Familial retinal detachment associated with COL2A1 exon 2 and FZD4 mutations.

BACKGROUND: To characterize the clinical and genetic abnormalities within two Australian pedigrees with high incidences of retinal detachment and visual disability. DESIGN: Prospective review of two extended Australian pedigrees with high rates of retinal detachment. PARTICIPANTS: Twenty-two family members from two extended Australian pedigrees with high rates of retinal detachment were examined. METHODS: A full ophthalmic history and examination were performed, and DNA was analysed by linkage analysis and mutation screening. MAIN OUTCOME MEASURES: Characterization of a causative hereditary gene mutation in each family. RESULTS: All affected family members of one pedigree carried a C192A COL2A1 exon 2 mutation. None of the affected family members had early-onset arthritis, hearing abnormalities, abnormal clefting or facial features characteristic of classical Stickler syndrome. All affected members of the familial exudative vitreoretinopathy pedigree carried a 957delG FZD4 mutation. CONCLUSIONS: Patients with retinal detachment and a positive family history should be investigated for heritable conditions associated with retinal detachment such as Stickler syndrome and familial exudative vitreoretinopathy. The absence of non-ocular features of Stickler syndrome should raise the possibility of mutations in exon 2 of COL2A1. Similarly, late-onset familial exudative vitreoretinopathy may appear more like a rhegmatogenous detachment and not be correctly diagnosed. When a causative gene mutation is identified, cascade genetic screening of the family will facilitate genetic counselling and screening of high-risk relatives, allowing targeted management of the pre-detachment changes in affected patients.

Visual field assessment and the Austroads driving standard.

PURPOSE: To compare the conventional (Humphrey 24-2) automated visual field testing with the Goldmann standard visual field test for driving, and to predict how many patients with glaucoma may not meet the Australian driving standard with respect to visual fields. METHODS: Four patients (retinitis pigmentosa, glaucoma or vigabatrin treatment) with marked visual field defects as determined by uniocular static computerized perimetry (conventional testing) were re-evaluated with binocular kinetic Goldmann IV4e target field test (Australian driving standard). A series of 48 consecutive patients seen by the Glaucoma Inheritance Study in Tasmania were assessed with both static computerized perimetry and the Goldmann IV4e target test. RESULTS: The four patients with severe visual field defects (on computerized perimetry) were found to meet the driving standard on the binocular Goldmann IV4e target test. On computerized perimetry, 15 of 48 patients from the Glaucoma Inheritance Study in Tasmania were found to have visual field defects of sufficient severity that they may not meet the driving standard. However, only five of these patients failed the driving standard for visual fields, two of whom were still driving. CONCLUSIONS: Patients with severe field defects on conventional uniocular automated perimetry may still meet the Goldmann standard visual field test for driving. Approximately 30% of glaucoma patients would have visual field loss shown on Humphrey 24-2 test of a severity that requires further testing to determine if they meet the driving standard. Ten per cent of glaucoma patients tested did not meet the driving standard for visual fields.