Advances in imaging in oculoplastics

Color Doppler imaging, computed tomography (CT) and magnetic resonance (MR) imaging are the most precious imaging tools for the clinician in the field of oculoplastics. Orbital and facial vasculature, with its dynamic changes and flow velocities seen in orbital varices, carotid-cavernous fistulas, and dural cavernous arteriovenous malformations, is best detected by Color Doppler imaging. Computed tomography remains the dominant imaging modality in the evaluation of orbital trauma. Helical CT axial scanning with multiplanar reconstruction and three-dimensional CT imaging are most helpful in assessing iatrogenic, traumatogenic, and teratogenic orbital abnormalities. Despite its poor histologic specificity, MR imaging provides superior soft tissue contrast, and contrast-enhanced MR imaging has an established role regarding soft tissue tumor infiltration. The greatest value of MR studies in the evaluation of orbital and palpebral tumors is that it has the capacity to show the precise relation between lesions and adjacent structures before the clinician contemplates a surgical approach. Finally, contrast-enhanced MR imaging proved to be a valuable vascularization indicator based upon the extent of relative enhancement within porous orbital implant in anophthalmic socket.     

Refractive error in children in a rural population in India

PURPOSE: To assess the prevalence of refractive error and related visual impairment in school-aged children in the rural population of the Mahabubnagar district in the southern Indian state of Andhra Pradesh. METHODS: Random selection of village-based clusters was used to identify a sample of children 7 to 15 years of age. From April 2000 through February 2001, children in the 25 selected clusters were enumerated in a door-to-door survey and examined at a rural eye center in the district. The examination included visual acuity measurements, ocular motility evaluation, retinoscopy and autorefraction under cycloplegia, and examination of the anterior segment, media, and fundus. Myopia was defined as spherical equivalent refractive error of at least -0.50 D and hyperopia as +2.00 D or more. Children with reduced vision and a sample of those with normal vision underwent independent replicate examinations for quality assurance in seven clusters. RESULTS: A total of 4414 children from 4876 households was enumerated, and 4074 (92.3%) were examined. The prevalence of uncorrected, baseline (presenting), and best corrected visual acuity of 20/40 or worse in the better eye was 2.7%, 2.6%, and 0.78%, respectively. Refractive error was the cause in 61% of eyes with vision impairment, amblyopia in 12%, other causes in 15%, and unexplained causes in the remaining 13%. A gradual shift toward less-positive values of refractive error occurred with increasing age in both boys and girls. Myopia in one or both eyes was present in 4.1% of the children. Myopia risk was associated with female gender and having a father with a higher level of schooling. Higher risk of myopia in children of older age was of borderline statistical significance (P = 0.069). Hyperopia in at least one eye was present in 0.8% of children, with no significant predictors. CONCLUSIONS: Refractive error was the main cause of visual impairment in children aged between 7 and 15 years in rural India. There was a benefit of spectacles in 70% of those who had visual acuity of 20/40 or worse in the better eye at baseline examination. Because visual impairment can have a significant impact on a child's life in terms of education and development, it is important that effective strategies be developed to eliminate this easily treated cause of visual impairment.     

Changes in Bruch's membrane in experimental hypercholesteremia in rats

PURPOSE: We investigated the effect of high cholesterol diet for the aging changes in Bruch's membrane of rats. METHODS: After feeding a 4% cholesterol diet for 15 weeks to three young rats 3 months old and four aged rats 23 months old, we observed the morphological changes of Bruch's membrane by electron microscopy, and made a comparison with rats fed an ordinary diet. RESULTS: In one young rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris formed multiple folds separated from the plasma membrane of the endothelium and showed lamellar thickening and crack in some areas. The elastic fiber layer in Bruch's membrane disappeared partly and some new microfibrils appeared. In one aged rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris showed more lamellar thickening with lumps in some parts. Compared with rats fed an ordinary diet, rats fed a high-cholesterol diet showed thickening of the basement membrane and the changes were more severe. CONCLUSIONS: Our data indicated that high-cholesterol diet might promote age-related changes of Bruch's membrane.     

