Cyanotoxins in desert environments may present a risk to human health.

There have been few studies concerning cyanotoxins in desert environments, compared with the multitude of studies of cyanotoxins in aquatic environments. However, cyanobacteria are important primary producers in desert environments, where after seasonal rains they can grow rapidly both stabilising and fertilising arid habitats. Samples of cyanobacteria from wadis - dry, ephemeral river beds - and sabkha - supertidal salt flats - in Qatar were analysed for the presence of microcystins, nodularin, anatoxin-a, cylindrospermopsin and anatoxin-a(S). Microcystins were detected by HPLC-PDA and ELISA at concentrations between 1.5 and 53.7ngg(-1) dry wt of crust. PCR products for the mycD gene for microcystin biosynthesis were detected after amplification of DNA from desert crust samples at two out of three sample sites. The presence of anatoxin-a(S) was also indicated by acetylcholine esterase inhibition assay. As a function of area of desert crust, microcystin concentrations were between 3 and 56µgm(-2). Based on the concentration of microcystins detected in crust, with reference to the published inhalation NOAEL and LOAEL values via nasal spray inhalation of purified microcystin-LR in aqueous solution, and the amount of dust potentially inhaled by a person from these dried crusts, the dose of microcystins could exceed a calculated TDI value of 1-2ngkg(-1)day(-1) for an average adult. The presence of microcystins, and potentially of anatoxin-a(S), in desert crusts has important implications for human health. Further studies are required to monitor desert dust storms for the presence of cyanotoxins. An understanding of the risks of inhaling particles containing cyanotoxins is also warranted.

[Polypoidal choroidal vasculopathy: clinical and angiographic features]. / Vasculopathie polypoïdale choroïdienne idiopathique: aspects cliniques et angiographiques.

OBJECTIVES: To clarify the clinical and angiographic characteristics of idiopathic polypoidal choroidal vasculopathy (IPCV) and its natural course. METHODS: Descriptive, prospective, consecutive case series of patients with presumed IPCV seen at Fort-de-France Hospital Center (French West Indies) between January and June 2006. All participants underwent complete eye examination and fluorescein and indocyanine green (ICG) angiography. The nature and location of the lesions were assessed in all eyes. Inclusion criteria were demonstration of characteristic lesions of IPCV on ICG angiography. RESULTS: Diagnosis of IPCV was made in 26 eyes of 14 patients, ten women and four men, all of Afro-Caribbean origin. The mean age was 77.4 years (range 60-92 years). Drusen were present in 13 eyes (50%), age-related macular degeneration (AMD) in one eye, and branch retinal vein occlusion in one eye. Twelve patients (85.7%) had bilateral involvement. Twelve eyes (46.2%) had visual acuity (VA) (Snellen) worse than 20/200, six eyes (23.1%) had VA between 20/200 and 20/100, and eight eyes (30.8%) had VA better than 20/100. On ICG angiography, lesions were predominantly located in the peripapillary area but also in the midperiphery, the macular and interpapillomacular areas, and the far periphery. CONCLUSION: Peripheral locations of IPCV and associations with drusen or AMD are not rare. The prognosis of the disease is poor in its natural course. Its etiology is unknown but genetic factors are probably involved. It is the main differential diagnosis for exudative AMD in black patients.

[Conjunctival squamous cell carcinoma. Four cases reported in the French West Indies]. / Carcinome épidermoïde conjonctival. A propos de quatre cas aux Antilles.

We report four cases referred to the Ophthalmologic Department of the University Hospital Center of Fort de France for the therapeutic management of a conjunctival malignant tumor. All cases reported involved conjunctival squamous cell carcinoma. All tumors were unilateral, one was localized, another was recurrent, one occurred in a patient with acquired immunodeficiency syndrome, and the last one was seen at the late stage of massive locoregional invasion. Three patients had surgery completed by corneolimbic cryotherapy. The last case was exentered. All of them consulted regularly. These four cases were collected over 5 years in approximately 15,000 patients examined per year in the University Hospital Center of Fort de France. Conjunctival squamous cell carcinoma is rare, even in Martinique, a tropical area. Careful attention to risk factors such as the sun exposure is recommended, as is the histologic diagnosis with any conjunctival tumour, since it changes quickly. The treatment must be adapted to the extension of the disease and to the patient's general health. The high rate of recurrence requires long-term follow-up in corneal and conjunctival intraepithelial neoplasia.

