Peripheral Vascular Leakage Findings of Asymptomatic Eyes Based on Fluorescein Angiography

PURPOSE: To report peripheral vascular retinal leakage findings of asymptomatic eyes based on fluorescein angiography, and investigate the associated factors. METHODS: Data were collected retrospectively from 47 subjects (94 eyes) and the peripheral leakage results based on fluorescein angiography were analyzed. The relationship between peripheral leakage findings and other factors including-arm-retinal circulation time (ARCT) and venous filling time (VFT), refractive error, age, hypertension, and diabetes- was evaluated. RESULTS: Ten eyes had peripheral leakage (21.3%). The mean age was 34.7 +/- 7.86 years in the non-leakage group and 44.3 +/- 9.63 years in the leakage group; the difference between the groups was statistically significant (p = 0.001). The mean spherical equivalent was -2.85 +/- 2.71 diopter in the non-leakage group and -3.46 +/- 3.62 diopter in the leakage group; the difference between the groups were not significant (p = 0.471). The mean ARCT was 10.50 +/- 2.06 seconds in the non-leakage group and 11.76 +/- 2.47 seconds in the leakage group; the difference between the groups was statistically significant (p = 0.041). The mean VFT was 9.70 +/- 1.91 seconds in the non-leakage group and 10.75 +/- 1.40 seconds in the leakage group; the difference between the groups was statistically significant (p = 0.048). CONCLUSIONS: Peripheral leakage can be found in asymptomatic eyes. Age, VFT, and ARCT were correlated to peripheral leakage findings based on angiography. These leakage findings were thought to be related with histological properties and physiological changes in peripheral retina.

A Case of Dengue Fever with Maculopathy / 감염과화학요법

Dengue fever is transmitted principally by Aedes aegypti, which is not infested in Korea. Therefore, all Korean patients with dengue fever are imported cases from endemic areas such as Southeast Asia. Although disease manifestation and complication of dengue fever are various, ocular involvement is rare. We encountered a patient infected with dengue virus, imported from the Philippines. After defervescence from dengue fever, he complained of blurred vision. Blot hemorrhage with retinal infiltration in the macular area was observed in both eyes. Maculopathy by dengue fever was treated with systemic and intraocular glucocorticoid for two weeks; his ocular condition then showed improvement.

Orbital Apex Syndrome in a Patient with Sphenoid Fungal Balls

Orbital apex syndrome (OAS) is a rare disease that presents with a complex of symptoms, including ophthalmoplegia, ptosis and visual loss. Due to the poor prognosis, making a prompt diagnosis and administering the appropriate treatment must be initiated without delay if OAS is suspected. We report here on a case of a patient with sphenoid fungal balls, and he presented with acute visual loss and ophthalmoplegia.

A Study of the Vascular Network of the Iris Using Flat Preparation

PURPOSE: This study was performed to examine the vascular network of the human iris using flat preparation. METHODS: The ciliary body-iris structures were separated from human eyeballs, and a portion of the irises were treated with trypsin to remove the pigment granules. These iris tissues were unfolded and placed onto glass slides using flat preparation, and the vascular network of each iris was examined by fluorescein microscopy. The ciliary body-iris structures separated from the remaining eyes were stained with hematoxylin-eosin without trypsin treatment and were examined by light microscopy. RESULTS: The long posterior ciliary artery formed several branches before entering the iris root, and such branches formed the major arterial circle of the iris with diverse diameters in the vicinity of the iris root and the ciliary process. In the pupillary margin, the iris vasculature network formed a cone shape and then formed an arcade by connecting to adjacent vasculatures. In the vicinity of the collarette, the iris vasculature network formed the minor arterial circle of the iris with diverse diameters perpendicular to the arcade of the iris network located in the pupillary margin. In the pupillary margin, the capillaries were somewhat thick and connected to the irregular traveling iris vein. CONCLUSIONS: The above findings explain the human iris vascular network and provide a theoretical basis for the sectoral filling of the iris vasculature seen in fluorescein iris angiography.

