Volume 56 · Issue 06 · 2020

Since the founding of the People’s Republic of China, the diagnosis and treatment technology of corneal diseases has developed rapidly. In the field of infectious keratopathy, China was the first country that discovered chlamydia trachomatis in the world, which promoted the study on the pathogenesis as well as the diagnosis and treatment of infectious keratitis, especially fungal keratitis. In the aspect of surgical technology, we have learned from other countries and innovated different types of transplantation surgeries suitable for patients with corneal diseases in China. Regarding the construction of eye banks, the cornea donation process and the operation techniques have been developed and standardized. In addition, to improve the cornea disease-related inspection level, new equipment such as specular microscopy and confocal microscopy has been introduced. These efforts have decreased corneal diseases from the first blinding eye disease to the second in our country. In the past 70 years, China’s diagnosis and treatment technology in corneal diseases has achieved remarkable progresses, but there are still many shortcomings. Standing on the shoulders of the older generations of ophthalmologists, we should continue to serve the patients with corneal diseases wholeheartedly. We would like to send congratulations on the 70th anniversary of Chinese Journal of Ophthalmology with this article. ( Chin J Ophthalmol, 2020, 56: 401-408)

Dry eye is a common ocular surface disease that can occur in more than half of cataract patients before surgery. The perioperative damage to ocular surface can lead to tear film insufficiency and a series of dry eye symptoms, which reduce the visual outcome and life quality of the patients. Therefore, clinicians should standardize the management of dry eye disease during the perioperative period of cataract surgery to further improve patients’ satisfaction with surgery, in terms of the evaluation and optimization of preoperative ocular surface, the protection of ocular surface during surgery, and the diagnosis and treatment of postoperative dry eye disease. ( Chin J Ophthalmol, 2020, 56: 409-413)

This article was published ahead of print on the official website of Chinese Journal of Ophthalmology on February 24, 2020. In China, the fight against the 2019 novel coronavirus (2019-nCoV) has been at a critical stage. It has been confirmed that the transmission of 2019-nCoV is mainly through respiratory droplets and contact. Some scholars also pointed out that the possibility of transmission through the digestive system and eyes should not be ignored. Whether infection with 2019-nCoV will develop eye symptoms and whether the virus will spread through eyes are confusing to the medical workers and the general public, and it is ophthalmologists’ responsibility to carry out in-depth discussions. Based on the ocular manifestations of viral diseases, this article analyzes whether the eye secretions and tears carry the virus, and whether ophthalmologists and patients are at a high risk for 2019-nCoV infection, and then presents the current research methods and the necessary prevention and control measures in the field of ophthalmology, with an aim to contribute to the fight against 2019-nCoV. ( Chin J Ophthalmol, 2020, 56: 414-417)

The definition and classification of dry eye has been the focus of the professional field of dry eye. In recent years, the research of dry eye has made continuous progress at home and abroad, and the understanding of dry eye has been deepened in different regions and organizations internationally. In view of this, on the basis of the "Expert Consensus on Clinical Diagnosis and Treatment of Dry Eye (2013)", relevant experts such as China Branch of Asian Dry Eye Association introduced new concepts, focused on clinical practical applications, and updated the definition and classification of dry eye, in order to play a greater role in guiding clinical related work.(Chinese Journal of Ophthalmology, 2020, 56:418-422)

With the development and popularization of artificial intelligence (AI) -assisted screening technology gradually established based on medical big data, AI-assisted screening system based on color fundus pictures has shown good sensitivity and specificity in the screening of glaucoma. In order to standardize the design and clinical application of AI glaucoma assisted screening system, the Glaucoma Group of Ophthalmology Branch of Chinese Medical Association, together with relevant experts, after extensive research and careful discussion, formulated unified standards for data collection, algorithm model construction, hardware requirements, data set establishment and labeling, AI screening scheme, AI screening report requirements, data security, etc. of AI glaucoma assisted screening system, so as to guide clinical work.(Chinese Journal of Ophthalmology, 2020, 56:423-432)

This article was published ahead of print on the official website of Chinese Journal of Ophthalmology on April 16,2020.

