Forty-six eyes with primary open-angle glaucoma(POAG) and 34 eyes which had previously undergone trabeculectomy for POAG were studied and the postural response of the intraocular pressure(IOP) compared with that of 80 normal eyes, In all groups the increment in IOP occurred when the subject changed from the sitting to the lying position. The pressure increment when changed from the sitting to lying position, averaged 2.4 mmHg in normal eyes, 3.6 mmHg in the group who were treated medically and 3.8 mmHg in the group who had undergone trabeculectomy. There was greater postural response in primary open-angle glaucoma patient compared to normal subject. And also there was no statistically significant difference of postural response in intraocular pressure between the group who were treated medically and the group who had undergone trabeculectomy. It is suggested that abnormal postural response of intraocular pressure in POAG appears to be retained and to be unaffected in those eyes which had undergone trabeculectomy.
Deception ; Glaucoma, Open-Angle* ; Humans ; Intraocular Pressure* ; Trabeculectomy*

Myopia is the most common refractive error throughout the world. Exact and relative etiologies of myopia have not been investigated in detail, although the high prevalence rate of myopia in school children has been well documented. Patients with myopia must endure the physical and financial burden of spectacles or contact lenses throughout their lives. The National Eye Institute estimated that the costs of refractive eye examinations amount to $1 billion annually, with another $1.5 billion spent on eyeglasses each year. The age of onset of myopia is frequently between 5 to 15 years. There has been a dramatic increase in the prevalence rates of myopia over the past decades in Korea and other parts of Asia. The prevalence rate was 8~15% in 1970s, 23% in 1980s, 38% in 1990s, and 46.2% in 2000s in Korean school children. The remarkable increase in Asian school children suggests that life style risk factors during the school periods may have a great impact on the development of school myopia and the overall population prevalence rate of myopia. Because the gene pool has not changed significantly over the past decades, the rapid increase of the prevalence rates of myopia has been attributed to increases in near-work activities and environmental factors. Atropine is effective in preventing myopia by a non-accommodative mechanism. Atropine is a broad-band muscarinic antagonist that binds to all five identified muscarinic receptors. Animal and clinical studies have shown that the M1-selective muscarinic antagonist, pirenzepine, is effective in reducing axial length enlargement and preventing myopia.
Age of Onset ; Animals ; Asia ; Asian Continental Ancestry Group ; Atropine ; Child ; Contact Lenses ; Eyeglasses ; Gene Pool ; Humans ; Korea ; Life Style ; Myopia* ; National Eye Institute (U.S.) ; Pirenzepine ; Prevalence ; Receptors, Muscarinic ; Refractive Errors ; Risk Factors

In order to investigate the risk factors of retinopathy of prematurity, we retrospectively reviewed the medical records of 153 premature badies alive and born in our hospital between October 1994 and January 1997. We performed analysis on birth weight, gestational age, duration of oxygen therapy, duration of oxygen therapy more than 40 percent, maxinmum and mean value of oxygen pressute and mean value of carbon dioxide pressure from arterial blood gas analysis in the first 2 weeks, the presence of multiple birth, surfactant therapy, corticosteroid therapy, and intraventricular hemorrhage. In univatiate analysis, birth weight, duration of oxygen therapy, value of oxygen pressure and mean value of carbon dioxide pressure from arterial blood gas analysis in the first 2 weeks, surfactant therapy, and corticosteroid therapy were statistically significant(p<0.05). Howeverm, in stepwise logistic regression analysis to correct the correlations in multiple variables, only birth weight and duration of oxygen therapy were significant risk factors in 95% confidence interval( 0.05, p<0.05). Birth weight, duration of oxygen therapy, and maximum value of oxygen pressure from arterial blood gas analysis in the first 2 weeks were significant risk factors in 90% confidence interval( 0.1, p<0.1).
Birth Weight ; Blood Gas Analysis ; Carbon Dioxide ; Gestational Age ; Hemorrhage ; Humans ; Logistic Models ; Medical Records ; Multiple Birth Offspring ; Oxygen ; Retinopathy of Prematurity* ; Retrospective Studies ; Risk Factors*

PURPOSE: To analyze innervated myotendinous cylinders (IMCs) in the extraocular muscles (EOMs) of normal subjects and strabismic patients. METHODS: The rectus muscles of 37 subjects were analyzed. Distal myotendinous specimens were obtained from 3 normal subjects, 20 patients with acquired strabismus, 11 with infantile strabismus, and from 3 with congenital nystagmus, and were studied by using light microscopy. Some specimens (6 rectus muscles) were also examined by transmission electron microscopy. RESULTS: IMCs were found in the distal myotendinous regions of EOMs. The IMCs of patients with acquired strabismus showed no significant morphological alterations. However, significant IMCs alterations were observed at the distal myotendinous junction of patients with congenital strabismus and congenital nystagmus. CONCLUSIONS: This study supports the notion that IMCs in human EOMs function mainly as proprioceptors, along with effector properties, and a disturbance of ocular proprioceptors plays an important role in the pathogenesis of oculomotor disorder. We suggest that a proprioceptive feedback system should be stimulated and calibrated early in life for the development of binocular vision.
Adolescent ; Adult ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Microscopy, Electron, Transmission ; Middle Aged ; Oculomotor Muscles/*innervation/physiopathology/ultrastructure ; Proprioception/physiology ; Strabismus/*pathology/physiopathology ; Young Adult

