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At least 1,045 records · Page 58Linked to original sources
PubMed2001

PDT to monkey CNV with ATX-S10(Na): inappropriateness of early laser irradiation for selective occlusion.

PURPOSE: There is controversy about which mode of laser irradiation, early irradiation with low-dose photosensitizer or late irradiation with high-dose, benefits the selective occlusion of choroidal neovascularization (CNV) in photodynamic therapy (PDT). In this study, using an amphiphilic photosensitizer, 13,17-bis (1-carboxypropionyl) carbamoylethyl-8-etheny-2-hydroxy-3-hydroxyiminoethylidene-2,7,12,18-tetraethyl porphyrin sodium (ATX-S10(Na); Photochemical Inc., Okayama, Japan), photodynamic and adverse effects of early irradiation on CNV-bearing monkey eyes were investigated. METHODS: Experimentally induced CNV lesions and normal retina were irradiated with a diode laser (670-nm wavelength) at a dose of 1 to 90 J/cm(2) at 1 to 19 minutes after intravenous injection of 2 mg/kg body weight of ATX-S10(Na). Vascular occlusion and CNV recurrence were evaluated by fluorescein and indocyanine green angiography and histologic analysis, until 4 weeks after irradiation. RESULTS: Of 45 different conditions, 23 did not induce CNV closure, 20 provided both CNV occlusion and retinal vessel damage, and 2 achieved selective CNV occlusion without retinal vascular injury. Recurrence of CNV was induced in 19 of 22 CNV-occluding conditions. ATX-S10(Na) angiography showed that dyes were similarly distributed between normal vessels and CNV at early time periods after injection, whereas they were preferentially accumulated in CNV after 30 minutes. CONCLUSIONS: In PDT with ATX-S10(Na), irradiation within 20 minutes of dye injection failed to induce selective CNV occlusion, probably because there is no significant difference in the biodistribution of dye between CNV and retinal vessels. It also caused frequent CNV recurrence after extensive inflammation in the irradiated retina.

Animals↗
PubMed2006

Vascular endothelial growth factor C promotes survival of retinal vascular endothelial cells via vascular endothelial growth factor receptor-2.

AIM: To determine vascular endothelial growth factor C (VEGF-C) expression in retinal endothelial cells, its antiapoptotic potential and its putative role in diabetic retinopathy. METHOD: Cultured retinal endothelial cells and pericytes were exposed to tumour necrosis factor (TNF)alpha and VEGF-C expression determined by reverse transcriptase-polymerase chain reaction. Secreted VEGF-C protein levels in conditioned media from endothelial cells were examined by western blotting analysis. The ability of VEGF-C to prevent apoptosis induced by TNFalpha or hyperglycaemia in endothelial cells was assessed by flow cytometry. The expression of VEGF-C in diabetic retinopathy was studied by immunohistochemistry of retinal tissue. RESULT: VEGF-C was expressed by both vascular endothelial cells and pericytes. TNFalpha up regulated both VEGF-C and vascular endothelial growth factor receptor-2 (VEGFR)-2 expression in endothelial cells in a dose-dependent manner, but had no effect on VEGFR-3. Flow cytometry results showed that VEGF-C prevented endothelial cell apoptosis induced by TNFalpha and hyperglycaemia and that the antiapoptotic effect was mainly via VEGFR-2. In pericytes, the expression of VEGF-C mRNA remained stable on exogenous TNFalpha treatment. VEGF-C immunostaining was increased in retinal vessels in specimens with diabetes compared with retinal specimens from controls without diabetes. CONCLUSION: In retinal endothelial cells, TNFalpha stimulates the expression of VEGF-C, which in turn protects endothelial cells from apoptosis induced by TNFalpha or hyperglycaemia via VEGFR-2 and thus helps sustain retinal neovascularisation.

Animals↗
PubMed2006

Inhibition of PKC beta by oral administration of ruboxistaurin is well tolerated and ameliorates diabetes-induced retinal hemodynamic abnormalities in patients.

