Volume 42 ·  Issue 09 ·  2006

Effectively improving the visual quality of intraocular refractive surgery is the prerequisite for clinical application of this kind of surgery. Visual quality is a comprehensive factor, which is related to surgical safety, calculation of intraocular lens materials and degrees, measurement of eyeball related parameters and psychophysical perception, etc. This article reviews the analysis of visual quality and its related factors in this kind of surgery.

Objective to investigate the effect of optical zone size on the high-order aberration of myopia after excimer laser in situ keratomileusis (LASIK). Methods 236 cases (461 eyes) of myopia treated with LASIK were divided into high, medium and low myopia groups. Each group was divided into subgroups Ⅰ ~ Ⅳ according to the different diameters of laser cutting optical zone (5.75, 6.00, 6.25 and 6.50 mm). The aberration of eyes was measured by wavefront aberrometer before and 6 months after surgery. The differences of total high-order aberration, horizontal aberration, vertical aberration and spherical aberration between different subgroups before and after surgery were analyzed by analysis of variance and q test. Results There was no significant difference in high-order aberration between different subgroups before surgery (P>0.05). At 6 months after surgery, the differences of total high-order aberration and spherical aberration between different subgroups in each group were statistically significant (P<0.05), and the larger optical zone subgroup was lower than the smaller optical zone subgroup. The differences between different pupil diameters in high myopia group were statistically significant (P<0.05), and the low myopia group was statistically significant (P<0.05) When the pupil diameter was 6.00mm, the difference between subgroups in high myopia group was statistically significant (P<0.05), and between subgroups Ⅰ and Ⅳ in low myopia group was statistically significant (P<0.05). There was no statistically significant difference in horizontal coma and vertical coma between different subgroups in each group (P>0.05). Conclusion The size of optical zone affects the total high-order aberration and spherical aberration after LASIK treatment of myopia, and the larger optical zone group is lower than the smaller optical zone group, and the effect is more obvious when treating high myopia.

Objective to investigate the dynamic changes of ORBSCAN Ⅱ after excimer laser in situ keratomileusis (LASIK) in myopia and the main factors affecting the anterior protrusion of the posterior corneal surface.Methods 216 myopic patients (230 eyes) were divided into 4 groups according to the equivalent spherical lens diopter: Group Ⅰ: -1.25~ -3.00D; Group Ⅱ: -3.13~ -5.75 D; Group III: -6.00~ -8.88 D; Group IV: -9.00~ -15.75 days, the corneal topography system of ORBSCAN Ⅱ was used to detect the corneal thickness map and the posterior corneal surface topography map before surgery, 1 month and 3 months after surgery, respectively. The thickness of the thinnest part of the cornea, the refractive power of the posterior corneal surface and the distance between the vertex of the posterior corneal surface and the ideal spherical surface (Diff value) were obviously changed after surgery compared with before surgery, and the differences were statistically significant compared with 1 month after surgery (t =22.79, -20.63, -15.90; P<0.05). Compared with 3 months after surgery, the differences were statistically significant (t =17.87, -17.98, -27.26; P<0.05). The differences were statistically significant compared with 3 months after surgery (t =17.87, -17.98, -27.26; P<0.05). The differences between different groups at the same time period after surgery were statistically significant (F =61.92, 4.74, 7.28; P<0.05; F =64.16, 5.12, 21.83; P<0.05). The multiple linear regression equations were Y =0.0941-0.000 53X1-0.000 471X2-0.0063X3+0.001 22X4 (F =13.48, P<0.01). The multiple linear regression equations were Y = -0.027-0.000 78X1+0.002 01X2-0.0055X3 (F =21.81, P<0.01). The difference between the Diff value of the posterior corneal surface (Y) and the difference between the thickness of the thinnest corneal area (X1), the intraocular pressure (X2) and the difference between the refractive power of the posterior corneal surface (X3) at 3 months and 1 month after operation were Y = -0.027-0.000 78X1+0.002 01X2-0.0055X3 (F =21.81, P<0.01). Conclusion ORBSCAN Ⅱ has important clinical significance in the screening and postoperative monitoring of myopic patients before LASIK, but the function of corneal thickness measurement is poor in the high myopic eyes after LASIK, so it is not suitable for screening criteria for reoperation The main factors affecting the anterior protrusion of the posterior surface of the cornea were corneal thickness, corneal transverse diameter and axial length; The main factors affecting the change of protrusion between 3 months and 1 month were the difference of corneal thickness between 3 months and 1 month postoperatively, the difference of refractive power of posterior corneal surface and preoperative intraocular pressure. These factors should be used as reference indexes for preoperative screening.

