Does levodopa improve vision in albinism? Results of a randomized, controlled clinical trial.

BACKGROUND: Dopamine is an intermediate product in the biosynthesis of melanin pigment, which is absent or reduced in albinism. Animal research has shown that supplying a precursor to dopamine, levodopa, may improve visual acuity in albinism by enhancing neural networks. This study examines the safety and effectiveness of levodopa on best-corrected visual acuity in human subjects with albinism. DESIGN: Prospective, randomized, placebo-controlled, double-masked clinical trial conducted at the University of Minnesota. PARTICIPANTS: Forty-five subjects with albinism. METHODS: Subjects with albinism were randomly assigned to one of three treatment arms: levodopa 0.76 mg/kg with 25% carbidopa, levodopa 0.51 mg/kg with 25% carbidopa, or placebo and followed for 20 weeks, with best-corrected visual acuity measured at enrollment, and at weeks 5, 10, 15, and 20 after enrollment. Side-effects were recorded with a symptom survey. Blood was drawn for genotyping. MAIN OUTCOME MEASURES: Side-effects and best-corrected visual acuity 20 weeks after enrolment. RESULTS: All subjects had at least one mutation found in a gene known to cause albinism. Mean age was 14.5 years (range: 3.5 to 57.8 years). Follow up was 100% and compliance was good. Minor side-effects were reported; there were no serious adverse events. There was no statistically significant improvement in best-corrected visual acuity after 20 weeks with either dose of levodopa. CONCLUSIONS: Levodopa, in the doses used in this trial and for the time course of administration, did not improve visual acuity in subjects with albinism.

Phenotypic variations in patients with a 1630 A>T point mutation in the PAX6 gene.

BACKGROUND: The extreme clinical case-to-case variability of aniridia, even within families, can cause difficulties in making the correct diagnosis, prognosis and treatment plan. We describe seven patients from two families demonstrating variable expression of this syndrome, all with the same single point mutation within the PAX6 gene. METHODS: Case presentations. The authors review the clinical ophthalmic findings of the aniridia-keratopathy syndrome from two families, one involving four generations, the other with two generations. Polymerase chain reaction amplification of all 14 exons of the PAX6 gene was performed for five patients. RESULTS: The iris findings varied from classic total absence to nearly normal iris appearance. Corneal changes were minimal in the younger patients but vision-impairing in the older. None of the patients had glaucoma. The five patients who underwent DNA analysis shared the same PAX6 point mutation defect (1630A>T). INTERPRETATION: Bilateral corneal changes progressing from mild opacification at the limbus to vascularized central keratopathy, especially in the presence of nystagmus, are highly suggestive of a PAX6 mutation. Such patients may theoretically benefit from early limbal stem cell replacement therapy.

Has rising pediatric obesity increased the incidence of idiopathic intracranial hypertension in children?

OBJECTIVE: Idiopathic intracranial hypertension (IIH) in children is an uncommon but significant cause of morbidity, including permanent visual loss. It is important to understand if, like obesity, IIH in children is on the rise and is related to that increase. The aim of this study is to compare the recent incidence rate of pediatric IIH in a tertiary care hospital with earlier data published from that same hospital. DESIGN: Retrospective chart review. PARTICIPANTS: All children aged 2 to 16 years diagnosed with IIH at the IWK Health Centre in Halifax between 1997 and 2007. METHODS: Charts of eligible patients were reviewed to ensure all diagnostic criteria for IIH were met. Incidence and obesity rates were calculated based on data from Statistics Canada. RESULTS: Twelve cases (5 males, 7 females) fulfilling the diagnostic criteria for IIH were identified, for an annual incidence of 0.6 cases per 100,000 children with no sex predilection (p = 0.51). Obesity was noted in 75% of patients examined (9/12). Children older than 12 years were more likely to be obese (6/6, 100%) compared with those younger than 12 years (3/6, 50%). CONCLUSIONS: The calculated incidence is lower than that found in an earlier study for the same geographic region (0.9 cases per 100,000 children) despite increasing obesity rates. This decrease may be a reflection of improved diagnostic techniques or may indicate that factors other than obesity govern IIH predilection in younger children.

Periocular granuloma annulare in four children.

Subcutaneous granuloma annulare is a skin condition that occurs on the lower extremities, hands, and scalp of healthy children. It rarely occurs in the periocular area, and when it does, the annular pattern is often absent. Histopathology is diagnostic and shows palisading histiocytes around areas of necrobiosis. Although benign in nature, the lesions tend to multiply, grow in size, and often recur. They usually resolve spontaneously and do not require treatment. Four cases of periocular subcutaneous granuloma annulare, from four different geographical areas, were identified through on-line postings on the worldwide mailing list of the Organization for Pediatric Ophthalmology and Strabismus (http://lists.ucsd.edu/mailman/listinfo/ped-ophth-1). These 4 patients are reported here, and a brief review of the literature is presented.