Ophthalmologic heterogeneity in subjects with gyrate atrophy of choroid and retina harboring the L402P mutation of ornithine aminotransferase

OBJECTIVE/PURPOSE

To investigate clinical variation in a genetically homogenous group of subjects with gyrate atrophy of choroid and retina with hyperornithinemia (GA). The group was made up of homozygotes and compound heterozygotes for mutation L402P in the ornithine aminotransferase (OAT) gene.

DESIGN

Cross-sectional study.

PARTICIPANTS

Thirty-five Finnish subjects (18 men) with GA with a mean age of 33 years (range, 5-74 years) carrying the Finnish founder mutation L402P.

METHODS

All subjects were examined between 1993 and 1995. The analysis was composed of, in addition to careful clinical evaluation, studies of visual fields with Goldmann perimeter, photographing of the eye fundi, and corneal electroretinography (ERG) recordings.

MAIN OUTCOME MEASURES

The changes in eye fundi, visual acuity, cataract changes in the lens, visual field constriction, and ERG responses were determined.

RESULTS

Myopia, early cataracts, and highly abnormal ERG were typical for the GA subjects. The changes progressed rather uniformly with age. However, visual acuity, funduscopic findings, and visual fields showed great phenotypic variation. Despite the great interindividual variation, both eyes of each subject were always similarly affected.

CONCLUSIONS

This study of 35 subjects with GA carrying a single mutation shows that the ophthalmologic symptoms and findings vary widely. The data also reveal that GA subjects are already affected by severe visual impairment in young adulthood. However, the diagnosis is often made very late.

Tissue distribution of the ND4/11778 mutation in heteroplasmic lineages with Leber hereditary optic neuropathy

Leber hereditary optic neuropathy (LHON) is a maternally inherited eye disease most commonly caused by mitochondrial DNA (mtDNA) point mutation at position 11778, 3460, or 14484. Approximately 14% of families show heteroplasmy for the pathogenic mutations but little is known about the mutational burden in different tissues of these heteroplasmic individuals. Consequently, estimating the risks of visual loss is difficult. This study presents quantitative mutation analyses of tissues representing all embryonal layers in two families heteroplasmic for the 11778 mutation. These analyses show that a high amount of mutated mtDNA in leukocytes is correlated with a high proportion of mutated mtDNA in other tissues.

Creatine corrects muscle 31P spectrum in gyrate atrophy with hyperornithinaemia

BACKGROUND

Eye fundus destruction and type II muscle fiber atrophy in gyrate atrophy of the choroid and retina with hyperornithinaemia (GA) may be mediated by elevated ornithine concentrations which strongly inhibit creatine biosynthesis. This results in deficiency of creatine phosphate (PCr), a key intracellular energy source, as we have demonstrated in skeletal muscle of the patients by 31P magnetic resonance spectroscopy (31P MRS).

MATERIALS AND METHODS

Possible correction of the relative PCr deficiency by long-term daily exogenous supplementation of creatine or its precursors was investigated in four GA patients receiving creatine and in five patients treated with guanidinoacetic acid-methionine combination. The relative PCr concentration, expressed as PCr/Pi (Pi; inorganic phosphate) or as PCr/ATP ratios, was compared with the values of untreated GA patients, and matched healthy volunteers.

RESULTS

Muscle PCr/Pi ratios (mean +/- SD) of the untreated and creatine supplemented GA patients and controls were 4.9 +/- 1.4, 7.9 +/- 0.4 and 8.4 +/- 1.3. Guanidinoacetate-methionine combination was similarly effective (respective PCr/Pi ratios: 4.9 +/- 0.7, 6.3 +/- 1.1 and 10.7 +/- 2.8).

CONCLUSION

Supplementation with creatine or creatine precursors almost normalised low muscle PCr/Pi ratios of patients with GA.

