Volume 44 ·  Issue 07 ·  2008

Refractive surgery has become one of the hotspots of ophthalmology in our country. After analyzing refractive surgery related papers, the author put forward the idea that enhancement shall be done through strengthen innovation consciousness, deepen and refining the target of academic papers, uniform of operation program and material collection, strengthen the combination of basic research and clinical research and strengthen study on binocular vision in research of refractive surgery.

Near "words" visual acuity testing is implemented in clinics to meet the exams for read demanding. Therefore, diversity formats or versions of near "words or characters" visual acuity occur.However, near visual acuity chart with the mandarin character as basic target has been debated all the time.It is due to the complexity of the mandarin characters and the comprehensive of reading while having the meaningful characters as basic targets. This article will be focused on these debates.

Myopia animal model plays an important role in mechanism study on myopia. Recently,mice are increasingly used in myopia animal model. Using mouse as myopic animal model has several advantages, especially in the mechanism study. However, the mice eye is much smaller in size than other animal eyes, therefore it is very difficult to measure the refraction and ocular dimensions in vivo. Here are summaries and comments round disputed issues which are expected to be useful for animal myopia researches.

Objective To select Chinese characters for Chinese visual acuity chart by using the method of Fourier frequency spectrum analysis. Methods BMP images were made for 1062 Chinese characters with small or medium number of strokes. The images were processed to derive frequency spectrum at the frequency domain by using a MatLab program. Euclidean distance from Cluster analysis was then used to classify and select the Chinese characters for optotypes of the visual acuity chart, based on their mean frequency spectrum from all the characters analyzed. Results Fifty and forty Chinese characters were selected from the groups of the small and the middle number of strokes respectively. Conclusions It is important and interesting to select Chinese characters by using Fourier analysis method for designing Chinese visual acuity chart that is consisting with the property of the visual system of the eye.

Objective To investigate the influence of flap thinkness of laser in situ keratomileusis (LASIK) and subepithehal keratomileusis on the forward shift of the posterior corneal surface in high myopia. Methods It was a case-control study. In this study, 151 fight high myopic eyes of patients [spherical equivalent range - 6. 00 to - 10. 00 diopter, 46 subepithelial keratomileusis eyes ( epithelial sheet group), 64 LASIK eyes with 110 μm flap thinkness (thin flap group) and 41 LASIK eyes with 130 μm flap thinkness ( normal flap group) ] were evaluated preoperatively and postoperatively with the Pentacam to determine the shape change in the posterior corneal surface. Changes in posterior shape were calculated by comparing refraction and elevation of posterior corneal surface in the part corresponding to the pupil center preoperatively and postoperatively. Results The mean estimated residual bed thickness (RBT) of epithehal sheet eyes, thin flap eyes and normal flap eyes was (362±23 ), (320 ± 25 ) and (300 ±21 ) μm,respectively. The RBT difference between epithelial sheet group and thin or normal flap group was statically significant ( F = 85.685, P < 0.001 ) and the difference between 2 LASIK groups was also significant (P <0.05). There was no significant difference between three groups in ablation depth (P > 0.05 ). The mean posterior corneal refraction and elevation change of epithelial sheet eyes, thin flap eyes and normal flap eyes in the pupil center was ( -0.12±0.14) D and (0.9 ± 1.8) μm, ( -0. 20 20. 22) D and ( 1.3 ± 1.6) μm,( - 0. 21 ± 0. 18 ) D and ( 1.5 ± 1.5 )μn, respectively. A significant correlation between posterior elevation and refraction change was present in all 3 groups. The amount of posterior corneal elevation change correlated significantly with the ablation depth in thin flap group and normal flap group ( r = 0. 265, 0. 311 ;P < 0. 05 ). Conclusion In treating high myopia, both subepithelial ablation and LASIK surgery induce tiny forward shift of posterior corneal surface when the RBT was thick enough. Deeper ablation or thicker corneal flap may increase the trend of forward shift of posterior corneal surface.

