[Macular functions in professional divers]. / Fonction maculaire chez le plongeur professionnel.

PURPOSE: Air diving is frequently practiced by professionals or sportsmen. Controversial data exist in the literature on the existence of retinal abnormalities in divers. PATIENTS AND METHODS: 18 divers (aged: 27-58y) who dived around 2000 times in their life were studied: half of them dived only with air while the others used an O2-enriched gas mixture (40 to 60%). None of them had presented a bend (decompression sickness). Visual acuity and ocular fundus examination have been explored. A quantification of color vision and central visual field, so as a fluorescein angiography have been performed. RESULTS: No alteration of visual acuity was noted; abnormalities in the color vision and the visual field are reported; however the angiographic lesions described in the literature have not been observed. DISCUSSION: The alterations of color vision were quite severe but not very frequent. No correlation was found with any characteristics or type of diving. CONCLUSION: These observations are comforting for sportive divers who do not dive very often nor very deep but an individual predisposition is suspected.

Impression Cytology with Transfer in xerophthalmia and conjunctival diseases.

During a countrywide survey, we assessed the prevalence of clinical signs of xerophthalmia and of major conjunctival diseases in a randomized sample of 2,445 subjects representative of the population of the Republic of Djibouti. On a part of this sample, conjunctival Impression Cytology with Transfer (ICT) test and a plasma retinol determination were performed. Xerophthalmia as a public health problem was displayed by clinical signs (Bitot's spots, corneal scars among preschool children), low plasma retinol levels and ICT test results: 9.3% with deficient cytology in the rural area and 12.3% in the urban one (age-standardized rates). Results of ICT were related to age (p < 0.00001). Vitamin A deficiency was prevalent not only in preschool children but also up to 15 years. Moreover, ICT results are influenced by conjunctival diseases: compared to age-matched controls, there were more abnormal cytologies among patients with trachomatous inflammation (p = 0.025), conjunctivitis (p = 0.024) or Limbal Vernal Keratoconjunctivitis (p = 0.015). Thus ICT shouldn't be performed among children with conjunctival diseases. In the region under study conjunctival diseases had high rates of prevalence: 16.4% of trachomatous scarrings in the urban area (standardized rate), 8% of conjunctivitis among rural preschool children, and 5% of Limbal Vernal Keratoconjunctivitis among children between 5 and 14 years in both areas.

Assessment of vitamin A deficiency in the Republic of Djibouti.

In a countrywide survey, we assessed the prevalence of vitamin A deficiency by clinical examination and impression cytology with transfer method (ICT) in a randomized sample of 2445 subjects representative of the population of the Republic of Djibouti. A plasma retinol determination was made on a part of this sample. Results lead to believe that serious vitamin A deficiency may periodically occur in Republic of Djibouti when nutritional conditions become poor. Meanwhile a large number of children, mostly in the rural area, have a marginal vitamin A status and are exposed to a high level of risk.

Climatic droplet keratopathy, exfoliation syndrome, and cataract.

During a countrywide survey we assessed the prevalence of climatic droplet keratopathy (CDK) in a randomised sample of 2446 subjects representative of the population of the Republic of Djibouti. The investigation of the relationship between CDK and two diseases considered to be related to exposure to ultra-violet light--namely, exfoliation syndrome and cataract--was planned as a case control study. In the rural area prevalence of CDK was five times higher than in the urban one (2.8% vs 0.5%) and varied according to districts. The highest rates were observed where the inhabitants' activities were related to the sea. The case control study revealed that the opacification of the lens was about three times commoner in patients with CDK than in patients without CDK (p = 0.03) and that the exfoliation syndrome was about six times commoner in patients with CDK than in controls of similar age, sex, climatic conditions, and lens status (p = 0.02). Moreover, we noticed that the sequelae of corneal perforations were about 30 times commoner in patients with CDK than in controls of similar age (p less than 0.00001).

[Corneal complications of climatic keratopathy]. / Complications cornéennes de la kératopathie de bietti.

The "keratopathie de Bietti" or climatic droplet keratopathy or keratopathie climatique (KC) is a degenerative disease of the cornea which is probably due to the exposure to ultraviolet rays. Usually the evolution is a progressive invasion of cornea by amber nodules which lift up the corneal epithelium. We observed that numerous patients suffered from severe corneal ulcerations which appeared to be spontaneous and which evolution was frequently disastrous. The aim of this work was to pick up epidemiologic data on KC in order to check the following hypothesis: the corneal opaquenesses, due to non traumatic perforations, would be more frequent among patients suffering from KC than among the rest of population. The study, carried out in Republic of Djibouti, dealed with two groups of people: an hospitable group of 217 patients suffering from a KC and a random sample of 2,446 persons among Djibouti people, from which a study ill-healthy was carried out among people from 40 years old. The mistakes were controled by adjustment on age and climatic conditions. The result is that corneal blindnesses which seemed to be spontaneous were more frequent in a significative way among people suffering from KC than among healthy people as old as ill people and living in the same conditions (12% against 0.7%; p = 0.003; Odds ratio adjusted on age: 31.8 IC: 8.8-115.20). On the etiopathogenic point of view the bacterial, fungal and deficiency causes could scarcely be accepted. The unfavourable evolution, resisting to all the treatments, drove to several hypothesis among them is responsibility of free amoebas as acanthamoeba.

[Epidemiological course of trachoma in Djibouti]. / Evolution de la situation épidémiologique du trachome a Djibouti.

A survey on a representative sample of population showed that inflammatory trachoma is rare in Republic of Djibouti. However, it is significatively more frequent in rural surroundings (0.4%, standard rates) than in urban surroundings (0.4%, standard rates) where it affects particularly people recently coming from border countries. In rural surroundings the frequency changes according to the distances from capital (p = 0.01). On the contrary, cicatricial trachoma is more frequent in the city (16.4%) than in rural surroundings (8.2%--Standard rates). The blindnesses caused by trachoma are relatively rare (0.1%) when entropiontrichiasis appear especially in urban surroundings (0.7%) where people from Arab Peninsula are the most affected (p = 0.008). When comparing with the 1968 situation, we notice a perceptible decrease of the prevalence of trachoma and also the disappearing of ethnic differences which existed at that time concerning the illness active forms. This good evolution is probably due to the effects of several mass campaigns added to an improvement of accessibility to medical care.