Analysis of the components of electrically evoked response using a monopolar recording technique.

PURPOSE: To assess the significance of the components of the electrically evoked response. METHODS: Twenty-three normal subjects, six patients with macular holes, and three patients with retinal artery occlusion were tested. The electrically evoked responses were recorded from an occipital electrode by applying an electric current of 0.3 mA-2.0 mA with a duration of 5 msec and a frequency of 1.85 Hz. RESULTS: In the normal subjects, three rhythmic waves (N1P1, N2P2, N3P3) were frequently found with fewer individual differences in their latencies than in flash visual evoked potentials. It was found that the amplitude of N1P1 became larger in proportion to the stimulus strength, and that the amplitudes of N2P2 and N3P3 reached their ceiling peaks. The amplitudes of N2P2 were significantly reduced in the affected eyes of patients with a unilateral complete break of the macula and branch retinal artery occlusion including the macular area. Conversely, in one patient with central retinal artery occlusion, whose visual acuity was good because the cilioretinal artery was patent, the amplitude of N1P1 was significantly reduced in the affected eye. CONCLUSIONS: N2P2 in electrically evoked response might originate mainly in the macular area. The analysis of N2P2 may be useful for further clinical applications of electrically evoked response.

Direct examination vs culture of biopsy specimens for the diagnosis of keratomycosis.

In two patients with fungal keratitis, direct examination of corneal biopsy specimens showed positive fungal elements, but cultures of biopsy specimens failed to disclose fungal growth. We compared the value of direct examination and culture of biopsy specimens in the diagnosis of keratomycosis in rabbits with experimental fungal keratitis caused by Fusarium solani, Aspergillus fumigatus, and Candida albicans. Cultures disclosed seven specimens (70%) positive for Candida and eight (80%) for Fusarium and Aspergillus keratitis, whereas direct examination showed positive fungal elements of Fusarium, Aspergillus, and Candida in all specimens.

Oral itraconazole and topical miconazole with débridement for Acanthamoeba keratitis.

We treated three patients who had Acanthamoeba keratitis with oral itraconazole, a new antifungal agent, topical miconazole, and surgical débridement of the lesion. In these patients, healing and regression of the keratitis began six or seven days after initiation of oral itraconazole and miconazole 0.1% eyedrops (every hour during the day). The clinical signs of corneal infection disappeared after nine weeks in Patient 1, after five weeks in Patient 2, and after eight weeks in Patient 3. Visual acuities improved markedly from hand motions to 20/30 in Patient 1, from counting fingers to 20/16 in Patient 2, and from hand motions to 20/40 in Patient 3. In these patients, no systemic or topical signs of toxicity or adverse reactions were noted during the course of treatment.

Refractive changes in diabetic patients during intensive glycaemic control.

AIMS: To evaluate the clinical course and the characteristics of transient refractive error occurring during intensive glycaemic control of severe hyperglycaemia. METHODS: 28 eyes of patients with persistent diabetes were included in this prospective study. During the observation period, patients underwent general ophthalmological examination and A-mode scan ultrasonography was performed at each examination-at days 1, 3, and 7, and then once every week or every other week until recovery of hyperopia. RESULTS: A transient hyperopic change occurred in all patients receiving improved control after hyperglycaemia. Hyperopic change developed a mean of 3.4 (SD 2. 0) days after the onset of treatment, and reached a peak at 10.3 (6. 1) days, where the maximum hyperopic change in an eye was 1.47 (0. 87) D (range 0.50-3.75 D). Recovery of the previous refraction occurred between 14 and 84 days after the initial assessment. There was a positive correlation between the magnitude of the maximum hyperopic change and (1) the plasma glucose concentration on admission (p<0.01), (2) the HbA(1c) level on admission (p<0.005), (3) the daily rate of plasma glucose reduction over the first 7 days of treatment (p<0.001), (4) the number of days required for hyperopia to reach its peak (p<0.001), and (5) the number of days required for the development and resolution of hyperopic changes (p<0.0001). There was a negative correlation between the maximum hyperopic change of an eye and baseline value of refraction (p<0.01). During transient hyperopia, no significant changes were observed in the radius of the anterior corneal curvature, axial length, lens thickness, or depth of anterior chamber. CONCLUSIONS: The degree of transient hyperopia associated with rapid correction of hyperglycaemia is highly dependent on the rate of reduction of the plasma glucose level. A reduction of refractive index in intraocular tissues, especially in lens, appears to be responsible for this hyperopic change.

