Tilted disc syndrome may mimic false visual field deterioration.

PURPOSE: Tilted disc syndrome is a congenital anomaly of the eye characterized by mostly upper temporal visual field defects. The aim of the present study was to evaluate the effect of gradual myopic correction in the improvement of visual field defects associated with tilted disc syndrome. METHODS: The visual field was examined in 38 eyes of 24 patients using standard Goldmann perimetry. The isoptres IV-4e, I-4e, I-3e and I-2e were plotted. The defective isoptres were tested again with gradually increasing myopic correction until no further change was noted. RESULTS: The most common type of defect was a relative upper temporal defect (19 eyes). Temporal relative defects were found in five eyes, upper altitudinal field defects in six eyes, an enlarged blind spot in four eyes, and an inferior field defect in one eye. The visual field defect partly or totally disappeared with increased myopic correction in 18 (50%) eyes. The mean improvement was 17.0 +/- 6.2 degrees and the mean additional myopic correction was 3.1 +/- 1.5 D. CONCLUSIONS: Even a small change in near correction during visual field examination may imply worsened or improved visual field defects in tilted disc syndrome. To prevent a false interpretation of field deterioration in a patient with tilted disc syndrome and glaucoma, visual field assessment should include examination with the myopic correction that provides the maximal improvement of the defective visual field.

Colour vision defects in occupational chronic solvent encephalopathy.

Occupational chronic solvent encephalopathy (CSE) is associated with a number of neurobehavioural disorders including defects of visual perception. The purpose of this study was to characterize colour vision defects in CSE patients. Colour vision was tested in bright illumination with the Farnsworth-Munsell 100-hue test in workers who had CSE due to occupational exposure to common industrial solvents. Before assessing colour vision, the subjects' ocular health and visual functions were evaluated. On the basis of this evaluation, 36 subjects with healthy eyes were selected and their colour vision was tested monocularly. The colour vision performance of the patient group was, statistically, significantly inferior to that of a control group matched by age at a group level. A mixed form of reduced colour sensitivity was found in 42% (n=15/36) of the cases, affecting the entire range of Munsell hues. No association was found between the length and intensity of exposure and colour vision performance. Our results show that CSE patients can have significantly impaired colour discrimination ability, although their eyes are healthy and their other visual functions are normal. This may indicate toxic damage to higher level visual processing, possibly the colour selective regions of the cerebral cortex.

A novel CACNA1F gene mutation causes Aland Island eye disease.

PURPOSE: Aland Island eye disease (AIED), also known as Forsius-Eriksson syndrome, is an X-linked recessive retinal disease characterized by a combination of fundus hypopigmentation, decreased visual acuity, nystagmus, astigmatism, protan color vision defect, progressive myopia, and defective dark adaptation. Electroretinography reveals abnormalities in both photopic and scotopic functions. The gene locus for AIED has been mapped to the pericentromeric region of the X-chromosome, but the causative gene is unknown. The purpose of this study was to identify the mutated gene underlying the disease phenotype in the original AIED-affected family. METHODS: All exons of the CACNA1F gene were studied by DNA sequencing. CACNA1F mRNA from cultured lymphoblasts was analyzed by RT-PCR and cDNA sequencing. RESULTS: A novel deletion covering exon 30 and portions of flanking introns of the CACNA1F gene was identified in patients with AIED. Results from expression studies were consistent with the DNA studies and showed that mRNA lacked exon 30. The identified in-frame deletion mutation is predicted to cause a deletion of a transmembrane segment and an extracellular loop within repeat domain IV, and consequently an altered membrane topology of the encoded alpha1-subunit of the Ca(v)1.4 calcium channel. CONCLUSIONS: Mutations in CACNA1F are known to cause the incomplete form of X-linked congenital stationary night blindness (CSNB2). Since the clinical picture of AIED is quite similar to CSNB2, it has long been discussed whether these disorders are allelic or form a single entity. The present study clearly indicates that AIED is also caused by a novel CACNA1F gene mutation.

Tilted disc syndrome and colour vision.

