Volume 43 ·  Issue 08 ·  2007

A good visual quality should not only have normal visual acuity, but also have normal contrast sensitivity, color vision, visual field and binocular visual function. The concept and correction technology of wavefront aberration have been introduced into ophthalmology in China, which plays an important role in finding and correcting the problems of visual quality. However, until now, the knowledge of wavefront aberration has not been popularized among ophthalmologists in China, and the research and clinical application are still insufficient, so this situation should be changed as soon as possible.

This paper briefly describes the historical development of orthokeratology, and puts forward the concept of modern orthokeratology. According to the research results of authoritative medical institutions at home and abroad in recent years, the effectiveness and safety of modern orthokeratology in reducing myopia and controlling the development of myopia are evaluated. Compared with the advanced level abroad, aiming at the misunderstanding in domestic use, this paper discusses the blind promotion and commercial operation in the initial stage from different angles; Exaggerating danger; At the same time, it is pointed out that with the development of new materials, new individualized design and wavefront aberration guidance technology in the future, the visual quality of orthokeratology will be further improved, and the efficacy of orthokeratology will be more durable, effective, safer and more comfortable, so as to promote the healthy development of modern orthokeratology in China.

Objective to evaluate the effects of long-term wearing orthokeratology lens on corneal thickness and corneal endothelial cells in myopic patients. Methods Using ultrasonic keratometer and non-contact corneal endothelial microscope, the corneal thickness and the density and morphological changes of corneal endothelial cells were measured and observed in 132 adolescent myopic patients (264 eyes) before and during wearing orthokeratology lens (oxygen permeability coefficient 100). Results No obvious changes in the corneal thickness and the corneal endothelial cell density were not observed (P>0.05), the mean area of corneal endothelial cells and the coefficient of cell variation were not significantly increased (P>0.05), and the hexagonal ratio of corneal endothelial cells was not significantly decreased (P>0.05). Conclusion Scientific orthokeratology treatment with high oxygen permeability material has little effect on corneal metabolism, and long-term wearing of orthokeratology lens is basically safe to control the development of myopia.

Objective to study the distribution of corneal anterior surface fourth-order spherical aberration (C12) in age-related cataract patients in China, and to analyze the related factors, aiming to guide the application of intraocular lens with spherical aberration elimination in cataract patients.Methods The corneal topography of 144 patients (188 eyes) with age-related cataract before operation was examined, and the data of corneal anterior surface curvature and height were output. The correlation between corneal anterior surface fourth-order spherical aberration and corneal curvature, corneal astigmatism and corneal morphological factor (SF) was analyzed by optical tracing conversion program. Results The corneal anterior surface fourth-order spherical aberration had large individual differences, the fluctuation range was-0.096~ +0.469 μ m; Three patients showed negative spherical aberration; The average value of the fourth-order spherical aberration coefficient is (0.231 ± 0.092) μ m; There was no significant correlation between corneal curvature and corneal astigmatism (r =0.134, -0.075; P>0.05), but there was a significant linear correlation regression relationship with corneal morphological factors (r = -0.725, P =0.000). Conclusion The corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal corneal In a few patients, the spherical aberration of the anterior surface of the cornea can be negative; There was no significant correlation between corneal spherical aberration and corneal curvature and corneal astigmatism, but there was a significant negative correlation with corneal morphological factor; The selection of spherical aberration intraocular lens needs to be individualized, which varies from person to person; Corneal morphological factors have certain reference significance for the relative individualized selection of spherical aberration intraocular lens.

Objective to investigate the influence of material and design factors on the spherical aberration characteristics of traditional intraocular lens (IOL). Methods the optical path system of IOL wavefront phase difference measurement was built in the laboratory, and the aberration measurement was carried out by Hartmann-Shack detector. Eight different types of IOL were divided into two groups: different material groups (SA60AT, AR40e, SI40NB, PC330UV) and different design groups (821T, PC155, PS53ANB, UV2265N). The continuous aberration measurement of each IOL in each group was carried out under 3, 4, 5, 6, 7 mm aperture (simulating pupil change), and the measurement results were analyzed. Results With the continuous expansion of the aperture, the spherical aberration of IOL in both groups increased linearly, and there was a positive correlation between the size of the aperture and the spherical aberration of IOL (r =0.6465, 0.7872; P<0.01); The total aberrations of 8, 5, 3, 2 and 2 of 8 kinds of IOL were in accordance with Rayleigh judgment under the aperture of 3~7 mm, respectively, and the coincidence decreased with the increase of the aperture. Among different material groups, the spherical aberrations of acrylate IOL with high refractive index were the largest (P<0.01), and the spherical aberrations of acrylate IOL with low refractive index were the smallest (P<0.01). The spherical aberrations of silicone gel and PMMA IOL were between the above two types of IOL; Among different design groups, the spherical aberration of biconvex (back>front) IOL is the largest (P<0.01), and the spherical aberration of convex-flat IOL is the smallest (P<0.01). The spherical aberration of biconvex (front>back) IOL and biconvex (front = back) IOL is between the above two types of IOL. Conclusion The aberration characteristics of IOL change greatly under different materials and designs and different apertures, which provides a reference for the continuous improvement of IOL.