Objective To evaluate the feasibility of multifocal LASIK for the correction of prepresbyopic myopia. Methods In this prospective,comparative case series,thirty-two patients were recruited into the study, mean age was ( 38.5±2. 7 ) years, standard LASIK using Planoscan was performed on the patient's dominant eye, while multifocal LASIK was performed on the nondominant eye. Routine examinations included distance and near vision, refraction, corneal topography, intraocular pressure, ultrasonic corneal pechymetry, contrast sensitivity function, amplitude of accommodation , depth of defocus, wavefront aberration. Results The mean follow-up duration was 6.67±2.75 (range, 6 to 11 months).In the nondominant eyes, the near visual acuity was statistically significant difference, better in the postoperative visual acuity, however, there was no statistically significant difference between preoperation and postoperation in dominant eyes. The Q value of 6 mm diameter in the nondominant eyes was 0.081±0.274 ( range,-0.53 to +0.53) and 0.464±0.266 (range, -0.02 to +0.99) in the dominant eyes, significant difference were noted between two groups. Topography revealed high degree refractive power zone of (5.64±3.05 )mm2 at central cornea in nondominant eves. The wavefront analysis showed that after the multifocal procedure, a positive spherical aberration was induced , which is opposite to that normally seen following a standard LASIK treatment for myopia. At 6 months, the nondominants eyes attained pseudoaccommodatin of (0.84±0.61 ) diopters (range,O to 2.25 D), the amplitude of pseudoaccommodation are related to corneal mulfifocal index, spherical aberration. However, amplitude of accommodation was decreased (0.10±0.67 )diopters in dominant eyes at 6 months visit . Conclusions The results of this study show that multifocal LASIK is safe and effective in preserving near vision for pre-presbyopic myopia patients . Muhifocal LASIK are reasonally to induce pseudoaccommodation by decreasing negative spheric aberration.

Objective To study the effect of accommodation on monochromatic higher-order aberrations in different pupil sizes in the young emmetropes. Methods Intervention trial design was used in the study. The monochromatic aberrations were measured in 12 eyes from 12 undulated young emmetropes in 4.0 mm, 3.0 mn, and 2.0 mm pupil sizes with a ray tracing wavefront aberrometer under accommodative stimuli from 0 to 4.00 D. Results RMS values of total high-order aberrations (HOAs), total coma, total higher-order astigmatism, total spherical, and total trefoil aberrations significantly decreased as pupil size decreased in the relax state. In 4.0 ,m, 3.0 mm, and 2.0 mm pupil sizes, the average root mean square (RMS) value of total coma was the highest item of HOAs in the relaxed state. With accommodation up to 3.00 D, the RMS of HOAs remained constant but changed significantly at 4. 00 D stimulation ( P < 0.05 ) in all these three pupil sizes. The 4th spherical aberration decreased and changed from positive to negative with increasing accommodation over 4.0 mm size, whereas it remained positive under all accommodative levels over the 3.0 nun and 2. 0 mm zones, and no trend was found. The 3rd order trefoil 0 changed from negative to positive with increasing accommodation, with 4.0mm, 3.0 mm, and 2. 0 mm pupil sizes. Conclusions In 4.0 mm, 3.0 mm, and 2.0 mm pupil sizes, under accommodative stimuli from 0. 00 to 4.00 D,dramatical trends amongst the HOAs, spherical, coma, and trefoil aberrations were demonstrated. Most of the higher-order aberrations induced by accommodation deserves further investigation. Simple elimination of the higher-order aberrations will be replaced by the optimization of aberrations.

