INTRODUCTIONThis study describes the pathologic changes in the retina of a group of young Asian subjects with myopia worse than -10 diopters spherical equivalent (SE) refraction.

MATERIALS AND METHODSThe study population consists of 20 male subjects undergoing preemployment screening for public service for a 1-year period from 2009 to 2010. A detailed series of visual tests of function, fundus examination and grading, ocular biometry and posterior segment optical coherence tomography were performed for all eyes.

RESULTSA total of 21 eyes with mean SE of -10.88 diopters, [standard deviation (SD) , 1.28 diopters], and mean age of 21.8 years (SD, 1.3 years) were included. Out of 21 eyes, 17 (81.0%) had beta peripapillary atrophy, 10 (47.6%) had clinically detectable optic disc tilt, 1 (4.8%) had positive T-sign and 18 (85.7%) had retinal tessellation, 4 (19.0%) had posterior vitreous detachment and 14 (66.7%) had peripheral retina degeneration. The mean retinal nerve fibre layer (RNFL) thickness was 92.48 mm (SD, 9.99 mm).

CONCLUSIONNone of the 21 highly myopic eyes had features of myopic retinopathy but most of these young males had clinically visible myopia-associated abnormalities of the optic disc, vitreous and peripheral retina. Generally, these eyes had thinner RNFL. Further longitudinal studies are required to investigate if these eyes will eventually develop complications of pathological myopia.

Adolescent ; Adult ; Age of Onset ; Choroid Diseases ; diagnosis ; Fluorescein Angiography ; Humans ; Male ; Myopia ; classification ; pathology ; Nerve Fibers ; pathology ; Ophthalmoscopy ; Optic Atrophy ; diagnosis ; Optic Disk ; pathology ; Optic Nerve Diseases ; diagnosis ; Posterior Eye Segment ; pathology ; Retina ; pathology ; Retinal Degeneration ; diagnosis ; Retinal Diseases ; diagnosis ; Retinal Vessels ; pathology ; Singapore ; Tomography, Optical Coherence ; methods ; Vision Tests ; Visual Acuity ; Vitreous Detachment ; diagnosis ; Young Adult

The viscosity of rabbit's vitreous filtrate was measured after intra-venous infusion of 30% urea in 10% glcuose solution and 10% glucose solution. The dosage administered was 1g per kg of body weight. As shown in table, the relative viscosity increased after infusion of urea and glucose solution and no difference was found in the extent of increase in viscosity between urea- and glucose-treated groups. The mechanism of viscosity increase and its relation to the intra-ocular pressure were discussed.
Body Weight ; Glucose ; Urea* ; Viscosity* ; Vitreous Body*

In order to investigate whether the lowering of the intraocular pressure by the compression of the eyebaIl is accompanied by the decrease of water content of the vitreous, rabbit's left eyes were compressed with digital pressure of approximately 2 kg while the right eyes were left undisturbed. The vitreous body and lens were taken immediately after the animals were sacrificed by air injection and their water contents were calculated by weighing. The water contents of the vitreous and lens showed no significant changes in spite of profound faIl of intraocular pressure. It was concluded that the 5 minutes pressure on the eyeball was ineffective to reduce the vitreous volume.
Animals ; Intraocular Pressure ; Vitreous Body ; Water*

The authors recently experienced two cases of cysticercosis in vitreous body. In the first case of a 27 years old Korean male had a balloon-like 11mm3 cyst in the vitreous body of the left eye. The cyst was extracted and microscopic examination revealed a well preserved cysticercosis cellulosae. In second case, the cyst with the size of 8mm3 in diameter was seen in vitreous body of the right eye of a 35 years old Korean male. Although ocular and cutaneous cysticercosis are common, but cysticercosis in the vitreous body rarely been reported in Korea.
Adult ; Cysticercosis* ; Humans ; Korea ; Male ; Vitreous Body*

The vitreous body is a gel-like structure occupying a space of about 4 cc posterior to the intraocular lens and provides an optically clear medium for light transmission. It has a complex physical and chemical composition and structure consists primarily of water, collagen, and hyaluronic acid. Floaters are tiny dark specks that can be seen in the visual field, especially when looking at the blue sky, a white wall, or any other uninterrupted, light colored expanse. They are created from tiny clumps in the clear, jelly-like substance inside the eyeball. Floaters occur in different sizes and shapes. They may appear as little dots, threads, or hairy clumps. Floating specks are most commonly caused by the posterior vitreous detachment due to thickening and shrinkage of the vitreous, frequently starting in middle ages but can also be caused by blood or inflammatory cells. In most cases, floaters are normal and harmless. However, a sudden increase in number may indicate a damage to certain internal structures of the eye. Any case with an acute onset of floaters or flashing lights should be carefully examined for the vitreoretinal condition. It should be borne in mind that the peripheral retina and vitreous can be visualized only in a dilated pupil, with careful examination using binocular indirect ophthalmoscopy or contact lens biomicroscopy.
Collagen ; Hyaluronic Acid ; Lenses, Intraocular ; Ophthalmoscopy ; Pupil ; Retina ; Telescopes ; Visual Fields ; Vitreous Body ; Vitreous Detachment ; Water

