Volume 52 · Issue 11 · 2016

This issue focuses on the research progress of ophthalmic epidemiological investigation. The responsible editorial committee responsible for the planning, composition and review of the key contents of this issue is Professor He Mingguang.

In China, the number of diabetic retinopathy (DR) patients is increasing rapidly. Prevention is the most effective method to reduce blindness and visual impairment caused by DR. The ophthalmic professionals who are interested in the DR prevention and treatment should promptly go to the communities, work together with general practitioners and community health personnel, make full use of community residents health archives, and gradually establish community DR screening protocols. Thus the efficiency of screening and early intervention of DR will be improved, and finally the high incidence and high prevalence of blindness related to DR will be controlled. (Chin J Ophthalmol, 2016, 52: 801-804)

Field epidemiological research is different from clinical patient-based disease diagnosis and research, mainly manifested by the following characteristics: First, the diagnosis of diseases can usually only rely on one-time examination, and cannot be confirmed through follow-up and follow-up visits; Second, due to the limitations of field research conditions, only relatively simple inspection equipment can be used for diagnosis; Third, on-site investigation usually involves multiple inspectors to jointly complete the inspection of the subject, which requires a standardized and repeatable inspection method; Fourth, there is a need for horizontal comparisons of studies in different regions and even different ethnicities, and standardized diagnostic criteria and examination methods are needed.

Chinese names for partial retinal lesions, such as aneurism (aneurysm) and telegiectasia, are not accurate enough, although they have been used for many years.

To establish an assessment system, including indexes and scoring methods, that can be used for performance evaluation of the provincial blindness prevention technical guidance group properly and effectively .

The indexes and scoring methods were set based on the core content of The " National Plan of Prevention and Treatment of Blindness (2012-2015)" , the specific requirement and target of the World Health Organization (WHO) "For the General Eye Health: Global plan of Action (2014-2019)" , and the current situation of the China's provinces and autonomous regions. These indexes should be of effectiveness, feasibility, comparability, guidance and advancing. Formed by a literature review of candidate indicators, the framework of the system is built by qualitative assessment. With the Delphi method, the system was further revised and improved. Empirical pilot study was then used to prove the feasibility, followed by the final qualitative analysis that establish the " Chinese provincial Blindness prevention technical guidance group performance evaluation system" .

Through the literature review and qualitative assessment, a six dimensional system framework was built, including 6 first-level indicators, 16 second-level indicators, and 29 third-level indicators through Delphi method evaluation. With the variation coefficient method, the coeffiences of the first-level index weight were calculated as: Organization and management 0.15, Development and implementation of blindness prevention plans 0.15, Implementation of blindness prevention projects 0.14, Training 0.17, Health education 0.18, and Cooperation and exchanges 0.21. The specific scoring method for this system is confirmed as: data and files check, field interview, and record interview, sampling investigation. Empirical pilot study was conducted in the Jilin, Guizhou and Gansu provinces, and the self-assessment results from local experts were consistent with the scores from the systems.

This system established is appropriate at current time, and it can effectively evaluate the performance of the Chinese provincial Blindness prevention technical guidance group. (Chin J Ophthalmol, 2016, 52:814-824)

To investigate the prevalence, underlying causes and risk factors of moderate or severe visual impairment and blindness in a population with type 2 diabetes in Xinjing Town, Shanghai, China.

A cross-sectional survey among local Han adult residents, who were previously diagnosed as type 2 diabetes, was conducted between October 2014 and January 2015. The survey was preceded by a pilot study; operational methods were refined and quality assurance evaluation was carried out. The best corrected visual acuity was recorded and classified following the modified World Health Organization grading system. Assigned ophthalmic doctors assured the leading causes of every blind or visually impaired eye. Binary logistic regression analysis was used to determine the related factors of blindness and moderate or severe visual impairment.

A total of 2 216 type 2 diabetic residents were enrolled, and 166 eyes (3.7%, 166/4 432) were blind. Cataract was the leading cause of blindness (39.8%); macular degeneration (18.0%) and eyeball atrophy (11.4%) were the second and third leading causes of blindness, respectively. Moderate or severe visual impairment was found in 376 eyes (8.5%, 376/4 432), and the most frequent cause was cataract (65.7%), followed by diabetic retinopathy (9.8%) and macular degeneration (9.4% ). Older age, female gender, earlier onset diabetes and a lower spherical equivalent in the better eye were associated with best corrected visual acuity<20/63 in the better eye.

