PURPOSE: To study the development, progression, and regression of experimental choroidal neovascularization (CNV) by correlating the cross-sectional images from sequential optical coherence tomography (OCT) with histopathologic sections of the same retinal regions. METHODS: Laser photocoagulation was performed in the posterior pole of the eye of 4 rhesus monkeys to induce CNV. Funduscopy, fluorescein angiography (FAG), and OCT were performed on day 1 and weekly for 13 weeks. Histological serial sections of CNV tissue were compared to corresponding OCT images. RESULTS: In the developmental stage of CNV, the CNV was observed by OCT as a nodular high reflex area continuing from the highly reflective retinal pigment epithelium (RPE). Histopathological studies showed that the CNV was composed of tightly packed proliferated RPE and immature vascular endothelial cells. In the active stage, OCT revealed a thick multi-layered high reflex area under the sensory retina. This high reflex area corresponded with the CNV membrane that consisted of newly formed blood vessels with wide vascular lumens and proliferated spindle-shaped RPE cells. In the regressive stage, OCT revealed a dome-like, white-colored highly reflective layer continuing from the RPE layer with moderate reflection beneath the layer. Histopathologically, the neovascular tissue was enveloped by mono-layered, cuboidal-shaped RPE cells with melanin granules. CONCLUSION: Optical coherence tomography images clearly demonstrated the positional relationship between the CNV and the RPE. Optical coherence tomography imaging provides information on the CNV which complements conventional examinations by funduscopy and FAG.

Animals↗

PubMedDate not supplied

Multicenter genetic study of retinitis pigmentosa in Japan: I. Genetic heterogeneity in typical retinitis pigmentosa.

A nationwide, multicenter study of typical retinitis pigmentosa (RP) was carried out in collaboration with 18 hospitals throughout Japan to obtain current information for genetic counseling. We analyzed the genetic heterogeneity of RP based on the parental consanguinity of 434 probands registered during a 6-month period in 1990. A gradual decline in the frequency of consanguineous marriage was recognized among the normal parents of RP patients. The relative frequencies of inheritance patterns were estimated as: autosomal recessive, 25.2%; autosomal dominant, 16.9%; X-linked, 1.6%; and simplex, 56.3%. A comparison of these results with previous reports in Japan revealed a decline in the relative frequency of autosomal recessive cases and an increase in simplex cases. This suggests a decrease in the incidence of autosomal recessive retinitis pigmentosa in Japan, as well as the necessity for exhaustive investigations aimed at identifying inheritance patterns for RP patients seeking genetic counseling.

Adolescent↗

PubMedDate not supplied

Multicenter genetic study of retinitis pigmentosa in Japan: II. Prevalence of autosomal recessive retinitis pigmentosa.

Retinitis pigmentosa (RP) is a group of genetically heterogeneous diseases with autosomal recessive (AR), autosomal dominant, and X-linked modes of inheritance. Autosomal recessive retinitis pigmentosa (ARRP) is the most common form in Japan. A genetic analysis was done to determine the prevalence of ARRP indirectly, to provide an estimation of changing trends in the overall prevalence of RP. Data on the frequency of consanguinity and marriage year of normal parents of 59 ARRP patients were obtained from a nationwide multicenter survey of typical retinitis pigmentosa conducted in 1990. The gene frequency of ARRP was 0.01145 (Dahlberg's formula). In 1990, the number of young symptomatic ARRP patients decreased, while the number of patients aged 40 years and older increased. The total number of symptomatic ARRP patients in 1990 was nearly 21% higher than in 1970. Despite a dramatic decline in consanguinity in recent decades in Japan, the number of ARRP patients has increased. This increase is attributed to greater longevity and overall population growth. Our results suggest that the total number of RP patients has not decreased, and may even have increased.

Adolescent↗

PubMedDate not supplied

Comparison of indocyanine green and fluorescein angiography of choroidal neovascularization.

We compared indocyanine green (ICG) and fluorescein angiography for evaluation of choroidal neovascularization (CNV). Cast preparations of CNV induced in monkey eyes by laser photocoagulation were correlated with ICG and fluorescein angiographies of the same CNV formations. Fluorescein angiography was more effective, in general, than ICG angiography in detecting CNV; however, CNVs with subretinal hemorrhage (2 of 35 sites) were visible only with ICG angiography. In early phase ICG angiography, CNV formations that casts showed to be dense or composed of thick vessels were seen, but less dense areas were not visible. Lesions that ICG angiography revealed as leaking were not differentiated morphologically from non-leaking areas by the CNV casts. This study confirms that only ICG angiography can identify CNV hidden by subretinal hemorrhage, although fluorescein angiography is otherwise superior. Indocyanine green angiography is indicated as a valuable complement to fluorescein angiography for evaluation of CNV.

Animals↗

PubMedDate not supplied

Occlusive thromboaortopathy (Takayasu's disease): cervical arterial stenoses, retinal arterial pressure, retinal microaneurysms and prognosis.

