A Scanning Electron Microscopic Study of the Basal Surface of the Corneal Endothelium and the Stromal and Endothelial Surfaces of Descemet's Membrane in Rats

The basal surface of the corneal endothelium and the stromal and endothelial surfaces of Descemet's membrane in rats were studied by scanning electron microscopy. We compared the fine structures of the two surfaces of Descemet's membrane both after sputter-coating with platinum and without sputter-coating. Fine structures were made clearly visible without metal coating by heating specimens to 300°C during observation. After sputter-coating, both surfaces of Descemet's membrane were composed of granular substances, but their sizes were larger on the stromal side than on the endothelial side. Both surfaces of Descemet's membrane observed without sputter-coating were composed of fine fibrous structures showing a felt-like appearance, but their diameters were thicker on the stromal surface. These results may reflect a difference in collagen types between the two surfaces of Descemet's membrane

Slow and Fast Oscillation Electrooculography in Central Retinal Vein Occlusion: A Comparison between Affected Eyes and Fellow Intact Eyes

Using an automated electrooculograph, the Nidek EOG-2, slow and fast oscillations (SO and FO) of an electrooculogram (EOG) were recorded in 21 patients with unilateral, ischemic central retinal vein occlusion (CRVO). Patient age ranged from 49 to 81 years (average: 68 years of age). Fellow eyes in all patients were intact, and served as controls. Results showed that the L/DSO (the light peak/dark trough ratio of the SO), the RfFO [the average ratio in percentage of the maximum amplitude in the dark period (AD)/the minimum amplitude in the light period (AL) during FO measurement], the dfFO (the average difference in ?V between AD and AL), and the df/mFO [the percentage ratio of the dfFO to the average amplitude of AD + AL (m)] were significantly decreased in the affected eyes compared with the fellow eyes. These results suggest that with regard to SO and FO origin and occurrence, the outer layer of the retina, especially the basal membrane of the retinal pigment epithelium or the choroid may be involved in the etiology of CRVO. These findings correlate with the grade of microcirculatory disturbance or ischemia in the inner layer of the retina. Furthermore, a statistically significant difference was detected in the correlation between each FO parameter and corrected visual acuity at the time of examination of the affected eyes. There was no significance between the SO parameter and the visual acuity. Therefore, it might be possible to presume that the FO parameters can be used as indicators for detecting the severity of macular functional disturbance and predicting the visual outcome for this entity

Blood Flow Changes in the Optic Nerve Head of Albino Rabbits Following Intravenous Administration of Brovincamine Fumarate, an Improver of Cerebral Circulation and Metabolism

Blood flow changes in the optic nerve head of normal, adult albino rabbits following intravenous administration of brovincamine fumarate (BV), an improver of cerebral circulation and metabolism, were investigated employing the hydrogen clearance method. In the BV (0.1 mg/kg)-administered group, the blood flow in the optic nerve head showed a gradual increase immediately after injection and reached a maximal value of 124.2 ± 7.3% against the value before injection at 20 min after injection, followed by a gradual decrease in blood flow. Statistical analysis showed a significant increase (P < 0.05) in blood flow at 10 to 40 min after injection, compared with the value before injection in the BV (0.1 mg/kg)-administered group, but no significant changes in blood flow were observed in either the BV (0.5 mg/kg)-administered group or the control group given no BV throughout the time course. No significant changes in the mean values of the mean blood pressure in the femoral artery, pulse rate, respiratory rate or rectal temperature were observed in any group throughout the experiment. These results indicate the different efficacy of the two doses to the relaxing action of the feeding vessels around the optic nerve head

Morphological Changes in Patient Lens Epithelial Cells after Intravitreal Silicone Oil Injection

The subject patient (47-year-old male) had received silicone oil injection into the vitreous cavity of his left eye for the treatment of retinal detachment in 1986. Two months later, the silicone oil was removed from the vitreous cavity, as the retina was reattached. Soon after the operation, the lens of the eye gradually became opaque to mature cataract, and his left visual acuity had fallen to hand motion upon his present admission to the hospital. The lens epithelium obtained by anterior capsulotomy during the extracapsular cataract extraction was examined morphologically by transmission electron microscopy. Inside the anterior lens capsule, abnormal epithelial proliferation was observed. The epithelial cells changed their shapes from cuboidal to spindle, accompanied by new basal lamina-like substances around them. The spindle-shaped cells stretched like pseudopodia. The extracellular matrices were abundant and composed of collagen fibers. Fragments and dissolved materials of the fibers were also seen in some specimens. Lipid-like substances and myelin-like structures were often observed in the relatively well preserved cytoplasm. As a result, it is surmised that cataract formation after intravitreal silicone oil injection may be associated with fibrous pseudometaplasia of the lens epithelial cells and phagocytosed silicone oil deposits in the epithelial cells

