Clinical and molecular characterisation of Bardet-Biedl syndrome in consanguineous populations: the power of homozygosity mapping.

Bardet-Biedl syndrome (BBS) is a ciliopathy with pleiotropic effect that manifests primarily as renal insufficiency, polydactyly, retinal dystrophy and obesity. The current phenotype-genotype correlation is insufficient to predict the likely causative mutation that makes sequencing of all 14 BBS genes an often necessary but highly complicated way to identify the underlying genetic defect in affected patients. In this study, homozygosity mapping is shown as a robust approach that is highly suited for genetically heterogeneous autosomal recessive disorders in populations in which consanguinity is prevalent. This approach allowed us to quickly identify seven novel mutations in seven families with BBS. Some of these mutations would have been missed by unguided routine sequencing, which suggests that missed mutations in known BBS genes could be more common than previously thought. This study, the largest to date on Saudi BBS families, also revealed interesting phenotypic aspects of BBS, including the first report of non-syndromic retinitis pigmentosa as a novel BBS phenotype.

Optic disc elevation in Down syndrome.

BACKGROUND: Optic disc elevation associated with Down syndrome is an uncommon phenomenon and raises the suspicion of an intracranial space-occupying lesion, thus necessitating the consideration of invasive and noninvasive investigations. METHOD OF STUDY: Four patients with Down syndrome and optic disc elevation without an underlying intracranial pathology are reported. Thorough ophthalmological and neuroradiological investigations were performed on each patient. Mild hyperopia occurred in three patients and myopia in one. CONCLUSIONS: We believe that in most Down syndrome patients with disc elevation, fluorescein angiography and/or clinical follow-up may be sufficient.

Peroxisomal bifunctional enzyme deficiency with associated retinal findings.

Peroxisomal disorders include single enzyme defects and defects of peroxisomal fatty acid oxidation enzymes. Peroxisomal bifunctional enzyme complex deficiency is a recently recognized abnormality of fatty acid metabolism. We present one patient with peroxisomal bifunctional enzyme deficiency in association with a flecked retina. This clinical association has only been previously reported once. The finding of a flecked retina in an infant presenting with hypotonia, seizures, and failure to thrive is highly suggestive of peroxisomal bifunctional enzyme complex deficiency.

Benign orbital fibrous histiocytoma simulating a lacrimal gland tumor.

The case of a patient with a lacrimal fossa mass that was believed to be a primary lacrimal gland tumor is reported. However, at lateral orbitotomy the tumor was found within the lacrimal fossa, but distinct from the lacrimal gland. Histopathology revealed a benign fibrous histiocytoma. The tumor was totally excised, has not recurred over a 3-year follow-up period. This mesenchymal tumor should be included in the differential diagnosis of lacrimal fossa mass in adults.

Posterior keratoconus. Case report with scanning electron microscopy.

We report the clinical and scanning electron microscopic findings in an older adult patient with unilateral posterior keratoconus. Clinically, the cornea showed typical posterior concavity with focal underlying anterior ectasia and an epithelial iron ring. Scanning electron microscopy of the cornea removed at penetrating keratoplasty revealed a pericentral posterior concavity. The endothelial layer was intact, with moderate endothelial cell pleomorphism. There were no excrescences of Descemet's membrane or endothelial tags. The lack of discrete irregularities on the posterior corneal surface in this case is different from previous descriptions of the pathological appearance of posterior keratoconus, which have been used to support a relationship of this condition to central corneal mesenchymal dysgenesis. This is the first report of scanning electron microscopic findings in posterior keratoconus.

Richner-Hanhart syndrome (tyrosinemia type II). Case report and literature review.

Richner-Hanhart syndrome (Tyrosinemia Type II) is an autosomal recessive disorder of amino acid metabolism characterized by ocular changes, painful palmoplantar hyperkeratosis, and mental retardation. Serum tyrosine increases due to tyrosine aminotransferase deficiency resulting in the deposition of tyrosine crystals in the cornea and in corneal inflammation. Patients are often misdiagnosed as having herpes simplex keratitis. We report on a child who presented with bilateral keratitis secondary to Tyrosinemia Type II diagnosed as herpes simplex keratitis.

Kohl: a hazardous eyeliner.

