Volume 44 ·  Issue 06 ·  2008

Bias is a common artificial error during sampling survey in eye diseases, and is a major impact factor for validity and reliability of the survey. The causes and the control measures of several biases regarding current sampling survey of eye diseases in China were analyzed and discussed, including the sampling bias, non-respondent bias, and diagnostic bias. This review emphasizes that controlling bias is the key to ensure quality of sampling survey. Random sampling, sufficient sample quantity, careful examination and taking history, improving examination rate, accurate diagnosis, strict training and preliminary study, aswell as quality control can eliminate or minimize biases and improve the sampling survey quality of eye diseases in China.

Nowadays, the number of ophthalmic population-based epidemiology survey is increasing in China. But some distinct shortcomings of the planning and conducting steps, such as wrong concept of the relationship between statistic correlation and risk factor, unnecessary large sample size, inappropriate sampling method, informal design of questionnaire, no pilot study, improper field study, incorrect data input and sort, no quality control, etc., are presented in some surveys, resulting in the poor reliability. Valuable epidemiology results could be obtained only after elucidation of these problems and using a standard design.

Objective To estimate the prevalence of refractive error in school-aged children in urban setting of Southern China. Methods In this population-based cross-sectional study, children aged 5 to 15 years old were randomly selected by clustering sampling and door-to-door survey, and were examined in 71 schools and 19 community stations from October 2002 to January 2003. The examination included visual acuity measurement, ocular motility evaluation, retinoscopy, autorefraction under cycloplegia and examination of the external eye, anterior segment, media, and fundus. Results Of 5053 children living in 4814 households enumerated, 4364 (86.4%) were examined. The prevalence of myopia (spherical equivalent, SE < -0.50 D) was 35.1% (95% CI: 33.2%-36.9% ) with retinoscopy, this rate increased from 3.3% in 5-year-old to 73.1% in 15-year-old. Females had a significantly higher risk of myopia (adjusted odds ratio : 1.29, 95% CI: 1.11-1.51 ). The prevalence of hyperopia ( SE ≥ + 2.00 D) was 5.8% (95%CI: 5.3%-6.3% ) and decreased from 16.7% in 5-year-old to less than 1% in 15-year-old.Astigmatism (cylinder ≥0.75 D) was presented in 33.6% of children examined with retinoscopy and in 42.7% with autorefraction. Conclusions The prevalence of myopia is high in Chinese school-age children living in urban Guangzhou, representing an important public health problem. The coverage and quality of refractive correction in the children need to be improved.

Objective To explore the clinical strategies for the screening of newborn eye diseases and obtain information concerning the incidence of newborn ocular diseases. Methods Newborns in a babyfriendly nursery were evaluated for mass screening of eye diseases 2 to 7 days after birth ( including reaction to light stimulation, external ocular examination and test for pupil red reflex) and those with abnormalities were subjected to diagnostic examination (external ocular examination with a hand-held slit-lamp, pupil red reflex and mydriatic examination). Newborns in neonatal intensive care unit (NICU) were subjected to screening 5 to 14 days after birth and then, together with those with high risk factors, received a comprehensive examination for screening and diagnostic purposes. The suspected cases were referred to department of ophthalmology for definite diagnosis. Results Among the 15 398 (91.65%) newborns who were enrolled the screening program, 12 different eye diseases (involving 1266 cases) were detected, with a prevalence of 8.22% . Of these eye diseases, 7 were congenital ocular diseases, involving 809 cases (5.254% ) and including congenital ptosis in 2 cases (0.013% ) , congenital corneal opacity in 6 cases (0.039% ), persistent pupillary membrane in 724 cases (4.702%), congenital cataract in 15 cases (0.097% ), persistent hyaloid artery in 54 cases (0.351% ), obstruction of nasolacrimal duct in 7 cases (0.046%) and lacrimal gland prolapse in 1 cases (0.007%). Five different diseases (457 cases, 2.968% ) detected were acquired in nature, including neonatal conjunctivitis in 391 ease (2.539% ),vitreous hemorrhage in 6 eases (0.039%), retinal hemorrhage in 34 cases (0.221%), and neonatal dacryocystitis in 23 cases (0. 149% ). Of 27 premature babies with body weight lower than 1500 g, 3 had retinopathy of prematurity (ROP, 6 eyes involved). Conclusions Early intervention is of great importance for the prevention and treatment of neonatal ocular diseases. The screening of newborn ocular diseases is not only feasible but also effective in the monitoring and control of the eye diseases in neonates.