Objective to explore the quadratic curve equation model and preliminary results of the mathematical model of Chinese individual cornea. Methods the three-dimensional coordinates of Cartesian space with the vertex of the cornea as the origin were established, the coordinates were rotated around the z axis, a new three-dimensional space coordinate system was established, and the transformation relationship between the old and new coordinates was clarified; The curvature of the anterior and posterior surfaces and the corneal thickness values d0 at the meridians of the corneal vertex, 0°, 30°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 270°, 300° and 330° measured by ORBSCAN Ⅱ corneal topography system were obtained at points 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0 and 4.5 mm from the corneal vertex, respectively, and substituted into a set of equations to solve the quadratic curve formulas x2= a2z2+ a1z (anterior surface truncation), x2= a1 (z-d0) 2+ a2 (z-d0) (posterior surface truncation, d0 is the central corneal thickness), and the truncation characteristics and eccentricity Q value of each section were determined; The mathematical expressions of the spatial morphology of the anterior and posterior corneal surfaces were summarized from the curve characteristics of each meridian truncation. Results The mathematical expressions of each meridian truncation on the anterior and posterior corneal surfaces were all elliptic quadratic curve trajectories. The curved surfaces on the anterior and posterior corneal surfaces were consistent with the mathematical expressions of ellipsoid quadratic surfaces. Conclusion A new expression of quadratic curve formula for the mathematical model of the anterior and posterior corneal surfaces of human eye was reported. In this small sample, the meridian truncations of the anterior and posterior corneal surfaces of normal Chinese people all conform to the morphological characteristics of elliptic quadratic curve, and the curved surface spatial morphology of the anterior and posterior corneal surfaces is ellipsoid.

Objective to investigate the efficacy and safety of iris clamping anterior chamber lens implantation in the treatment of high myopia. Methods A total of 12 eyes (21 eyes) underwent anterior chamber lens implantation in our center from August 2005 to February 2006. The observation indexes included naked eye visual acuity, best corrected visual acuity, intraocular pressure, corneal topography, pupil morphology, corneal endothelial count, lens position and morphology in the anterior chamber, and intraocular lens surface pigmentation. Results The best corrected hyperopia spherical degree was (-17.28±2.95) D, astigmatism was (-1.90±1.02) D, and the average implantation degree was (-14.53±9.47) D. The average follow-up time was (13.2±2.1) months. 17 eyes were followed up 12 months after operation. Compared with the best corrected distance visual acuity before operation, the naked eye distance visual acuity was improved in 1 row of 5 eyes (29.41%), 2 rows of 4 eyes (23.53%), 3 rows of 3 eyes (17.65%), and 4 rows of 2 eyes (11.76%). Compared with the best corrected distance vision before operation, the best corrected distance vision after operation was improved in 4 eyes (23.53%) in 1 row, 2 eyes (11.76%) in 2 rows, 2 eyes (11.76%) in 3 rows, 2 eyes (11.76%) in 4 rows, 5 eyes (29.41%) in 5 rows or more. The intraocular pressure before operation was (17.25±2.92) mm Hg (1 mm Hg =0.133 kPa), (17.14±2.52) mm Hg at 6 months and (17.16±2.57) mm Hg at 12 months after operation, the difference was not statistically significant (P>0.05); The preoperative corneal endothelial count was (2627.89±229.36) /mm2, (2605.28±239.22) /mm2 at 6 months and (2603.17±237.12) /mm2 at 12 months, and the difference was not statistically significant (P>0.05). Conclusion Iris clamping anterior chamber lens implantation is safe, effective and has good predictability in the treatment of high myopia; However, the long-term effect needs further observation.