To screen for novel coronavirus related conjunctivitis among patients with coronavirus disease 2019.

Prospective series case study. Eighty-one patients diagnosed as coronavirus disease 2019 in Guangxi Zhuang Autonomous Region People's Hospital were enrolled with ophthalmological consultation and screening for novel coronavirus related conjunctivitis, including the inquiring of eye symptoms and checking for conjunctivitis-related signs. Novel coronavirus nucleic acid testing of conjunctival swabs was performed on patients with clinical manifestations of conjunctivitis.

Only 3 of the 81 patients (3.70%) complained of eye discomfort, which appeared on day 16.67±9.29 after the diagnosis of coronavirus disease 2019. The eye signs were not typical of viral conjunctivitis. Novel coronavirus nucleic acid tests of conjunctival swabs were negative in both eyes. There was no evidence to support the diagnosis of novel coronavirus related conjunctivitis. The remaining 78 patients showed no clinical symptoms or signs of conjunctivitis.

The occurrence of novel coronavirus related conjunctivitis may be low in patients with coronavirus disease 2019.(Chin J Ophthalmol, 2020, 56: 433-437)

This article was published ahead of print on the official website of Chinese Journal of Ophthalmolog on Apirl 22,2020.

Angiotensin converting enzyme 2 (ACE2) and Transmembrane serine protease 2 (TMPRSS2) are the key proteins for 2019-nCoV entry into host cells. To evaluate the potential infection risk of 2019-nCoV on ocular surface, we compared ACE2 and TMPRSS2 expression among different eye tissues.

Experimental study. Thirty mice were assigned to male, female, aged, diabetic and non-diabetic groups, with 6 mice in each group. Real-time PCR was performed to quantify ACE2 and TMPRSS2 gene expression in conjunctiva, cornea, lacrimal gland, iris, lens, retina, lung, heart, kidney, and liver from male mice. Immunohistochemistry staining was applied to visualize the distribution of the two proteins in different mice tissues, and in human corneal and conjunctival sections. Published transcriptome datasets were extracted to generate the expression comparasion of ACE2 and TMPRSS2 between human conjunctival and corneal tissues, and results were analyzed using Mann-Whitney U test. Female mice, aged mice, STZ-induced diabetic mice, diabetic group control mice were also subjected to ACE2 expression analysis. Results were analyzed using Student’s t-test.

The expression of ACE2 and TMPRSS2 genes were the highest in conjunctiva among all the six mice eye tissues explored. The expression of these two genes in conjunctiva were lower than that in kidney and lung. ACE2 and TMPRSS2 shared similar expression pattern with the staining concentrated in corneal epithelium, conjunctival epithelium and lacrimal gland serous cells. The expression levels of ACE2 showed gender difference. Female mice had lower ACE2 in conjunctiva and cornea than male mice, with the expression levels being only 43% (t=3.269, P=0.031) and 63% (t=4.080, P=0.015) of that in the male conjunctiva and cornea, respectively. Diabetic mice expressed more ACE2 in conjunctiva (1.21-fold, P>0.05) and lacrimal gland (1.10-fold,P>0.05) compared with the control group. No significant difference on ACE2 expression was found between the aged and young adult mice. The expression level of human conjunctiva ACE2 and TMPRSS2 were significantly higher than that in the cornea (P=0.007), with 5.74-fold and 12.84-fold higher in the conjunctiva than in the corneal epithelium cells, which resembled the situation in mice.

The observation of high-level ACE2 and TMPRSS2 expression in conjunctiva among the 6 eye tissues examined suggests that conjunctiva serves as an infection target tissue of 2019-nCoV. (Chin J Ophthalmol, 2020, 56:438-446)

To investigate the cellular changes and quantitative analysis of basal cell density (BCD) and corneal epithelial thickness (CET) in limbal stem cell deficiency (LSCD) by in vivoconfocal microscopy (IVCM).