Experimental retinal detachment was attempted in albino rabbits by the injection of hyaluronidase (2 TRU) between the retina and vitreous body. Retinal detachment was successfully induced in 12 eyes(62.5%) after 1-4 days. Hyaluronidase injection combined with mechanical injuries of the retina produced retinal detachment in 5 eyes(60.0%). When the retinal detachment was produced, amplitudes of the a- and b-waves decreased, maximum reduction being 41.6%(a-wave) and 34.5%(b-wave). Ten to 14 days after the treatment ERG waves began to increase gradually. ERG waves rose slightly in cases in which no detachment had been successfully produced.
Hyaluronoglucosaminidase ; Rabbits* ; Retina ; Retinal Detachment* ; Retinaldehyde* ; Vitreous Body

Alpha-chymotrypsin, trypsin and hyaluronidase were added to the rabbit's vitreous humor which was filtered through the glass filter. The viscosity was measured by Ostwald type viscosimeter with O.5mm capillary bore size. The relative viscosity of normal vitreons humor was 1.085. The relative viscosities of vitreous humor, to which 1mg and 2mg of alpha-chymotrypsin and 100 H.U.M. and 200 H.U.M. of trypsin were added, showed no significant changes. On the other hand, the vitreous humor which had been treated by 100 T.R.U. of hyaluronidase showed a marked reduction in the viscosity. The viscosity of normal vitreous humor, which had been preserved at 20 degrees for 3 hours, was significantly reduced.
Capillaries ; Glass ; Hand ; Hyaluronoglucosaminidase* ; Trypsin* ; Viscosity* ; Vitreous Body*

Experiments were performed in order to investigate the absorption of the ultrasound by the ocular tissues. Transducers of 5 and 10 MHz and diameters of 5 and 10mm were used. The amplitudes of echoes reflected from the flat metallic surface were measured as the reference echo after the ultrasonic beam passed through the cornea. crystalline lens, vitreous body, outer coats of the eyeball and the whole eyeball. The crystalline lens absorbed ultrasound most strongly whereas outer coats and vitreous body absorbed modorately. The absorption by the cornea was negligibly small compared with other tissues of the eye.
Absorption* ; Cornea ; Lens, Crystalline ; Transducers ; Ultrasonics ; Ultrasonography* ; Vitreous Body

Estimation of postmortem interval (PMI) is one of the important research contents in forensic pathology, and it has always been the focus and hot spot of research work. In recent years, scholars at home and abroad have made some research progress in estimating PMI by using ocular tissue. After death, the changes of cornea, aqueous humor, iris, lens, vitreous humor and retina all show time sequence change rule highly related to PMI. This paper reviews the research progress of PMI estimation based on the morphological, biochemical, molecular and genetic material changes of different ocular tissue structures after death, and discusses the existing problems and development trends.
Humans ; Postmortem Changes ; Time Factors ; Autopsy ; Vitreous Body ; Forensic Pathology

Tissue plasminogen activator(tPA) is a fibrin-specific fibrinolytic agent that has recently been shown to be effective in accelerating the clearance of hyphema. Intravitreal injection of tPA can promote rapid lysis of experimental intravitreal fibrin clots. The purpose of this study was to investigate the efficacy of intravitreal tPA injection for the treatment of vitreous hemorrhage in normal phakic non-vitrectomized rabbit eyes. Vitreous hemorrhages were produced by intravitreal injections of 0.05 ml of autologous whole blood in 25 rabbit eyes with intact vitreous. The injection of 25 or 100 micrograms of tPA in 15 eyes resulted in the clearance of vitreous hemorrhage in 99 +/- 19 or 34 +/- 6.5 days, respectively. This was significantly faster than in the control eyes in which the clearance was not seen until 131 +/- 17 days later. No tractional retinal detachment was observed.
Animals ; Rabbits ; Retina/drug effects ; Tissue Plasminogen Activator/*therapeutic use ; Vitreous Body/drug effects ; Vitreous Hemorrhage/*drug therapy