Objective to compare the reading speed of Fast Series Visual Presentation (RSVP), Full Screen and Paper Display mode, and to obtain the critical font size and critical visual reserve (RA) in RSVP mode. Methods Thirty subjects with visual acuity threshold not less than 1.0 (corrected vision or naked eye vision) participated in this experiment. The visual acuity threshold of all subjects (3m detection distance) was measured by self-designed eye chart. The reading speed of 10 font sizes (4.0~33.0 lbs) under RSVP mode and two font sizes (10.0 and 13.0 lbs) under full screen and paper display modes was measured. Results The visual acuity threshold of 30 subjects at 40 cm reading distance was (2.2 ± 0.3) lbs. Under RSVP mode, the reading speed increased significantly with the increase of font. When the font size was (7.8 ± 0.4) lbs, the reading speed reached the maximum value: (258.0 ± 34.4) words/min, and then remained constant. The reading speed was positively correlated with RA. When RA was 3.5 ± 0.4, the reading speed reached the maximum value. When RA was 3.5~15.0, the reading speed was always at the maximum value. Full screen display [10 lbs: (354.1 ± 58.7) words/min; 13 lbs: (369.2 ± 56.4) words/min] and paper display [ The reading speed of both full screen and paper display was greater than that of RSVP [10 lbs: (262.0 ± 35.0) words/min; 13 lbs: (258.7 ± 34.5) words/min], and the difference was statistically significant (P<0.01). Conclusion The critical font size of RSVP is 7.8 lbs in young people with normal vision, which suggests that the critical font size in static presentation should be greater than 7.8 lbs. The font size at maximum reading speed is generally 3.5 times of visual acuity threshold.

Objective to compare the effects of anterior surface optically modified aspheric intraocular lens and traditional spherical intraocular lens on ocular aberration and visual function of phacoemulsification cataract aspiration intraocular lens implantation. Methods 169 cases (169 eyes) of senile cataract patients who were supposed to undergo phacoemulsification cataract aspiration intraocular lens implantation were randomly divided into two groups, aspheric intraocular lens implantation (experimental group) and traditional spherical intraocular lens implantation (control group) respectively. Results Three months after surgery, the total spherical aberration of intraocular lens eyes with pupil diameter of 5 mm was (0.024 ± 0.076) μ m in the test group and (0.217 ± 0.137) μ m in the control group, and the difference was statistically significant (P<0.05), while the difference of corneal spherical aberration between the two groups was not statistically significant (P>0.05). The contrast sensitivity of 4.0° and 2.5° viewing angles was 39.18±11.94 and 28.30±12.07 in the test group and 33.28±11.84 and 24.50±8.20 in the control group, respectively, and the difference was statistically significant (P<0.05); The glare sensitivity of 6.3°, 4.0°, 2.5° and 1.6° angles were 30.90±9.21, 27.09±8.45, 19.20±8.71 and 12.08±4.44 in the test group, and 27.08±8.24, 23.30±6.24, 15.53±4.37 and 10.04±4.20 in the control group, respectively, with statistical significance (P<0.05); There was no significant difference between the two groups (P>0.05). Conclusion Compared with the traditional spherical intraocular lens, aspherical intraocular lens can reduce the spherical aberration of intraocular lens, improve the visual contrast and improve the visual quality of cataract patients after operation.

Objective to investigate the efficacy and safety of high-density porous polyethylene (HDPP) -wrapped glass tube implantation into lacrimal duct bypass. Methods 26 patients (26 eyes) with obvious eporrhea symptoms and lacrimal duct recanalization could not be performed. Among them, 10 patients with lacrimal punctule and lacrimal duct absence and lacrimal sac were performed conjunctiva nasal dacryocyst anastomosis combined with HDPP-wrapped glass tube implantation into lacrimal duct bypass, and 16 patients with lacrimal punctule and lacrimal duct absence and lacrimal sac were performed HDPP-wrapped glass tube implantation into lacrimal duct bypass alone. The postoperative follow-up was carried out for 4~28 months. The surgical indications, surgical methods and success rate were recorded, the occurrence of surgical complications were observed, and the data results were analyzed. Results Postoperative eporrhea symptoms disappeared or improved significantly. 23 patients (88.5%) had unobstructed prosthetic duct irrigation, 21 patients (80.8%) were satisfied with the surgical results, and there was no prosthetic duct discharge or severe displacement. Conclusion HDPP-wrapped glass tube implantation in lacrimal duct bypass can effectively solve the symptoms of epiphora in patients with lacrimal duct recanalization, with high success rate, safe and effective operation.