Prospective case-control study. A total of 35 eyes of 23 patients diagnosed with LSCD and 25 eyes from normal subjects were included in this study. Based on slit-lamp presentation and the global consensus on classification, the LSCD patients were classified into LSCD Ⅰ, LSCD Ⅱ and LSCD Ⅲ. Confocal images of the central cornea, and the superior, inferior, nasal and temporal limbus were inspected by IVCM. Morphologic characteristics of LSCD were summarized. The BCD and CET in all locations were measured. ANVOA or Kruskal-Wallis test was used for analysis when appropriate. A receiver operating characteristic was used to detect the diagnosis efficiency of BCD and CET.

The characteristics in the corneal epithelium of LSCD on IVCM included nested corneal epithelial cells, goblet cells with hyper-reflective spots, irregular basal cells and decreasing subbasal nerve density. The mean BCD of the LSCD group was (8 976±1 096) cells/mm² in the central cornea. Compared to the control group, the BCD in the central cornea, superior, inferior, nasal and temporal limbus decreased by 30.2%, 26.0%, 28.7%, 29.3% and 30.2%, respectively (all P<0.007). The CET in the central cornea was (47.3±8.1) μm. The CET in the central cornea, superior, inferior, nasal and temporal limbus decreased by 27.9%, 23.7%, 20.6%, 26.9% and 23.1%, respectively, compared to the control group (allP<0.007). There was a decline of BCD and CET in more serious LSCD. Additionally, the decline of BCD and CET was shown in the unaffected region. The receiver operating characteristic showed the diagnosis efficiency of BCD in the corneal center and limbus (0.931 and 0.916) was superior to CET (0.853 and 0.817).

There was a series of characteristic cellular changes in LSCD on IVCM. Both BCD and CET decreased significantly in LSCD. The BCD had higher diagnostic efficiency for LSCD.(Chin J Ophthalmol, 2020, 56:447-455)

To investigate the corneal topographic characteristics of the parents of patients with keratoconus (KC) and the correlation with their offspring.

Case-control study. Twenty-six patients (49 eyes) with KC, who were 15 males and 11 females, and (18.83±2.74) years old, 48 parents (96 eyes) of patients with KC, who were 23 males and 25 females, and (44.14±1.70) years old, and 44 controls (88 eyes), who were 22 males and 22 females, and (42.81±4.03) years old, were enrolled in Qingdao Eye Hospital. The indexes in the Belin/Ambrósio Enhanced Ectasia Display were acquired with Pentacam topography. The basic indicators were flat K/steep K/maximum K (Kmax) curvature and astigmatism, thinnest pachymetry (TP), and front/back elevation (Ef/Eb); the Belin indexes included deviation of normality of the front/back elevation (Df/Db), deviation of average pachymetry progression/normality of corneal thinnest point/normality of relational thickness (Dp/Dt/Da), overall deviation of normality (Do), minimum/maximum/average pachymetric progression indices (PPImin/PPImax/PPIave), and Ambrósio’s average and maximum relational thickness indices (ARTave/ARTmax). All parameters in the groups of parents and controls were compared by Mann-Whitney U test. The ROC curve was used to analyze the differential value of each abnormal index. In addition, the ratio of abnormal indicators in the Belin/Ambrósio Enhanced Ectasia Display was statistically analyzed. Partial correlation analysis was used to find the correlation between the parameters of KC patients and their parents, and binary logistics regression analysis was used to predict the prevalence in children through the parental indicators.