Usefulness of Computerized Objective Visual Acuity Test System Using Suppression Method

PURPOSE: The objective visual acuity test is mandatory in certain cases, such as infants, nonverbal subjects, and subjects who need legal assistance. We designed an objective system for visual acuity test (SOVAT) consisting of three components: stimuli applied via a suppression method, display and evaluation and made a suppression method as stimuli component for SOVAT. Usefulness of the SOVAT was evaluated. METHODS: The visual stimuli were presented on a high-resolution head-mounted display (HMD). An eye movement tracking program and gaze monitoring device allowed us to monitor the patient's fixation status during the test. The suppression method, in addition to a conventional induction method, was developed to use with the SOVAT and its accuracy and confidence level were evaluated. RESULTS: On the basis of clinical data, we present the reference values for the SOVAT as below. For the induction method, objective visual acuity (smallest pixel size), the presumed subjective visual acuity was 3: 0.35-0.6, 7: 0.05-0.25, 12: below 0.05 and for the suppression method it was 1: 0.6-1.0, 1.5: 0.4-0.7, 3: 0.15-0.4, 5: 0.1-0.2. CONCLUSIONS: SOVAT using this suppression method to assess objective visual acuity proved to be more useful than that with a conventional induction method, especially in the range of high visual acuity.

Change of Intraocular Pressure in Trabecular Meshwork Rupture Associated with Traumatic Hyphema

PURPOSE: To report the relationship between the extent of rupture of the trabecular meshwork and intraocular pressure changes in traumatic hyphema patients. METHODS: Ninety-five trabecular meshwork rupture patients were selected from a group of traumatic hyphema patients. Identification and measurement of the rupture of the trabecular meshwork were performed by gonioscopy, and intraocular pressure was measured by Goldmann applanation tonometry until 3 months after the trauma. RESULTS: There were statistically significant differences of IOP between the traumatic eyes and the contralateral eyes at day 2, 3, 5, and 1 month (p=0.000, 0.018, 0.001, 0.040, respectively). IOP was highest at the 2nd day post-trauma, and dropped by the 5th day, after which it rose slightly. The relationship between the extent of trabecular meshwork rupture and the difference of IOP was positive at the 2nd day post-trauma (r=0.259) and negative at the 6th day post-trauma (r=-0.296); these differences are statistically significant (p=0.020, p=0.041, respectively). CONCLUSIONS: A rupture of the trabecular meshwork can be measured using gonioscopy, and the change of IOP in a trabecular meshwork rupture increases as the extent of the rupture of the trabecular meshwork increases.

Transitional Zone of the Corneal Endothelium: Flat Preparation and Ultrastructural Findings

PURPOSE: To evaluate the morphological characteristics of the transitional zone between the corneal endothelium and the trabecular meshwork by flat preparation and electron microscopy. METHODS: The materials comprised 12 eyes examined by the flat preparation and 7 eyes by the electron microscopy. The specimens were derived from the transitional tissue between the corneal endothelium and the trabecular meshwork. The specimens in the flat preparation were stained with hematoxylin-eosin and examined by light microscopy. The specimens for scanning electronic microscopy (SEM) and in transmission electronic microscopy (TEM) were examined through routine processes. RESULTS: In the specimens examined by the flat preparation, unlike peripheral corneal endothelial cells, the endothelial cell nuclei in the transitional zone were overlapped and morphologically oval. On SEM, unlike typical hexagonality and tight interdigitation of corneal endothelial cells, the endothelial cells in the transitional zone were partially successive, spaced intercellularly, and morphologically irregular. On TEM, the endothelial cells in the transitional zone were partially successive. CONCLUSIONS: The loss of cell-cell contact of endothelial cells in the transitional zone may lead to the potential proliferation capacity of endothelial cells in the transitional zone under specific conditions. Therefore, further studies on the proliferation capacity of endothelial cells in the transitional zone are needed together with more research on cell biology.