Vigabatrin, a gabaergic antiepileptic drug, causes concentric visual field defects

OBJECTIVE

To determine whether there is a causal link between vigabatrin treatment and concentric visual field defects and to evaluate the prevalence of these visual field constrictions.

BACKGROUND

While the GABAergic antiepileptic drug (AED) vigabatrin was being clinically developed, only rare cases (less than 1:1000) of symptomatic visual field constriction and retinal disorders were reported. During 1997 to 1998, concentric visual field constrictions were described in case reports of mostly drug-resistant epilepsy patients receiving vigabatrin concurrently with other AEDs.

METHODS

Ophthalmologic tests including Goldmann perimetry were performed on 32 adult patients on long-term successful vigabatrin monotherapy (treatment duration 29 to 119 months) and on 18 patients on carbamazepine monotherapy (treatment duration 32 to 108 months). Eighteen healthy adults served as controls.

RESULTS

None of the patients complained about vision problems when asked to participate into the study. Thirteen out of the 32 (40%) epilepsy patients treated with vigabatrin monotherapy had concentrically constricted visual fields (9% severely, 31% mildly constricted), whereas none of the carbamazepine monotherapy patients or normal controls presented with a visual field defect (chi-square test, p = 0.0001). The extents of the visual fields were significantly constricted in vigabatrin group as compared with the visual fields of the patients in carbamazepine group or healthy controls (analysis of variance, Scheffe F-test, significant at 99%).

CONCLUSIONS

The use of vigabatrin seems to increase the risk of a unique and specific pattern of bilateral, mainly asymptomatic visual field constriction. This risk should be considered when using vigabatrin. Visual field testing should also be performed before treatment and during routine follow-up for patients on vigabatrin.

Muscle creatine phosphate in gyrate atrophy of the choroid and retina with hyperornithinaemia--clues to pathogenesis

BACKGROUND

In gyrate atrophy of the choroid and retina with hyperornithinaemia (GA), inherited deficiency of ornithine-o-aminotransferase leads to progressive fundus destruction and atrophy of type II skeletal muscle fibres. Because high ornithine concentrations inhibit creatine biosynthesis, the ensuing deficiency of high-energy creatine phosphate may mediate the pathogenesis.

MATERIALS AND METHODS

Relative concentrations of inorganic phosphate (Pi), creatine phosphate (PCr) and ATP in resting calf muscle were recorded in 23 GA patients and 33 control subjects using 31P-magnetic resonance spectroscopy (MRS). Eight patients with autosomal recessive retinitis pigmentosa with matched control subjects constituted an additional reference group.

RESULTS

The PCr/Pi and PCr/ATP ratios (means +/- SD) were lower for the GA patients than for healthy control subjects [4.66 +/- 0.37 vs. 9.75 +/- 2.17 (P < 0.0001) and 2.85 +/- 0.37 vs. 3.70 +/- 0.50 (P < 0.05) respectively]. In retinitis pigmentosa the respective values were 9.12 +/- 2.57 and 4.25 +/- 0.45. Age and stage of the disease had no effect.

CONCLUSION

Muscle 31P-MRS spectra were markedly abnormal in all GA patients.

Papillary hypertrophy of the upper tarsal conjunctiva during contact lens wear: a 4-month study with ethyl-6-O-decanoyl-glucoside

PURPOSE

We studied the potential effect of ethyl-6-O-decanoyl-glucoside (EDG) on papillary hypertrophy in contact lens wearers who were recruited on the basis of papillary hypertrophy and a long history of contact lens wear. The contact lens care solutions were 0.00025% chlorhexidine acetate (CHX) with or without 0.005% EDG.

METHODS

Nineteen subjects wearing both ionic and non-ionic contact lenses for 6-18 hours used either CHX or CHX+EDG as a cleaning and disinfecting agent. CHX and CHX+EDG was used simultaneously by each subject but in different eyes during two consecutive periods of 8 weeks. Symptoms and signs were recorded at three examinations during the study. The protein content of contact lenses and tryptase activity of tear fluids were measured.