Objective to investigate the types of TGFBI gene mutation in Thiel-Behnke corneal dystrophy in China, and to understand the gene mutation loci in 5 generations of autosomal dominant Thiel-Behnke corneal dystrophy families. Methods 10 patients and 2 normal subjects from 1 autosomal dominant Thiel-Behnke corneal dystrophy family were examined in ophthalmology. 5 ml of peripheral blood was collected, and the genomic DNA was extracted by salting out method. The specific primers of TGFBI exons 4, 7, 8, 11 and 12 were amplified by PCR, and the amplified products were sequenced to detect the mutation. Results the amplified products of TGFBI exons 4, 7, 8, 11 and 12 were sequenced directly in two directions. The change of G → A was found in exon 12 of TGFBI gene, which was located in exon 12 of TGFBI gene, resulting in the substitution of arginine at position 555 of the encoding protein by glutamine (R555Q). This sequence change was observed in all affected members of the family, but no other normal individuals in the family

Objective to investigate the prevalence of low vision and blindness and the causes of blindness in some people aged 50 and above in Nan'an District, Chongqing, and to explore the effectiveness of prevention and treatment of blindness and the changes of blindness and visual impairment.Methods From April to July, 2005, the whole random sampling method was used to conduct visual and eye examinations in people aged 50 and above in 29 basic sampling units in Nan'an District, Chongqing. The number of examined people was 5079, and the examination rate was 89.4%. Before the formal investigation, the two examination groups were repeatedly tested for consistency. Results According to the WHO visual impairment standard, the prevalence of blindness in the examined population was 1.8%. The older the age, the higher the prevalence of blindness, and the more obvious in the elderly aged 80 and above. Cataract blindness still ranked first, but the prevalence of cataract blindness decreased significantly from 40.0% to 31.6%; Fundus disease was the second cause of blindness; Conclusion Cataract is the first cause of blindness, followed by fundus disease. The prevalence of blindness caused by cataract has decreased, and the prevention of blindness mainly by cataract surgery has achieved initial results. It is suggested to increase the prevention and treatment of age-related eye disease, fundus disease and glaucoma.

Premature infant retinopathy is a kind of retinal vascular proliferative disease that occurs in premature infants with short gestational weeks and low birth weight. The incidence of premature infant retinopathy is different in different countries and different races, and the outcome of the disease is also different under the same intervention measures. This suggests that premature infant retinopathy may be related to genetic factors. At present, it is believed that several genes play a role in premature infant retinopathy, so it is necessary to review the research status of related pathogenic genes of premature infant retinopathy.

ephrin-B2, a member of tyrosine kinase family, binds to its receptor EphB4, participates in the development of blood vessels and the formation of budding blood vessels, and plays an important role in embryonic vascularization.

Amniotic membrane is the thickest basement membrane in human body. Because it has many biological functions such as promoting epithelial repair, inhibiting inflammatory reaction and inhibiting neovascularization, amniotic membrane transplantation has become one of the effective methods for treating many kinds of ocular surface diseases.

A 27-year-old male patient came to our hospital on June 28, 2006 due to "gradual blurring of vision in his right eye for more than 5 months". Five months ago, the patient felt that his right eye vision decreased without obvious inducement, and occasionally accompanied by discomfort such as redness, pain and grinding of his eyes. The patient had a full-term natural delivery, no history of asphyxia, and appeared a rash on his face 1 month after birth, after which the skin of his whole body gradually turned dark, dry, with little sweat, but no photosensitivity.

Dichlorvos is an organophosphorus pesticide, which is easily caused by inappropriate use. We have diagnosed and treated one case, and the report is as follows. The patient was a 33-year-old female who was in coma for 1 week after oral dichlorvos 2 months ago. After waking up, she had pain in both eyes, multiple punctate dark shadows in front of her eyes, and her visual acuity decreased progressively.

A 78-year-old male came to our hospital on March 14, 2007 due to red left eye, photophobia for more than 2 months and sudden decrease of visual acuity for 5 days. He had been suffering from rheumatoid arthritis for 5 years; The patient underwent phacoemulsification and intraocular lens implantation in the left eye 3 months ago due to senile cataract in the left eye. The operation went smoothly, but the corneal condition was unknown.