Biomedical subjects
Publications and source records attributed to R Makabe.
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Since 1969, 1,179 eyes with central serous chorioretinopathy have been examined with fluorescein fundus angiography. The classic form with fluorescein leakage (type I) decreased in incidence from 86.4% to 55.4%, while an atypical form with frequent serous pigment epithelial detachment (type II) increased from 12.6% to 33.0%, and the mixed form (type I + II) increased from 1 to 11.6%. In type I with delayed healing laser coagulation of the leakage was performed, which improved the visual acuity from 0.64 to 0.92 an average (n = 122), while in cases without laser coagulation the percentage improved only from 0.66 to 0.84 on average (n = 34) with a statistically significant difference (t = 2.64, P < 0.01). Laser coagulation was especially beneficial in the mixed form (n = 16), in which the visual acuity improved from 0.42 to 0.86 on average. The proportion of women increased from 10.7 to 17.9%. The patient age tended to be higher in women more than in men.
We treated patients with Kaposi's sarcoma of the lid or conjunctiva, molluscum contagiosum and papilloma of the lid with dye laser photocoagulation. This therapeutic device is extremely efficient as the chosen wavelength of 577 nm is absorbed selectively by haemoglobin. Since Kaposi's sarcoma is a haemoglobin-containing tumour composed of endothelial cells and papilloma is a benign tumour composed of connective tissue and branching vessels, dye laser photocoagulation causes selective damage to abnormal vessels and surrounding connective tissue. After local anaesthesia a small incision was made at the margin of the lesion five patients each with papilloma and with molluscum contagiosum. In six patients with Kaposi's sarcoma no incision had to be done. Starting from the incision or the margin of the Kaposi's sarcoma 50-100 shots of 0.3-0.5 mm diameter and 1 s duration were applied until the lesion was completely gone. We used a dye laser with 577 nm wavelength and 1 W energy. In patients with papilloma, the tumour basis was coagulated and the tumour itself underwent histological examination. There was a marked decrease of the size of the lesion or even complete disappearance. Since Kaposi's sarcoma in AIDS patients can be relatively fast growing, resulting in cosmetically irritating manifestations and, rarely, haemorrhages, treatment may become necessary. AIDS patients with molluscum contagiosum may also benefit from treatment, as spreading of DNA virus particles may result in viral follicular conjunctivitis. Dye laser photocoagulation, however, cannot protect against relapse.
We have recently seen a number of patients with angle-closure glaucoma who had been treated for glaucoma simplex (primary open-angle glaucoma). The main cause of this misdiagnosis was gonioscopy, as its findings are subject to the impression of the examiners. For objective examination of the chamber angle and the iris configuration, B-scan ultrasonography was performed using a contact eye cup filled with saline. Two groups of patients were noted in particular. The first group contained relatively young patients, more men than women, with plateau iris and a central normal, deep anterior chamber. The second group consisted of patients with presumed glaucoma simplex. The findings were quite different between eyes. In the eye with a higher IOP, pronounced optic nerve damage and visual field defect, the chamber angle was distinctly more narrow and closed. Most of the patients were treated with beta-blocker drops, which they felt were agreeable.
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Twenty-six eyes with acute idiopathic senile macular holes and visual acuity of between 0.02 and 0.5 were treated by laser coagulation with krypton red. The laser burns were placed in a ring around the hole, at the border of the retinal detachment. A few weeks after treatment marked regression of the detachment was seen. During the follow-up period (3-18 months) visual acuity improved in 18 eyes, deteriorated in 1 and was unchanged in 7.
We have recently been referred patients with visual field contraction from simulation or aggravation. For unmasking, we used optokinetic nystagmus, which can also be induced by stimulation of the peripheral retina. At electronystagmography the central portion of the screen was covered from 20 degrees-60 degrees by means of a black disk in front of the projection nystagmus drum. In the centre of the screen a light spot was installed, which blocked the nystagmus. On turning off the light spot, the optokinetic nystagmus was registered when there was no visual contraction at this degree. The examination was successful except for one case with coarse, spontaneous nystagmus in all 18 eyes of 10 patients, in which a visual field contraction from simulation or aggravation was suspected.
Using a thin B-scan probe the anterior chamber angle was ultrasonographically studied using a contact eye cup filled with saline. The width of the chamber angle was measured on the display video copy and compared with the gonioscopic findings. Sixty-four eyes with primary glaucoma and 53 nonglaucomatous eyes were examined. In eyes with gonioscopic narrow angle the real ultrasonographic width of the chamber angle was varied considerably from case to case. In eyes where the chamber angle was not visible by gonioscopy it was not always closed. The correlation between the width of the angle and the depth of the anterior chamber was weak. There was often a plateau iris, which was demonstrated clearly by B-scan ultrasonography.
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Central serous chorioretinopathy was treated by laser photocoagulation of the site of fluorescein dye leakage. In 22 cases, in most of which the leakage was located in the nasal macular area or close to the foveola, krypton red was used, and in 85 cases argon blue-green. There was a significantly greater improvement after treatment with the krypton laser, and healing also tended to be faster than with the argon laser.
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Retinal sensitivity is examined by projecting the aiming beam of an argon krypton laser photocoagulator onto the fundus through a contact lens. Even at normal intensity the brightness of the projected aiming on the retina is much greater than the maximum-intensity light target in ordinary scotometry. The discrepancy between scotomata when comparing the results of ordinary and laser scotometry suggests a potential for recovery of visual function, especially in macular diseases. This examination is practicable even if there is slight opacity of the media. By setting the laser beam at sufficiently low intensity, relative scotomata can be detected.
In comparative studies covering 142 eyes a "night myopia" of 0.5 to 1.5 D was found in 33 eyes with the Nyktometer (Rodenstock) and in 23 eyes with the Mesoptometer I (Oculus). In 17 eyes the same degree of "night myopia" was determined with both instruments, while in 16 eyes it was found to be more severe when measured with the Nyktometer than with the Mesoptometer. In one eye this myopia was only found with the Mesoptometer. This more severe "night myopia" measured with the Nyktometer is probably attributable to "instrument myopia."
Laser trabeculoplasty was performed to treat medically uncontrolled open-angle glaucoma (glaucoma chronicum simplex). Twenty-five eyes were treated with a red krypton laser, while in 110 eyes the usual blue-green argon laser was used, and in 14 eyes a pure green argon laser, under the same conditions. After treatment with the krypton laser the average drop in intraocular pressure at 24 hours was 4.8 mm Hg; at 4 weeks it was 2.3 mm Hg, and at 3 months there was no longer any appreciable effect. In the cases treated by argon laser the pressure drop was significantly greater and lasting, averaging 7.8-8.2 mm Hg from 24 hours after the treatment onward for at least 12 months. There was no difference between the blue-green and the green argon laser as regards pressure drop and improvement in outflow facility.
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