Objective To investigate the ocular optical imaging quality among corneal astigmatism subjects under different corrections by using the Point Spread Function analysis system (PSF). Methods PSF 1000 analyzer was used to measure retinal image quality of eyes of 26 subjects with corneal astigmatism ( sphere ranged from - 3.00 to - 6.00 DS, cylinder ranged from - 0. 75 to - 3.00 DC), who were fully corrected with three different methods respectively: spectacles (SPE), rigid gas permeable contact lenses (RGPCL) and toric soft contact lenses (TSCL). The modulation transfer function (MTF) curve was recorded and evaluated. 12 points of the MTF curve (equivalent to the 12 points of Lag Mar VA chart) were chosen for analysis. Equivalent moderate myopia 26 subjects without astigmatism were set up as control group. Results The MTF curve of each eye is enantiomorphous symmetrical Compared with the control group ( < -0. 75D), with 3.0 mm pupil, there's no statistical difference under low spatial frequency, the difference between middle and high frequency is significant ( P < 0.05 ). With 6. 0 mm pupil, there is statistical difference in all frequencies (P < 0.01 ). With simulated 3.0 mm pupil and 6.0 mm pupil, MTF values of all these three methods are statistical different. With 3.0 mm pupil, the MTF value of eyes fitted with RGPCLs is higher than that fitted with TSCLs except in the following frequency 3.00 , 3.78,4. 78,different in all frequencies ( P < 0.05 ). In all these three methods, MTF values with simulated 3.0 mm pupil are significantly higher than that with simulated 6.0 nun pupil ( P < 0.01 ). Conclusions PSF analytical method is available for offering objective data of retina imaging quality. RGPCL and its induced tear film is improved not only correcting the corneal astigmatism, but also enhances the ocular optical quality by reducing diffraction, dispersion and other high order of aberration.

Objective To observe and investigate corneal stromal layer's changes of healthy elderly with phaccemulsification operation. Methods The experimental design was prospective, one replicated measurement, one interventional method case series. Analysis of central corneal stromal layer's changes (including corneal thickness, keratocyte density of anterior and posterior corneal stromal layer and morphological changes) of 19 patients (22 eyes) just before operation and 1 week, 1 month, 3 months and 6 months after operation with CMTF and NCSM. The statistical test method of the three parameter groups was least significant difference. The significant sterling was P < 0.05. Results (1) Corneal thickness: 1 week after operation, corneal thickness was significantly thicker than before operation as well as 1 month, 3months and 6 months after operation ( P < 0.05 ). Comparisons of the differences of other pairs of corneal thickness showed no significant differences ( P > 0.05 ). (2) Keratocyte density: Keratocyte density in the posterior stromal before operation was (627±184)/mm2 and only the 1 month after operation group was significantly higher than before operation ( P < 0. 05 ). Keratocyte density in the anterior stromal before operation was (859 ± 137)/mm2. Comparisons of the differences of each pair of groups before and after operation showed no significant differences (P >0.05). (3) CMTF images displayed microfolds (4 eyes) in the middle and posterior stromal layers before operation. Different changes in stromal edema at an early stage after operation were observed within 3 months after operation, including different degrees of high-reflecting images and pathological microfolds (16 eyes). Keratocyte activation and fibroblast-like cells could also be found after operation. Conclusions Phacoemulsification can injure the corneal stromal layers. CMTF test is a useful method to reveal corneal pathological changes in four-dimension space ( three-dimension space +time).

