Volume 57 · Issue 04 · 2021

Myopia has emerged as a public health problem with its increasing prevalence in children and adolescents in China. The Chinese government has begun to take action to address this issue in recent years. In 2018, the Implementation Plan of the Myopia Prevention and Control for Children and Adolescents was issued by the Ministry of Education and other seven ministries and commissions. The plan emphasizes the myopia prevention and management will be a powerful national strategy to a major crisis of children′s health in China. Based on the current situation and characteristics of myopia in children and adolescents in China, this article analyzes the key points and difficulties of related work, so as to provide scientific ideas and references for prevention and control of myopia in China. (Chin J Ophthalmol, 2021, 57:241-244)

Adolescent myopia has become one of the researchers′ focuses among visual problems around the world. Carrying out a scientific and efficient epidemiological study on myopia is an essential basis for discovering the rules of the occurrence and the development of myopia, exploring related influencing factors and identifying the mechanisms, which are critical for the policy-making for myopia control. The epidemiological studies of myopia at home and abroad have a long history of exploration, standardization and unification, and are enriched by new technologies and up-to-date discoveries. Based on the characteristics of social development and the prevalence of adolescent myopia in the past six decades, the epidemiological studies on myopia are divided into four stages in this article. Each stage is specified and analyzed to identify the difference in research methods and strategies. The main scientific issues and research elements in the current epidemiology of myopia in adolescents are put forward. (Chin J Ophthalmol, 2021, 57:245-250)

The concept of diagnosis and treatment of keratoconus is constantly updated. Today, we are not only concerned with how to delay the progress of the disease, but also with the preservation of useful vision for patients as well as improvement of visual quality. With the precise and individualized application of excimer laser and femtosecond laser technology in ophthalmology, corneal cross-linking combined with excimer laser ablation for the irregular cornea has become a new strategy for keratoconus. However, questions have been raised and caused ophthalmologists′ thinking. Are patients with keratoconus who have progressively thinned corneas suitable for excimer laser ablation? Which is better when the combined strategy is applied, simultaneous or sequential surgery? Based on the research data from home and abroad, we comprehensively sort out various treatment methods for the focus issues. It is hoped that this article can provide guidance for the rational selection of an optimal clinical solution to keratoconus. (Chin J Ophthalmol, 2021, 57:251-253)

Eye burns, which are usually caused by chemicals such as acidic, alkaline and heat-related substances, are true medical emergencies. These substances can lead to potential permanent damage to the eyelids, cornea, ocular surface and intraocular tissues. In severe cases, eye burns may result in blindness. Currently, there is a lack of uniform and standardized guidelines for the diagnosis and treatment of eye burns. As a result, a considerable number of patients have a poor prognosis. Therefore, the Cornea Group of Chinese Ophthalmological Society has developed this consensus statement after thorough discussions, hoping to provide guiding opinions on the clinical diagnosis and treatment of eye burns. (Chin J Ophthalmol, 2021, 57:254-260)

To predict the prevalence of myopia among Chinese students aged 6-18 years under different intervention scenarios from 2021 to 2030.

The multi-state Markov model was developed based on the transition process of study stages and myopia statuses. The development of myopia was simplified into two statuses: non-myopia and myopia. Students aged 6-18 years were also divided according to their study stages including senior kindergarten, primary school (from Grade 1 to 6), junior school (from Grade 1 to 3) and high school (from Grade 1 to 3). The parameters were extracted from the National Myopia Investigation in 2018 and published articles of cohort studies. The transition probability was applied to simulate the intervention scenarios, and sensitivity analysis was carried out.

The cumulative incidence of myopia among Chinese school-aged children and adolescents would increase consistently. It would be 91.3% (min to max: 83.7% to 96.7%) upon graduation from high school. Without any intervention, the myopia prevalence would increase to 61.8% (min to max: 55.4% to 69.5%) by 2030 among Chinese school-aged children and adolescents. And the myopia prevalence among students in primary schools, junior schools and high schools would be 45.6% (min to max: 40.2% to 54.3%), 81.3% (min to max: 72.6% to 91.0%) and 90.5% (min to max: 82.4% to 96.7%), respectively, all higher than the national target. If the interventions could achieve 70% of the desired effect, the myopia prevalence would be lower than the national target at each stage.

Without effective interventions, the prevalence of myopia among students aged 6-18 years may keep increasing in the next ten years. If the interventions achieve the desired effect, the national target for myopia prevention and control could be reached. It is urgent to identify more effective interventions and call on the whole society to participate in the myopia prevention action to achieve the national goal by 2030. (Chin J Ophthalmol, 2021, 57: 261-267)

To investigate the repair of subepithelial nerve fibers in different areas of the cornea and the difference of corneal transparency 12 months after small incision lenticule extraction (SMILE), femtosecond laser in situ keratomileusis (FS-LASIK) and excimer laser in situ keratomileusis (LASEK) in high myopia.