Prolonged depolarization in rods in situ

Intracellular recordings were made from rods in the superfused retina of the marine toad (Bufo marinus). It was found that injection of a brief depolarizing current pulse (0.04-1 nA) evoked a distinctive, long-lasting response, here called "the prolonged depolarization." The response appears to be regenerative, has a stereotypical waveform, is typically about 6 mV in amplitude and 3 s in duration, and has a relatively long recovery period (10-60 s). As a rule, the response cannot be directly evoked by light but the current-evoked response is significantly enhanced in the presence of steady illumination. The light-evoked hyperpolarization and the depolarizing spikes of the rod are both attenuated in the presence of the prolonged depolarization. The prolonged depolarization is not an altered manifestation of the depolarizing spikes of toad rods since both can be recorded simultaneously and steady illumination suppresses the spikes while enhancing the prolonged depolarization. The response is enhanced in chloride-free superfusate and also appears to be enhanced by the use of electrodes containing chloride. The response is markedly shortened in superfusates that lack calcium or contain 1-5 mM cobalt. On this and other evidence, it is suggested that the response may be generated by the sequential action of calcium channels and calcium-activated chloride channels. Although rarely evoked by light, the prolonged depolarization of toad rods is otherwise remarkably similar to the prolonged depolarization of turtle cones. It is proposed that the prolonged depolarization, in contrast to the feedback depolarization of cones, arises from mechanisms common to both rods and cones.     

Refractive error in children in an urban population in New Delhi

PURPOSE: To assess the prevalence of refractive error and related visual impairment in school-aged children in an urban population in New Delhi, India. METHODS: Random selection of geographically defined clusters was used to identify a sample of children 5 to 15 years of age. From December 2000 through March 2001, children in 22 selected clusters were enumerated through a door-to-door survey and examined at a local facility. The examination included visual acuity measurements, ocular motility evaluation, retinoscopy and autorefraction under cycloplegia, and examination of the anterior segment, media, and fundus. Myopia was defined as spherical equivalent refractive error of at least -0.50 D and hyperopia as +2.00 D or more. Children with reduced vision and a sample of those with normal vision underwent independent replicate examinations for quality assurance in four of the clusters. RESULTS: A total of 7008 children from 3426 households were enumerated, and 6447 (92.0%) examined. The prevalence of uncorrected, baseline (presenting), and best corrected visual acuity of 20/40 or worse in the better eye was 6.4%, 4.9%, and 0.81%, respectively. Refractive error was the cause in 81.7% of eyes with vision impairment, amblyopia in 4.4%, retinal disorders in 4.7%, other causes in 3.3%, and unexplained causes in the remaining 5.9%. There was an age-related shift in refractive error from hyperopia in young children (15.6% in 5-year-olds) toward myopia in older children (10.8% in 15-year-olds). Overall, hyperopia was present in 7.7% of children and myopia in 7.4%. Hyperopia was associated with female gender. Myopia was more common in children of fathers with higher levels of education. CONCLUSIONS: Reduced vision because of uncorrected refractive error is a major public health problem in urban school-aged children in India. Cost-effective strategies are needed to eliminate this easily treated cause of vision impairment.     

Changes in T-lymphocyte subpopulations in uveitis

Examinations of 30 patients with uveites, carried out by the method developed by Moretta et al., have revealed changes in T-lymphocyte subpopulations, mainly of the immunodeficiency type, with the reduction of the total T-lymphocyte count in 53.3% of patients and a significant decrease of the T mu/T gamma coefficient in 60% of patients. Stage II immunodeficiency status has been diagnosed in the majority of patients with generalized and anterior uveites. Stage II T-helper deficit has been most frequently detected in uveites coursing for 1-3 years with an exudative hemorrhagic component. The detection of the types and variant of immunoregulatory lymphocyte disorders helps choose the treatment strategy, including immunocorrecting drugs.     

p53 expression in pterygium in two climatic regions in Turkey

Purpose:

To assess accumulation of p53 protein in samples of primary pterygium from people living in two different climatic regions in Turkey.

Materials and Methods:

Group 1 included 101 pterygium specimens from people in Adana located in southern Turkey. Group 2 included 39 pterygium specimens from people in Ankara, located in the middle of Turkey. Climatic conditions throughout the year are sunnier and warmer in Adana than they are in Ankara. The control group (Group 3) included 30 specimens of conjunctiva that had been excised during cataract surgery from 30 patients without pterygium. The pterygial specimens and control conjunctiva were studied by immunohistochemistry using antibodies against p53 protein. Pearson''s chi-square test was used to compare the p53 immunoreactivity.