[Leukemic infiltration of the optic nerve]. / Infiltration leucémique du nerf optique.

INTRODUCTION: We report a case of unilateral leukemic infiltration of the optic nerve caused by acute lymphoblastic leukemia. CASE REPORT: A 30-year-old woman with acute lymphoblastic leukemia beginning 3 months before was referred for left visual loss. The left fundus showed optic disc engorgement by infiltrating tumor, with numerous hemorrhages and exudates caused by optic nerve leukemic infiltration. CONCLUSION: Optic nerve leukemic infiltration is considered as central nervous system damage with severe prognosis. Treatment is based upon systemic and intrathecal chemotherapy and central nervous system radiation.

Isolated conjunctival ulcerations as the first sign of Behçet's disease.

PURPOSE: To report an unusual incident of isolated conjunctival ulcerations which preceded all other signs of Behçet's disease. METHODS: Description of a 34-year-old woman of West Indian origin with an unremarkable medical history presenting with bilateral bulbar conjunctival ulcerations. RESULTS: The authors noted the presence of a diffuse bilateral conjunctival hyperemia which was more pronounced at the temporal bulbar conjunctiva of the right eye and the nasal conjunctiva of the left eye, each having one ulceration. The rest of the ophthalmologic examination was normal. One month later, the appearance of buccogenital aphthosis led to the diagnosis of Behçet's disease. CONCLUSIONS: This observation is unusual, as the conjunctival ulcerations are isolated and precede the onset of all other symptoms of Behçet's disease. Conjunctival ulcerations are rarely seen with Behçet's disease, but are characteristic enough to be included among the diagnostic criteria.

Isolated conjunctival ulcerations as the first sign of Behets disease.

PURPOSE: To report an unusual incident of isolated conjunctival ulcerations which preceded all other signs of Behets disease. METHODS: Description of a 34-year-old woman of West Indian origin with an unremarkable medical history presenting with bilateral bulbar conjunctival ulcerations. RESULTS: The authors noted the presence of a diffuse bilateral conjunctival hyperemia which was more pronounced at the temporal bulbar conjunctiva of the right eye and the nasal conjunctiva of the left eye, each having one ulceration. The rest of the ophthalmologic examination was normal. One month later, the appearance of buccogenital aphthosis led to the diagnosis of Behets disease. CONCLUSIONS: This observation is unusual, as the conjunctival ulcerations are isolated and precede the onset of all other symptoms of Behets disease. Conjunctival ulcerations are rarely seen with Behets disease, but are characteristic enough to be included among the diagnostic criteria.

Visual phenotype of multiple sclerosis in the Afro-Caribbean population and the influence of migration to metropolitan France.

PURPOSE: To describe the visual phenotype of multiple sclerosis (MS) in the Afro-Caribbean population living in Martinique (French West Indies) and to specify the influence of the migration to metropolitan France on ocular impairment. DESIGN: Prospective consecutive observational case series. METHODS: A complete ophthalmologic examination was performed. PARTICIPANTS: A total of 112 patients of Afro-Caribbean origin with MS satisfying McDonald's diagnostic criteria, divided into 53 cases (47.3%), the non-migrant patients (group NM), who had never left the Caribbean basin, and 59 cases (52.7%), the migrant patients (group M), who had lived in metropolitan France for at least 1 year before age 15. RESULTS: MS first manifested as an impairment of the optic nerve in 41 cases (36.6%): 25 cases (47.1%) in group NM and 16 cases (27.1%) in group M. Visual function was recovered in 13/25 cases (52%) in group NM compared to 13/16 cases (81%) in group M. Two-thirds of patients presented with a clinical ocular impairment, which was bilateral in 58.5% of cases in group NM. Fourteen cases (12.5%) met the criteria of neuromyelitis optica, nine cases (17%) in group NM and five cases (8.5%) in group M. In group NM, when the initial visual attack did not regress, the visual Expanded Disability Status Scale (EDSS) score was 5+/-1.5 ; 75% of patients had monocular blindness and 50% binocular. CONCLUSIONS: In the non-migrants (group NM), MS manifested more frequently with an optical neuropathy, the ocular impairment was more severe, and corresponded to neuromyelitis optica in 17% of the cases; a visual presentation and the absence of complete recovery from the first attack represented a factor of poor prognosis. This series is the largest description of the visual phenotype of MS in patients of African origin. The results confirm the preferential impairment of the optic nerve in the black population in the course of the disease. The migration towards an area of high prevalence of MS influences the visual phenotype in terms of a lower incidence and less severe prognosis of ocular impairment.