The prevalences of moderate or severe visual impairment and blindness in our population with type 2 diabetes were high. (Chin J Ophthalmol, 2016, 52: 825-830)

To analyze the influence of the eye biological parameters, height, and weight on the school-age children's refractive status.

Cross-sectional study. A total of 1 656 children (1 656 eyes), aged from 7 to 14 years, were selected from 8 schools in Wenzhou during June 2012 and June 2013. The height and weight of each child were measured, and the body mass index (BMI) was calculated. The eye biological parameters, including axial length (AL), corneal power (C=1/CR), anterior chamber depth (ACD), and white to white (WTW), were measured by IOLMaster (version 5.0, Carl Zeiss, Germany), and the AL/CR was calculated. Refraction was measured by fast cycloplegic retinoscopy, and the spherical equivalent (SE) was calculated. Only right eyes were included in the analysis. SPSS16.0 was used to analyze the data. The correlations of the equivalent spherical power, the eye biological parameters, height, weight, and BMI were evaluated. Linear regression analysis was used for the SE, AL, and AL/CR.

The prevalence of myopia in 7- to 14-year-old school-age children was 50.2% on the average, 48.4% in boys, and 51.7% in girls. The average SE was (-1.07±1.74) D. With adjustment of the age, gender, urban and rural areas, there was an association between the SE and AL, AL/CR, ACD, height and weight. The correlation coefficient was -0.663, -0.730, -0.416, -0.365, and -0.281, respectively (P<0.05). There was no significant correlation between the SE and WTW, corneal power and BMI. Regarding the different refractive statuses, there was a stronger correlation between the SE and AL, AL/CR in children with hyperopia, moderate myopia or high myopia than those with emmetropia or mild myopia (P< 0.01). In the older children, the correlation between the SE and AL, AL/CR was stronger. Linear regression analysis showed SE= 26.55-9.11·AL/CR and 23.0-1.02·AL.

There was an association between the SE and AL, AL/CR, ACD, height and weight in school-age children. In children with hyperopia, moderate myopia, high myopia or at an older age, the correlation was more significant between the SE and AL, AL/CR. (Chin J Ophthalmol, 2016, 52:831-835)

To determine the diagnostic performance of confocal scanning laser ophthalmoscope (cSLO)-based retinal imaging in the epiretinal membrane (ERM) patients.

Prospective case series study. Twenty-six patients (32 eyes) with ERM determined by spectral domain optical coherence tomography (SD-OCT) were recruited from June 2015 to October 2015 in the Beijing Tongren Eye Center. All subjects underwent retinal imaging using the cSLO-based Heidelberg MultiColor (Spectralis HRA-2; Heidelberg Engineering) technology and the traditional color fundus camera. A special grading score was used to analyze every retinal image according to the SD-OCT results.

In the ERM patients, the largest average grading score in the cSLO-based retinal imaging was 3.44±0.80 with the blue and green enhanced MultiColor image, followed by the standard MultiColor image (2.84± 0.85), green laser image (2.16±0.77) and blue laser image (2.09±0.78), and they all had statistical differences compared with the grading scores of retinal imaging using the traditional color fundus camera (all P<0.001). No significant difference was found in grading scores between using the infra-red laser imaging (1.13±0.71) and the traditional color fundus camera (P=0.282).

In the detection of ERM, the imaging quality of cSLO-based Heidelberg MultiColor technology is better than the traditional color fundus camera technology. Combined with SD-OCT sectional analysis, it can help diagnose and monitor ERM. (Chin J Ophthalmol, 2016, 52: 836-839)

To study the compensation mechanism of aberrations between anterior and posterior corneal surface, and to investigate the correlations between corneal aberrations and K values, intraocular pressure and central corneal thickness.