Objective To understand the risk factors of primary angle-closure glaucoma. Methods One to one matched case-control study was conducted in this study. One hundred and ninety two PACG cases and 192 controls, matched by age and gender, were collected from Department of Ophthalmology, Affiliated Hospital of Nantong University. All of the participants were investigated for their demographic information,behavioral habits, disease history, glaucoma family history and received clinical ocular examinations. The difference between these two groups was analyzed. Results Several factors, including hypertension ( OR =2.004,P =0.009), glaucoma family history (OR = 6.726,P =0.003), presbyopia (OR =3.192,P =0.031 ), shallow anterior chamber ( OR = 12.804, P = 0. 000) and high cup-to-disc ratio ( OR = 9.401, P =0.007 ) were associated with PACG by multiply Logistic regression. The results did not support that smoking, drinking, myopia, diabetes mellitus and blood style were related to PACG. Conclusion Follow up the populations with glaucoma family history, shallow anterior chamber or high cup-to-disc ratio are the main procedures for the decrease of incidence of PACG.

Objective To assess the prevalence and risk factors for trachoma among primary school children in Datong City, China. Methods An epidemiological survey was carried out in Datong City in 2006. Children aged 6 to 14 years old in primary school were selected by a cluster sampling in which class shift was the sampling unit. Trachoma was clinically assessed according to the simplified classification for trachoma proposed by the World Health Organization (WHO). If the child was clinically diagnosed as trachoma, a conjunctival swab would be taken for detecting C. trachomatis by antigen test and polymerase chain reaction (PCR). Results A total of 1236 children were examined and 135 cases of trachoma were found, the prevalence of trachoma was 10.9% (95% CI: 9.2% -12.6% ). Follicular trachoma was found in 86.7% of the cases and intense trachoma in 13.3%. The overall prevalence of trachoma was higher for females than for males (13.1% versus 8. 8%, P =0.016). Thirteen (9.6% ) cases were positive in C.trachomatis antigen test, and 86 (63.7% ) cases were positive by PCR. Poor ocular hygiene and sharing wash cloth and face basin with households were the main risk factors. Conclusion Trachoma is endemic among primary school children in Datong City in China.

Objective To investigate the long-term loss and variation of corneal endothelial cells after radial keratotomy. Methods By the way of case-control study, 51 myopia ( 101 eyes) patients who underwent RK in Beijing Friendship hospital, from January 1989 to December 1996 is the RK group. 51 myopia (102 eyes) outpatients who have no other eye diseases is the control group. The volunteers are the outpatients of Department of Ophthalmology in Beijing Friendship Hospital from November 2006 to March 2007. Corneal endothelial cells are examined by Topcon SP2000 non-contact corneal endothelial microscope.To survey corneal endothelium of center, superior, inferior, temple side and nasal side, to study endothelial cell density, average areas, coefficient of cell variation in size and hexagonality. Results The differences of endothelial cell density, average areas, hexagonality are no significant between the RK group and the control group with the same age stage( P > 0.05 ). The differences of coefficient of cell variation are significant. In the 30 year old stage, the result of center is t = 3.742, P = 0. 000, the result of superior is t = 3. 627, P =0.000, the result of inferior is t = 3.180, P = 0.002, the result of nasal side is t = 2. 448, P = 0.016, the result of temple side is t =3.149 ,P =0.002. In the 40 year old stage, the result of center is t =4. 446 ,P =0.000, the result of superior is t = 2.444,P =0.017, the result of inferior is t =2. L13,P =0.038, the result of nasal side is t = 3.214,P = O.002, the result of temple side is t = 2.680, P = 0.009. In the 50 year old stage, the result of center is t = 2.360, P = 0.024, the result of superior is t = 2. 600, P = 0.013, the result of inferior is t = 2.787, P = O.008, the result of nasal side is t = 2.144, P = 0.038, the result of temple side is t = 2. 177,P =0.036. But the differences of coefficient of cell variation have no relationship with the time of RK( P > 0.05 ). The differences of endothelial cell density, average areas, coefficient of cell variation in size and hexagonality are no significant among different incision group (P > 0.05 ). There are impalpable changes in the morphology of endothelial cells, coefficient of cell variation in size is greater than the control with the same age stage. Conclusion If proforming other eye operations to RK patients, it is necessary to evaluate the corneal endothelial cells before operations.