PURPOSE: To assess ocular and systemic safety and pharmacodynamic effects of the oral PKC beta selective inhibitor ruboxistaurin (RBX; LY333531) mesylate in patients with diabetes. METHODS: This was a double-masked, placebo-controlled, parallel, randomized, single-center clinical study evaluating the effect of oral administration of RBX (8 mg twice a day, 16 mg per day, or 16 mg twice a day) or placebo for 28 days in patients with no or very mild diabetic retinopathy on mean retinal circulation time (RCT), retinal blood flow (RBF), treatment-emergent adverse events, and other safety parameters. RESULTS: Twenty-nine persons aged 18 to 65 years with type 1 or 2 diabetes were evaluated. The only treatment-emergent adverse event with a statistically significant difference among treatment groups was abdominal pain, which was more common in placebo-treated subjects (P = 0.049). Statistically significant effects of RBX were observed on several hematologic and laboratory parameters, but values were within the normal reference range and none of the changes was deemed clinically meaningful. In patients receiving 16 mg RBX twice daily, the diabetes-induced increase in RCT was ameliorated, with a baseline-to-endpoint difference of -0.84 seconds (P = 0.046) relative to placebo. Increasing RBX dose was linearly associated with greater effect on RCT (P = 0.03). Similar results were observed with RBF. CONCLUSIONS: RBX was well tolerated at doses up to 16 mg twice daily for 28 days in patients with diabetes. It ameliorated diabetes-induced RCT abnormalities. No serious safety problems were identified in this patient population. Compared with prior published data, these findings represent the first direct human evidence of both bioavailability of RBX to retinal vessels and amelioration of diabetes-induced retinal hemodynamic abnormalities by an oral PKC beta inhibitor.

Administration, Oral↗
PubMed1982

Histopathologic study of an unusual form of retinitis pigmentosa.

An ultrastructural study was done on a postmortem donor eye from an 84-year-old male with night blindness, pericentral ring scotomas, attenuated retinal arterioles, and intraretinal bone spicule pigmentation distributed around the midperiphery. Unusual findings observed 3 years prior to death were preserved central vision and peripheral visual field and rod and cone electroretinogram amplitudes reduced only about 60% below normal. Ultrastructural examination of the retina revealed apparently normal numbers of cones in the fovea, reduced numbers of rods on the foveal slope, absence of photoreceptors in the midperiphery, and large areas of preserved rods and cones in the far periphery in all quadrants. Other conspicuous findings were the presence of autophagic vacuoles in remaining cones and nonpigmented epithelial cells around some retinal vessels in the midperiphery. Comparison of visual acuities, visual fields, and fundus appearance reported at age 54 and at age 81, combined with ultrastructural observations of the retina at age 84, suggested that this patient's condition was minimally, if at all, progressive over the last 30 years of his life. Classification of this disease as pericentral retinitis pigmentosa is considered.

Aged↗
PubMed1989

[Morphological and immunohistochemical studies on degenerative changes of the retina and the optic nerve in neonatal rats injected with monosodium-L-glutamate].

Degenerative changes in the retina and the optic nerve were investigated morphologically and immunohistochemically following administration of monosodium-L-glutamate (MSG) in rats. MSG (5mg/g b.w.) was injected subcutaneously every other day for 5 times after birth. The retina and the optic disc was observed ophthalmoscopically at 1, 3 and 6 months after birth. At the same stage, morphological and immunohistochemical changes were also investigated under light microscopy. The neuron of the retinal ganglion cell was identified immunohistochemically with antiserum to neurofilament 200 kD (NF). Glial cells were stained with antisera to glial fibrillary acidic protein (GFAP) and S-100 beta protein, and myelin of oligodendrocytes was also stained with antiserum to myelin basic protein (MBP). Histologically the inner layer of the retina was selectively destroyed, and the optic nerve also showed degeneration, changing into a thin strand. The retinal vessels were narrow and coarse, however, they extended to the peripheral region. Although immunohistochemical staining with NF antiserum was scarcely detected both in the retina and in the optic nerve, glial stainings with GFAP and S-100 beta protein antisera were widely observed in the perivascular space of the retina and in the glial column of the optic nerve. These findings indicated that the ganglion cells and their neurons are significantly affected by MSG, but the retinal vessels and glial cells are rarely affected. Ophthalmoscopically, the optic discs of rats treated with MSG were small and deeply excavated. The vitreous vessels persisted in most cases even at 6th months after birth.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1981