Objective Physiological level of reactive oxygen species (ROS) has been shown to play an important role in mitogen-stimulated cell signaling in many cell types. Both EGF and bFGF can induce ROS generation in human lens epithelial cells. But the role of ROS and Redox signaling on EGF and bFGF-stimulated cell proliferation is not clear. This study was to investigate the control of EGF and bFGF-induced cell proliferation by Redox signaling in human lens epithelial cells (SRA 01/04), using specific inhibitors to Redox signaling. Methods EGF and bFGF-induced cell proliferation was measured by [methyl-<'3>H]thymidine incorporation assay. In some experiments, cell proliferation was also measured by typan blue negative cell counting parallel with <'3>H-thymidine incorporation assay. The inhibitors used in this study include: catalase (specific enzyme to detoxify hydrogen peroxide ), N-acetyl-L-cysteine (free radical scavenger), DPI (inhibitor for NADPH oxidase ) and AACOCF3 (specific inhibitor for cytosolic phosphohpase A2, which had been shown to play important role in ROS generation in our previous study). Serum starved SRA 01/O4 cells were pretreated with these inhibitors for 30 minutes before exposure to EGF or bFGF (20 μg/L). In short term study, all these inhibitors were removed before adding growth factor,while in long term study, inhibitars ware maintained in the medium along with growth factor. Cells were kept growing in the medium with 20 μg/L EGF or 20 μg/L bFGF for 48 hours. Then cell proliferation was quantified by [ methyl-<'3>H ] thymidine incorporation assay or by cell counting. Results We found that catalase, NAC, DPI and AACOCF3 were able to suppress EGF and bFGF-induced cell proliferation in both short term and long term study. In EGF study, 20 μg/L EGF produced about 26% (t =7.093,P <0.01 )increase in DNA synthesis after 48 hours. Pretreatment of the cells for 30 minutes with 1×10<'5> U/L catalase,0. 5 mmol/L NAC, 0.1 μmol/L DPI or 0.5 μmol/L AACOCF3 inhibited EGF-stimulated DNA synthesis by 18.0% (t =6.132,P<0.01), 24.6% (t =6.188,P<0.01), 28.5%(t=6.386,P<0.01) and 16.4% (t = 3.705, P = 0.001 ) respectively. The inhibition was dose-dependent and was proved by typan-blue negative cell counting. If the cells were treated with inhibitors for 48.5 hours ( long term study), the lowest concentrations to inhibit cell proliferation were much lower than those used in short term study. Treatment of the cells with 0.5 × 10<'5> U/L catalase, 0.2 mmol/L NAC, 0.01 μmol/L DPI and 0.1 μmol/L AACOCF3 led to suppression on DNA synthesis significantly. Similar results were detected in bFGF study. 48 hours treatment with 20 μg/L bFGF induced about 28.8% (t =9. 523 ,P <0. 01 ) increase in cell proliferation. If the cells were pretreated with 1 × 10<'5> U/L catalase, 0. 5 mmol/L NAC, 0. 1μmol/L DPI or 0.5 μmol/L AACOCF3 for 30 minutes, bFGF-stimulated cell proliferation was suppressed by 24.5% (t = 6.697,P <0.01), 22.2% (t =6.693,P<0.01), 23.9% (t =6.661,P <0.01) and 30.5% (t =8.959,P <0.01)respectively. If cells were treated with inhibitors for 48. 5 hours, the lowest concentration of catalase, NAC,DPI and AACOCF3 to inhibit cell proliferation significantly was 0.5 × 10<'5> U/L(t =21.641 ,P <0.01 ), 0.2mmol/L(t = 11.218,P <0.01), 0.01 μmol/L(t =4.570,P <0.01 ) and 0. 1 μmol/L(t =5.426,P <0.01 ) respectively, lower than those used in short term study. Conclusions We conclude that mitogenic stimulus function of EGF and bFGF in human lens epithelial cells appears to be mediated via ROS to activate cell proliferation. Inhibition of Redox signaling, either by removal of ROS ( the role of catalase and NAC) or blocking ROS generation ( the role of DPI and AACOCF3 ), eradicate EGF and bFGF-stimulated cell proliferation. It is proposed that Redox signaling may play an important role in cell proliferation in human lens epithelial cells.

Objective To study the pathological characteristics of epiretinal membranes (ERMs) in retinopathy of prematurity (ROP), and to discuss the pathogenesis of ROP. Methods It was a retrospective case series. Thirty-four ERMs obtained from twenty-four patients with stage 5 ROP during opensky vitrectomy were examined by light microscopy ( HE staining). Fifteen ERMs of them were examined by transmission electron microscopy. Glial fibrillary acidic protein staining (GFAP) of two ERMs were observed. Spearman rank correlation analysis of SPSS 11.0 software and random-effects model of STATA 7.0software were used to make statistical analysis. Results Collagen was the main component of the ERMs.The amount of neovascularization was highly correlated with the age and postconceptual age ( r = - 0.469,-0.482 ;P < 0.05, respectively), but no statistically significant correlation with the gestational age and birth weight(r = -0.179, -0.272 ;P > 0.05 ). The amount of the fibroblasts varied in different specimens. It was related to the gestational age, age and postconceptual age ( Z = -1.99, -3.45, -3.64;P <0.05 ). No obvious relationship was found between the amount of the fibroblasts and the birth weight ( Z = 0.21, P >0.05). Electron microscopy showed a wide variety of cell types, which scattered in the ERMs, including fibroblasts, myofibroblasts, vascular endothelial cells, macrophages and other inflammatory cells. GFAP staining of the ERMs was positive, and staining positive cells were mostly distributed on the retinal side of the ERMs. Conclusions Fibroblasts and myofibroblasts were the main cells of the ERM of ROP. The regression of the ERM of ROP was correlated to the actual age and postconceptual age, and it had no relationship with the birth weight. The glial cells played an important role in the progression of ROP.