RESULTS

The degree of papillary hypertrophy did not decrease in either the CHX or CHX+EDG groups. Also, there were no differences in protein content of lenses nor tryptase activity of tear fluids in either group. There was a significant correlation between papillary hypertrophy and tryptase activity during the study.

CONCLUSIONS

Despite the earlier finding that EDG prevents development of papillary hypertrophy in contact lens wearers, EDG still cannot reverse established signs of papillary hypertrophy.

Ophthalmologic findings in long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency caused by the G1528C mutation: a new type of hereditary metabolic chorioretinopathy

OBJECTIVE

The purpose of the study was to determine the nature and course of ophthalmic abnormalities in long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency, a recently discovered disorder of mitochondrial fatty acid beta-oxidation.

STUDY DESIGN

The study design was a cohort (case series).

PARTICIPANTS

A retrospective review of the records of 15 children who had died during their first 2 years was performed. Also performed were a longitudinal reanalysis and cross-sectional clinical examination of four long-term survivors aged 5 to 31 years.

MAIN OUTCOME MEASURES

Visual acuity, refraction, visual fields, ophthalmoscopy, fluorescein angiography, biometry, corneal topography, electroretinography (ERG), visual-evoked potentials (VEPs), color vision, and dark adaptation were measured.

RESULTS

In seven children, ophthalmoscopic findings were within normal limits at 3 days to 13 months of age (median, 4.8 months). In 11 children, a granular retinal pigment epithelium (RPE), with or without pigment clumping in the macula, was seen at 4 months to 5 years of age (median, 9 months). Two long-term survivors, 16 and 31 years of age, eventually had circumscribed atrophy of the choroid, RPE, and retina, which coincided with a posterior staphyloma type 1. They had progressive axial myopia starting at 6 and 12 years of age and later paracentral scotomas leading to poor central vision. They suffered from early difficulty with mesopic vision, glare, and a severe generalized color vision deficiency that started as a tritanomaly. A third survivor was mildly myopic at 5 years of age. All four surviving patients had visually insignificant, flake-like supranuclear opacities in the lens. The ERG initially was normal but deteriorated during the first decade and later was unrecordable. The VEP responses remained fairly normal. Initially, angiography showed no blockade of the choroidal fluorescence because of the thin RPE. Filling of choroidal vessels was delayed, and the choriocapillaris and, later, larger choroidal vessels in the posterior pole became nonperfused.

CONCLUSIONS

In LCHAD deficiency, the fundus is normal at birth (stage 1). Soon, however, pigment dispersion occurs in the RPE (stage 2), followed by circumscribed chorioretinal atrophy, occlusion of choroidal vessels, and deterioration of central vision, often with relative sparing of the peripheral fundus (stage 3). Finally, posterior staphylomas and central scotomas may develop (stage 4). Developmental cataract, progressive myopia, and deterioration of visual fields and color vision are new findings in LCHAD deficiency. The chorioretinopathy and abnormal ERG precede the development of myopia and posterior staphyloma, which, in turn, coincide with the loss of macular vision. The authors postulate that the RPE or choriocapillaris is primarily affected. Awareness of the characteristic ocular features is important because of an opportunity for dietary treatment, genetic counseling, and prenatal diagnosis.

Evaluation of glaucoma patients referred to a university clinic during one year

PURPOSE

In the spring of 1994, the post-referral waiting time for glaucoma patients at our institution was approximately 7 months. In an attempt to evaluate and possibly reduce this waiting time we compared the referral criteria to the actual treatment requirements of 472 patients admitted for glaucoma in 1995.

RESULTS

175 patients were referred as glaucoma suspects, 134 as chronic simple glaucoma, and 123 as capsular glaucoma. In addition, 40 patients were referred as other types of glaucoma. Elevated IOP was the main criterion for referral in 133 (76%) of glaucoma suspects. The diagnosis of glaucoma could not, however, be confirmed in 54 (31%) glaucoma suspects. 93 (69%) patients with simple open angle glaucoma and 103 (84%) patients with capsular glaucoma were also referred because of IOP > or = 22 mmHg. Maximally tolerated medication was not used by 44% of open angle glaucoma patients at time of referral.