[Electron microscopical and chemical investigations of the pathological changes of the vitreous body].

By means of vitrectomy in vivo investigations of the pathologic changes of the vitreous body including histology and chemical analysis have become feasible. The electron microscopical examinations of the tissue particles gained by means of vitrectomy displayed collagen fibrils which were partly irregular, most of the mesh-work being split up. The periodicity of these fibrils was about 64 nm, similar changes had been observed in human vitreous following perforating injuries, as well as in rabbit vitreous after blood injections. All typical stages of the lysis of red cells and their phagocytosis by large macrophages could be demonstrated. In order to get an accurate chemical analysis of the material resulting from vitrectomy it was first to all necessary to find out a method which enabled us to compare the concentrations of different chemical substances in the material gained by vitrectomy with the content of these substances in the whole vitreous body. Of 16 pairs of human post mortem eyes, enucleated between 3 and 5 hours after death, one eye was submitted to vitrectomy under constant suction- and infusion-pressure and cutting rate, the duration of surgery being different (3-9 min.); in each fellow-eye the whole vitreous body was removed. The comparison of the different concentrations of chemical substances showed a typical correlation. This method was performed in 13 clinical cases suffering from different kinds of vitreal changes. The concentration of protein was found to have increased in cases suffering from intravitreal hemorrhages, in cases suffering from shrinkage of the vitreous body after spontaneous complete resorption of intravitreal bleedings and in one case suffering from intravitreal membranes after endophthalmitis; in cases suffering from subvitreal bleedings the protein content of the vitreous body was approximately normal. The pathology leakage of the retinal vessels as it can be found in cases suffering from proliferative diabetic retinopathy caused no significant increase of the intravitreal protein concentration. The concentrations of lactic acid and glycogen were examined in order to find out if anaerobic glycolysis could be proved in the vitreous body of eyes suffering from ischaemic retinopathy. Only one case showed an increased concentration of lactic acid, in 3 cases there was a reduced content of glycogen. In these 3 cases the possibility of the existence of anaerobic glycolysis could be excluded, because in rabbits a rapid excretion rate of exceeding concentrations of lactic acid via retinal vessels had been found.

Adult↗
PubMed1996

[Ophthalmologic findings in patients with sudden deafness].

UNLABELLED: The etiology of sudden hearing loss is still not known. Among other pathomechanisms, vascular disorders have been proposed as an underlying cause. We investigated patients with sudden hearing loss for signs of microcirculation disorders. PATIENTS: Thirty-one patients (15 males and 16 females, mean age 37.5 years) were admitted because of sudden hearing loss. In addition, all patients underwent thorough ophthalmologic examination. RESULTS: Refraction, vision, intraocular pressure and excavation of the optic nerve were normal. In 81% of all cases abnormal conjunctival vascular ectasia were detected. The fundus of 53% of the patients was characterized by slight tortuosity of arterial retinal vessels. The first 11 patients received an ocular electrophysiological examination and showed normal ERG, P-VEP and dark adaptation. Standard perimetry (TAP 2000 ct) revealed no abnormalities in 29 patients, 2 glaucoma patients had small arcuate scotomas. However, 90% of all 29 scotoma-free patients were abnormal in the white-noise campimetry (TEC, Oculus). Testing for color vision (Roth 28 HUE, desat.) revealed abnormally high values (right 120, left 131). CONCLUSION: Although patients with sudden hearing loss appeared healthy in the standard eye examination, the more sensitive tests of white-noise campimetry and color vision, together with the conjunctival vascular ectasia and the tortuosity of arterial retinal vessels, indicated a disturbed microcirculation.