PURPOSE: To study colour vision in patients with tilted disc syndrome. METHODS: Colour vision was examined using Boström-Kugelberg (B-K) plates, Farnsworth-Munsell 100-hue test (FM-100) and Farnsworth panel D-15 and Lanthony desaturated panel tests. RESULTS: A total of 35 eyes of 21 patients were examined. Seventeen eyes (49%) of 11 patients were found to have a colour vision defect in at least one eye. The severity of the colour vision defect differed between eyes for six of eight patients with bilateral tilted discs. In two of these patients, colour vision was normal in one eye. Seven patients had a unilateral tilted disc and three of these individuals had a colour vision defect in the affected eye. Of all eyes with a colour vision defect, a red-green defect was found in four eyes (24%), a blue defect in one eye (6%), and a mixed defect in 12 eyes (70%). Colour vision defects were not related to visual acuity or to severity of visual field defects. CONCLUSIONS: This is the first report of colour vision defects in tilted disc syndrome. In the differential diagnosis of tilted disc syndrome, chiasmal lesions and glaucoma, the examination of colour vision may add valuable information. Further, it is recommended that young people with tilted disc syndrome undergo an examination of colour vision so that they can be given appropriate career guidance.

Colour vision and retinal nerve fibre layer photography in patients with an Acrysof Natural intraocular lens.

PURPOSE: To study colour vision and retinal nerve fibre layer (RNFL) photographs in patients with an Acrysof Natural intraocular lens (IOL). METHODS: We carried out a randomized double-blind study. An Acrysof Natural IOL (model SN60AT) was implanted in 25 eyes of 19 patients and an Acrysof IOL (model SA60AT) was implanted in 27 eyes of 18 control patients. The patients returned for colour vision tests and fundus photography 1-6 months after the surgery. RESULTS: Standard pseudoisochromatic plates, part 2, were correctly interpreted and the Farnsworth-Munsell 100-hue test (FM 100) total and individual box scores were normal in all IOL eyes. In the FM 100 hue test there were no significant differences in the results of the total error scores or the error scores of the individual boxes between the eyes with Acrysof Natural and those with Acrysof lenses. The yellow coloration of the Acrysof Natural IOL did not affect the visibility of the RNFL in photographs. CONCLUSIONS: The Acrysof Natural IOL did not affect colour vision in the tested patients, even in the blue region of the spectrum, and can be implanted in patients who need to have normal colour vision for the purposes of their occupation. The Acrysof Natural IOL does not interfere with RNFL photography and can also be used in patients with glaucoma.

Color vision and contrast sensitivity in epilepsy patients treated with initial tiagabine monotherapy.

The purpose of the study was to determine whether the use of a GABAergic antiepileptic drug (AED), tiagabine, affects color vision and contrast sensitivity. Twenty newly diagnosed patients with partial epilepsy (aged 19-72 years), receiving tiagabine as their initial monotherapy for 5-41 months were examined. Color vision was examined with the Standard Pseudoisochromatic Plates 2 (SPP2), with the Farnsworth-Munsell 100 Hue Test (FM100) and with the Color Vision Meter 712 (CVM) anomaloscope. Contrast sensitivity was measured with the Pelli-Robson letter chart. Three patients excluded from the color vision evaluation for congenital red-green color vision defects. Seven out of 17 patients (41%) had acquired color vision deficit examined with the FM100. The CVM anomaloscope revealed minor defects in two patients. Contrast sensitivity function was within normal ranges. The present study suggests that AED therapy with tiagabine, like with other established and newer AEDs may interfere with color perception.

Dominant optic atrophy: correlation between clinical and molecular genetic studies.

PURPOSE: To assess the clinical picture and molecular genetics of 14 Finnish families with dominant optic atrophy (DOA). METHODS: The clinical status of family members was based on the assessment of visual acuity, colour vision, visual fields and optic nerve appearance; 31 individuals were affected, two suspect and 21 unaffected. A total of 30 coding exons and exon- intron boundaries of the OPA1 gene were sequenced in order to detect mutations. RESULTS: Half the patients were diagnosed at the age of < or = 20 years. Ten out of 20 affected individuals followed up for > or = 6 years had a progressive disease and 10 had a stable disease. According to WHO criteria, 36% of the affected patients were visually handicapped. Eight OPA1 pathogenic mutations, all but one novel, and 18 neutral polymorphisms were detected. CONCLUSION: The most sensitive indicators of DOA were optic disc pallor and dyschromatopsia. With molecular genetic analysis, asymptomatic mutation carriers and DOA cases with a mild clinical outcome were ascertained. No mutational hotspot or Finnish major mutation in the OPA1 gene could be demonstrated as most families carried a unique mutation. No obvious genotype- phenotype correlation could be detected. Detailed clinical assessment and exclusion of non-DOA families prior to mutation screening are necessary for obtaining a high mutation detection rate.