CONCLUSION

The clinical follow-up of glaucoma patients and glaucoma suspects should primarily take place at an ophthalmologist's office and the new effective glaucoma drugs and laser treatments should also be more actively in use. The cooperation between the referring ophthalmologists and the university clinic should be improved. Hospitalisation turned out to be unnecessary because, with a few exceptions, all procedures could have been performed on an out-patient basis, which is a general practice in most glaucoma clinics today. The university clinic should focus only on those patients who need special evaluation or surgical treatment.

mtDNA haplotype analysis in Finnish families with leber hereditary optic neuroretinopathy

The mitochondrial DNA (mtDNA) sequence variation of 24 Finnish Leber hereditary optic neuroretinopathy (LHON) probands was characterized by sequencing and restriction endonuclease analyses. All LHON-associated substitutions and Caucasoid haplogroup-specific mutations were screened in the families. Analysis of the mtDNAs revealed that the Finnish LHON families have two unique features: an absence of the ND6/14484 mutation and a high number of families (10/24) without the primary mutations ND1/3460 and ND4/11778. Furthermore, the LHON families showed considerable mtDNA heterogeneity: among 24 families 22 haplotypes were detected. Overall, the haplogrouping of LHON families was similar to other European populations. However, the frequency of ND4/11778-positive families in haplogroup J was high, which may indicate that background mutations in this haplogroup together with the ND4/11778 primary mutation promote the penetrance of LHON.

Mutations in subunit 6 of the F1F0-ATP synthase cause two entirely different diseases

A lowered efficiency of oxidative phosphorylation was recently found in a Leber hereditary optic neuropathy (LHON) proband carrying a mutation in the mtDNA gene for subunit 6 of the membrane-bound F0 segment of the F1F0-ATP synthase [9]. This phenotype was transferred to cytoplasmic hybrid cells together with the mutation, proving its functional significance. Increasing the respiratory rate in the mitochondria from this mutant raised the ATP/2e- ratio back to normal values. A different mutation in the same mtDNA gene has been found in patients with the NARP syndrome [10]. Although the ATP/2e- ratio is also decreased in this mutant, in this case an increase in the respiratory rate could not compensate for it. Whilst both mutations affect subunit 6 of the proton-translocating F0 segment, the LHON mutation induces a proton leak whereas the NARP mutation blocks proton translocation. Hence, the latter will have much more destructive metabolic consequences in agreement with the large clinical differences between the two diseases.

An expanded CAG repeat sequence in spinocerebellar ataxia type 7

Expanded CAG repeat sequences have been identified in the coding region of genes mutated in several neurodegenerative disorders, including spinocerebellar ataxia type 1 and Machado-Joseph disease. In all disorders described to date the CAG expansion codes for an elongated polyglutamine chain. An increased polyglutamine chain size leads to a more severe disease, thus correlating with the genetic anticipation seen in repeat expansion disorders. Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant spinocerebellar ataxia with anticipation and a progressive degeneration of the cerebellar cortex. Using repeat expansion detection (RED), a method in which a thermostable ligase is used to detect repeat expansions directly from genomic DNA, we have analyzed 8 SCA7 families for the presence of CAG repeat expansions. RED products of 150-240 bp were found in all affected individuals and found to cosegregate with the disease (P < 0.000001, n = 66), indicating strongly that a CAG expansion is the cause of SCA7. On the basis of a previously established correlation between RED product sizes and actual repeat sizes in Machado-Joseph disease, we were able to estimate the average expansion size in SCA7 to be 64 CAG copies.