One hundred and sixty-one subjects (300 eyes) with myopia and myopic astigmatism were recruited randomly. Corneal aberrations (anterior, posterior and total) in three different optical zones (2 mm, 4 mm, and 6 mm) centered on the corneal vertex were assessed with a corneal topographer (Sirius). We also calculated compensation factors (CFs) as a measure of the relative efficiency of the aberration compensation mechanism. Astigmatism was divided into corneal astigmatism and non-corneal astigmatism. Mann-Whitney U test was utilized for the comparison of different aberrations and CFs between the two astigmatism groups. Spearman correlation was applied to analyze the correlations between corneal aberrations and K values, intraocular pressure and central corneal thickness.

As the order of the aberrations elevated from the second to the seventh, the RMS values decreased significantly. The larger the optical zone, the greater the values of aberrations and the lower the percentage of the compensation mechanism among all the Zernike terms. At the same time, as the order of the aberrations increased, the predominance of the compensation mechanism was increasingly obvious. Slight compensation of spherical aberration (Z₄⁰) was observed in the peripheral. In the center of the analyzing zones (2 mm), compensation mechanism represented in coma (Z₃^±1), and it disappeared in the peripheral. We detected slight compensation of the corneal astigmatism (Z₂^±2) in the surrounding zone, although the compensation factors were closed to zero in diverse optical zones. Superposition was found in trefoil (Z₃^±3) straightly. Nevertheless, a tendency towards compensation was discovered with the enlargement of the optical zones. And the secondary spherical aberration (Z₆⁰) behaved compensation continuously. However, similar compensation was discovered between the right eye and left eye in different analyzing optical zones. There were significant correlations between the flattest K values and Z₂^±2, Z₃^±3and Z₄⁰ in the anterior, posterior and total cornea. It was similar with the steepest K values. When the optical zone expanded to 6 mm, Z₃^±1 and Z₄⁰ significantly decreased with intraocular pressure (r_coma=-0.188, P<0.05. r_spherical=-0.147, P<0.05). No correlation was found between various aberrations and central corneal thickness (P>0.05).

Compensation dominated in the corneal center, while the percentage decreased gradually as the optical zone extended. Slight compensation in astigmatism and spherical aberration between the anterior and posterior cornea may be benificial to the scotopic visual quality. Corneal aberrations were significantly related to K values and intraocular pressure. (Chin J Ophthalmol, 2016, 52: 840-849)

To investigate ocular changes in the monocularly deprivation myopic model of mutant Lumican transgenic mice. Comparing influences on biological parameters and sclera development between Lumican transgenic and form deprivation mice, and to prepare for further study of pathogenesis of pathological myopia (PM).

Experimental research. Lumican transgenic mice and wild mice were monocularly lid-sutured at ten days after birth. All eyes were divided into 6 groups, group A(32 eyes): control eyes in transgenic mice; group B(34 eyes): sutured eyes in transgenic mice; group C(34 eyes): fellow eyes in transgenic mice; group D(28 eyes): control eyes in wild mice; group E(32 eyes): sutured eyes in wild mice; group F(32 eyes): fellow eyes in wild mice. Refraction was measured by streak retinoscopye and axial length was measured by vernier caliper at 8 weeks (56 days) after birth. Lumican expression was detected by quantitative real-time PCR in all groups.

The refraction in group B and group E were (-0.38±1.10) D and (0.14±1.26)D respectively, which were significantly different compared with contralateral groups and normal control groups (F=9.525, 10.067; P<0.01). The mean axial length were also increased in group B ((3.28 ± 0.07)mm and group E (3.24 ± 0.09)mm, (F=7.183, 6.671; P<0.05). Expression level of Lumican mRNA in sclera was increased in group B, which was significantly different from group A and group C (F= 6.262; P<0.05). The expression of Lumican mRNA was increased in group B and C when compared with group E and F (t=4.772, 2.218, P<0.05).

Form-deprivation in mutant Lumican transgenic mice causes myopic changes in deprived eyes. The gene expression level of Lumican in sclera of transgenic mice is significantly increased compared with contralateral eyes or that of wild group. Lumican mutation may effect the development of PM, and the interaction of genetic and environmental factors may lead to development of PM. (Chin J Ophthalmol, 2016, 52: 850-855)

To explore the effects of transthyretin (TTR) on biological behavior of retinal pigment epithelial cells (RPECs) and retinal microvascular epithelial cells (RMVECs).