Visual function in epilepsy patients treated with initial valproate monotherapy.

PURPOSE: To investigate whether initial valproate (VPA) monotherapy for the treatment of epilepsy causes visual field defects and visual dysfunction. METHODS: In a cross-sectional study, visual fields were examined with the kinetic Goldmann and automated Humphrey perimeters, contrast sensitivity function with the Pelli-Robson letter chart and colour vision with the Standard Pseudoisochromatic Plates Part 2 (SPP 2) and Farnsworth-Munsell 100 Hue test (FM 100) in eighteen epilepsy patients (aged 18--50 years, 30.2.+/-10 years, mean+/-S.D.) treated with initial valproate monotherapy for 2--20 years (8.4+/-5.1 years). RESULTS: None had vigabatrin-type, concentric visual field defect with the kinetic Goldmann or automated Humphrey perimetries. In the Humphrey perimetry, the mean deviation for the group was within normal limits varying from -2.53 to 0.59 dB (-0.74+/-0.80 dB) in the right eye and from -2.66 to 0.67 dB (-0.78+/-0.82 dB) in the left eye. In the FM 100 test, acquired colour vision deficiency was found in two out of 18 patients (11%, 95% CI: 0--25%). However, the mean total error score was lower in the patient group than in the control group. All patients had normal contrast sensitivity function. CONCLUSIONS: The use of VPA in the treatment of epilepsy is not associated with visual field defects similar to vigabatrin, but may induce abnormalities in colour vision.

Combined hearing and visual impairment and depression in a population aged 75 years and older.

BACKGROUND: Depression is associated with both visual and hearing impairment. Little is known about the relationship between combined hearing and visual impairment and mood in this age group. The aim of this population-based study was to investigate the association between functional sensory impairment, especially combined sensory impairment and depressive symptoms and depression diagnosed according to the DSM-IV criteria. METHOD: The study group consisted of 470 adults, population-based sample, aged 75 years or older. We used the Snellen eye charts with E-letters and reading charts to evaluate the functional visual acuity. The ability to conduct a face-to-face conversation, the hearing aid use and the self-reported hearing problems were used to assess the functional hearing acuity. Depression was identified with two different methods. A geriatrician interviewed the subjects and the DSM-IV checklist was used to determine whether they met the criteria for major depression. The Zung Depression Status Inventory (DSI) was used to identify depressive symptoms. The cut off points of 40/80 and 48/80 in the DSI-score was used. RESULTS: Seventy-two persons (15%) of the study population had depression diagnosed according to the DSM-IV criteria. Twelve per cent of subjects in the Functional Hearing Impairment (FHI) group, twenty per cent in the Functional Visual Impairment (FVI) group, eighteen per cent in the Combined Sensory Impairment (CSI) group and fifteen per cent in the Adequate Sensory Function (ASF) group suffered major depression. The differences between these groups were insignificant. The occurrence rates of the DSI score equal or over 40 points was 50% in the FHI group, 53% in the FVI group, 70% in the CSI group and 45% in the ASF group. The difference between the ASF group and sensory impairment group including FHI, FVI and CSI groups was statistically significant (p = 0.03). CONCLUSIONS: Depressive symptoms, but not major depression, were common if elderly persons had combined sensory impairment.

Visual functions and adverse ocular effects in patients with amiodarone medication.

PURPOSE: To study visual functions and ocular adverse effects of long-term amiodarone medication. METHODS: We performed an eye examination of 22 patients with long-term amiodarone medication. In addition to corrected visual acuity, colour vision was studied with the Standard Pseudoisochromatic Plates part 2 and Farnsworth-Munself 100 hue test. Contrast sensitivity was examined with the Pelli-Robson chart. Visual fields were tested by Goldmann and Friedmann perimetry. RESULTS: Two patients with otherwise healthy eyes had abnormal blue colour vision test results. Otherwise colour vision, contrast sensitivity, and visual field test results were within normal range or could be explained by eye diseases such as cataract. Corneal drug deposits were found in 100% of the examined eyes. Slight anterior subcapsular lens opacities were found in 22.2%. Dry eyes were diagnosed in 9.1%. The eye fundi did not reveal any abnormalities that could be thought of as caused by amiodarone. CONCLUSION: The slight blue colour vision defect found in two patients with otherwise healthy eyes might represent an early sign of the optic nerve impairment which is a rare complication of amiodarone medication. The number of corneal and lens changes as well as dry eyes were found at levels previously described.