Objective To investigate retrospectively the clinical manifestation and the final visual prognosis through a long-term fellow-up study. Methods It was retrospective case series study. Twenty four patients (26 eyes ) were diagnosed with Coats disease from 1962 through 2006 at the Department of Ophthalmology, Peking Union Medical Hospital, Chinese Academy of Medical Sciences. Age, visual acuity,time of initial visit, method of treatment and the condition of eye fundus for each patient were documented.The time of follow-up ranged from 1- 44 years, averaged 5 years. Results Age of the patients at initial visit ranged between 1 to 18 years old, 7 years on average. Eighteen patients (75%)were male and 6 were female (25%). Twenty two cases were unilateral and only 2 female patients were bilateral. In 26 eyes, 7 eyes exhibited capillary irregular dilatation, miliary aneurysms and nonperfusion area on fluorescein angiography located at peripheral fundus; 15 eyes were complicated with exudative retinal detachment. Four eyes reached end stage with no light perception or only finger count. Laser photocoagulation was performed in 21 eyes. In 10 eyes, retinal exudates and hemorrhages were absorbed with improvement of visual acuity. Ten eyes with extensive retinal detachment including macula underwent closed vitrectomy, the best visual acuity was 0.1 after surgery. Conclusions The onset of Coats disease is in early young childhood. Abnormal vascular lesions and military aneurysms appeared at peripheral fundus with early retinal exudation involving the macula. Early treatment with laser coagulation could obtain good visual prognosis. The supplement treatment is required for new lesions occurring during the long- term follow-up period.

Objective To summarize the clinical characteristics of retinal arterial macroaneurysm and to improve the diagnosis accuracy in order to differentiate it from other fundus diseases. Methods It was a retrospective case series. Results of fluorescein angiography or indocyane angiography, associated with ultrasound, OCT and several other examinations were analyzed in 22 patients (22 eyes) with retinal arterial macroaneurysm. Results There were 6 men and 16 women in the 22 patients. The age of all the patients was from 54 to 82 years, and the mean age was 70 years. In the 22 patients, the patient with a single macroaneurysm was 19, and with two macroaneurysms was 3. All 22 patients were affected unilaterally.Macroaneurysms were found only in the temporal artery branches ( 16 eyes in superior branch and 6 eyes in inferior branch). All macroaneurysms were located in the branches graded 1 to 3. All patients showed preretinal hemorrhage and/or vitreous hemorrhage. Sixteen patients suffered from hypertension and five patients had diabetes mellitus. The patient with best corrected visual acuity < 0.05 was 10,0.05 to 0.2 was 6,0.3 to 0.6 was 5 and ≥0.7 was 1. All patients showed retinal arteriosclerosis. After the treatment, 11 patients were pursued, and the patient with best corrected visual acuity < 0.05 was 1,0.05 to 0.2 was 4 and ≥0.7 was 1.Conclusions Clinical features of retinal arterial macroaneurysm include focal dilation of retinal artery with hemorrhages and exudates,associated with retinal arteriosclerosis. These clinical characteristics can be used to differentiate retinal arterial macroaneurysm from other fundus diseases.