Neovascularization in Branch Retinal Vein Occlusion Combined with Arterial Insufficiency

The aim of this study is to elucidate the association of neovascularization in branch retinal vein occlusion (BRVO) combined with major arterial insufficiency (MAI), compared with BRVO alone. The authors retrospectively reviewed the charts, color photographs, and fluorescein angiograms of 304 patients (308 eyes) who had BRVO from 1990 to 2002 at Hanyang University hospital. Patients with BRVO combined with MAI and patients with BRVO alone were differentiated by angiographic appearance. Of the 308 eyes, 12 (3.9%) had neovascularization, all of which were in the 56 eyes of the MAI group for which the neovascularization rate was 21.4%. Neovascularization in BRVO was more strongly associated with the non-perfusion caused by MAI, rather than with the extent of the non-perfusion area that originated from retinal capillary obstruction. MAI is considered as a risk factor for neovascularization and hence could be a prognostic factor.

Morphological Characteristics and Intercellular Connections of Corneal Keratocytes

PURPOSE: To investigate the morphological characteristics of keratocytes and the interconnection of keratocytes with adjacent keratocytes using the flat preparation method and scanning electron microscopy with a frontal section of the human corneal stroma. METHODS: The thin, corneal collagen lamellae were carefully dissected from the cornea (n=7), which had been stained by the flat preparation method. The remaining tissue was fixed in 3% glutaraldehyde and observed by transmission electron microscopy following the frontal section. RESULTS: The flat preparation revealed the corneal fibroblasts between the lamellae of the collagen fibers and showed that the ramifying cellular processes of the keratocytes were in contact with the cytoplasmic processes or cell bodies of neighboring fibroblasts. Two types of discrete subpopulations of keratocytes were identified: a smaller, cellular type of keratocyte with spindle-shaped nucleus with heterochromatin, and a larger, cellular type with a large indented nucleus with relatively scanty cytoplasm. Collagen fibers ran parallel to each other toward the fenestration of the cytoplasmic wall of the keratocyte. CONCLUSIONS: These flat preparation method results showed that the keratocytes within the corneal stroma are interconnected with the adjacent keratocytes, which indicates the presence of a functional communicating network through the keratocyte circuits within the stroma. A smaller, cellular type of keratocyte with spindle-shaped nucleus was morphologically differentiated from a larger, cellular type with a large, indented nucleus by flat preparation and transmission electron microscopy.

Axoplasmic Transport of Herpes Simplex Virus Co-Cultured with Ciliary Nerve

PURPOSE: To investigate the replication of HSV within cultured cell and axonal transport of HSV within the axon of the ciliary nerve following the injection of HSV into a cultured ciliary nerve. METHODS: The explant of the ciliary nerve was cultured with a medium containing nerve growth factor for 30 days when the suspension of HSV-1 (Kos strain) was introduced into the culture dish to co-culture with the ciliary nerve. The ciliary nerve was examined with transmission electron microscopy 30 days after culture and 6 days after co-culture with HSV. RESULTS: The ultrastructure of the explant of the ciliary nerve co-cultured with HSV showed that the viral capsid acquired a viral envelope and viral core, and a capsid and inclusion body within the nucleus. The enveloped virus was scattered within the vesicles of the cytoplasm. The virus-like particles were identified at the axonal fibers. CONCLUSIONS: The co-culture of the explant of the ciliary nerve and HSV showed the replicative process of the HSV within the cultured cell. The virus-like particles within the axon showed the evidence axonal transport of the virus under culture conditions.