[Melanocytoma of the optic disc. Three case studies]. / Mélanocytome de la papille: à propos de trois observations.

PURPOSE: Melanocytoma is a rare benign tumor that usually occurs as a pigmented lesion in the optic nerve head. It seems to be more frequently encountered in the Black population. We report three cases of melanocytoma observed in Martinique, where 90% of the population is of African origin. OBSERVATIONS: The first and second cases were found on routine ophthalmic examination. These patients had a heavily pigmented lesion that obscured part or all of the optic disc with slight extension into the adjacent nerve fiber layer of the retina. The tumor's margins were finely fibrillated. Fluorescein angiography demonstrated a homogenous hypofluorescent black tumor obscuring the optic disc vessels, with no tumor vessels visible. There were no juxtapapillary choroid vascular abnormalities. The third case was discovered on visual field examination. This melanocytoma was accompanied by papillary edema. CONCLUSION: Only three cases of melanocytoma have been noted from 1994 to 2004 in 150,000 Caribbean patients examined in the University Hospital Center of Fort de France. The rarity of melanoma and the predisposition to melanocytoma are important epidemiologic factors in the etiologic search for pigmented tumor within the Black population. Yearly fundus examination is useful for monitoring growth and detecting malignant transformation.

[Glaucoma screening in Martinique. Results in 813 hospital employees]. / Dépistage du glaucome en Martinique: résultats au sein d'une population de 813 salariés hospitaliers.

INTRODUCTION: Several US and Jamaican studies have shown that glaucoma is more severe in black populations than in Caucasian populations, which would lead to the assumption that the people of Martinique have a high glaucoma risk. METHODS: A prospective study was conducted in workers of Fort de France University Hospital with the occupational medicine unit. Intraocular pressure was measured with a pulse air tonometer (Topcon CT 60) and visual field abnormalities were detected with automated perimetry using Humphrey frequency doubling technology (FDT). Patients with known glaucoma or with intraocular pressure over 21 mmHg and/or a visual field abnormality were referred to ophthalmology examination to diagnose ocular hypertension, open-angle glaucoma or normal-pressure glaucoma. RESULTS: The occupational medicine unit examined 813 workers. The sex ratio was 0.36, mean age was 45.35+/-8.4 years (22-64 years), and mean ocular pressure was 12.1+/-2.62 mmHg (6-28 mmHg). Roughly 20% of workers had a family history of glaucoma. We found 22 patients with glaucoma (2.7%) (CI95: 1.6%-4%): 12 patients had open-angle glaucoma (1.5%) and 10 patients were diagnosed with normal-pressure glaucoma (1.3%). Glaucoma prevalence increased with age, reaching 8% in patients over 55 years of age. Of patients with normal-pressure glaucoma, 42.9% had a family history of glaucoma. CONCLUSION: Our results confirm previous data from the literature that found higher glaucoma prevalence in black people and in particular in the mixed-race population of Martinique. In addition to this ethnic feature, the insularity of Martinique could support glaucoma expression. Easy and fast to use, FDT associated with the pulse air tonometer provides early detection of glaucoma.

[Hypophysis metastasis of a hypernephroma tumor revealed by a chiasma syndrome]. / Métastase hypophysaire d'un hypernéphrome révélée par un syndrome chiasmatique.

In a 45-year-old man with a hypernephroma tumor of the right kidney, a metastasis in the pituitary gland of this neoplasm was diagnosed 9 years after removal of this kidney. He complained of bitemporal hemianopsia and slight impairment of vision. A hypernephroma metastasis in the pituitary gland is very rare and few have been reported to date. In general, these metastases occur in cases with multiple metastasis to many organs, which suggests that the appearance of pituitary metastasis represents extensive disease. Many of these patients present diabetes insipidus. Visual defects are frequently associated. The Goldmann perimeter is important to detect visual field anomalies. MRI is the key radiological exam to localize the tumor. Surgery is the preferred treatment and should be undertaken quickly if visual function is affected. The histological exam should be made to confirm the diagnosis.