Endogenous Nocardia asteroides endophthalmitis in a patient with systemic lupus erythematosus.

We report a case of endogenous Nocardia endophthalmitis in a patient with systemic lupus erythematosus (SLE). He developed a parafoveal lesion in the right fundus while on systemic corticosteroid and antibiotic treatment. Initially we suspected a fungal origin and treated him with antifungal drugs. The intraocular disease progressed without improvement and advanced to the vitreous cavity. Nocardia asteroides was found in a specimen obtained at pars plana vitrectomy and was also cultured from the same specimen. The intraocular infection was controlled by antibacterial drugs, though the visual acuity of the right eye was reduced to only light perception owing to heavy vitreous opacity and secondary cataract. This case is the first report of endogenous Nocardia endophthalmitis in Japan and also the first case of this disease reported from outside the United States of America.

Analysis of vasocontractile responses to endothelin-1 in rabbit retinal vessels using an ETA receptor antagonist and an ETB receptor agonist.

To study the role of endothelin receptor subtypes in rabbit retinal arteries, endothelin-1 (ET-1)-induced vasoconstriction was analyzed using the ETA receptor antagonist BQ-123 and the ETB receptor agonist BQ-3020. A cumulative injection of ET-1 (1 approximately 100 pmole) into the posterior vitreous body in anesthetized rabbits caused dose-dependent vasoconstriction in the retinal arteries, and ultimately caused complete obstruction. Fifteen minutes after BQ-123 (1 mumole) was injected into the posterior vitreous body, the dose-response curve of ET-1 was significantly shifted to the right. Intravitreal injection of BQ-3020 caused a significant retinal vasoconstriction only at the highest dose (1000 pmole). Therefore, in rabbit retinal arteries, ET-1-induced vasoconstriction appears to be mediated mainly through ETA receptors.

Optimum form of posterior chamber intraocular lenses to minimize aberrational astigmatism.

To optically determine the optimum form for a posterior chamber intraocular lens (PC IOL), we calculated the aberrational astigmatism induced by tilt and decentration of the PCIOL using an exact raytracing. First, the position and the radii of curvatures of the IOL were determined to make an emmetropic eye model using a paraxial raytracing. Next, the chief rays originating from the fovea centralis were traced backward through the tilted and/or decentrated PC IOL, the center of the pupil and the cornea, using trigonometric raytracing. Finally, the maximum and minimum aberrational astigmatism were calculated based on the Coddington's Equations for the sagittal and the tangential foci of the ray. All the refractive parameters in Gullstrand's No. 1 schematic eye were adopted. The effect of varying anterior corneal asphericity on the results was also examined. Four forms of polymethylmethacrylate PC IOLs (refractive index: 1.491) were analyzed; a plano-convex IOL with the curved surface facing the cornea, and three bi-convex forms with the ratio of anterior-to-posterior radii of curvatures of 1:4, 1:2 and 1:1, respectively. The 1:4 bi-convex form showed the lowest values for the maximum aberrational astigmatism calculated at every combination of tilt and decentration except 0 degrees tilt and/or 0 mm decentration. The aberrational astigmatism with the 1:4 bi-convex form of PC IOL did not exceed 1.0 D at the maximum tilt and decentration. The variation of anterior corneal asphericity did not influence the results. We conclude that the 1:4 bi-convex form of PC IOL minimizes the postoperative astigmatism induced by tilt and/or decentration of the lens.