Catalytic activity of complex I in cell lines that possess replacement mutations in the ND genes in Leber's hereditary optic neuropathy

Short-chain ubiquinone analogues act as electron acceptors and as inhibitors in the lymphoblast mitochondria of ND1/3460 mutants, which indicates structural changes in the ubiquinone-binding domain of Complex I in this mutant. The ND4/11778 mutant and two secondary ND5 mutants studied are associated with reductions of at least 50, 35 and 30% in the catalytic rate constant, respectively. However, the efficiency of oxidative phosphorylation is unaffected in all these ND mutants. The rate of respiration is only slightly limited by Complex I in lymphoblast mitochondria. Consequently, there is a 30-35% reduction in the electron flow through Complex I compared with that through Complex II, and an increased lactate/pyruvate ratio, in the ND1 and ND4 mutants, but these factors were unaffected in the secondary ND5 mutants. Energy metabolism is thus less severely affected in the secondary mutants than in the primary mutants, which supports the division into these two categories. An increased ubiquinone-10 content in the mitochondrial membrane of all the mutants, and enhanced succinate dehydrogenase and citrate synthase activities in the ND4 mutant, are proposed to be compensatory changes. The efficiency of these changes and the level of kinetic limitation of respiration by Complex I in each tissue are proposed to determine the clinical development of the disease.

A mitochondrial mutation at nt 9101 in the ATP synthase 6 gene associated with deficient oxidative phosphorylation in a family with Leber hereditary optic neuroretinopathy

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Time-resolved fluorometry in the diagnosis of Leber hereditary optic neuroretinopathy

We have applied time-resolved fluorometry (TRF) to construct a DNA hybridization assay for the diagnosis of Leber hereditary optic neuroretinopathy (LHON). A rapid and reliable detection of the most prevalent mitochondrial DNA (mtDNA) point mutation associated with LHON is demonstrated. In addition, the TRF-method can be used in the quantification of heteroplasmy, a phenomenon commonly present in mtDNA mutations. The assay includes PCR amplification of a fragment encompassing the mutation site followed by hybridization reactions with allele-specific europium (Eu)-labelled oligonucleotide probes. A time-resolved fluorometer is used to measure the bound label. The TRF assay was successfully used to demonstrate the ND4/11778 mutation in patient samples. For quantification of heteroplasmy, synthetic target oligonucleotide mixtures with known ratios of wild-type and mutated sequences were used as standards to control the hybridization step. The assay allowed the detection of heteroplasmy ranging from 5 to 95%. This was also shown in a family with several heteroplasmic members.

Quantification of point mutations associated with Leber hereditary optic neuroretinopathy by solid-phase minisequencing

About two-thirds of patients with Leber hereditary optic neuroretinopathy (LHON) harbor mutations in mitochondrial DNA at positions 11778 (ND4) or 3460 (ND1). Thus, the clinical diagnosis of LHON can often be confirmed with mutation analysis. Detection of pathogenic mutations and quantification of heteroplasmy has mainly relied on PCR and restriction site analysis and densitometric scanning. We applied the recently developed solid-phase minisequencing method, based on primer-guided nucleotide incorporation, to the simultaneous detection and quantitation of the ND4/11778 and ND1/3460 mutations. The method was highly sensitive, heteroplasmy as low as 1.5% being easily detected. Rapid, reproducible, and accurate results prove solid-phase minisequencing to be the method of choice for quantitative analysis of LHON mutations.

The spectrum of mitochondrial DNA mutations in families with Leber hereditary optic neuroretinopathy

The mitochondrial complex I genes were sequenced in seven Leber hereditary optic neuroretinopathy (LHON) families without the ND4/11,778 and ND1/3460 mutations. Four replacement mutations restricted only to LHON families were found, one in the ND1 gene at nt 4025, and three in the ND5 gene at nt 12,811, 13,637, and 13,967. The mutations did not change evolutionarily conserved amino acids suggesting that they are not primary LHON mutations in these families. They may be considered as secondary LHON mutations serving as exacerbating factors in an appropriate genetic background. A complex III mutation, cyt b/15,257, has been suggested to be one of the primary mutations causing LHON. Its presence was determined for 23 Finnish LHON families, and it was detected in two families harboring the ND4/11,778 mutation. Similarly, complex IV mutation COI/7444 was screened in Finnish LHON families, and it was found in one family carrying the ND1/3460 mutation.