Objective To study the mechanisms of the Twist gene and cell transition during the angiogenesis in a mouse model of oxygen induced retinopathy. Methods It was a experimental study. 40new born C57/BL mice were divided into two groups;the control group, which were fed in the room air, and the study group, which were fed 7 days in the normal environment, followed by exposure to hyperoxia (75% O2) for 5 days. The mice were sacrificed at post born 12 day and post born 17 day. The Twist and VE-cedherin expression were detected with immunohistochemistry. The total retinal RNA was extracted and the expression level of the VE-cadherin, vimentin and twist were examined with RT-PCR method. Results Immunohistochemistry proved there was no significant difference at post born 12 day. At post born 17 day,compared with the control group (75.36±7.04), VE-cadherin expression of hyperoxia group( 65.19±8.39 )decreased ( F = 8.616, P = 0.009). Compared with the control group ( 82.14±6.32), Vimentin expression of hyperoxia group (95.09±14.13 ) increased, compared with the control group (93.30±6.37 ), Twist expression of hyperoxia group ( 119.48±7.90) increased ( F = 66.557, P = 0.000 ) significantly. RT-PCR examination revealed there exist the interaction between Vimentin, Twist expression and the detection time (F = 5.508, P = 0.032;F = 17.760, P = 0.001 ;respectively). At post born 12 day, compared with the control group ( 0.77±0.10 ), VE-cadherin expression of hyperexia group ( 0.64±0.09 ) decreased ( P =0.047 ). Compared with the control group ( 0. 24±0.05 ), Vimentin expression of hyperoxia group (0.39±0.09)inereased(P =0.033). At post born 17 day, compared with the control group(0.75±0.12), VE-cadherin expression of hyperoxia group(0.51±0.07) decreased more obviously( P = 0.002), compared with the control group ( 0.36±0.06 ), Vimentin expression of hyperoxia group (0.70±0.14 ) increased ( P =0.000). Compared with the control group(0.89±0.11 ), Twist expression of hyperoxia group( 1.24 ±0.15 )increased( P = 0.003 ). Conclusion Twist, as a cell transition gene, participated in the angiogenesis of the oxygen induced retinopathy, and that the Twist induced endothelium-mesenchymal transition may be one of the main reasons.

Objective To investigate the effect of insulin or (and) high glucose on the vascular endothelial growth factor (VEGF) expression in bovine retinal microvascular endothelial cells (BREC).Methods It was a experimental study. BREC were cultured with selective culture media. Passaged cells were cultured in normal (5 mmol/L) or high glucose (30 mmol/L) medium for 3 days. Equimolar mannitol was supplemented for osmotic controls. Cells were serum-deprived overnight in Dulbeceo's modified Eagle's medium containing 0.2% w/v bovine serum albumin and then incubated in the absence or presence of 100nmol/L insuhn for 24 hrs. Cells were harvested and the expression of VEGF mRNA was analyzed by Realtime PCR. VEGF protein level was determined by HUVEC proliferation assay, immunofluorescence and western-blot. Results Insulin or (and) high glucose significantly increased VEGF mRNA ( F = 5.67,9.04 ;P <0.05) and protein (F=5.50,5.57;P<0.05) expression. However, the combined effect of insulin and high glucose is weak in contrast to insulin or high glucose alone. Conclusions High glucose attenuated insulin-induced VEGF expression. Therefore, VEGF may be not the major factor that lead to transient worsening of diabetic retinopathy after acute insulin therapy in diabetes.

Corneal neovascularization is one of the tough problems in the cornea diseases, but its pathogenesis is still unclear. Binding of angiopoietins family and its receptor Tie2 set up the signal transducting system of Ang/Tie2, which plays the important role in the angiogenesis and regulation. Recently, the study of the signal transducting system of Ang/Tie2 has archived some progression in the corneal neovascularization. So this article reviewed the advances of related role of angiopoietins family and its receptor in the pathogenesis and regulation of corneal neovascularization including the structure and function of angiopoietins and its receptor Tie2.