Objective to investigate the relationship between corneal astigmatism and second-order wavefront aberration in Chinese myopic patients and the influence and role of corneal astigmatism in the composition of ocular aberration. Methods WASCA wavefront aberration analyzer designed by Shack-Hartmann principle was used to detect the ocular aberration of 484 myopic astigmatism eyes in 246 outpatients, and the third and fifth Zernike coefficients (C3 and C5) were analyzed under the pupil diameter of 6.0mm; The corneal astigmatism of 484 eyes was obtained by using Humphrey corneal topography. The corneal astigmatism was divided into 5 groups of corneal astigmatism (including 0° and 180°), inverse corneal astigmatism and oblique corneal astigmatism (including 45° and 135°). The correlation between J45 (JCC cylindrical lens with 45° or 135° axis) and J0 (JCC cylindrical lens with 90° or 180° axis) and the second-order aberration was analyzed respectively. The mean values of corneal astigmatism obtained by vector analysis were-1.34D ×6.87°, -1.03D ×23.15°, -0.48D ×89.55°, -0.91D ×156.87° and-1.02D ×176.74°; The values of J45 and J0 of corneal astigmatism in each group are linearly correlated with C3 and C5, respectively. The coefficients of R2 of J45 and C3 are 0.138, 0.119, 0.090, 0.526, 0.501, respectively, and the coefficients of R2 of J0 and C5 are 0.711, 0.736, 0.864, 0.866, 0.785, respectively. Conclusion Corneal astigmatism is closely related to the second-order wavefront aberration of the eye, and the correlation between them is axial-dependent.

Methods Computer-controlled closed-circuit enhanced priority fixation (COPL) system was used to examine the visual acuity of infants and young children in the form of general survey. The reliability and success rate of this system and method were analyzed, and the visual development trend of 599 normal infants and young children aged 2~72 months and preschool children were analyzed. Results The results of two tests in all age groups showed good repeatability; The success rate of this examination method is higher than 90%, which reflects the advantage of strengthening priority attention in COPL system.Children aged 2~12 months and 42~72 months cooperate better in the examination, while children aged 12~42 months are in active state, the cooperation rate is slightly lower, but also much higher than that reported in previous literature; With the increase of children's age, their visual acuity increases gradually. By estimating the developmental trend line graph of scatter plot, it can be seen that the visual acuity of children improves significantly at 12 months after birth, and then the visual acuity increases steadily, the visual acuity changes tend to be relatively slow at 30~36 months, and the visual acuity development of the barred acuity enters a plateau stage after 36 months. Conclusion The application of computer-controlled COPL visual acuity detection system has good clinical effect on the visual acuity examination of preschool children, and can be effectively applied to the study of visual acuity development of preschool infants and young children, so as to understand the speed of visual acuity development of barred acuity in different age groups, its mature age and the highest degree of development.

Objective to investigate the role and mechanism of the relationship between regulation and vergence in the occurrence and development of delayed myopia. Methods This study included 34 college students, including 11 emmetropia and 23 delayed myopia (-2.00~ -6.00D, 14 delayed stable myopia and 9 delayed progressive myopia). Eye movement parameters were measured including far and near strain, accommodation response, accommodation convergence and positive and negative relative regulation. The reactivity and calculated AC/A of each group were analyzed and compared. Results The reactivity AC/A of delayed progressive myopia group was significantly higher than that of emmetropia group or delayed stable myopia group (P<0.05), but the difference of calculated AC/A was not statistically significant (P>0.05); At high demand (3.00 D visual target), the modulation response A in emmetropia group was significantly higher than that in delayed progressive and stable myopia group (P<0.05); The data of distal and proximal ocropia and positive relative adjustment in each group obeyed the approximate normal distribution (P>0.05). There was no significant difference in distal and proximal ocropia and negative relative adjustment between delayed myopia group and emmetropia group (P>0.05). However, the proximal ocropia in delayed myopia group had a tendency to esotropia compared with emmetropia group, and the absolute value of positive relative adjustment in delayed myopia group was significantly lower than that in emmetropia group (P<0.05). Conclusion Regulation, vergence and their interaction play an important role in the development of delayed myopia, and reactive AC/A is the key parameter.