Electron transfer properties of NADH:ubiquinone reductase in the ND1/3460 and the ND4/11778 mutations of the Leber hereditary optic neuroretinopathy (LHON)

We report the electron transfer properties of the NADH:ubiquinone oxidoreductase complex of the respiratory chain (Complex I) in mitochondria of cells derived from LHON patients with two different mutations in mitochondrial DNA (mtDNA). The mutations occur in the mtDNA genes coding for the ND1 and ND4 subunits of Complex I. The ND1/3460 mutation exhibits 80% reduction in rotenone-sensitive and ubiquinone-dependent electron transfer activity, whereas the proximal NADH dehydrogenase activity of the Complex is unaffected. This is in accordance with the proposal that the ND1 subunit interacts with rotenone and ubiquinone. In contrast, the ND4/11778 mutation had no effect on electron transfer activity of the Complex in inner mitochondrial membrane preparations; also Km for NADH and NADH dehydrogenase activity were unaffected. However, in isolated mitochondria with the ND4 mutation, the rate of oxidation of NAD-linked substrates, but not of succinate, was significantly decreased. This suggests that the ND4 subunit might be involved in specific aggregation of NADH-dependent dehydrogenases and Complex I, which may result in fast ('solid state') electron transfer from the former to the latter.

DXS26 (HU16) is located in Xq21.1

We have localized a single-copy DNA probe, HU16 (locus DXS26), to Xq21.1. The probe was isolated from a human-mouse hybrid X;13 library and mapped with human-mouse hybrids containing different portions of the human X chromosome and DNA from male patients with different X-chromosomal deletions. The following order of loci is proposed: Xcen-(DXS72,DXS169)-(DXS232,DSX26)-DXS1 21-DXS233-DXS165-TCD-DXS95-DXYS1-Xqter. HU16 will be useful in the study of the putative genes that reside in Xq21 and whose defects lead to deafness and mental retardation.

Familial olivopontocerebellar atrophy with macular degeneration: a separate entity among the olivopontocerebellar atrophies

A family with hereditary, neuropathologically confirmed olivopontocerebellar atrophy (OPCA) associated with macular degeneration is described. The mode of inheritance was autosomal dominant. The first symptom was insidious, progressive visual loss caused by macular degeneration. Another early sign was slow saccades. Some years after the visual symptoms, gradually progressing cerebellar dysfunction and pyramidal signs developed. Computed tomography of the brain indicated cerebellar and pontine atrophy. Finally the patients were blind, due to a severe chorioretinal atrophy, and disabled because af motor dysfunction. The present study, together with a review of other reported families with OPCA associated with macular degeneration, suggests that this disorder is a specific and clinically recognizable subtype of OPCA.

Fundus findings in Leber's hereditary optic neuroretinopathy

The acute stage of Leber's hereditary optic neuritis is characterized by dilated disc arterioles accompanied, in some cases, by superficial peripapillary hemorrhages. Decreased vision caused by centrocecal scotoma is accompanied by slow and deficient capillary filling in the papillomacular bundle and arteriovenous shunting in the upper and lower vascular arcades. These and other vascular changes disappear in the more advanced stages (optic atrophy) of the disease.