RPECs were cultured with exogenous TTR to explore the effect of TTR on the proliferation of RPECs. The expression of TTR of RPECs was silenced by TTR specific small interfering RNA and the expression of TTR was detected by using Western blotting to identify the efficacy of TTR silence. The level of vascular endothelial growth factor (VEGF) massage RNA was detected by using RT-PCR to identify the interaction between VEGF and TTR. The different proliferation and migration abilities of RMVECs with different expressions of TTR were measured by transwell system.

MTT assay showed that RPECs with 0 μmol/L TTR glowed faster than with 4 μmol/L TTR ( t=18.08, P<0.0001). The expression level of TTR was decreased in the small interfering RNA group as compared with the negative control group (P<0.05). RT-PCR assay showed no differential expression of VEGF after the silencing of TTR (P>0.05). The transwell assay showed RMVECs with the silence of TTR proliferated more slowly than RMVECs without the treatment (t=4.901, P=0.0012), and also migrated more slowly (t=4.213, P=0.0029).

TTR can inhibit the proliferation of RPECs and promote the proliferation and migration of RMVECs without the help of VEGF, the mechanism of which may be worth further study. (Chin J Ophthalmol, 2016, 52: 856-860)

Leiomyoma is a benign tumor that originates from smooth muscle cells and occurs in the gastrointestinal tract and uterus. Intraocular leiomyoma is rare, mainly in the ciliary body and anterior choroid, and extremely rare in the posterior choroid. It is difficult to distinguish from choroidal melanoma and choroidal metastatic cancer. A case of posterior choroidal leiomyoma admitted to Beijing Tongren Eye Center is reported as follows:

posterior polymorphous corneal dystrophy (PPCD) is a hereditary eye disease that mainly involves the corneal endothelium and posterior elastic layer. It has no clinical symptoms in the early stage and is often discovered accidentally during eye examination. On September 29, 2015, the author admitted a patient with PPCD with increased intraocular pressure and glaucomatous optic nerve damage in the fundus as the first symptom. The report is as follows.

The patient was a 47-year-old male. He went to the Department of Ophthalmology of Dushanzi People's Hospital in Xinjiang because of decreased visual acuity and deformed vision in his left eye for 2 months. Two months ago, the vision of the left eye decreased and the vision was deformed. He was diagnosed as "fundus hemorrhage" in an outside hospital. He was given hemostasis and other drugs, but the symptoms did not improve. Physical health in the past, and no abnormalities were found in the general examination. Eye examination: visual acuity was 1.2 in the right eye and 0.3 in the left eye (uncorrectable). No abnormalities were observed in the anterior segment of both eyes. For fundus examination, seeQuintessence Picture 1。 For FFA inspection, seeQuintessence Picture 2。 Automatic visual field examination showed a dark spot in the center of the left eye and normal in the right eye. Clinical diagnosis: vascular streaks in both fundus; Choroidal neovascularization of the left eye.

Diabetic retinopathy has become the main cause of the sight impairment and blindness among the adult population. Early detection of diabetic retinopathy helps to prevent and reduce the damage to eyesight. The development of diabetic retinopathy telescreening systems has been rapid. The operation modes, key technologies, economic benefits and new progression of diabetic retinopathy telescreening systems are reviewed. (Chin J Ophthalmol, 2016, 52: 868-871)

Visual field is an important means of the assessment of visual function. In our daily life, the actual visual function is consist of both eyes. Therefore, the binocular visual field test is significant to understand the real visual function. Currently, the binocular vision assessment methods included Esterman visual test and Integrated visual fields. The IVF includes: binocular summation, best location, best eye and average eye. In this review, the significance of binocular visual field inspection, binocular visual field integration methods and its practical application in daily life and clinical glaucoma research work are summarized. We hope that it can do some favors to clinical and scientific researches of assessment and application of binocular visual field. (Chin J Ophthalmol, 2016, 52: 872-875)

Myopia is a public health problem in the world and its prevalence and incidence are rising in recent years. Studies have shown that myopia is a kind of complex genetic diseases. And sclera-remodeling plays an important role in the development of myopia. The recent research advances in association with both sclera-remodeling relevant gene polymorphisms and myopia are reviewed in this article. (Chin J Ophthalmol, 2016, 52: 876-880)