Diabetic retinopathy is a major cause of blindness. It is important to study the healthrelated quality of life (HRQoL) in diabetic retinopathy. The HRQoL is typically measured through one of the two different techniques: questionnaires and patient preferences/utilities. The HRQoL questionnaires can be generic, function specific, or disease specific. Considering to patient preferences, two methods are commonly used to quantify utilities : the time tradeoff technique (TTO), and the standard reference gamble.Each method has its own characteristics. This paper reviews the results of recent domestic studies on the effects of diabetic retinopathy and diabetic macular edema on the quality of life.

Duplicate carcinoma, also known as multiple primary carcinoma, refers to the occurrence of two or more primary malignant tumors in single or multiple organs of the same patient at the same time or successively. Duplicate carcinoma is more common in digestive tract, head and neck, etc<' [1-4]>, the incidence rate of malignant tumor is about 0.4% ~10.7% of the total number of patients<' [5]>. First reported by Billroth in 1879<' [6]>. Ocular malignant tumors combined with other organs are relatively rare, and they are easy to be misdiagnosed as metastatic cancer and give up treatment. Two cases were encountered in the Department of Ophthalmology of the Fourth Hospital of Hebei Medical University, which are reported as follows.

Rosacea is a chronic inflammatory disease with unknown etiology, which often involves the facial skin and eyes of patients. The face often shows skin erythema, telangiectasia and sebaceous gland hyperplasia in the forehead, cheeks, nose and mandible, which is easily identified clinically; If the patient's eye is involved, its clinical manifestations are often atypical and difficult to identify, which can easily lead to misdiagnosis by clinicians. In 2007, two patients with rosacea complicated with binocular lesions were diagnosed and treated in our hospital, and the reports are as follows.

choroidal osteoma is a rare benign tumor, and very few cases are accompanied by choroidal IleOVagcularization (CNV), which leads to sharp decline of visual acuity, and clinical treatment is difficult. One patient was admitted to our hospital, and good treatment results were achieved. The report is as follows.

A 65-year-old male came to our hospital on January 25, 2008 due to intermittent redness and pain in his left eye combined with blurred vision for more than 1 year. A year ago, the patient had redness and pain in his left eye without obvious reason, and no increased secretion. He was diagnosed with scleritis in the local hospital, and was given gentamicin and dexamethasone eye drops. After improvement and discontinuation of the drug, he relapsed and repeated, and his visual acuity decreased. Four months ago, black matter appeared and prominent in his left eye, and the local hospital gave oral prednisone (20 mg/d) and glucocorticoid eye drops for eye treatment, but the symptoms of eye pain and redness were not relieved.

Lipid peroxidation is one of the main mechanisms causing oxidative damage to cells. Many scholars believe that retinal lipid peroxidation is closely related to the occurrence of age-related macular degeneration. The physiological effects of erythropoietin (EPO) as a growth factor in hematopoietic system have been well known, but it has been shown in recent years in animal experiments and clinical applications to have certain curative effects on retinal diseases. The mechanism of its curative effect has not been elucidated yet, and it is believed that it may be related to antioxidation.

At 14: 25 on May 12, 2008, the daily diagnosis and treatment in the Ophthalmology Center of West China Hospital of Sichuan University was going on in an orderly manner. Outpatients were being examined and treated, and some inpatients were undergoing surgery on the spot.

The rapid development of computer perimeter and the continuous improvement of technology have not reduced the inherent defects of visual field examination, which is a subjective psychophysical test. The results of computer visual field examination still have detection errors due to the influence of patients, examiners, examination environment, perimeter and other factors<' [1-3]>, resulting in different degrees of distortion in the visual field detection results. However, various reliability indexes in the computer visual field detection results cannot fully reflect the reliability of the visual field.

The National Symposium on Clinical Rational Drug Use in Ophthalmology, sponsored by the editorial department of Chinese Journal of Ophthalmology, the journal of Chinese Medical Association, was held in the beautiful southern city of Guilin from April 24 to 27, 2008. The conference lasted for 4 days, and more than 100 doctors and researchers from all over the country engaged in ophthalmology and related specialties attended.