Fundus findings in Leber's hereditary optic neuroretinopathy. III. Fluorescein angiographic studies

Fluorescein angiography was performed in nine members of families with Leber's disease. Serial studies were obtained in four men observed from asymptomatic to atrophic stages. Peripapillary microangiopathy was observed in six of nine asymptomatic eyes. Arteriovenous shunting occurred in the telangiectatic vascular bed. These changes remained stable in some eyes and progressed in others. In the acute stage, arteries and telangiectatic vessels were maximally dilated and flow was rapid. Angiography showed florid shunting in lower and upper vascular arcades and reduced filling of papillomacular capillaries. Vessels of the shunting vascular bed gradually narrowed irregularly. In the atrophic stage, disc vascularity diminished and arteriovenous circulation time increased markedly. Arterioles narrowed and peripapillary microangiopathy disappeared. These findings support our contention that Leber's disease is a hereditary vascular neuroretinopathy.

Monoclonal IgG immunoglobulinemia with subsequent myeloma in psoriatic arthritis

A 42-year-old man had suffered from skin psoriasis for 27 years, psoriasis arthritis for 6 years and corneal crystalline deposits for 1 year, when an IgG-kappa monoclonal immunoglobulin was detected in his serum electrophoretic pattern. All the diagnostic studies for multiple myeloma were negative. However, 16 months later he developed this disease.

Interferon-alpha and interferon-gamma production capacity of idiopathic isolated optic neuritis patients

Interferon-alpha and interferon-gamma production by idiopathic isolated optic neuritis (ON) patients was studied. The production capacity was compared with that in two control groups: patients with iritis and healthy control subjects. A sensitive and reliable interferon bioassay was applied for interferon level measurements. Statistically significant differences were not found between patients and control groups in either interferon-alpha production or interferon-gamma production.

Ophthalmoscopic findings in Leber's hereditary optic neuropathy. II. The fundus findings in the affected family members

Eighteen men and four women had Leber's disease. Fundus photographs obtained in three cases showed the following: Peripapillary microangiopathy, present from the beginning, slowly increased during the presymptomatic stage. At the end of the presymptomatic stage, the nerve fiber layer became swollen. During the acute stage, retinal vessels on and around the disc were dilated, tortuous, and telangiectatic. Nerve fiber layer hemorrhages occurred in two eyes. As atrophy appeared first in the papillomacular bundle and then in the remaining retina, the vascular bed involuted, leaving a capillary-poor retina with attenuated arterioles and a pale optic disc. The final degree of atrophy varied. Fifteen of the affected persons were blind with severe optic atrophy, but in seven optic atrophy was only partial, causing less visual handicap. Our results suggest that Leber's disease is primarily an intraocular, not a retrobulbar, optic neuropathy. It should be redesignated as Leber's hereditary neuroretinopathy.

Ophthalmoscopic findings in Leber's hereditary optic neuropathy. I. Fundus findings in asymptomatic family members

A neuro-ophthalmological examination was performed on 47 asymptomatic offspring in the female line and 13 offspring in the male line in families with Leber's hereditary optic neuropathy. Fourteen (61%) of the 23 asymptomatic males and nine (38%) of the 24 asymptomatic females in the female line had telangiectatic microangiopathy of the peripapillary arterioles and capillaries. Increased tortuosity of capillaries, medium-sized arterioles, and venules were also seen in the fundi of several asymptomatic family members. The 13 offsprings in the male line did not have microangiopathy. Nerve fiber abnormalities were not seen in asymptomatic persons. The photographically verified findings are described, classified, and discussed. It is suspected that Leber's disease is primarily a microvascular disorder. The vascular abnormalities detected in the asymptomatic family members probably indicate increased risk of Leber's disease developing. During the prospective follow-up of three years, three asymptomatic boys with microangiopathy have experienced Leber's disease.

Do visual evoked potentials give relevant information to the neuro-ophthalmological examination in optic nerve lesions?