Factors associated with increased aqueous flare in psoriasis.

PURPOSE: To evaluate the changes in aqueous flare in psoriasis patients and to identify the factors that influence the level of aqueous flare. METHODS: We examined the 68 eyes of 34 psoriasis patients and the 68 eyes of 34 healthy subjects with a laser flare-cell meter. Complete dermatologic and ophthalmic examinations were performed on the psoriasis patients. RESULTS: Flare was significantly higher in psoriasis patients than in normal controls (P <.000l). The factors that increased flare significantly were age and Psoriasis Area and Severity Index. Flare was not significantly associated with sex, psoriasis type, duration of disease, and cyclosporin therapy. A flare increase was significantly correlated with serum total protein and immunoglobulin (Ig) A, but not with albumin, IgG, and IgM. CONCLUSIONS: Psoriasis patients, even without ocular symptoms, had slight damage to the blood-aqueous barrier. Multiple linear regression analysis showed that flare had the strongest correlation with the severity of psoriasis.

Ultrastructural fragility and type IV collagen abnormality of the anterior lens capsules in a patient with Alport syndrome.

PURPOSE: To investigate ultrastructural and immunohistological abnormalities of the lens capsules in a patient with Alport syndrome. METHODS: Two anterior lens capsules were obtained at phacoemulsification from a 43-year-old female patient with bilateral lenticonus who was affected by Alport syndrome. The right capsule was examined by transmission electron microscopy and the left capsule was stained with two monoclonal antibodies against the triple-helical domains of type IV collagen alpha2 and alpha5 chains. RESULTS: Numerous vertical dehiscences with many disrupted interdigitations were observed in the right anterior lens capsule. Decreased reactivity of monoclonal antibodies against type IV collagen alpha5 chain and normal reactivity against the alpha2 chain were shown in the left anterior lens capsule. CONCLUSION: The ultrastructural fragility of the anterior lens capsules in this patient with Alport syndrome appears to be associated with the abnormality of the type IV collagen molecules including the alpha5 chain.

Successful treatment of a senile diabetic woman with cataract with goshajinkigan.

A 65-year-old woman with diabetes mellitus (DM) and suffering a cataract in the left eye, that was resistant to Western medical treatment, was treated with goshajinkigan (GJ), a herbal medicinal drug, in combination with eye drops. This treatment remarkably improved the visual disturbance due to the senile cataract. Ten days after commencement of the GJ treatment, her visual acuity did not deteriorate any further. There was also no further deterioration of DM condition. These results suggest that GJ may be valuable in the treatment of diabetic women with cataracts.

[Investigation of glutathione-S-transferase isozymes in human lenses].

Glutathione-S-Transferase (GST) isozymes in human lenses were investigated by the immunoenzymatic method using antibody against human liver GST2 and GST3 after polyacrylamide gel isoelectric focusing (western blotting method). Also, rocket immunoelectrophoresis was carried out for the detection of GST1. It was found that GST1 in lens also showed a polymorphism. The GST2 was not found in human clear lenses as well cataractous lenses. In addition, crossreacting materials against both antisera of GST2 and 3 were detected in the pH 6-7 area of the gel in all human lenses.

[Localization of glutathione-S-transferase in transparent and cataractous human lenses].

The localization of glutathione-S-transferase (GST) activity was investigated in 15 cataractous lenses obtained by intracapsular extraction of senile cataract. Additionally, 8 clear lenses, obtained from donor eyes in cases of corneal transplantation or of traumatic lens luxation, were used as controls. The lenses were divided into the central and peripheral portions with a trephine. The activity of GST was quantitated in each portion according to the method described by Habig. GST activity in clear lenses was significantly higher in the peripheral portion than in the central portion and in the former it was significantly higher in clear lenses than in cataractous ones. The ratio of GST activity between central and peripheral portions (C/P) was significantly higher in cataractous lenses than in clear ones. These findings suggested that the scavenging system of the human clear lens is more active in the equatorial portion than in the central portion. Nevertheless the activity of GST in human cataractous lenses decreased more significantly in the peripheral portion than in the central portion. These findings indicated that the human cataract usually develop from equatorial portion of lens.

