, hyperaemia, papillary reaction) were very similar in the 2 groups. Inclusions and polymorphonuclear cells were found for up to 21 days, and mononuclear cells were found on days 7 to 25. Serum antibodies were first detected on day 10 and reached a peak on day 21. The intensity of inflammation was significantly higher on day 2 in the animals which had been scraped. After this the severity of the inflammation and the course of disease were similar in the 2 groups.

Chlamydiae are small bacteria that have a unique life cycle. There are two species, Chlamydia psittaci and C. trachomatis, which cause a wide spectrum of clinical disease, including neonatal conjunctivitis and pneumonia, sexually transmitted disease, psittacosis, and trachoma. The importance of chlamydial disease in public health is being increasingly recognized, and the incidence in developed countries seems to be increasing. An understanding of chlamydial disease, its prevention and treatment, is essential for the infection control practitioner, who can play a significant role in patient education.

The authors' epidemiologic studies of trachoma on Taiwan and experimental monkey eye infections with and without Chlamydia trachomatis immunization are reviewed for the data they provide on the pathogenesis of trachoma. These studies indicate that trachoma is an immunopathologic disease in which the more severe progressive trachoma infections with pannus and scar formation occur only after reinfection. This hypothesis is supported by a 10-year study of 32 family households that were followed with repeated clinical and laboratory observations. Although most cases of active trachoma healed spontaneously, there were 26 persons in nine families who developed clinical and laboratory evidence of 29 episodes of new trachoma eye infection. On the basis of the clinical disease, its persistence, and the laboratory findings, these 29 new infections could be divided into 10 primary, nine secondary, and 10 tertiary infections. Details of the different stages of infection leading to chronic trachoma are presented.

Various techniques which use monoclonal antibodies to detect Chlamydia trachomatis in clinical specimens are reviewed. An investigation comparing the efficacy of immunofluorescent staining with Giemsa staining in detecting Chlamydia in conjunctival scrapings from cases of active trachoma is presented. Sixty-two eyes of schoolboys with moderate to severe trachoma were studied. Giemsa staining detected chlamydial inclusion bodies in 34 percent of the specimens. Free elementary bodies were detected by fluorescent monoclonal antibody in 21 percent. Eleven percent were positive by both Giemsa and immunofluorescence and 55 percent were positive by either Giemsa and/or immunofluorescence. The addition of fluorescent monoclonal antibody assay to routine Giemsa staining resulted in an increase in the yield of positive specimens by 29 percent.

Guinea-pigs were repeatedly infected with guinea-pig inclusion conjunctivitis agent. Reinfection caused severe conjunctival inflammation, and repeated reinfection led to chronic inflammation lasting for many months. This was followed by the development of pannus, follicles on the palpebral conjunctivae, scarring of the lower palpebral conjunctiva, and deformities of the lower lid. Reinfection was accompanied by small numbers of inclusion-bearing cells, small numbers of polymorphonuclear cells, and high numbers of mononuclear cells. There was no increase in the level of serum antibodies. The chronic conjunctivitis was associated with high numbers of mononuclear cells and no inclusions or polymorphonuclear cells. The response to reinfection appears to be a delayed-type hypersensitivity reaction, and we suggest that the chronic inflammation, pannus, scarring, and lid deformities associated with hyperendemic trachoma may be due to repeated reinfection combined with delayed-type hypersensitivity.

A prospective study of 2,000 eyes of 1,000 consecutive unselected ophthalmic outpatients showed that Herbert's pits and superior tarsal conjunctival concretions are significantly associated conditions. Fifty per cent of eyes with Herbert's pits were found to have superior tarsal conjunctival concretions, compared with four per cent of eyes without Herbert's pits. Furthermore, a strong correlation between the degree of Herbert's pits and the degree of development of concretions was demonstrated.

In a study of 141 cases in different stages of trachoma, a definite change was observed in the curvature of upper part of cornea, which had become ectatic. The difference in curvature depended on the stage and severity of the trachoma. Most of the patients had fourth stage trachoma. Also, the degree of ectasia was greatest in the late stages of the disease--a point that must be kept in mind when lamellar keratoplasty is done in this type of case.

A detailed study was made of the prevalence and associations of trachoma in a prospective, randomised population based study of 9058 Palestinian Arabs living in the West Bank and Gaza Strip, and in a prospective study of 1,000 consecutive unselected ophthalmic outpatients at St John Ophthalmic Hospital, Jerusalem. Trachoma was found to be widely distributed throughout the two regions. This chiefly occurred as a mild, self limited disease, interspersed with discontinuous pockets of blinding disease. The highest prevalence was found in the Hebron and Jericho districts. Sub-populations at increased relative risk included females, older age groups, rural dwellers, patients with pre-disabling or disabling lesions, and patients with moderate to severe active trachoma. An increased recovery of bacteria by culture of the lids and conjunctiva of patients with moderate to severe trachoma was noted. Prevalences of lacrimal disease, dacryocystitis, and acute bacterial ulcer were significantly greater among outpatients with trachoma than among those without trachoma. No difference in prevalence of either mucopurulent conjunctivitis or herpetic dendritic keratitis was demonstrated between patients with and without trachoma. An increased prevalence of trachoma was found in communities without a continuous year-round supply of running water compared with communities with this facility.

A simplified method of evaluating both the intensity of active inflammatory disease and the visually disabling lesions of trachoma is presented. Evaluation of the active disease is based on the scoring of clinical signs, lymphoid follicles, and papillary hypertrophy. The irreversible lesions of trachoma are classified as conjunctival scarring, trichiasis and/or entropion, and corneal scarring.

Microscopical examination of 927 Giemsa-stained conjunctival smears from children with chronic trachoma in southern Tunisia showed 93 (10 per cent.) with typical trachoma (chlamydial) inclusions in epithelial cells. The accompanying cytological features were a useful indicator for inclusions. Inclusions were found only in slides with numerous polymorphonuclear neutrophils (PMNs) and separation of the epithelial cells. When these two features alone were present, 3 per cent. of the smears were inclusion-positive; when many lymphocytes were present also, 25 per cent. were inclusion positive; when other cytological features (plasma cells, macrophages, blastoid, and stem cells) were present as well, 70 per cent. of the smears were inclusion-positive. The occurrence of these sets of cytological features can be a useful guide for selecting smears for intensive examination for chlamydial inclusions. Immunofluorescent (FA) staining and Giemsa staining of 527 pairs of matched smears detected trachoma agent in 67 (13 per cent.); in thirty by both methods, in thirteen by Giemsa staining alone, and in 24 by FA alone. The examination of Giemsa-stained smears for chlamydial inclusions is a useful technique for the diagnosis of trachoma or inclusion conjunctivitis by laboratories that do not have the specialized facilities for the identification of these chlamydial infections by the technically more complex procedures of immunofluorescent staining or isolation in embryonated eggs or tissue cultures.