Adult↗
PubMed2004

Histological examination of an eye with endogenous Aspergillus endophthalmitis treated with oral voriconazole: a case report.

PURPOSE: To report the histological findings of an eye with severe Aspergillus endophthalmitis after oral treatment with voriconazole. METHODS. Case report. RESULTS: Histopathological examination revealed no fungal elements in choroidal or retinal vessels. The hyphae were mainly restricted to the vitreal side of the preretinal inflammatory infiltrate. Since the treatment with voriconazole had not been completed at the time of enucleation, the clinical course with potential further limitation or regression of the lesion remains unsettled. CONCLUSIONS: Endogenous Aspergillus endophthalmitis is a devastating condition often associated with immunodeficiency. The pathogenesis of this entity implies the primary invasion of choroidal and retinal vessels. The lack of antifungal drugs with high blood-ocular permeability results in an extremely poor visual prognosis. Our histological examination indicates promising activity and ocular penetration of the new antifungal agent voriconazole.

Administration, Oral↗
PubMed2002

Morphologic predictive factors for development of optic disc hemorrhages in glaucoma.

PURPOSE: To evaluate which optic disc parameters are predictive factors for the development of disc hemorrhages in chronic open-angle glaucoma. METHODS: The prospective comparative clinical observational study included 432 eyes of 281 white patients with chronic open-angle glaucoma. Mean follow-up time was 38.8 months (median, 31.5). Eyes in the whole study group were divided into those with an optic disc hemorrhage during the follow-up period (hemorrhagic group; n = 38; 8.8%), those without disc hemorrhages and with neuroretinal rim loss as sign of progression of glaucoma (rim loss group; n = 42; 9.7%), and those with neither disc hemorrhages nor neuroretinal rim loss (stable group; n = 352; 81.5%). Color stereo optic disc photographs were obtained repeatedly in all patients and subjected to qualitative and morphometric evaluation. RESULTS: At baseline, neuroretinal rim area was significantly (P < 0.03) smaller and the beta zone of parapapillary atrophy (temporal lower sector) was significantly (P < 0.03) larger in the hemorrhagic group than in the stable group. Both study groups did not vary significantly (P > 0.05) in optic disc size and shape, optic cup depth, alpha zone of parapapillary atrophy, and retinal vessel diameter. In multivariate analysis, the neuroretinal rim area was the only significant predictor of hemorrhages. The hemorrhagic group and the rim loss group did not differ significantly (P > 0.05) in any optic disc parameter measured. CONCLUSIONS: In chronic open-angle glaucoma, morphologic predictive factors for the development of disc hemorrhages are small size of neuroretinal rim and, possibly, a large parapapillary beta zone. Development of disc hemorrhages is independent of optic disc size and shape, size of alpha zone of parapapillary atrophy, retinal vessel diameter, and optic cup depth. Optic nerve heads in eyes with eventual development of disc hemorrhages and in eyes with eventual progressive rim loss without observed disc hemorrhages do not differ markedly in appearance.

Adolescent↗
PubMed1980

[Protein concentrations in the aqueous humor in Coats' disease (author's transl)].

Elevated protein concentrations in the aqueous humor, without Tyndall phenomenon, were found in a case of Coats' Disease. In particular, proteins of smaller size were involved. The permeability of the retinal vessels was presumed to be impaired. The resulting increase in protein concentrations in the aqueous humor could be the cause of the secondary glaucoma in Coats' Disease.

Albumins↗
PubMed1995

Clinical investigation of the combination of a scanning laser ophthalmoscope and laser Doppler flowmeter.