A cohort study. From June 2018 to October 2019, 30 patients with high myopia (60 eyes) were selected for corneal refractive surgery in the Department of Ophthalmology, Affiliated Hospital of Qingdao University, including 16 females (32 eyes) and 14 males (28 eyes). According to the mode of operation, the patients were divided into the SMILE group (n=10), FS-LASIK group (n=11) and LASEK group (n=9). The repair of subepithelial nerves in different areas of the cornea was observed by laser confocal microscopy 12 months after operation,and the morphological parameters were analyzed by ACCMetrics software. The parameters included corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal nerve fiber length (CNFL), corneal nerve fiber total branch density (CTBD) and corneal nerve fiber width. The Pentacam anterior segment analyzer was used to measure the optical density of the cornea in different diameters. The nerve fiber parameters and corneal optical density were compared by random block analysis of variance, and multiple comparisons were performed between groups by the Turkey test.

Twelve months after operation, there was no significant difference in the CNFD among the three groups(all P>0.05). The CNBD around the upper corneal incision in the SMILE group, FS-LASIK group and LASEK group was (7.81±7.93), (9.61±7.18) and (21.25±15.55) branches/mm², respectively. The CTBD was (22.00±16.02), (24.44±11.42) and (54.37±22.13) branches/mm², respectively. The values in the LASEK group significantly differed from the other two groups (HSD=2.823, -3.010, 3.053, -3.048, P<0.01). The CNFL was (9.19±3.25), (12.88±3.52) and (15.75±2.36) mm/mm², respectively. The value in the SMILE group was significantly different (HSD=-3.151, -4.418; P<0.0l). The corneal optical density after SMILE was 13.16±0.72 in the 0-6 mm diameter area(HSD=-4.164, -4.489; P<0.01), 16.12±3.18 in the 6-12 mm diameter area(HSD=-3.918, -3.493;P<0.01) and 14.06±1.36 in the total diameter (HSD=-6.031, -5.519;P<0.01), which differed significantly from the other two groups.

Twelve months after SMILE for high myopia, the nerve repair around the superior corneal incision is slightly worse than that after FS-LASIK and LASEK, but the nerve repair in other areas has some advantages, and the corneal transparency is better. (Chin J Ophthalmol, 2021, 57:268-276)

To investigate the regulation of basic fibroblast growth factor (bFGF) and transforming growth factor (TGF)-β2 in human scleral fibroblasts (HSFs) by the adenovirus-mediated Lumican gene mutation, and to illustrate the effect of this mutation on myopia.

Experimental study. The HSFs were isolated and cultured from human scleral tissues. The 3rd to 5th generation HSFs were transduced with Lumican mutant (c.596T>C) adenovirus, Lumican wild-type adenovirus, and defective adenovirus as the mutant group, wild group, and negative control group, respectively. Untransduced HSFs were defined as control group. The operation was conducted three times in each group. The expression levels of Lumican, bFGF and TGF-β2 were detected by qPCR. Statistical analysis of gene expression differences between groups was performed by fold changes. The differences were analyzed by one way ANOVA combined with LSD-t test.

The expressions of Lumican in the mutant group and the wild group were 103.146-fold and 398.646-fold increased compared to the control group with significant difference (t=-16.641, -21.729; P<0.05). There was no statistical difference between the negative control group and the control group (t=1.689, P>0.05). The expressions of bFGF and TGF-β2 in the mutant group were 2.812-fold and 2.346-fold increased compared to the control group with significant difference, and higher than the other groups (t=-3.921, -4.851; P<0.05). There was no significant difference among the wild group, negative control group and control group (P>0.05).

The Lumican mutation (c.596T>C) increased the expressions of bFGF and TGF-β2 in HSFs. It indicates that the Lumican mutation (c.596T>C) may change the metabolism of extracellular matrix in the sclera by regulating bFGF and TGF-β2 to participate in scleral remodeling during the process of myopia. (Chin J Ophthalmol, 2021, 57:277-283)

To design a valid and reliable questionnaire to determine various causes of asthenopia for use by clinicians and researchers.