[Acanthamoeba isolation from contact lens solution of contact lens wearers without keratitis].

Acanthamoeba keratitis seems to be associated with wearing contact lenses. As controls, we surveyed contact lens wearers without keratitis. Contact lens solutions of 93 persons were examined in order to identify risk factors for contamination by Acanthamoeba. Therefore, the contact lens disinfection system and storage schedules were studied in each case. Acanthamoeba organisms were isolated from 4 specimens (4.3%). The incidence of Acanthamoeba was higher in specimens of soft contact lens solution than in those of hard contact lens solution, and all the Acanthamoeba positive cases had been using tap water.

[Comparison of electrically evoked response (EER) and visual evoked potential (VEP) by topography and dipole-tracing].

To study the possibility of the clinical application of the electrically evoked response (EER) of the visual system, we analyzed P2 of EER as well as P100 of flash VEP by means of topography and dipole-tracing. By applying a constant electric current of 1.0 mA (duration 5 msec, frequency 1.39 Hz) and a strobo flash light of 0.6 Joules (frequency 1.39 Hz) to each eye, P2 and P100 were recorded respectively. It was found that the source generators of P2 and P100 showed the same localization and dipole vector. The results indicated flat the significance of P2 in applying EER clinically was comparable to the P100 of VEP.

[Electrically evoked responses in patients with macular holes].

The Electrically Evoked Response (EER) was analyzed in 7 patients with macular holes in order to determine whether EER reflects macular function. The EER was recorded from an occipital electrode (Oz) by applying a constant electric current of 1.0 mA with a duration of 5 msec and frequency of 1.85 Hz. In five patients with unilateral complete break of macula, each amplitude for the P2 component from the affected eyes was significantly smaller than that from contralateral eyes. However there was no such difference in both eyes of two patients with bilateral macular holes. No significant difference was shown in the amplitude for the P1 and P3 components of EER. These results strongly suggest that the retinal origin of P2 may mainly be in the macular area and that analysis of P2 might be useful to determine further clinical applications of EER.

[Quantitative evaluation of aqueous flare in psoriasis using a laser flare-cell meter].

We evaluated aqueous humor protein concentration in psoriasis using a laser flare-cell meter, which can quantify aqueous flare precisely and objectively. Psoriatic severity was evaluated on the basis of psoriasis area and severity index (PASI) score. Aqueous flare was measured in 40 eyes of 20 psoriasis patients (sixteen psoriasis vulgaris, three guttate psoriasis, and one psoriatic arthritis) and 28 eyes of 14 normal controls. Aqueous flare value was significantly higher in psoriatic patients than in normal controls (p < 0.01). There was no difference between psoriasis vulgaris and the other types of psoriasis. Aqueous flare value was higher in patients with psoriatic history longer than 10 years than in those with less than 10 years (p < 0.05), and also higher in patients with severe psoriasis (PASI score > 10) than in those with mild psoriasis (PASI score < 10) (p < 0.05). But no statistically significant differences in aqueous flare value were found among cyclosporin, etretinate, and psoralen ultra violet A therapies. These findings strongly suggest that patients suffering from psoriasis have slight damage of the blood-aqueous barrier even if they have no ocular symptoms, and that the degree of blood-aqueous barrier damage increases with time and severity of psoriasis.

[Analysis of the components of the electrically evoked response (EER) of the visual system by topography and dipole-tracing].