In this report we present the clinical applications of a new noninvasive method of imaging in high definition the topography of perfused retinal vessels. By the combination of a laser Doppler Flowmeter with a scanning laser system the retinal circulation can be visualized and quantified. The principles of measuring blood flow by laser Doppler flowmetry are based on the laser Doppler effect: laser light scattered by a moving particle is shifted in frequency. The scanning laser system is a modified laser scanning tomograph (technical data: retinal area of measurement, 2.7 x 0.7 mm; 10 degrees field with 256 points x 64 lines; horizontal digital resolution, 10 microns; wave-length, 670 nm; light power, 100 micro W; data acquisition time, 2.048 s). Every line is scanned 128-times at a line-sampling rate of 4000 Hz. By the performance of discrete fast fourier transformation over 128 intensities of each retinal point the laser Doppler shift is calculated for each retinal point. With these data a 2-dimensional map of the retinal perfusion with 256 x 64-points is created. The brightness of the picture point is coded by the value of the Doppler shift. By this method we examined health eyes with normal intraocular pressure (IOP) and artificially increased IOP and eyes with glaucomatous optic nerve atrophy, proliferative diabetic retinopathy with areas of capillary occlusion, arterial hypertension with microinfarction of the retina, and central retinal artery occlusion. The application of "scanning laser Doppler flowmetry" (SLDF) leads to the visualization of perfused vessels and capillaries of the retina in high resolution. The examination of perfused retinal arterioles, veins, and capillaries by this method represents the anatomical situation. In SLDF the area of normal or impaired retinal circulation becomes visible (capillary nonperfusion, proliferative vascular structures), whereby the extent of the perfusion is proportional to the brightness of the imaged vessel; the brighter the vessels or capillaries, the higher the blood flow inside the vessels. Retinal areas with low capillary flow are "dark" and show no visible vessel. In imaging of an eye with central retinal artery occlusion, retinal arterioles, veins, or capillaries were invisible due to the lack of retinal perfusion. Only ciliary-source vessels of the optic nerve head were bright and visible, indicating normal ciliary circulation. SLDF facilitates the visualization of perfused retinal capillaries and vessels in high resolution. The representation of the function of the retinal circulation by SLDF leads to an image similar to the anatomical situation. The two-dimensional mapping of local blood flow leads to a physiological picture of the retinal perfusion with visible vessels and capillaries.

Adult↗
PubMed2000

Ocular manifestations of infection with the human immunodeficiency virus in an African pediatric population.

PURPOSE: To describe the ocular manifestations of HIV/AIDS infection in an African pediatric population. METHODS: From 1984 to 1990, all children with HIV infection attending the Department of Pediatrics of the 'Centre Hospitalier de Kigali', Rwanda, were referred to the Department of Ophthalmology for ophthalmic examination. RESULTS: A total of 162 HIV-infected children were examined. The overall rate of ophthalmic involvement was 54%. The most common finding was a perivasculitis of the peripheral retinal vessels, observed in 38% of the patients. Cytomegalovirus (CMV) infection of the retina was diagnosed in three patients. Isolated cotton-wool spots of the retina were not observed. Ophthalmic herpes zoster and conjunctival xerosis responding to vitamin A administration were each seen in two patients. One third of a subset of children tested for lacrimal function had evidence of decreased tear secretion. CONCLUSION: Our data, in agreement with other series reported in the literature, indicate that cotton-wool spots and CMV retinitis, the most common ocular manifestations of HIV/AIDS in adults, are much less prevalent in children. The high incidence of perivasculitis in the present series, not observed or only seen in a few cases in other series, suggests that this ocular sign is more prevalent in African children. Our working hypothesis is that perivasculitis of the retinal vessels, lymphoid interstitial pneumonitis, parotitis, and lacrimal gland involvement are the expression of a diffuse infiltrative lymphocytosis syndrome, similar to what has been described in adults.