PURPOSE: Extraocular muscle (EOM) consists of two layers, orbital and global layers which are readily distinguished by their histology. This study was conducted to investigate the changes of histology, myosin heavy chain (MHC), and MHC isoforms of the global and orbital layers of EOM after tenotomy. METHODS: Forty-two New Zealand white rabbits were used. The rectus muscles were harvested at day 3, week 1, week 2, week 4, and week 8 after EOM tenotomy. EOM mass change was measured. The EOM were serially sectioned in coronal plane and stained with Masson's trichrome. The diameters of muscle fibers and cross sectional areas of two layers were measured in the middle of the muscles. Changes of MHC isoforms were also measured using immunohistochemistry. RESULTS: The EOM mass was decreased at all periods of surgery especially at day 3 and week 1, increased maximally at week 8. The diameters of EOM fibers in global layer were decreased at day 3, week 1, and week 2 after EOM tenotomy and increased maximally at week 8. The immunohistochemical stains of fast and slow MHC were weakened in the global layer at week 1 after tenotomy. CONCLUSIONS: EOM changes due to atrophy appeared at day 3, week 1, and week 2 after EOM tenotomy while EOM atrophy was recovered at week 4 and week 8 after the surgery. These changes did not appear on the EOM orbital layer but was shown in EOM global layer. These results were due to the histological and functional differences between the EOM global and orbital layers.
Atrophy ; Coloring Agents ; Immunohistochemistry ; Muscles ; Myosin Heavy Chains ; Orbit ; Protein Isoforms ; Rabbits ; Tenotomy*

PURPOSE: To determine the effect of prior orbital decompression on the outcome of strabismus surgery in patients with thyroid ophthalmopathy. METHODS: The medical records of patients operated on for strabismus related to thyroid ophthalmopathy were retrospectively reviewed RESULTS: Thirty patients were included in this study. Seventeen patients had previously undergone orbital decompression, thirteen patients had not. There was no significant difference between the two groups in the average angle of preoperative horizontal or vertical deviation, the average numbers of muscle operated on, the percentage of unidirectional surgery and the outcome of strabismus surgery. CONCLUSIONS: The previous orbital decompression surgery has no significant effect on the outcome of strabismus surgery in patients with thyroid ophthalmopathy.
Decompression* ; Humans ; Medical Records ; Orbit* ; Retrospective Studies ; Strabismus* ; Thyroid Gland*

PURPOSE: To study the changes in the amount and isoform pattern of the myosin heavy chain (MyHC) in rabbit extraocular muscle (EOM) fibers after recession. METHODS: Sixteen New Zealand white rabbits were used. Recession surgery was performed on the right superior rectus (SR) muscle by 3 mm in eight rabbits, and performed by 8 mm in other eight rabbits. The left SR muscles were left intact as the control groups. The SR muscles in both eyes were harvested from two rabbits from each recession group at 3 days and 1, 2, and 4 weeks after surgery. The changes in MyHC amount and isoform pattern were analyzed by gel electrophoresis. RESULTS: Total MyHC content decreased from 1 week after surgery in the 3-mm recessed group and from 3 days in the 8-mm group. The type IIb MyHC (MyHCIIb) plus EOM-specific MyHC (MyHCeom) showed similar proportional changes to the total MyHC at the different time points after surgery. CONCLUSIONS: The fast MyHCIIb plus the superfast MyHCeom decreased after EOM recession, and these results appear to be related to the changes in the global layer rather than in the orbital one. This suggests that the global layer might be the fast and the superfast twitch portions of rabbit EOM, which perform the fast saccades in ocular movements.
Electrophoresis ; Eye ; Muscles ; Myosin Heavy Chains ; Myosins ; Orbit ; Protein Isoforms ; Rabbits ; Saccades