The visual evoked potentials (VEPs) and neuro-ophthalmological examinations of 134 patients were compared. The VEPs were abnormal in 95% of the eyes with optic neuritis. Defective color vision was found in 99%, visual field defects in 88%, decreased vision in 66% and an afferent pupillary defect in 55%. 29 patients with optic neuritis were followed up with repeated tests. VEPs and color vision recovered more slowly than visual acuity and visual field. Abnormal VEPs were observed in 68% of 50 MS patients. An analysis of symptomatic and asymptomatic eyes showed that testing of color vision, visual field and red-free ophthalmoscopy were equally as useful diagnostic tools as VEPs. 4 (8%) of the MS patients had abnormal VEPs despite a normal neuro-ophthalmological examination; 94% of MS patients with symptoms and 47% of MS patients without visual symptoms had abnormal VEPs. VEPs were pathological in 59% of 24 patients with traumatic or compressive optic nerve diseases or optic atrophies of unknown etiology. The neuro-ophthalmological examination was more sensitive than VEPs in the diagnosis of these disorders. A neuro-ophthalmological examination is in most cases sufficient to diagnose optic nerve lesions. VEPs are of diagnostic aid especially in mild optic nerve lesions.

Prognosis of optic neuritis with special reference to cerebrospinal fluid immunoglobulins and measles virus antibodies

Forty-eight patients with optic neuritis (ON), first seen in 1970 to 1973, were neurologically and neuroophthalmologically reexamined after 7 to 10 years. Twenty-seven patients (56%) had probable MS, and 9 (19%) had possible MS. During the attack of ON, the cerebrospinal fluid (CSF) samples and serum/CSF measles antibody ratios were studied. Twenty patients had increased relative immunoglobulin G (IgG) (% of total protein) in their CSF; 19 of these had probable or possible MS. However, 17 of 28 patients with a normal relative IgG value had also developed MS. CSF electrophoresis was abnormal in 20 patients with ON; reexamination showed that 19 had probable or possible MS. Sixteen of 27 patients with normal electrophoresis had also developed MS. Serum/CSF measles antibody ratio had decreased in 19 patients; 13 of these had probable MS and 3 had possible MS. Of 29 patients with a normal measles antibody ratio, 14 had probable MS and 6 had possible MS. The conclusion is that examination of the CSF in ON gives valuable prognostic information because increased relative IgG, abnormal electrophoresis, or a decreased measles antibody ratio implies a high risk of developing MS. A normal CSF does not, however, rule out the possibility of dissemination.

Computerized tomography of the orbits. A report of 196 patients

The value of orbital CCT scans was studied by grouping the CCT scans of 196 patients into clinical diagnostic categories. In 83% of patients with suspected Graves' ophthalmopathy, CCT confirmed the diagnosis. The CCT scan differentiated patients with Graves' disease from those with orbital pseudotumour or malignancies. The CCT scan was positive in 92% or patients with proven orbital malignancies. In 73% of patients with proptosis of unknown aetiology, and in 56% of patients with ocular motility problems, the CCT scan led to the diagnosis. The CCT scan ruled out orbital mass lesions in cases of optic neuritis, optic atrophy or vascular malformations. The greatest value of the CCT scan was in the localization and determination of the size and shape of various orbital lesions and in the accurate follow-up of those lesions utilizing serial scans.

The early phase in Leber hereditary optic atrophy

Clinical, ophthalmoscopic, perimetric, and color vision tests and visual evoked responses were recorded in symptomatic and asymptomatic eyes in five members of a family with Leber hereditary optic atrophy. The presymptomatic eyes showed abnormalities in the retinal nerve fiber layer. Optic nerve dysfunction was found before central vision failed. The appearance of degenerating retinal nerve fibers, particularly in the papillomacular bundle, was documented photographically in the weeks after the onset of visual symptoms. Treatment with prednisone and hydroxocobalamin did not reverse or halt serious impairment of vision.

Parotid carcinoma and posterior fossa schwannoma following irradiation. Report of a patient treated in infancy for benign ear disease

A 23-year-old man had received irradiation for a benign ear problem at the age of 1 year. Twenty year later, a malignant left parotid carcinoma and a right jugular foramen schwannoma developed. Earlier reports in the literature suggest that radiation can induce tumors in the head and neck. The localization of both tumors and the histological features of the parotid tumor suggest that they were radiation-induced.