In order to examine the possibility of the clinical application of the electrically evoked response (EER) of the visual system, we analyzed the significance of the various components of the EER by means of topography and dipole-tracing. By applying a constant electric current of 1.0mA (duration 5msec) to each eye, three rhythmical waves were recorded within 200msec from the stimulation. The peaks of these waves were named N1, P1, N2, P2, N3, P3. Among those components of EER, we found P2 to be localized in the visual cortex, though the other components did not show any specific localization. The results indicated the significance of analyzing P2 in order to further investigate the possible clinical applications of EER.

[A specular microscopic study on irradiated rabbit corneas--report I. Early injury of the cornea].

To evaluate the effects of ionizing radiation on the cornea, one eye of healthy mature albino rabbits (n = 5) was irradiated with 20 Gy of X-rays (250 kV, 12 mA). Corneal observation was done with a slit-lamp biomicroscope and a specular microscope before irradiation, and follow-up observations were done at one week and 4 weeks after irradiation. Specular microscopic photographs were analyzed with a digitizer. Although slit-lamp biomicroscopy did not show any abnormal findings in the cornea, specular microscopy revealed a significant enlargement of the mean cell area of the superficial corneal epithelium at 4 weeks after irradiation. There were no significant changes in the corneal endothelium during this study. These results strongly suggest that high doses of X-ray irradiation could induce corneal epithelial injury at the early phase, even when by slit-lamp biomicroscopy shows no abnormal findings in the cornea.

[The effect of subconjunctival injection of endothelin-1 on intraocular pressure in the rabbit].

Endothelin-1 (ET-1) is a potent vasoconstrictive peptide produced in part by vascular endothelial cells. In order to investigate its effects on the episcleral vascular system and intraocular pressure (IOP), we injected ET-1 (3, 10, 30, 100, 300, 1,000 pmol) into the subconjunctival space of rabbits and measured IOP with a manometer. Injection of a dose higher than 10 pmol caused a transient increase of IOP. Mean maximum elevation rate of IOP for each dose of ET-1 was 14.9 +/- 0.9%, (mean +/- standard error) 43.5% +/- 9.5%, 40.8 +/- 7.5%, 46.9 +/- 9.8%, and 84.1 +/- 22.6. Next, we injected 1,000 pmol into the subconjunctival space, and continuously measured IOP and ocular pulse pressure with a manometer. IOP increased rapidly after ET-1 injection. Maximal increase of IOP was observed at 22.7 +/- 9.2 min after ET-1 injection, and IOP decreased after the peak. The ocular pulse pressure increased with IOP elevation and decreased with the IOP reduction. We speculated that the transient elevation of IOP was caused by increase of aqueous outflow resistance, and the decrease of IOP was caused by decrease of aqueous outflow resistance and decrease of blood flow in the ciliary body and the choroid. This strongly suggests that subconjunctival injection of ET-1 could have a large effect on the episcleral vascular system, aqueous outflow, and blood flow in the ciliary body and the choroid.

[Endothelin-1-induced vasoconstriction in retinal blood vessels in the rabbit].

Endothelin-1 (ET-1) is an endothelium-derived potent vasoconstrictor peptide which is synthesized in retinal vessels. In order to investigate its effect on retinal blood vessels, we injected ET-1 intravitreally (10(-12), 3 x 10(-12), 10(-11), 3 x 10(-11), 10(-10) mole) and examined the change in diameters of retinal arteries in rabbits by fundus photography. After injection of a high dose (10(-10) mole) of ET-1, fluorescein angiography was used to investigate whether complete occlusions of retinal blood vessels occurred or not. 3 x 10(-12) mole ET-1 induced contraction of retinal arteries and the contraction of those induced by 10(-10) mole ET-1 showed complete occlusion. A medium dose (10(-11) mole) of ET-1 caused repeated vasospasms and segmental vasoconstrictions of retinal blood vessels. Fluorescein angiograms revealed that retinal blood flow was interrupted transiently by injection of a high dose (10(-10) mole) of ET-1. These findings suggested that intravitreal injection of ET-1 could provide a new model of experimental transient occlusion of retinal vessels in rabbits.