PURPOSE: To study the changes in the amount and isoform pattern of the myosin heavy chain (MyHC) in rabbit extraocular muscle (EOM) fibers after recession. METHODS: Sixteen New Zealand white rabbits were used. Recession surgery was performed on the right superior rectus (SR) muscle by 3 mm in eight rabbits, and performed by 8 mm in other eight rabbits. The left SR muscles were left intact as the control groups. The SR muscles in both eyes were harvested from two rabbits from each recession group at 3 days and 1, 2, and 4 weeks after surgery. The changes in MyHC amount and isoform pattern were analyzed by gel electrophoresis. RESULTS: Total MyHC content decreased from 1 week after surgery in the 3-mm recessed group and from 3 days in the 8-mm group. The type IIb MyHC (MyHCIIb) plus EOM-specific MyHC (MyHCeom) showed similar proportional changes to the total MyHC at the different time points after surgery. CONCLUSIONS: The fast MyHCIIb plus the superfast MyHCeom decreased after EOM recession, and these results appear to be related to the changes in the global layer rather than in the orbital one. This suggests that the global layer might be the fast and the superfast twitch portions of rabbit EOM, which perform the fast saccades in ocular movements.
Electrophoresis ; Eye ; Muscles ; Myosin Heavy Chains ; Myosins ; Orbit ; Protein Isoforms ; Rabbits ; Saccades

A number of studies have documented the reasonable efficacy and safety of radial keratotomy, but most based upon results obtained in low or moderate myopia or short term follow up after surgery. We complied 5 year and longer follow up data on 91 consecutive radial keratotomy surgeries on high myopia (over -6.00 diopters) performed by one surgeon 5 year-follow up was obtained on 21 (23%) of these eyes. The mean spherical equivalent before surgery was -11.02 diopters (D), the average keratometry value was 44.40 D, and all of the eyes had an uncorrected visual acuity of 0.04 or less. The average change in spherical equivalent was 3.44 D for eyes examined at 1 year, compared with 3.05 D for eyes at 3 years and 2.87 D at 5 years after surgery. Average keratometry value were 42.30 D at 1 year, 41.60 D at 3 years, and 41.30 D at 5 years after surgery. In our study, the decrease in spherical equivalent of 0.57 D was statistically significant (P < 0.05), as was the reduction in average keratometry value of 1.00 D. The effect of the surgery on spherical equivalent continued to regress through all the 5 years of follow up. However, the keratometric measurement decreased up to 5 years which indicated progressive flattening of the cornea. Also we divided these eyes into 2 groups, lower-myopic group (-6.00 D~-9.75 D) and higher-myopic group (over -10.00 D). In each category, the changes in spherical equivalent were 3.60 D, 2.21 D at 5 years, compared with 3.65 D, 3.25 D at 1 year respectively. The efficacy of radial keratotomy was lower, and the change of spherical equivalent between 1 year and 5 years was larger in the higher-myopic group than in the lower-myopic group. The results show that both radial keratotomy effectiveness and long term stability decrease in higher myopic cases.
Adolescent ; Adult ; Cornea/*surgery ; Female ; Follow-Up Studies ; Humans ; *Keratotomy, Radial ; Male ; Middle Aged ; Myopia/*surgery ; Treatment Outcome ; Visual Acuity

A number of studies have documented the reasonable efficacy and safety of radial keratotomy, but most based upon results obtained in low or moderate myopia or short term follow up after surgery. We complied 5 year and longer follow up data on 91 consecutive radial keratotomy surgeries on high myopia (over -6.00 diopters) performed by one surgeon 5 year-follow up was obtained on 21 (23%) of these eyes. The mean spherical equivalent before surgery was -11.02 diopters (D), the average keratometry value was 44.40 D, and all of the eyes had an uncorrected visual acuity of 0.04 or less. The average change in spherical equivalent was 3.44 D for eyes examined at 1 year, compared with 3.05 D for eyes at 3 years and 2.87 D at 5 years after surgery. Average keratometry value were 42.30 D at 1 year, 41.60 D at 3 years, and 41.30 D at 5 years after surgery. In our study, the decrease in spherical equivalent of 0.57 D was statistically significant (P < 0.05), as was the reduction in average keratometry value of 1.00 D. The effect of the surgery on spherical equivalent continued to regress through all the 5 years of follow up. However, the keratometric measurement decreased up to 5 years which indicated progressive flattening of the cornea. Also we divided these eyes into 2 groups, lower-myopic group (-6.00 D~-9.75 D) and higher-myopic group (over -10.00 D). In each category, the changes in spherical equivalent were 3.60 D, 2.21 D at 5 years, compared with 3.65 D, 3.25 D at 1 year respectively. The efficacy of radial keratotomy was lower, and the change of spherical equivalent between 1 year and 5 years was larger in the higher-myopic group than in the lower-myopic group. The results show that both radial keratotomy effectiveness and long term stability decrease in higher myopic cases.
Adolescent ; Adult ; Cornea/*surgery ; Female ; Follow-Up Studies ; Humans ; *Keratotomy, Radial ; Male ; Middle Aged ; Myopia/*surgery ; Treatment Outcome ; Visual Acuity