Objective To compare the outcomes of bimanual microincision phacoemulsification with conventional small incision cataract surgery. Methods A randomized prospective study of 280 consecutive cases (280 eyes) was conducted. All patients were randomly assigned to receive bimanual microincision cataract surgery (MICS group) or small incision cataract surgery (SICS group). The PHACO time (PT) and the average power (AP) were recorded, then absolute PHACO time ( APT = PT x AP) was calculated.The differences in PT, AP, APT and BCVA between these two groups were compared. Visual acuity,anterior chamber flare value, thickened pachymetry and endothelial cells loss were recorded 1 day and 3 months after surgery. In addition, surgically induced astigmatism was analyzed. Results The mean PT, AP and APT of MICS group were significantly lower than those in the SICS group (0.76 ±0.36) rain versus (0.87 ± 0.49)rain, 10.93% ± 4.78% versus 16.09% ± 7.38% and (8.99 ± 7.23 ) rain versus ( 15.27 ±12.10)min, respectively (P < 0.01 ). At 3 months, the vertical astigmatic changes of MICS group was statistically lower than that of the SICS group [ ( 0.37 ± 0.32 ) D versus ( 1.28 ± 0.77 ) D, P = 0.000 ].There were no significant differences in the visual acuity, anterior chamber flare value, endothelial cells loss and the thickened pachymetry at 1 day and 3 months after surgery between these two groups ( P > 0.05 ).Conclusions Bimanual microincision cataract surgery could significantly reduce PHACO power, enhance energy efficiency and reduce surgically induced astigmatism. However, MICS does not reduce surgical trauma and postoperative inflammation as compared to conventional SICS.

Objective Mapping the mutation gene for a Chinese family with autosomal dominant cataract. Methods It was a retrospective study. Thirty-two individuals in this family, including fifteen patients, eight normal siblings and nine spouses, were investigated and 8 ml blood was collected from each member under informed consent. Genomic DNA of all 29 members was isolated by standard protocol. A genome wide scan was performed after PCR amplification for microsatellite makers on autosomal chromosomes. LOD score was calculated by Linkage 5.1 and GeneHunter software. Results Positive Lod score were obtained in 10 microsatellitc makers ( D20S186, D20S163, D20S915, D20S152, D20S98,D20S904, D20S875, D20S112, D20Sl140, D20S432) on chromosome 20q, and the maximum LOD score with D20S904 was 6. 02. Conclusions Haplotype construction and muhipoint analysis mapped the mutation gene in this inherited cataract family to the chromosome 20p12. 120p11.23 region between D20S186 and D20S912, which is an approximately 5.47 centimorgan length. This is the second congenital cataract locus linked to chromosome 20q.

Objective To screen and identify the abnormal proteins expressed by hypoxia human retinal pigment epithelium (RPE) in vitro. Methods It was a experimental study. Protein of normal/hypoxia human RPE cells in exponential phase of growth was extracted, and frozen by liquid nitrogen for proteome study. All samples were performed isoelectric focusing electrophoresis (IEF), separated by isoelectric point (pI); progressed sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE) and separated by protein molecular weight (Mr). 2D-gels revealed by coomassie brilliant blue, analyzed by Image Master 2D Elite. Differential proteins spots were screened in normaL/hypoxia RPE cell. For identification of differential proteins, peptide masses were analyzed by matrix-assisted laser desorption ionization time-offlight mass spectrometry (MALDI-TOF/MS). Results Five hunderd and seventy-eight protein spots were obtained in normal group( matching rate within group was 92.90% ), and hypoxia group 559 (91.41%). The average matching rate between two groups was 85.47%. There were 32 differential protein spots, which volume value changed ≥ 2.0 times. 7 spots were selected randomly for MS, and 5 proteins were identified successfully: HSP70 and HSP60 up-regulated; while β-actin, β-tubulin and proxiredoxin 3 down-regulated. Conclusions Findings of the in vitro study provide the evidence for expression changes of many proteins in RPE cell with hypoxia state; some of those regulated proteins can result in increasing stress capability obviously in cells, while the major cytoskeletal proteins down-regulated,and the ability of sustained-shapes, keeping order internal structure in cells decreasing. Proteome analysis provides a useful platform in systematic screening of various protein expressions in CNV related diseases.

Choroidal neovascularization (CNV) is a major cause of vision loss in various ocular fundus diseases. The purpose of traditional therapies was to treat established CNV, but they only have limited effects. Drug treatment targeting the pathogenesis of CNV has become a hot research topic recently. Anecortave acetate is an angiostatic steroid which shows distinct mechanism of action in inhibiting neovascularization, making it different from the anti-VEGF agents (Pegaptanib, Ranibizumab and Bevacizumab). As the studies on the mechanism of CNV going more deeply, effective treatment targeting the pathogenesis of CNV will bring hope for these patients.