AIDS-Related Opportunistic Infections↗
PubMed2002

Opacification of a hydrophilic acrylic intraocular lens with exacerbation of Behçet's uveitis.

Behçet's disease is 1 of the most common causes of uveitis in the Eastern world. Its common ocular complications are uveitis, cataract, and obliteration of retinal vessels. Phacoemulsification with intraocular lens (IOL) implantation in patients with Behçet's disease is known to be a safe procedure. We managed a patient with Behçet's disease who had aggravated uveitis and opacification of a hydrophilic acrylic IOL (ACRL-C160, Ophthalmed) 4 months after cataract surgery. Recalcitrant uveitis despite maximum tolerable medication and IOL opacification with vitreous opacity necessitated an IOL exchange and trans pars plana vitrectomy. After the procedure, the eye became quiescent. However, the visual acuity was 20/200 because of the obliteration of retinal vessels.

Acrylic Resins↗
PubMed1987

Heparin prophylaxis for intraocular fibrin.

The authors have evaluated the use of heparin as a method to prevent postoperative intraocular fibrin clot formation in the rabbit after vitrectomy and cyclocryotherapy. In addition, they have studied the effect of a heparin infusion on intraocular bleeding after sectioning of retinal vessels. Heparin was administered by several different routes. The extent of the postoperative fibrin clot, as well as the number of days until its clearing, were recorded. A single anterior chamber injection, heparin supplementation of the infusion solution, or a single intravenous (IV) injection, all resulted in a statistically significant reduction of postoperative intraocular fibrin. Once daily subcutaneous injections alone did not produce a reduction in postoperative fibrin. No ocular bleeding complications developed postoperatively. A constant heparin intraocular infusion of 10 IU/cc did not change the bleeding time after sectioning of a retinal vessel.

Animals↗
PubMedDate not supplied

Diabetic complications and their relationships to risk factors in a Japanese population.

The relationship between diabetic complications and age, sex, duration, mode of therapy, body weight, control of blood glucose, blood pressure, and serum triglyceride and cholesterol was analyzed in a population with non-insulin-dependent diabetes in Japan. The prevalences of complications in the subjects varied from 6.5% for cerebrovascular strokes to 85.1% for sclerotic changes in retinal vessels; 35.8% of the patients had diabetic retinopathy and 19.8% had proteinuria. Univariate and multivariate analyses revealed that control of diabetes (blood glucose, mode of therapy, and duration) was closely correlated with retinopathy and proteinuria. However, blood glucose did not correlate with coronary insufficiency or cerebrovascular strokes. These macrovascular complications were related to aging and blood pressure. The data suggested that not only good glycemic control but also sufficient antihypertensive therapy was necessary for treating diabetic patients. The coefficient of determination of the risk factors was calculated for each diabetic complication. Except for sclerotic changes in retinal vessels, the coefficients were too small to fully explain the development of diabetic complications, especially for macrovascular diseases. The current data suggest that susceptibility of the individual patients to the diabetic complications is an important determinant.

Blood Glucose↗
PubMed2003

[Influence of ciliary-retinal arteries on functional damage in open-angle glaucoma].

PURPOSE: The pattern of functional perimetric loss and morphologic neuroretinal rim loss in glaucoma depends on the localization of the central retinal vessel trunk in the lamina cribrosa. The purpose of the present study was to determine if the pattern of perimetric loss and rim loss are influenced by the presence and position of cilioretinal arteries. PATIENTS AND METHODS: Using automated perimetry and 15 degrees color stereo optic disc photographs of the optic disc, we compared 20 open-angle glaucoma patients exhibiting cilioretinal arteries in the temporal horizontal disc region with 70 open-angle glaucoma patients without cilioretinal arteries. RESULTS: Eyes with cilioretinal arteries and eyes without cilioretinal arteries did not differ significantly in global visual field indices nor in the mean defect for the central 10 degrees. No differences were detected for the areas of optic disc, neuroretinal rim, ratios of the temporal horizontal area-to-total area of rim and ratio of temporal horizontal rim area-to-nasal rim area. CONCLUSIONS: In contrast to the position of the central retinal vessel trunk, the presence and position of cilioretinal arteries do not markedly influence the pattern of glaucomatous damage.