Impression Cytology of Herpetic Simplex Keratitis in Rabbits

PURPOSE: To use impression cytology to examine the structural changes in corneal epithelial cells infected with the herpes simplex virus in rabbit eyes. METHODS: Corneal surfaces of 7 rabbits were scratched using a 25-gauge needle. Herpes simplex virus (type 1, Kos strain) was inoculated to the injured cornea. As the corneal diseases were observed using slit lamp biomicroscopy, impression cytology was performed for 18 days after inoculation. Specimens were stained with hematoxylin-eosin and examined using optical microscopy. RESULTS: Corneal lesions consisted mainly of round epithelial cells, inflammatory cells, ballooning cells, multinucleated giant cells, and various inclusion bodies. Over time, the corneal epithelial cells peeled away as a result of corneal edema in the corneal lesions. Dendritic lesions were also observed. In the recovery phase, the number of detached cells and infiltrated inflammatory cells decreased. CONCLUSIONS: It was presumed that dendritic lesions might have been formed at the scratched cornea region, thereby aggravating the epithelial cells falling off as a result of the infiltration of inflammatory cells. These cytopathologic effects occur in experimental herpes simplex keratitis.

Histological Changes of the Vitreous and Retina in Retinal Lattice Degeneration

PURPOSE: To investigate of the histological characteristics of the lattice degeneration of the human peripheral retina. METHODS: The histological characteristics of the lattice degeneration of the retina was checked by flat preparation and serial section of the lattice lesion in three eyes was investigated by transmission electron microscopy. RESULTS: Flat preparation showed lattice lesion with a hole at the lateral margin with overlying sclerotic vessel and pigment clumping within the lesion. The ultrastructural initial findings showed that the collagen filament in the vitreous cavity was continuous with Muller fiber of the retina with the defect of the inner retina. The full-thikness defect of the sensory retina leaded to the retinal hole. The vascular wall was replaced and occluded by fine fibrillar collagen. The glial cell proliferated into the neural tissue of the sensory retina. These glial cells may secrete long spacing collagen (LSC) and curvilinear material shown at the area of the sensory retinal defect and near the vitreoretinal interface. CONCLUSIONS: These results suggest that the thinning of the retina occurs from the inner retina leading to retinal hole as the lattice degeneration progresses. LSC and curvilinear material are suggestive of derivatives derived from the extracellular material secreted from the glial cell.

Ultrastructural Findings of Cultured Ciliary Nerve

PURPOSE: To investigate the cellular changes and cellular characteristics of myelinated nerve fiber, unmyelinated nerve fiber and Schwann cell under the culture conditions of the explant of the long ciliary nerve. METHODS: The ciliary nerve was obtained from the eyecup after removal of the cornea and intraocular contents following the division of the eyeball at the limbal zone. The explant of the ciliary nerve was cultured with DMEM medium containing nerve growth factor in an incubator with a 5% CO2 atmosphere. The cultured ciliary nerve was examined with phase contrast microscopy at 35 days after culture and stained in the culture dish with 1% methylene blue. The cultured ciliary nerve was also examined with transmission electron microscope. RESULTS: The phase contrast microscopy showed monolayered Schwann cells and cells with thin cytoplasmic processes. The ultrastructure showed myelinated nerve fiber, unmyelinated nerve fiber and Schwann cells entrapped in the nerve fiber. The axoplasm of the myelinated nerve fiber showed the degeneration of microorganelles whereas the unmyelinated nerve fiber showed well preserved microorganelles such as neurofilaments and mitochondria within the axoplasm. CONCLUSIONS: These findings suggest that the axoplasm of the unmyelinated nerve fiber under these culture conditions is relatively better preserved than that of the myelinated nerve fiber probably due to the absence of the myelin sheath. Further study will be required to investigate whether the myelin sheath of the ciliary nerve derived from peripheral neuropathy may affect the functional change of the anterior segment of the eye.