[Ciliary body melanoma in a black patient: a case report]. / Mélanome du corps ciliaire chez un patient de race noire.

Uveal melanomas are rare in the black population. We report the case of an 81-year-old black man who presented a ciliary body melanoma of the left eye. Ophthalmological examination revealed a mass arising from the ciliary body and choroid. Diagnosis of ciliary body melanoma, made from clinical examination and ocular ultrasound, may be difficult in some cases due to its similarity to other eye tumors. Uveal melanomas mainly affect Caucasians but they are not unknown in blacks.

[Evaluation of single-injection caruncular sub-Tenon's anesthesia]. / Evaluation de l'anesthésie caronculaire sous-ténonienne en une seule injection.

INTRODUCTION: Because of its complications, particularly globe perforation, retrobulbar injection has been progressively replaced by peribulbar anesthesia. However, with peribulbar anesthesia, the excessive rate of imperfect blockade requires supplemental injection. We have been performing local anesthesia using caruncular sub-Tenon single injection for many years. This technique is evaluated. PATIENTS AND METHODS: A prospective study has been carried out on 183 eyes. Regional anesthesia was given by a caruncular sub-Tenon single injection. For each case, we studied akinesia, analgesia, pain before, during, and after surgery, the number of supplemental injections, eyeball orientation, and surgical conditions. RESULTS: A total motor blockade was obtained in 157 cases (85.8%) and total lid akinesia in 176 patients (96.2%). Eight patients (4.4%) needed a second injection. During surgery, 10 patients complained of pain (5.5%). We found 27 eyes (14.7%) were divergent and 12 (6.5%) were convergent. Surgical conditions were good or very good in 90% of cases. No complications due to the injection (perforation or lesion of the eyeball or the optic nerve) were noted. CONCLUSION: Single-injection caruncular sub-Tenon anesthesia is an alternative technique to classical peribulbar anesthesia. This technique is efficient, simple, easy to learn, reproducible, and seems to have a low rate of complications.

[Diabetic retinopathy in Martinique: results of a cross-sectional survey based on 771 patients]. / La rétinopathie diabétique en Martinique: résultats d'une enquête transversale sur 771 patients.

INTRODUCTION: Because of the gravity of diabetic retinopathy in Martinique, a cross-sectional survey was conducted between March and September 1996 to estimate the prevalence of this complication on this island. PATIENTS AND METHODS: Clinical data, obtained by examining and questioning 771 diabetic patients (recruited among the usual practice of the ophthalmologists), were analyzed using Epi-Info. RESULTS: Some form of diabetic retinopathy was present in 42%. of the patients and 8.3% presented proliferative retinopathy. A total of 78% of the patients presented a non-insulin-dependent diabetes mellitus, essentially women. Medical supervision of the diabetes and its ophthalmologic complications proved to be insufficient. Principal risk factors found for the prevalence and severity of diabetic retinopathy were a long duration of diabetes, insulin-dependent type diabetes among women and the whole population, age among men, mode of treatment (insulin), and hypertension. DISCUSSION: These results are higher than those usually reported in France. This can be explained by diet and racial factors: the population is mainly of African and Indian descent. Risk factors are the same as those already described in earlier studies. To improve these prevalences, strategies should include classic methods risk factors correction, patients education, increasing coordination between the different medical specialists), but should also take into account the particularities of this Caribbean population such as racial, economic, historical, and sociocultural factors.

Stem vascular architecture in the rattan palm Calamus (Arecaceae-Calamoideae-Calaminae).