Results:

The p53 immunoreactivity in Groups 1 and 2 was greater than it was in the control group (P<0.001). There were no differences in p53 immunoreactivity between Groups 1 and 2 (P= 0.060).

Conclusion:

The p53 immunoreactivity was not correlated with ultraviolet irradiation exposure. The p53 immunoreactivity in our pterygium specimens suggests that pterygium could be a result of uncontrolled cell proliferation.     

Vitrectomy in traumatic cataracts and in the complications of surgery in congenital cataract in children

Vitrectomies were carried out in 35 children with traumatic cataracts and complications of surgery for cataracts, caused by injury to the posterior lenticular capsule and incorporation of its fragments to the vitreous. Complete removal of lenticular rudiments rapidly eliminated phacogenic iridocyclitis and improved visual acuity. Improvement of visual functions was attained in 66.6% cases; in 33.4% cases visual acuity did not change. Hemorrhages to the vitreous cavity occurred in 4 cases with pronounced iridocyclitis; therefore, a corneal approach is preferable for cases with pronounced iridocyclitis.     

新世纪我国斜视弱视研究进展

近5年来,在中华医学会眼科学分会的指导和全体专业人员的共同努力下,我国斜视、弱视基础和临床研究取得了长足进步。我们的科研人员和临床工作者在弱视分子和神经机制研究、视觉发育的可塑性研究、弱视的脑功能成像研究、眼外肌滑车（Pulley）研究以及斜视弱视的诊断、治疗及流行病学研究方面均付出了辛苦的劳动,取得了丰硕的成果。我们期待在未来的10年中,本学科的工作能不断发展、不断提高。     

Ocular findings in leukemia in childhood

Primary and therapy-induced ocular manifestations of leukemia in 25 of 103 children suffering from the disease (60 patients with ALL, eight with AML, two with CML, 33 with NHL) were kept under observation for an average period of five years. The lens was involved in 10%, the retina in 9%, the optic nerve in 7%, and the orbit in 4% of these cases. The present authors' findings concurred with those published in the literature to date, in that they could not find a pathognomonic combination or a specific frequency of ocular symptoms related to one of the four types of leukemia.     

Immunoglobulins in tear in trachoma patients.

Tear immunoglobulin concentrations have been measured in 100 healthy people and 62 patients in different stages of trachoma. In healthy people the average IgA level was 27-8 mg/100 ml. There was no significant difference in the IgA level in various age groups and between the sexes. IgG was detected in 92 samples, and it was less than 1 mg/100 ml. IgM in tears was detected in only one sample. IgD was not detected in any specimen. In tracoma cases, the mean IgA level was found to be significantly lower (22-0 mg/100 ml) than in healthy people. There was no significant difference in IgA level between different stages of trachoma, IgG, IgD, and IgM could not be detected in any sample from the trachoma cases.     

Expression of FLT4 in hypoxia-induced neovascular models in vitro and in vivo

AIM: To investigate the expression of FLT4 in retina with oxygen induced retinopathy (OIR) and in brain endothelial cell lines (bEnd3) under hypoxia conditions in mice. METHODS: Fifty-two one-week-old C57BL/6J mice were divided into control group and hypoxia group. The mice of hypoxia group were exposed to 75% oxygen for 5 days and then returned to the room air to induce retinal neovascularization. Mice in control group were raised in the environment of room air at the same time. The expressions of FLT4 mRNA and protein were checked with RT-PCR and Western Blot analysis at postnatal day 14, 17 and 21 ( P14, P17 and P21) respectively. 125mmol/L CoCl2 were added to the culture medium of bEnd3 cell, proteins were extracted in 12, 24, 48 and 72 hours and FLT4 levels were examined by Western Blot analysis. RESULTS: The mRNA and protein level of FLT4 expressed in P14 and P17 OIR mice retina statistically up-regulated as compared with those in control group, but there was no statistical difference between OIR group and control group at P21. FLT4 levels increased significantly in 12, 24 and 48 hours hypoxia intervened bEnd3 cells, its levels in 72 hours increased mildly but showed no significance. CONCLUSION: FLT4 levels increase in OIR mice retinas and bEnd3 cells in hypoxia. It may play an important role in endothelial cells proliferation in hypoxia and retinal neovascularization in OIR mice.     