Histological Characteristics of the Interface of Corneal Stroma and Descemet's Membrane

PURPOSE: This study was carried out to clarify the histological characteristics of the interface of the corneal stroma and Descemet's membrane of the human eye. METHODS: Nighteen donor eyes without corneal pathology were examined by scanning and transmission electron microscopy. The Descemet's membrane including the corneal endothelium was cheked for scanning electron microscopy. The junctional characteristics of the posterior corneal stroma and Descemet's membrane was examined by transmission electron microscopy. RESULTS: The scanning electron microscopy showed that collagen sheet faced each other at the right angle near the Descemet's membrane and penetrated the Descemet's membrane with the irregular arrangement. The transmission electron microscopy showed that the electron-dense collagen filaments extended to the posterior stroma from Descemet's membrane. The arrangement of electron-dense collagen filaments paralleled with the arrangement of the collagen fibrils of the posterior stroma. CONCLUSIONS: The interface of the corneal stroma and Descemet's membrane was composed of two-typed extracellular materials without the intercellular specificatons.

Flat Preparation and Scanning Electron Microscopic Findings of Corneal Guttata

PURPOSE: The corneas obtained from 38 donor eyeballs were examined whether corneal guttata was present or not by flat preparation(15 eyeballs) and scanning electron microscopy(23 eyeballs) in order to investigate the relationship between age and the incidence of corneal guttata. METHODS: The corneal endothelial cells with Descemet's membrane were prepared on slides flat and examined by light microscope. The surface of the corneal endothelial cells was examined by scanning electron microscopy. RESULTS: The endothelial excrescences with pigment deposit were shown at the corneal periphery near the trabecular meshwork. The oval to round shaped corneal warts were isolated or confluent in shape. The corneal endothelial cells were variable in size. The cytoplasmic processes were observed on the surface of the bare Descemet's membrane. The fibrillar structure of the degenerating cytoplasm of the corneal endothelial cells over the corneal warts was shown with central pit. The fibrillar excrescences over Descemet's membrane was in banded structures. CONCLUSIONS: In normal cornea, corneal guttata was observed by flat preparation in all cases over 43 years. The endothelial edema was noted in two eyes combined with corneal guttata with the degeneration or loss of corneal endothelial cell.

Serologic Test and Therapeutic Drugs of Episcleritis and Scleritis

PURPOSE: To evaluate serologic tests and therapeutic drugs of the patients with episcleritis and scleritis. METHODS: Retrospective chart review was performed for above patients that had been followed from 1986. 8. 8 to 2001. 6. 4. RESULTS: Of a total of 26 patients, 5 patients (38.5%) with episcleritis and 7 patients (53.8%) with scleritis showed seropositivity. Rheumatoid factor (RF) (26.1%) and antinuclear antibody (ANA) (26.1%) were most commonly positive. Eleven patients (84.6%) with episcleritis group were given topical steroid, 3 patients (23.1%) were treated with systemic drugs due to ocular lesions, and 6 patients (46.2%) with systemic drug for underlying systemic diseases. In scleritis group, 11 patients (84.6%) were treated with topical steroid, 2 patients (15.4%) with systemic drugs for ocular lesions, and 7 patients (53.8%) with systemic drug for underlying systemic diseases. An average period of treatment time was 6.4 weeks in episcleritis and 11.1 weeks in scleritis. CONCLUSIONS: Serologic tests help document the underlying disorders in patients with scleritis and in those with persistent or often recurred episcleritis. Also treatment of episcleritis and scleritis requires understanding possible effects of systemic drugs adminstered for underlying disorder on ocular lesion, and requires cooperation with internists and rheumatolgists.