Eighty-one young Japanese patients with occlusive thromboaortopathy (Takayasu's disease) were classed into three groups according to the degree and extent of diameter stenosis in the 4 cervical arterial systems, as determined by serial aortography. Class I was made up of 63 patients with 70% or greater stenosis in less than 3 systems, including 33 patients without systemic hypertension (Class Ia). Class II was made up of 6 patients with 70% or greater stenosis in 3 systems and less than 50% stenosis in the remaining 1, including 5 patients without systemic hypertension (Class IIa). Class III was up of 12 patients with 70% or greater stenosis in 3 systems and 50% or greater stenosis in 1 system. Ophthalmodynamometric systolic pressure in patients in Class III was significantly lower than that in patients in Class IIa (p less than 0.001), but there was no significant difference between patients in Classes Ia and IIa. Microaneurysms and/or arteriovenous anastomoses in the retinal vessels were found in all but one patient in Class III and in only one patient in combined Classes I and II. These results indicate that each of the ophthalmodynamometric values and fundoscopic findings are very helpful in identifying the markedly severe occlusive lesions (Class III) of the 4 cervical arterial systems. In this chronic disease, however, angiography is most useful for evaluation of these severe lesions, to monitor progression from Classes I and II to Class III, in which the prognosis is rather poor.

Adult↗

PubMedDate not supplied

Treatment with bifemelane for optic nerve damage following high intraocular pressure in rat eyes.

This study found that pretreatment with 4-(o-benzylphenoxy)-N- methylbuty-lamine hydrochloride (bifemelane hydrochloride, Celeport) reduced ischemia-reperfusion injury in rat eyes. Bifemelane (25 mg/kg) was injected intraperitoneally 30 minutes before an ischemic insult, then acute ischemia of the retina and optic disc was induced by increasing intraocular pressure to 110 mmHg for 45 minutes. After one week, the axonal count of the optic nerve was investigated using electron microscopy. The control group consisted of vehicle-treated eyes which received normal saline. The axon count was 93.4 +/- 7.9 for the bifemelane treated group, and 79.2 +/- 6.4 for the controls. The axon count in the treated group was significantly higher. These results suggest that bifemelane, which prevents cerebral nerve cell damage from ischemia, can reduce ischemic retinal nerve cell injury.

Animals↗

PubMedDate not supplied

Optical coherence tomographic findings of idiopathic polypoidal choroidal vasculopathy.

BACKGROUND AND OBJECTIVE: To identify the histological level of abnormal vessels associated with idiopathic polypoidal choroidal vasculopathy (IPCV), we examined IPCV with Optical Coherence Tomography (OCT). PATIENTS AND METHODS: Fourteen patients diagnosed with IPCV were examined with Indocyanine green (ICG) angiography and OCT. RESULTS: ICG angiography demonstrated branching vascular networks with polypoidal dilatations at the terminals beneath the retinal pigment epithelium (RPE). OCT showed dome-like elevation of the RPE, and moderate reflex or nodular appearance were seen beneath the RPE. CONCLUSION: The abnormal vessel associated with IPCV is supposed to be choroidal neovascularization with polypoidal dilatations at the terminals between Bruch's membrane and RPE. We consider that this disease is a peculiar form of age-related macular degeneration.

Aged↗

PubMedDate not supplied

Occult retinal pigment epithelial detachment in hyperviscosity syndrome.

We document and evaluate a serous retinal detachment in a patient with hyperviscocity syndrome. Optical coherence tomographic images of the serous retinal detachment in a patient with hyperviscocity syndrome were correlated with slit-lamp biomicroscopic findings, fundus photographs, fluorescein angiograms, and indocyanine green angiograms. Fluorescein angiography demonstrated venous and capillary bed abnormalities but no leakage or pooling of fluorescein corresponding to the retinal pigment epithelial detachment (PED) beneath the serous retinal detachment. Indocyanine green angiogram disclosed a delay of intrachoroidal circulation. Optical coherence tomography (OCT) revealed a large retinal pigment epithelial detachment beneath the serous retinal detachment. The occult retinal PED beneath the neurosensory retinal detachment was detected only by OCT in a patient with hyperviscosity syndrome. We suggest that gamma globulin, which is the hyperviscosity material, accumulated in the subretinal pigment epithelial space and blocked the leakage or pooling of fluorescein corresponding to the retinal pigment epithelial detachment.

Diagnosis, Differential↗

PubMedDate not supplied

N-methyl-N-nitrosourea-induced photoreceptor apoptosis in the mouse retina.

Retinal degeneration induced by a single intraperitoneal injection of N-methyl-N-nitrosourea (MNU) in male and female albino (GRS/A and DDD/1) and colored (C57BL) mice at 7 weeks of age was examined morphologically 1, 3, 7, 14 and 21 days after the treatment. A dose of 60 mg/kg body weight evoked progressive retinal degeneration in all mice. All albino and colored mice had a comparable progression of photoreceptor cell degeneration by an apoptotic mechanism, as confirmed by morphological and TUNEL methods. Apoptosis had already taken place 1 day after the treatment and was completed by Day 7. This process resulted in a thin remnant of retina with complete loss of photoreceptor cells-21 days after the treatment. During the course of apoptosis, the pigment epithelial cells were maintained in a continuous layer in all strains of mice. In colored mice, several layers of the swollen pigment-enriched cells were seen between the inner nuclear layer and the pigment epithelial layer 14 and 21 days after the treatment. In summary, the destruction of photoreceptor cells by the apoptotic process was the mechanism by which retinal degeneration was induced by MNU.

Animals↗