Objective to investigate the effects of micro-keratome excimer laser subkeratomileusis (Epi-LASIK) and ethanol infiltration excimer laser subkeratomileusis (LASEK) on corneal stromal cells. Methods Fifty New Zealand white rabbits were randomly numbered, one eye (96 eyes) underwent Epi-LASIK, the other eye underwent LASEK, and the remaining 2 eyes (4 eyes) did not undergo surgery. The apoptosis of corneal stromal cells was observed by nucleotide terminal transferase-mediated dUTP gap labeling (TUNEL) method, the proliferation and transformation of corneal stromal cells into myofibroblasts were observed by immunohistochemistry of Ki-67 and α-SMA protein in corneal tissue and immunoblotting method. The effects of haze formation were analyzed by counting and semi-quantitative analysis. Results TUNEL positive cells appeared more in corneal stroma after Epi-LASIK and LASEK, and the peak was reached at 24 days after surgery It reached the peak at 72 h, and the difference between the two groups was statistically significant within 1 week (t =3.81, 5.85, 5.09, 5.59, all P<0.01). α-SMA positive cells appeared significantly at 1 week after operation, and the expression was still high at 3 months after operation. The number of positive cells reached the peak at 1 month after operation, and the expression of α-SMA protein was consistent with the change of α-SMA positive cells, which indicated that the increase in LASEK after operation was statistically significant compared with EPI-LASEK (t =2.97, 7.19, 6.73, all P<0.01). Conclusion EPI-LASEK had less apoptosis, weaker proliferation and transformation into myofibroblasts than LASEK, suggesting that EPI-LASEK had less haze reaction than LASEK.

Objective to investigate the prevalence and causes of blindness and low vision among people aged 60 and above in urban population of Nantong City, Jiangsu Province. Methods A random cluster sampling method was used to sample 8 out of 14 communities in Xinchengqiao Street, and all people aged 60 and above were examined. Small hole vision and daily life vision were examined respectively, and the external eye, anterior segment and fundus of the eye were examined by slit lamp microscope and direct ophthalmoscope. Pre-test was conducted before formal investigation. Results A total of 3352 people were examined, and the number of examined was 3040, with a response rate of 90.69%. According to small hole vision and World Health Organization visual impairment standards, the prevalence rates of binocular blindness and low vision were 1.35% and 1.84%, respectively, among which females were 1.92% and 2.33%, and males were 0.66% and 1.24%, respectively; The prevalence of blindness and low vision increased with age; According to the standard of daily life vision and visual impairment, the prevalence rates of binocular blindness and visual impairment were 1.58% and 13.59%, respectively, of which 2.10% and 15.98% were female, 0.95% and 10.66% were male, respectively; The prevalence of blindness and visual impairment also increased with age; The primary cause of blindness in both eyes is also cataract. Conclusion The prevalence of blindness in urban population aged 60 years and above in Nantong is lower than that in North China, South China and West China. The prevalence of blindness and low vision in women and illiterates is higher than that in men and non-illiterates, respectively. The main causes of blindness in urban population in Nantong are cataract, fundus abnormality, refractive error and corneal scar or opacity, etc.