Editor's note: On May 12, 2008, at 2: 28: 4 pm, an earthquake of magnitude 8.0 occurred in Wenchuan County, northern Sichuan, China, which shocked the whole country and the world. This earthquake caused great loss of life and property, and was a sudden and huge disaster. This disaster affected everyone in the whole country, and also affected the hearts of 23 000 ophthalmologists across the country. Some of our colleagues have gone to the disaster area to directly serve the people affected by the disaster.

The 18th International Congress of Eye Research (ICER) will be held at the Beijing Wuzhou Crown Hotel and Beijing International Convention Center from September 24 to 29, 2008. Before the formal conference, satellite conferences on retinal degeneration and cataract will also be held in Chengdu and Xi'an, respectively.

Bausch & Lomb's new product launch event was held in Chengdu on November 11, 2007. At this meeting, Bausch & Lomb Ophthalmic Surgery Products Company of the United States strongly promoted the Zyoptix XP lamellar knife developed with Hansatome as the design platform by adopting 2 years' clinical experience and many suggestions of global surgical experts, emphasizing its characteristics of "extraordinary accuracy, super reliability, great value and practicality". Lu Wenxiu, Wang Zheng, Arthur Cheng (Hong Kong, China) and other well-known experts discussed the clinical experience and experience of using Zyoptix XP lamellar knife with ophthalmologists from all over the country. The demonstration of the on-site prototype brought a brand-new operation experience to all the guests.

In order to promote the academic exchange of ophthalmology between regions, improve the level of diagnosis and treatment of eye diseases, activate the academic research atmosphere of ophthalmology in various regions, strengthen the academic communication between Chinese Journal of Ophthalmology and ophthalmologists in various regions, and collect and organize relevant research papers for Chinese Journal of Ophthalmology, this journal jointly held a series of exchange activities on the progress of diagnosis and treatment of corneal diseases and the draft meeting of Chinese Journal of Ophthalmology in Shanghai, Shenyang and Beijing from March to April 2008.

In order to promote the academic exchange of ophthalmology between regions, improve the level of diagnosis and treatment of eye diseases, activate the academic research atmosphere of ophthalmology in various regions, strengthen the academic communication between Chinese Journal of Ophthalmology and ophthalmologists in various regions, and collect and organize relevant research papers for Chinese Journal of Ophthalmology, this journal jointly held a series of exchange activities on the progress of diagnosis and treatment of ischemic ophthalmology and the draft meeting of Chinese Journal of Ophthalmology in Kunming, Yunnan Province with Beijing Zizhu Pharmaceutical Co., Ltd. from April 3 to 7, 2008.

In recent years, the clinical ophthalmologists have obtained satisfactory clinical results with the success rate of 86.0% ~95.7% in the treatment of chronic dacryocystitis using ND: YAG laser. We retrospectively analyzed 103 cases (108 eyes) of chronic dacryocystitis treated by laser lacrimal duct plasty in the Department of Ophthalmology of the Fourth Hospital of Xi'an from April 2000 to April 2005.

The injury of retinal ganglion cells caused by chronic ocular hypertension is the same as the typical injury response of chronic degeneration of central nervous system, that is, the injured retinal ganglion cells mediate the process of environmental immune damage in r cells, resulting in further nerve cell damage.By enhancing the immune response mediated by T lymphocytes, the retinal ganglion cells in "marginal damage" can be protected [1-2].

Congenital aniridia is an eye disease with iris dysplasia as the main feature and involving the whole eyeball [1]. It mostly occurs in both eyes, and the incidence rate is between 1:96,000 and 1:64,000, which belongs to autosomal dominant inheritance [2]. In 2005, a family with congenital aniridia was diagnosed and treated in the Ophthalmology Center of West China Hospital of Sichuan University, and the report is as follows.

The patient was a 32-year-old female who had high myopia in both eyes for more than 10 years and came to the Department of Ophthalmology of Changzhou Second People's Hospital affiliated to Nanjing Medical University on January 19th, 2007. Ocular examination showed that the visual acuity was 0.04 in the right eye and 0.10 in the left eye. The corrected visual acuity was-18.00 D → 0.3 in the right eye and-14.00 D → 0.8 in the left eye. The anterior chamber depth was>3.0 mm.