Fast and Slow Oscillation Electrooculography in Harada Disease

We assessed clinical utility of fast and slow oscillations (FO and SO) of the electrooculogram (EOG) in Harada disease. In 12 eyes of 4 female and 2 male subject patients aged 18 to 77 years (average: 41.8 years), FO and SO were recorded using an automated electrooculograph, the Nidek EOG-2, in the acute period before treatment and in the remission period under corticosteroid therapy. FO parameters, namely the RfFO [the average ratio in percentage of the maximum amplitude in the dark period (AD)/the minimum amplitude in the light period (AL) during FO measurement] and the dfFO (the average difference in ?V between AD and AL) were evaluated. The L/DSO (the light peak/dark trough ratio of the SO) was calculated as an SO parameter. The RfFO, dfFO and L/DSO showed low values in 7 (58.3%), 10 (83.3%) and 8 (66.7%) out of all 12 eyes in the acute period, respectively. In the remission period, values in the normal range were obtained in 12 (100%), 11 (91.7%) and 8 (66.7%) out of 12 eyes in the RfFO, dfFO and L/DSO, respectively. In mutual relation to each RfFO, dfFO and L/DSO in the acute and remission periods, all 12 eyes showed recovery values both in the RfFO and dfFO in the remission stage after systemic administration of corticosteroids, but 4 out of 12 eyes (33.3%) showed no recovery in the L/DSO. The FO may therefore well reflect the affected or ameliorated conditions in the outer layers of the retina and the choroid in Harada disease, in contrast to the SO. However, further observations are requested in more Harada disease patients

Clinical Evaluation of a Three-Dimensional Ultrasonography System in the Ophthalmic Field

Clinical use of a 3-dimensional ultrasonography system with a new ophthalmic imaging device using conventional 2-dimensional ultrasound tomography in the ophthalmic field was evaluated in 5 patients with different ocular conditions. With the system, surface rendering and volume measurement were easy in 3-dimensional ultrasonographic examinations. In a patient with rhegmatogenous retinal detachment, the surface rendering made the image cube transparent, revealing interior surface details. In a patient with lens luxation resulting from Marfan's syndrome, the shape of luxated spherophakia was detected stereographically. In a patient with choroidal detachment, we could evaluate the effect of administration of aspirin on the amelioration of this disease by measuring the volume of the choroidal lesion. In a patient with aberration of a lens fragment into subretinal space during cataract surgery, we grasped the whole ocular condition in the 3-dimensional image only by just one manipulation. In a patient with optic disc melanocytoma, we could detect the volume change in detail using the 3-dimensional images-saving system. No discomfort occurred in these patients during examination. Based upon the above findings, we considered that this device was useful in making diagnosis and grasping the whole ocular conditions and outcome in breathtaking 3-dimensional views, and in causing no discomfort for patients

Assessment of Macular Function by Multifocal Electroretinography and Optical Coherence Tomography before and after Panretinal Photocoagulation in Diabetic Retinopathy

We evaluated macular function before and after panretinal photocoagulation (PRP) in diabetic retinopathy using a multifocal electroretinogram (mfERG) and optical coherence tomogram (OCT). In mfERGs, the 1st positive wave (P1) minus the 1st negative wave (N1) amplitude (P1 ? N1 amplitude), the P1 peak latency and the response density were measured in 7, 19, 37 and 103 hexagonal areas or elements (Areas 1, 2, 3 and 4) within a central radius of 5, 7, 10 and 20 degrees, respectively. The mean retinal thickness was estimated from 9 calculation points at the foveal region within 5 degrees; the central and each of the other 4 points at a distance of 250 ?m and 500 ?m from the central por tion on horizontal and vertical sections on OCT. The P1 peak latencies from the 4 areas were remarkably prolonged in 14 eyes of 9 patients with preproliferative or early proliferative diabetic retinopathy showing no clinically significant macular edema before PRP as compared with those in 15 normal control eyes, without a tendency of recovery throughout the course after PRP except for area 1. The P1-N1 amplitudes and the mean response density levels from the 4 areas were remarkably decreased in the diabetic eyes before PRP as compared with those in the control eyes, followed by a maximum decrease in both parameters at 3 months after PRP. However, remarkable recoveries were detected in both decreased parameters from the 4 areas at 6 months after PRP. The mean foveal retinal thickness on OCT was remarkably increased in the diabetic eyes before PRP as compared with the thickness in 16 normal control eyes. Most remarkably, a transient increase in thickness was detected in diabetic eyes 1 month after PRP, followed by a tendency of recovery 3 to 6 months after PRP. These results indicate that mfERG and OCT examinations are useful in the assessment of macular function before and after PRP in diabetic retinopathy, especially within 5 degrees of the central portion, and that the effects of PRP on macular function in this entity seem to be reversible at the foveal region, although we need to do further investigation in relation to the outcome of visual acuity

Effects of Metoclopramide Hydrochloride, a D2-Selective Dopamine Receptor Antagonist, on the Fast Oscillation of the Electrooculogram

Fast oscillation (FO) of an electrooculogram (EOG) was recorded in both eyes of 10 healthy volunteers before and after administration of metoclopramide hydrochloride (MTCL), a D2-selective dopamine receptor antagonist, paying particular attention to sex concerning sensitivity to dopamine in young subjects. Healthy volunteers were divided into male and female groups; 5 males (10 eyes) aged 21 to 23 years (average, 21.8 years) and 5 females (10 eyes) aged 19 to 25 years (average, 21.8 years). As an FO parameter, the dfFO (the averaged difference in ?V between maximum amplitude in the dark period and minimum amplitude in the light period during FO measurement) was evaluated. The mean level of dfFO significantly increased between phase A (the initial 10 min before intravenous injection of 10 mg of MTCL) and phase B (10 min after the injection) in the male and female groups (P < 0.01 and P < 0.025) and between phase A and phase C (the additional 10 min after the injection) in both groups (P < 0.01 and P < 0.05). The mean level of dfFO in the female group was significantly higher than that of the male group in phase B (P < 0.05). As a control, the experimental procedure was performed with physiological saline administration, and no changes were observed. The data suggest that there exists some difference between young males and females generation concerning sensitivity to dopamine and that young females may show a higher-than-male sensitivity to dopamine in the occurrence of FO potential