Objective to explore the method of culture and preservation of corneal organs, the characteristics of cornea after preservation and the feasibility of transplantation. Methods the corneas of 36 adult New Zealand rabbits were sealed in a 32℃ incubator with specific fetal bovine serum preservation solution; At different time points from 1 to 4 weeks after preservation, the cornea was removed from the preservation solution and transferred into the dehydration solution with high osmolarity for 48 h for later use; Then compare the changes of corneal endothelial cell density and corneal thickness before and after preservation, and observe the histological characteristics of corneal endothelium and the contamination during preservation; Allogeneic penetrating keratoplasty was performed on rabbit corneas after organ culture and preservation, and the graft status was observed within 1 week after operation; Fluorescence-labeled anti-MHC-Ⅱ molecular antibody was used to label dendritic cells in the cornea after preservation, and their distribution and changes after preservation were observed. Results the method of preservation of corneal organs was successfully established, and the contamination rate of cornea during preservation was about 8.3%; The rabbit corneas were transparent after dehydration within 4 weeks; At the third week of preservation, the peripheral area of the posterior corneal elastic layer had fine wrinkles; At the 4th week of preservation, there were obvious folds in the whole cornea; The density of rabbit corneal endothelial cells decreased with the prolongation of preservation time, and the density of rabbit corneal endothelial cells decreased by 15.7% on average after 4 weeks of preservation; The corneal thickness of rabbits increased with the prolongation of preservation time, and the central corneal thickness reached 0.7 mm at the 4th week of preservation; Histological observation showed that the corneal endothelial cells were closely adhered to the posterior elastic layer; Dendritic cells were distributed in the limbal epithelial layer of cornea and sclera, and all disappeared at the third week of preservation; Conclusion The corneal organ culture and preservation method established in this study can maintain the activity of the preserved cornea within a certain period of time, and the immunogenicity of the cornea decreases.

Objective to investigate the drug release characteristics of sodium alginate-retinoic acid (AGS-RA) microspheres prepared from retinoic acid and sodium alginate in animals in vitro and in vivo. Methods the retinoic acid was dissolved in organic solvent, mixed with 1.5% sodium alginate uniformly, and the alginate-retinoic acid microspheres were prepared by electrostatic microcapsule generator. The shape and size of the microspheres were observed and measured under microscope, and the drug content of the microspheres was determined by ultraviolet spectrophotometer; In the in vitro drug release experiment, the in vitro release law of RA was determined by ultraviolet spectrophotometer and high pressure liquid phase method; The pharmacokinetic characteristics of aqueous humor were observed by injecting AGS-RA microspheres through the vitreous cavity in vivo. Results the size of AGS-RA microspheres was (95.2443 ± 8.6265) μ m; The drug content is (1.7644 ± 0.0453) μ g/mg; In vitro experiments showed that the RA drug of AGS-RA microspheres was released uniformly within 28 days of observation; The pharmacokinetic studies of aqueous humor showed that the drug released almost uniformly within 6 weeks [the concentrations of aqueous humor RA at 1, 3 days, 1, 2, 3, 4, 5 and 6 weeks were (23.79 ± 0.15), (33.45 ± 0.48), (19.95 ± 0.79), (21.12 ± 0.47), (19.65 ± 0.35), (20.01 ± 0.25), (18.24 ± 0.27), (18.5 ± 0.68) ng/ml, respectively], with only one release peak on the third day.

Objective to investigate the effect of doubling of hematopoietic stem cells (HSCs) on retinal microvascular endothelial cells in diabetic mice. Methods Mouse stem cell growth factor (SCF) 200 μ g · kg-1 · d-1 combined with recombinant human granulocyte colony-stimulating factor (rhG-csf) 50 μ g · kg-1 · d-1 were used to mobilize HSCs in diabetic mice and non-diabetic mice for 5 consecutive days. Neonatal retinal vascular endothelial cells were labeled with CD31 and 5-bromodeoxyuracil (BrdU) immunohistochemistry, and mature retinal vascular endothelial cells were labeled with PAS staining.Semi-quantitative RT-PCR was used to detect the expression of vascular endothelial growth factor (VEGF), soluble vascular endothelial growth factor receptor 2 (VEGFR-2) and angiopoietin 2 (ang-2) in retina. Results Autologous stem cell mobilization could double the number of CD34- /low and Sca1+ -producing cells in the peripheral blood of normal mice and diabetic mice. The number of CD31-labeled neovascularized cells was increased and the rate of endothelial cell regeneration was accelerated in the immunohistochemical sections of diabetic mice. In the immunohistochemical dual staining of BrdU and CD31, the dual expression of two kinds of antigens in neonatal capillary endothelial cells was observed. Autologous stem cell mobilization could significantly increase the content of VEGFR-2 in mice retina, and significantly down-regulate the expression of VEGF and ang-2 in diabetic mice. Conclusion Autologous stem cell mobilization could significantly increase the content of VEGFR-2 in mice retina, and significantly reduce the expression of VEGF and ang-2 in diabetic mice Bidirectional regulation of vascular leakage-related factors such as VEGF and ang-2 to achieve therapeutic vascular remodeling.