The items to be included in the first version questionnaire were selected based on its definition and literature review. The second version was improved from patients interviews and the Delphi method. In this phase, 17 experts, 97 patients [47 males, 50 females, age (34.42±14.62) years old] with asthenopia and 20 controls [9 males, 11 females, age (33.50±7.31) years old] were involved to generated item list. In the Validation phase, we conducted two round interview through 275 asthenopia patients [97 males,186 females,age (34.42±14.62) years old] and 49 controls [17 males,32 females,age (35.79±8.88) years old]for item reduction and questionnaire validity and reliability assessment. Exploratory factor analysis was performed to reduce items and derive the subscale that each item belongs to. Internal consistency was calculated for all resulting subscales, using Cronbach′s α coefficient, spilt-half reliability and repeatability. The repeatability of the questionnaire was measured by Pearson correlation analysis.

Our initial questionnaire contained 52 symptoms and 2 self-evaluation questions. After the item reduction and assessment, 19 items were selected and classified into three domains through factor analysis. Cronbach α for the three subscales of this version was between 0.79 and 0.85, while for the complete questionnaire it was 0.90, with a spilt-half reliability of 0.80. Factor analysis showed the three components had eigenvalues>3 and these explained 54.3% of the variance.

The 19-item asthenopia questionnaire has acceptable psychometric properties, making it a valid and reliable tool for ophthalmologists and optometrists to evaluate asthenopia as well as to seek causes. It has the potential to be used in clinical trials and outcome research. (Chin J Ophthalmol, 2021, 57:284-291)

To evaluate the effect of extended depth of focus contact lenses on the accommodation of presbyopic eyes.

It was a double-blind randomized controlled trial. Thirty eyes of 30 emmetropic volunteers (15 males, 15 females) who were staff or family members of Hainan Eye Hospital, aged (49.6±4.5) years, were selected. Non-dominant eyes were fitted with soft contact lenses with an extended depth of field. The subjects and examiners were double-blind. Visual acuities of the subjects were examined at 5 m, 40 cm and 60 cm distance before and after the contact lens wear. Meanwhile, the monocular accommodative amplitude, monocular accommodative facility (±1.00 D), accommodative response, binocular positive/negative relative accommodation and accommodation convergence/accommodation at 40 cm distance were measured. The data were analyzed by paired t test and Wilcoxon signed rank test before and after the contact lens wear, and a P value less than 0.05 was considered statistically significant.

Before and after the contact lens wear, the visual acuity at 40 cm was 4.59±0.14 and 4.69±0.10, and the difference was statistically significant (t=4.16, P<0.01). The visual acuity at 60 cm was 4.74±0.10 and 4.74±0.12, and the difference had no statistical significance (t=0.626, P>0.05). The distance visual acuity was 5.00±0.06 and 4.96±0.06, and the difference was statistically significant (t=3.89, P<0.01). The monocular accommodative amplitude was significantly improved from (3.26±0.26) D to (4.00±0.51) D (t=7.59, P<0.01). The monocular accommodative facility was also significantly improved from (2.67±1.60) cyc/min to (3.53±1.87) cyc/min (t=2.17, P<0.05). There was no statistically significant difference in the positive and negative relative accommodation (t=1.90, 0.66; P>0.05). The accommodation convergence/accommodation and adjustment lag had no statistical significance (Z=0.83, 0.11; P>0.05).

Wearing contact lenses with an extended depth of field can improve the near vision and accommodation of presbyopes (Chin J Ophthalmol, 2021, 57:292-296)

Surgeon Introduction Yao Ke, Chief Physician, Prof. Chairman of Ophthalmology Branch of Chinese Medical Association, Head of Cataract and Intraocular Lens Group, Editor-in-Chief of Editorial Committee of Chinese Journal of Ophthalmology. Member of the International Council of Ophthalmology, Fellow of the International Academy of Ophthalmology, President-elect of the Asia-Pacific Society of Cataract and Refractive Surgery, and Head of the Asia-Pacific Society of Ophthalmology in China. Obtained 7 national invention patents, and successively undertook and completed more than 30 national, provincial and ministerial major projects, such as key projects of the National Natural Science Foundation of China, national support projects of the Eleventh Five-Year Plan and the Twelfth Five-Year Plan, and key and general projects of national funds. The first winner won three second prizes of national scientific and technological progress awards, more than 10 provincial and ministerial scientific and technological major contribution awards and Swiss Ophthalmology Alfred Vogt Award.