Changes in corneal curvature in accommodation

PURPOSE: To determine the changes in corneal curvature in accommodation. SETTING: Department of Ophthalmology, St. Luke's International Hospital, Tokyo, Japan. METHODS: Twenty-eight eyes of 14 healthy volunteers with a mean age of 38.9 years (range 28 to 65 years) were enrolled in this prospective study. Corneal topographies were taken before and during accommodation. Subjects achieved maximal accommodation by gazing at a target letter "A" in front of the eye. Keratometric values (K-values) obtained by topographies before and during accommodation were compared. RESULTS: Steepened corneal curvatures during accommodation were observed with the difference-plot view. Maximum K-values for the central 3.0 mm, 5.0 mm, and 7.0 mm corneal diameters significantly increased by a mean of 0.62 diopters (D) +/- 0.83 (SD) (P =.0005, paired t test), 0.60 +/- 0.90 D (P =.0015), and 0.72 +/- 0.65 D (P<.0001), respectively. Respective minimum K-values significantly increased by a mean of 0.62 +/- 0.83 D (P=.0005), 0.67 +/- 0.68 D (P<.0001), and 0.64 +/- 0.62 D (P<.0001). No statistically significant relationship was found between age and change in K-values. CONCLUSION: The results suggest that changes in corneal curvature in accommodation participate in the mechanism of accommodation.     

Ophthalmological findings in nephropathia epidemica in Lapland

We report ophthalmological findings in 15 cases of nephropathia epidemica. The patients, 13 men and 2 women, were 20 to 62 (mean 30) years of age. The onset of the disease was characterized by high fever, nausea, headache, abdominal pain, backache, somnolence, red throat, proteinuria, and oliguria. The symptoms subsided rapidly during the polyuria stage. Transitory myopia occurred in 8 patients (53%). Conjunctival injection and haemorrhages were seen in 3 patients (20%). One patient had acute glaucoma with oedema in the cornea and shallowing of the anterior chamber, with subsequent anterior uveitis and haemorrhages in the ocular fundus, and another patients had acute glaucoma. Three patients had photophobia which occurred in 2 patients without any glaucoma or anterior uveitis.     

内毒素诱导的大鼠葡萄膜炎的巨噬细胞中Toll样受体4的表达

目的 探讨在内毒素诱导的Wistar大鼠葡萄膜炎中Toll样受体4(TLR4)阳性细胞与虹膜组织中巨噬细胞的动态变化和分布.方法 实验研究.Wistar大鼠50只,用随机数字法随机分为5组,每组10只,分别为正常对照(0 h)组、6 h组、12 h组、24 h组及48 h组.除0 h组外其余各组均足垫部注射霍乱弧菌内毒素200μg,注射后于裂隙灯显微镜下观察双眼前节炎症反应变化.按实验分组于0、6、12、24、48 h处死大鼠.取虹膜一睫状体及脉络膜组织.通过葡萄膜铺片免疫组织化学方法检测TLR4和巨噬细胞的标记CD163的表达.人工计数虹膜中TLR4~+与CD163~+的细胞并计算细胞密度,计算圆形和多形性的CD163~+细胞占所有CD163~+细胞的百分比.进一步采用免疫荧光双标记检测TLR4和CD163共表达的情况.通过单因素方差分析分别对大鼠虹膜内阳性细胞密度以及圆形、多形性CD163~+细胞的百分比进行统计学检验.结果 正常大鼠虹膜睫状体组织不表达TLR4.6 h组有2只大鼠虹膜内可见少量TLR4~+细胞,12～48 h组所有大鼠虹膜内TLR4~+细胞明显增多(F=167.2,P＜0.001),虹膜内TLR4~+细胞密度分别为(506.1±39.5)个/mm~2(12 h组)、(492.3±54.5)个/mm~2(24 h组)及(663.8±150.2)个/mm~2 (48 h组).在注射LPS后12～48 h期间TLR4~+细胞形态无明显变化.0～48 h组大鼠虹膜内均有CD163~+细胞,0 h组圆形和多形性CD163~+细胞百分比为13%,12～48 h组其百分比约为80%,且圆形细胞主要位于虹膜基质层.免疫荧光双标记可见TLR4和CD163的共表达,TLR4位于细胞膜,CD163位于细胞质.5组大鼠脉络膜内均未见TLR4表达.结论 内毒素诱导的大鼠葡萄膜炎中虹膜内TLR4表达增高,部分虹膜固有巨噬细胞表达TLR4.TLR4可能在葡萄膜炎的发生发展中起一定作用.     