The failure of mammalian optic nerve to regenerate successfully after injury is closely related to the existence of inhibitory microenvironment in central nervous system, except for the low regeneration ability of retinal ganglion cells. Myelin-related inhibitory molecules produced by oligodendrocytes are important components of this inhibitory microenvironment. At present, the main inhibitory molecules identified are Nogo, myelin-related glycoprotein and oligodendrocytes myelin glycoprotein, which transduce inhibitory signals through the same receptor complex. By blocking inhibitory molecules and their receptors or changing the intrinsic state of neurons, the inhibitory effect of inhibitory molecules can be overcome, and the axonal regeneration of retinal ganglion cells can be promoted, which brings hope for the repair of human optic nerve injury.

In recent 10 years, the research in the field of molecular biology has made great progress, including the practical applications of RNA interference technology, proteomics, molecular mapping and nanotechnology, etc. The intersection and promotion of biomedicine and other disciplines have provided a strong impetus for the development of biomedicine, and the progress in ophthalmology is also the same. In order to deepen the understanding and understanding of the internal relationship between some systemic diseases and ocular diseases and their therapeutic mechanisms, the author briefly reviews the latest progress in the field of molecular biology related to ophthalmology research for reference.

The photoinduced decomposition of femtosecond laser allows precise cutting at any position in corneal tissue. It can be used in corneal stromal cutting, making incision for corneal stromal ring implantation, making corneal flap during excimer laser in situ keratomileusis, and completing femtosecond laser keratomileusis. It is a brand-new method for correction of refractive error.

The 6th Asian Cataract Research Conference (ACRC) was successfully held at Beijing International Hotel on June 3-7, 2006. More than 300 cataract research experts, scholars and clinicians from the United States, Japan, South Korea, Britain, Australia and all over the country attended the meeting.

On October 18, 2001, the National Committee for the Approval of Scientific and Technological Terms and the National Language and Character Working Committee held a "Seminar on the Usage of 'Xiang' and 'Xiang'" at the Chinese Academy of Sciences. The meeting carefully analyzed the reasons for the confusion between the usage of "like" and "like" in the scientific and technological circles. The National Science and Technology Glossary Committee and the State Language Commission considered it necessary to make a clear definition of the usage of this word again. Experts at the meeting believed that: elephant refers to the form and appearance of nature, people or things; Image refers to the image of a person or object made by imitation, comparison, etc., and also includes the image that is the same or similar to the original object formed by reflection and refraction of light. Examples of word collocation of the words "Xiang" and "Xiang": Xiang: phenomenon, image, impression, sign, representation, object image, scene, celestial phenomenon, body image, crisis image, mental image, conformation, magnetic image, heteropole image, blood image, split image, observatory, phenomenological coefficient, wave-particle duality, etc.

Retinal hypoxia is a well-recognized cause of retinal neovascularization. In the past, animal models of retinal neovascularization induced by high concentration of oxygen were mostly studied, but the effects of high concentration of oxygen and low concentration of oxygen on retinal vascular development were rarely compared. During the retinal development, vascular endothelial growth factor (VEGF) plays an important role in regulating retinal vascularization.

Abnormalities of tear film (quality and quantity) and eye surface caused by any reason can cause dry eye syndrome, and in severe cases, it can lead to obvious decrease of vision and affect work and life. At present, the clinical treatment of dry eye syndrome often uses tear replacement and maintaining the retention time of tear in the eye as much as possible. These belong to passive tear increase methods. Cyclosporine A, punctual embolization and autologous submandibular gland transplantation all have certain curative effects, but there are also shortcomings. The ideal treatment of dry eye syndrome should be non-invasive and can promote the active secretion of tear from the lacrimal gland. Acupuncture therapy in traditional Chinese medicine is in line with the above two points. There are few related literature reports on acupuncture treatment of dry eye syndrome [1-6], most of which are clinical studies, while there are few studies on the mechanism of acupuncture treatment of dry eye syndrome.

retinopathy of prematurity (ROP) was the leading cause of blindness in children in western developed countries in the middle of the 20th century [1-4]. In recent years, ROP has been increasing in middle-income countries [5, 6]. For example, in rural Thailand and the Philippines, ROP has not been reported, but in cities with premature infant treatment institutions, ROP is an important cause of blindness in 15% of children [7]. With the improvement of neonatal intensive care level in China, the survival rate of premature infants with low birth weight is increasing continuously, and the incidence of ROP is also increasing [8, 9].