The patient was a 39-year-old female. Because of blurred vision in his right eye for 4 days, he went to the Ophthalmology Center of Qingdao Municipal Hospital. Four days ago, the patient had blurred vision in the right eye without obvious trigger, no obvious eye pain, headache, and no tearing from fear of light. The patient had undergone anti-glaucoma surgery in another hospital due to glaucoma 18 years ago, the specific situation is unknown. The whole body examination showed no abnormalities. Ocular examination: visual acuity was 0.1 (-1.00 DS-5.00 DC ×1° =0.4) in the right eye and 0.1 (-10.00 DS =0.6) in the left eye; IOP was 14 mmHg (1 mmHg =0.133 kPa) in the right eye and 20 mmHg in the left eye; There was no redness or swelling in the eyelid of the right eye, no congestion and edema in the bulbar conjunctiva, diffuse filter vesicles in the upper bulbar conjunctiva, transparent cornea, acceptable depth in the anterior chamber, imprisonment of the lens in the anterior chamber in front of the iris, and pupil diameter of about 8 mm (Quintessence Picture 1), unresponsive to light; The optic disc of the fundus is clear, the color is light red, the ratio of the optic cup to the optic disc diameter is 0.6, and the retina is in place; No obvious abnormalities were observed in the left eye. Clinical diagnosis: Total dislocation of right eye lens; High myopia in both eyes; After anti-glaucoma surgery in the right eye.

Atropine is a classical drug with a wide use in clinical practice. In ophthalmology, atropine can be used for cycloplegia before optometry, and the treatment of amblyopia, iridocyclitis, malignant glaucoma, etc. In recent years, the "old drugs with new application " research and application of atropine for myopia prevention and control has become a hotspot and the efficacy of atropine has been preliminarily recognized. However, before the widely used in clinical, the safety of atropine draws attention. Researches concerning side effects of atropine were searched. The most common problem is photophobia due to dilated pupils, followed by poor near visual acuity, allergy and inflammation, local irritation. Other side effects include withdraw rebound, dry eyes, elevation of intraocular pressure, system reactions, photic damage and toxicity. Among them, some side effects are theoretical yet, and the long-term effects of some side reactions are not clear. Further research and exploration is needed to serve clinical evidence. At present, investigational usage for myopia prevention and control in clinical trials of atropine can be beneficial. Safety observation and efficacy evaluation are equally important in the course of application. (Chin J Ophthalmol, 2021, 57: 299-304)

Coronaviruses are a common class of respiratory viruses that can cause human infections. 2019 novel coronavirus(2019-nCoV), a new coronavirus that has recently caused a pandemic, has affected millions of people and put tremendous pressure on the health systems of almost every country in the world. Coronaviruses are known to spread from person to person through droplets or contact. The 2019-nCoV has also been found in the conjunctival secretions and tears of some clinically diagnosed patients. To assess whether the eye is one of the transmission routes of the virus, we review literature, and summarize the anatomy of the eye-nose pathway, the expression of the virus receptor in the eye, the preclinical animal studies, and the clinical data. We analyze the possibility of eyes as a means of transmission and propose some suggestions of ocular protection. (Chin J Ophthalmol, 2021, 57: 305-310)

Myopia is a high-incidence disease worldwide. Studying the occurrence and development mechanism of myopia is the basis of scientific prevention and control of myopia. Recent clinical research results show that outdoor activities have the effect of preventing and controlling myopia, which may be related to the increase of dopamine level in retina by light. It is confirmed that there is a correlation between environmental factors such as close work and outdoor activities and retinal biochemical substances and axial changes. It is proposed that scleral hypoxia, remodeling and choroidal blood flow play an important role in the occurrence and development of myopia. This article focuses on the relevant research progress, and provides reference for clinical research and prevention and control of myopia.(Chinese Journal of Ophthalmology, 2021, 57:311-314)

In recent years, myopia in children and adolescents in China tends to be younger and developing rapidly, and the prevention and control work has been highly valued by the country. Controlling the development of myopia is a key task in the field of optometry, and orthokeratology can play an important role in this aspect. This paper focuses on summarizing the progress and improvement of orthokeratology in accuracy, rigor, depth, durability and safety monitoring degree, as well as the management and control strategy, combined application and special attention matters of orthokeratology, in order to demonstrate the new progress of orthokeratology in the treatment of myopia in recent years, improve the clinical understanding level, expand the research scope, and provide reference and guidance for clinical work.(Chinese Journal of Ophthalmology, 2021, 57:315-318)

Eye health is an important part of national health. 2020 is not only the final year of the "13th Five-Year Plan" eye health plan, but also the year of the goal of the "Vision 2020" action initiative. China has made remarkable progress in eliminating avoidable blindness, improving the three-level blindness prevention and eye health service system, and building ophthalmic resource capacity. On the basis of summarizing the development status of China's eye health and combining the suggestions in the World Vision Report of the World Health Organization, the 2020 National Eye Health Work Exchange Conference and International Eye Health Exchange Conference reached a consensus on the direction and focus of China's eye health work during the 14th Five-Year Plan period.(Chinese Journal of Ophthalmology, 2021, 57:319-320)