The Morphological Change of Iris and Ciliary Body in the Korean Fetal Eyes according to Gestational Age

PURPOSE: This study was performed to investigate the morphological change of the iris and ciliary body of human eyes during fetal period. METHODS: Under the Registry of Congenital malformation, fetuses were supplied by the Department of Pathology of Seoul National University. We selected 81 eyes enrolled with the gestational age between 8 and 40 weeks, and examined under light microscope. RESULTS: The development of iris and ciliary body began from 12 weeks. During the gestational age 15-18 weeks, marginal sinus and the fold of iris and ciliary body were formed. At the gestational age 18 weeks, the iris sphincter located in front of marginal sinus was certainly distinguished, and the vessels of ciliary body formed. During the gestational age 19-22 weeks the minor folds of ciliary body were formed between the original it. During the gestational age 23-27 weeks marginal sinus was being diminished and dilator muscle was seen. During the gestational age 28-30 weeks the dilator muscle of iris was certainly developed and the longitudinal and circular muscle of ciliary body were distinguished. During the gestational age 34-40 weeks the adultlike appearance of the iris and ciliary body became apparent. CONCLUSIONS: The mesenchymal cells located in the anterior rim of optic cup began to develop after the gestational age 12 weeks. If the develpment of the iris and ciliary body was arrested around the gestational age 15-22 weeks, the congenital malformation of the iris and ciliary body could appear.

Morphological Changes of Retinal Vessel Under Tissue Culture

PURPOSE: This study was performed to investigate the growth pattern of the retinal vessel including retinal vascular endothelial cell and pericyte. METHODS: The sensory retina was detached from the eyecup obtained from donor's eye. The retinal vessel which was separated from the sensory retina was cultured in tissue culture media for 2, 3 and 4 weeks separately and examined by transmission electron microscopy. RESULTS: On the second week of tissue culture, both the retinal vascular endothelial cells and pericyte were intact in morphology in nuclear and cytoplasmic pattern. Both cells were partially detached from the surrounding basement membrane. On the third week of tissue culture, the cytoplasm of the retinal vascular endothelial cells and pericyte were degenerated, whereas the vascular endothelial cell were intact in nuclear and cytoplasmic profiles which were still partially surrounded by the basement membrane. CONCLUSIONS: These findings suggest that the survivability of the retinal vascular endothelial cells and pericyte may be limited for 2 and 3 weeks, separatedly under the ordinary culture medium.

Ultrastructure of the Optic Neuritis Induced by Herpes Simplex Virus-1 Injection in Rabbits

PURPOSE: This study was performed to investigate the ultrastructural changes of the optic nerve after intravitreal injection of herpes simplex virus-1. METHODS: Herpes simplex virus was separated from the culture media after observing the cytopathic effect on cultured vero cells. Viruses were then injected on the optic nerve head of 21 rabbit eyes. Eyes were enucleated at 1, 2, 3, 5, 7, 10, and 14 days after injection of herpes simplex virus and examined under the electron microscope. RESULTS: The intranuclear inclusion body was noted in eyes examined at 2 days after injection. The histopathological changes were perivascular infiltration of inflammatory cells, cytoskeletal degeneration of large diameter of myelinated nerve, demyelination of axonal nerve fiber, and the accumulation of mitochondria within axonal nerve fiber. CONCLUSIONS: These results suggest that optic neuritis may be induced by herpes simplex virus. The accumulation of mitochondria may be related to the interruption of the axonal transport through the axonal nerve fibers of optic nerve.

Histochemical Electron Microscopic Findings of the Distribution of the Glycosaminoglycans of Cultured Sensory Retina

PURPOSE: This study was performed to investigate the distribution of glycosaminiglycans by the activated retinal neuronal cell on the cultured retinal tissue. METHODS: The retinal tissue was obtained from the donor eyeball without the pathological findings of the retina. The dissected retinal tissue was cultured for 2 weeks in the culture media and reacted with ruthenium red dye to observe the glycosaminoglycans reaction with transmission electron microscopy. RESULTS: The histochemical reaction to ruthenium red on the cultured retina tissue was prominent on the internal limiting membrane, intercellular space between the axons and dendrites at the outer and inner plexiform layers and interphotoreceptor matrix. CONCLUSIONS: These findings suggest that GAGs may be released into the extracellular spaces between the axons and dendrites, which modulate the retinal circuits.