Climbing stems in the rattan genus Calamus can reach lengths of well over 100 m, are long-lived, and yet their vascular tissue is entirely primary. Such a combination suggests that stem vasculature is efficient and resistant to hydraulic disruption. By means of an optical shuttle and video recording of sequential images we analyzed the stem of a cultivated species. The stem has vascular features that are unusual compared with those in arborescent palms and seemingly inefficient in terms of long-distance water transport. Axial bundles are discontinuous basally because leaf traces, when followed downwards, always end blindly below. Furthermore, there is no regular distal branching of each leaf trace at its level of departure into a leaf, so that neither a continuing axial bundle nor bridges to adjacent axial bundles are produced as in the standard palm construction. Instead, the axial bundles in the stem periphery are connected to leaf traces and to each other by narrow and irregular transverse or oblique commissures that are not the developmental homologues of bridges. As in other palms, metaxylem within a leaf trace is not continuous into the leaf so that the only connection to a leaf is via protoxylem. Within the stem, protoxylem (tracheids) and metaxylem (vessels) are never contiguous, unlike in other palms, which suggests that water can only move from metaxylem to protoxylem, and hence into the leaf, across a hydraulic resistance. We suggest that this minimizes cavitation of vessels and/or may be associated with an unknown mechanism that refills embolized vessels. Also, the metaxylem can be significant in stem water storage in the absence of abundant ground parenchyma.

[Lisch nodules: description of 2 clinical cases and their significance]. / Les nodules de Lisch: description de deux cas cliniques et signification.

We report two cases of Lisch nodules in both eyes in two women. It was the only ocular manifestation of their Von Recklinghausen disease. The other general signs of their disease were cutaneous neurofibromas. Lisch nodules are melanocytic hamartomas consisting of melanocytic cells containing various quantities of pigment. They can be found in 90 to 100% of neurofibromatosis patients over 6 years of age. They are practically pathognomonic of type 1 neurofibromatosis and their finding is an important diagnostic argument. They must be distinguished from other iris nodules: nevus, melanoma, inflammatory nodules, and development anomalies.

[Prospective study of eye burns at the Fort de France University Hospital]. / Etude prospective des brûlures oculaires par bases au CHU de Fort de France.

PURPOSE: We report the results of a three-years prospective study focusing on ocular alkali burns conducted in the University hospital of Fort de France (French West Indies). PATIENTS AND METHODS: This case record survey included all alkali burns evaluated by ophthalmologists in the emergency unit of the Fort de France hospital. All recruited patients were either called to identify the alkali (pH determined with a Prolab pH-meter) or underwent an anterior chamber puncture showing evidence of an aqueous humor pH above 8. The recorded data were: age, gender, cause of burn, in case of aggression the relation between the victim and the aggressor, initial clinical findings, Ropper Hall classification. The therapeutic protocol was initiated according to this classification. The course of the ocular burn was noted. Economical and medicolegal consequences were assessed from duration of off work time and from information provided by the public prosecutor respectively. RESULTS: Twenty-four patients who had 39 burned eyes were included. Most ocular burns (18) were caused by aggressions with Alcali (ammonia, pH = 12.8). Most victims were men accused of adultery. In the West Indies, Alcali is thought to have power to drive away evil spirits. Most victims were young men (mean age 42 years). Eight court suits have been filed and in 5 cases the judge dismissed the charge. In 13 eyes, the delay to the first ocular wash was 30 minutes and resulted in serious ocular burn (Ropper Hall class 3 or 4). After application of the therapeutic protocol, 6 of these eyes recovered in an average 55 days; 3 required limbal autograft, 2 were successful. Three of these severe burns were complicated by spontaneous perforation (1 eye), atrophy (1 eye), and leucoma (1 eye). One patient was lost to follow-up. All minor ocular burns (Ropper Hall class 1 and 2) healed within an average 12 days (range 3-38 days). CONCLUSION: Particular circumstances of ocular alkali burns in Martinique (French West Indies) have been indentified in this study which established the seriousness of these burns and their social and sometimes legal consequences. The importance of prevention is emphasized. It would seem that minor ocular alkali burns do not require a treatment duration longer than 15 days. Finally, the clinical data reported in this study show that a delay of several minutes is required for the development of severe ocular alkali burns.

[Surgical technique of limbal autotransplantation in severe and recent eye burns]. / Technique chirurgicale de l'autotransplantation limbique dans les brûlures oculaires graves et récentes.

We report our surgical technique of limbal autograft for recent severe ocular burns. Our procedure is a modified Kenyon and Tseng technique. We discuss our main observations when using this procedure for serious ocular burns which demonstrate the physical signs best indicating surgery, the limbal region to be used, and optimal postoperative follow-up.