Adult↗
PubMed2003

Influence of cilioretinal arteries on neuroretinal rim and parapapillary atrophy in glaucoma.

PURPOSE: The pattern of neuroretinal rim loss and increase in the area of parapapillary atrophy in glaucoma depend on the localization of the central retinal vessel trunk in the lamina cribrosa. The purpose of the present study was to determine whether, in a similar way, the pattern of rim loss and progression of parapapillary atrophy are influenced by the presence and position of cilioretinal arteries. METHODS: Color stereo optic disc photographs (15 degrees) for morphometric evaluation of the optic nerve head were used to compare the appearance of the optic disc in 41 patients exhibiting unilateral or bilateral cilioretinal arteries in the temporal horizontal disc region with the optic disc morphology of 127 patients without cilioretinal arteries. The areas of the neuroretinal rim and alpha and beta zones of parapapillary atrophy were measured in the total disc and in four disc sectors. RESULTS: Eyes with and eyes without cilioretinal arteries did not differ significantly in the areas of neuroretinal rim and alpha and beta zones of parapapillary atrophy, when measured in the whole optic disc and in the four disc sectors separately; in ratios of the temporal horizontal area to total area of rim and parapapillary atrophy; and in the ratio of temporal horizontal rim area-to-nasal rim area, neither in an interindividual comparison nor in an intraindividual intereye comparison. CONCLUSIONS: In contrast to the position of the central retinal vessel trunk, presence and position of cilioretinal arteries do not markedly influence the pattern of neuroretinal rim loss and progression of parapapillary atrophy in glaucoma.

Chronic Disease↗
PubMed1979

Leber's optic neuropathy: a clinical and visual evoked potential study of affected and asymptomatic members of a six generation family.

Fourteen clinically affected and 40 asymptomatic members of a six generation family with Leber's optic neuropathy have been studied clinically and by recording pattern-reversal visual evoked potentials. While 12 of the affected members had suffered the typical sequential bilateral failure of vision, in 2 the condition was still monocular after periods of 12 and 14 years. Reduced vascularity of the optic nerve head was found in 11 of these cases, all of whom had some degree of optic atrophy, and showed a significant correlation with the visual acuity. Excessive tortuosity of peripheral retinal vessels was noted in 6 cases and was a prominent feature in the unaffected eye of one of the subjects with monocular visual impairment. In cases with advanced visual impairment the VEP was absent bilaterally, while in those with less severe involvement responses which were delayed, desynchronized and much small than normal could still be recorded. Two subjects with early bilateral clinical involvement had normal or minimally abnormal responses. Repeat studies in 6 subjects after intervals of up to fifteen months showed no change in 4 and a deterioration in 2. It is concluded that the VEP findings in clinically affected subjects are in keeping with a severe demyelinating lesion of the optic nerve with associated nerve fibre loss. Mild impairment of colour vision, pallor or reduced vascularity of the optic nerve head, excessive tortuosity of retinal vessels, a small central scotoma, and/or mild abnormalities or atypical features of the VEP were found in 16 of the 40 asymptomatic family members studied. Such abnormalities were present in 50 per cent of descendants from the female lineage who were at risk of developing the disease, and also in 30 per cent of descendants from male lineages who were not at risk. These findings suggest that there is a stage prior to the onset of visual impairment during which subtle abnormalities may be detected in individuals at risk of developing or transmitting the disease. The finding of asymptomatic abnormalities in descendants from male lineages could be accounted for by transmission of a partial form of the disease by affected or unaffected males, which would be in accord with a cytoplasmic mechanism of transmission for the disease.

Adolescent↗