Kohl is a widely used traditional cosmetic. It is mainly worn around the eyes in the Middle East, Asia and Africa. The elemental composition of twenty-one kohl specimens originating from various parts of Saudi Arabia, India and the Middle East was determined by energy dispersive X-ray analysis (EDAX). The data indicates the presence of significant lead levels in two thirds (14/21) of the kohl specimens ranging from 2.9-100% (mean 48.5%). Other less frequent elements present in kohl preparations include aluminum, carbon, iron, titanium, calcium, magnesium, oxygen, silver silicon, sulfur and antimony. Seven kohl specimens were totally lead-free, four had a lead content in the range of 2.9-34.1% and ten had lead levels in excess of 84%. Carbon levels in excess of 60% were detected in six kohl samples. Antimony was present in only one kohl specimen at a concentration of 7.8%. Five western made eyeliner pencils analyzed for comparative purposes consistently revealed iron as a common constituent (mean 46%) but no lead or carbon were detected in these specimens. The findings of this study indicate that modern kohl preparations contain a number of metals derived from natural sources in addition to carbon. The predominance of lead in the kohl preparations tested is of major concern due to the documented adverse effects in humans and the increased susceptibility of children to lead intoxication. Application of lead-containing kohl needs to be considered as a source of lead in evaluating patients with symptoms of lead intoxication in regions where this tradition prevails. The documented toxic effects of lead in humans and the increased sensitivity of children to lead exposure serve to emphasize potential health risks of using traditional lead containing kohl preparations and the need for increased surveillance and regulation of the manufacture of kohl.

Uveal involvement in systemic angiotropic large cell lymphoma. Microscopic and immunohistochemical studies.

BACKGROUND: Angiotropic large cell lymphoma is a rare, generally fatal disease characterized by multifocal proliferation of neoplastic mononuclear cells within the lumens of blood vessels. METHODS: The authors report the clinical and immunohistochemical features of four patients with angiotropic large cell lymphoma. RESULTS: All patients presented with central nervous system symptoms, and three of the four had fever of unknown origin and anemia. The diagnosis was established by postmortem examination of the eyes in four patients and additionally by autopsy in three of the four patients. Two of the three autopsied patients had rare foci of extravascular involvement. One patient had erythrophagocytosis. Immunohistochemical stains on paraffin-embedded sections confirmed the diagnosis of lymphoma in all four patients. CONCLUSION: The results of this study support the B-cell lymphocyte origin of angiotropic large cell lymphoma.

Pink hypopyon: a sign of Serratia marcescens endophthalmitis.

Endogenous bacterial endophthalmitis in infants is uncommon. We recently examined and treated an infant who presented with pink hypopyon which followed a Serratia marcescens septicaemia. Culture of the aspirate from the anterior chamber showed no red blood cells, and grew Serratia marcescens, which was also isolated from the tip of the child's umbilical artery catheter. The presence of a pink hypopyon in the absence of hyphaema may suggest the diagnosis of Serratia marcescens endophthalmitis.

Bacterial keratitis after penetrating keratoplasty.

Bacterial keratitis continues to be a serious problem in developing countries. The authors studied 881 patients who had undergone penetrating keratoplasty (total of 947 procedures) from January 1983 to March 1986 at the King Khaled Eye Specialist Hospital, Riyadh, Saudia Arabia. All patients were followed for at least 6 months. Clinical evidence of bacterial keratitis developed in 113 (11.9%) eyes with penetrating keratoplasties in 108 patients. The causative organisms among those patients included: Streptococcus pneumoniae, 29 (26%); Staphylococcus epidermidis, 24 (21%); Pseudomonas aeruginosa, 13 (12%); Staphylococcus aureus, 5 (4%); Hemophilus influenzae, 5 (4%); Moraxella spp, 5 (4%); alpha-hemolytic streptococcus, 5 (4%); and other bacteria, 27 (25%). In addition, postoperative epithelial defects that required hospital admission for treatment developed in 21 (2.2%) patients. Herpetic keratitis developed in three (0.3%) patients and fungal keratitis developed in 1 (0.1%). Statistically significant predisposing risk factors included: trichiasis (P less than 0.0001), epithelial defects (P less than 0.0001), soft contact lens wear (P less than 0.0001), and eroding sutures (P less than 0.0001). The authors believe that the incidence of postoperative bacterial keratitis can be minimized or avoided by appropriate selection of patients for penetrating keratoplasties as well as good preoperative and postoperative management of associated ocular conditions.