Neuro-ophthalmological examinations in craniopharyngiomas in childhood]

The results of ophthalmologic examinations of 50 children with craniopharyngiomas are analyzed. The condition was diagnosed on the basis of clinical examinations, roentgenography, angiography, brain scintigraphy, and computer-aided tomography. In 48 cases the diagnosis was confirmed by histologic findings. The mean age of the patients was 9 years 6 months, both boys and girls were included in the study group. Vision acuity deterioration was detected in 69.6% of children, optic disk edema in 22% and atrophic changes of the disk in 52% of the examinees. Vision field defects were revealed in 67.7%, nystagmus in 4 cases, oculomotor nerve paresis in 6 cases. The authors emphasize timely employment of conventional and present-day x-ray examinations, that are highly informative in such conditions, in all the patients with vision disorders of unknown origin and with suspected compression of the visual routes.     

Toll样受体在眼科的研究现状

Toll样受体是自身免疫的关键受体，它参与宿主对致病微生物的识别和防御等感染免疫过程，也与人体的获得性免疫密切相关，是目前免疫学研究的重点和热点。眼球作为感染性和免疫性疾病的好发部位，在感染免疫和获得性免疫方面与全身摹他器官有相似之处，但是其独特的解剖特点，例如血房水屏障、血视网膜屏障、角膜的无血管化等，使其免疫学特点的特异性也非常明显。就Toll样受体的特点以及在眼科的研究现状进行综述。     

Changes in rhodopsin kinase and transducin in the rat retina in early-stage diabetes

To establish changes in phototransduction in diabetes, the effects of high glucose on rhodopsin kinase (RK) and transducin (G(t)), as well as recoverin, were examined in the retina of STZ-induced diabetic rats. Diabetes was induced by single intraperitoneal injection of STZ (50mg/kg) to Sprague-Dawley (SD) rats and the animals were sacrificed after 6 weeks. Immunohistochemistry (IHC) and Western blot analysis were carried out using antibodies against RK and G(talpha) (alpha subunit of G(t)) in the STZ-induced diabetic retina and the control retina. The expression level of recoverin protein was also analysed. In the diabetic retina, while the expression of RK protein increased, that of G(talpha) and recoverin proteins decreased. RK immunoreactivity (IR) appeared generally in the retina, and its signal increased in the outer limiting membrane (OLM), some rod cells in the outer segment layer (OSL) and at the tip of the outer plexiform layer (OPL) in the diabetic retina. G(talpha)-IR also appeared in the OPL and in photoreceptor layer. In the diabetic retina, G(talpha)-IR significantly decreased in the OPL, indicating RK-IR increase. This study illustrates the alterations in RK, G(talpha) and recoverin in the diabetic retina that may induce dysfunctions in phototransduction even in early-stage diabetes.     

Postoperative complications in laser in situ keratomileusis

Laser in situ keratomileusis (LASIK) has become the most common procedure to correct refractive errors in North America. Increasing numbers of patients and surgeons are choosing LASIK in the management of low and moderate myopia, astigmatism, and hyperopia. LASIK presents a unique group of postoperative challenges and complications. It is important to be able to identify these complications in the early and late postoperative periods and to provide effective management. In this article, we review the most commonly encountered early and late postoperative complications after LASIK and the most current methods in prevention and treatment.     

Surgical results in congenital glaucoma and in glaucoma in young persons

The paper analyses results after observation over 38 patients (52 eyes operated on) divided into 2 groups: group I included 19 patients (29 eyes) with primary congenital glaucoma (hydrophthalmos) and group II consisting of 19 patients (23 eyes) with glaucoma associated with congenital anomalies. Trabeculotomy ab externo was made in 16 eyes, sinusotrabeculectomy after Kernz--in 9 cases. Trabeculotomy after Grusha and Sokolovski? was made in 10 eyes, valvar trabeculotomy after Nesterov--in 17 eyes. It is pointed out that as a result of microsurgical operations hypotensive effect was achieved in 90.4% of cases both in immediate and remote terms. The obtained results once again confirm that early diagnosis and timely surgical treatment of hydrophthalmos is a necessary condition for a favourable prognosis of the disease.