A good anti-glaucoma surgical scheme should not only effectively reduce intraocular pressure, but also reduce the damage and interference to ocular tissue structure and physiological function as much as possible. During my study and work in the Department of Ophthalmology of the Affiliated Hospital of the University of Bordeaux, France, 192 patients with open angle glaucoma were treated with a new anterior chamber drainage device, ExpressTM, from 2003 to 2004, and the results were satisfactory.

cytomegalovirus (CMV) retinitis is characterized by "pizza-like" fundus changes, which often suggest that patients have low systemic immunity. Considering human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS), systemic immunosuppressants and chemotherapeutic drugs are caused. In 2005, we treated a patient with CMV retinitis caused by long-term systemic immunosuppressants. His ocular manifestations and diagnosis and treatment are analyzed and reported as follows.

The patient was a 46-year-old male with bleeding in his left eye after being pricked by a tree branch. He came to our hospital on April 22, 2005. Two hours before admission, the patient fell due to drunkenness, and his face landed on the ground and was pricked by a tree branch. After the injury, the patient lost consciousness, left limb movement disorder and urinary incontinence. The left eyelid was highly swollen and bleeding. General examination: superficial coma, agitation, physical examination did not cooperate; The muscle strength of the left upper and lower limbs was 0, and the muscle strength of the right upper and lower limbs was grade Ⅱ; Left side Babinski sign (+), Chaddock sign (+). Eye examination: No vision was detected due to unconsciousness; The left eyelid was highly swollen, with dark purple congestion under the skin, and the broken end of the branch was inserted into the orbit, with the end exposed 2.0 cm, the transverse diameter 2.0 cm, the vertical diameter 1.5 cm, and the edge was rough (Figure 1); The eyeball cannot be inspected.

The patient was a 48-year-old male who came to our hospital on September 20, 2005 because he found white circles at the edge of the cornea in both eyes. The patient had no obvious abnormalities in the whole body examination. Eye examination showed that the naked eye visual acuity was 0.6 in the right eye and 0.9 in the left eye. The eye position of both eyes was correct, the eye movement was not abnormal, the conjunctiva was not congested, the peripheral senile ring of both corneas was changed, the stromal layer in the central region was opaque, the subepithelial crystal was opaque, the pupil was not round, the iris was not abnormal (Figure 1, 2), the lens and vitreous body were transparent, and the fundus was not abnormal.

The patient was a 72-year-old male who came to our hospital in October 2003 because of "no vision in his right eye for 8 years". Twenty years ago, the patient had a history of glaucoma, and the symptoms of eye distension were relieved by drug treatment, but his vision gradually declined. In the past 8 years, the right eye completely lost sight. Eye examination: the right eye visual acuity and light perception were 0.6 in the left eye, the right eye cornea was transparent, the anterior chamber was clear, the circumferential depth was 1CT, the iris had a hole at 5 or 11 o'clock, many irises had atrophy, the pigment of the pupil margin was everted, and the light response disappeared (Figure 1).

An 18-year-old male was admitted to the Department of Ophthalmology of West China Hospital of Sichuan University on July 13, 2004 due to redness and swelling of his right eye, decreased visual acuity for 1 1/2 months, aggravated with distension and pain for 6 days. In March, 2004, the patient developed headache, and the local hospital diagnosed it as "cold", but the treatment did not improve. On April 19, 2004, the patient was diagnosed as "appendicitis" due to abdominal pain, and underwent "appendectomy". Postoperatively, the patient was diagnosed as "intestinal tuberculosis", and was given anti-tuberculosis treatment. After 5 days of treatment, he developed fever and intermittent confusion, but the treatment did not improve.