Clinical KC was diagnosed in 1 of the 48 parents (2.08%) of patients with KC. There was no statistically significant difference in anterior surface parameters such as K1, K2, Kmax, astigmatism and Ef, but differences in the thickness [522.00 (493.00, 542.75) μm versus540.00 (523.25, 559.50) μm] and posterior surface elevation value [8.00 (4.00, 11.00) μm versus5.00 (3.00, 8.00) μm] were statistically significant. Except for Df, the other Belin/Ambrósio indicators such as Do (Z=-4.551, P=0.000), PPImax (Z=-3.959,P=0.000) and ARTave (Z=-4.792, P=0.000) indicated significant difference. The ROC curve analyses showed ARTave had the greatest value in the identification of KC patients (AUC=0.705), PPImax had the best sensitivity (0.845), and Eb had the best specificity (0.837). The ratio of suspicious indicators between the parents’ group and the control group was 1.5∶1, and the ratio of pathological indicators was 3∶1. There was a correlation in multiple parameters between KC patients and their parents (all P>0.05). Do/Eb/TP indices of mothers and Do/Kmax indices of fathers were the major influence factors for the disease in the offspring, with a diagnosis rate of 85.6%.

The corneal topographic map of the parents of patients with KC showed that the index of the anterior surface was normal, but the thickness was thinner and the posterior surface was higher. According to Belin's analysis, all indicators except Df were abnormal. Moreover, the ratio of suspected and pathological indicators increased. These data suggested that the corneal topography of parents of patients with KC had features of subclinical KC. Compared with the traditional index, ARTave was of the highest value in the identification of subclinical KC. There was a strong correlation between parents of patients with KC and offspring. The Do and Kmax indices of paternal parents and the Do, Eb and TP indices of maternal parents were good predictors of children’s disease. (Chin J Ophthalmol, 2020, 56:456-464)

To observe the clinical effect of corneal staining in patients with corneal leucoma.

Restrospective case series study.Thirty eyes of 30 patients (17 males, 13 females) with corneal leucoma who underwent corneal interlamellar staining at Beijing Aier-Intech Eye Hospital from October 2014 to July 2018 were included. The mean age was 31.50±15.66 years. Postoperative follow-up was more than 1 year. All the patients underwent appearance examination, anterior segment examination with a slit lamp, B-scan examination and anterior segment OCT examination preoperatively and postoperatively. The effect of corneal staining, patient satisfaction and the incidence of complications were investigated.

The corneal epithelium of all the patients healed completely within 1-3 days after operation. The mean follow-up period was 30.68±18.02 months (range, 12.37-58.10 months). During the postoperative follow-up period, no staining permeation or inflammatory reaction in the anterior chamber occurred. The corneal color and appearance were well maintained in 18 patients (72.0%). Seven patients (28.0%) showed mild corneal color-fading. One patient was treated with enucleation and orbital hydroxyapatite implantation because of eye atrophy and corneal banding degeneration caused by the primary disease at 4 years after operation. The surgeon was satisfied with the improvement of the appearance of all cases; 22 patients (88.0%) were satisfied with the postoperative appearance. No significant complications were observed in all the cases.

Corneal interlamellar staining is one of best choices for the treatment of corneal leucoma. It has advantages of quick postoperative recovery, long-standing color staining and good cosmetic effect. The operation is simple and easy to carry out and there is no obvious damage to eye tissues. (Chin J Ophthalmol, 2020, 56:465-472)

One patient with abnormalities found due to routine neonatal fundus screening was seen to the ophthalmology department. After long-term follow-up, fundus photography, fundus fluorescein sodium angiography and chromosome gene examination of peripheral blood were performed, and the diagnosis of Down syndrome-related retinopathy was made.(Chinese Journal of Ophthalmology, 2020, 56:473-474)

Surgical introduction Huang Ting, professor, chief physician, director of keratology department of Sun Yat-sen Ophthalmology Center, Sun Yat-sen University. He is a member of the Keratology Group of Ophthalmology Branch of Chinese Medical Association, a member of the Keratology Professional Committee of Ophthalmologists Branch of Chinese Medical Doctors Association, and a member of the Editorial Committee of Chinese Journal of Ophthalmology.

The patient was a 33-year-old male. Because of difficulty in opening eyes in the morning and occasional aggravation of eye pain at night for 1 month, he went to Beijing Tongren Eye Center, Beijing Tongren Hospital affiliated to Capital Medical University. Past physical health, no history of ocular trauma, surgery or systemic disease. Other hospitals were diagnosed as dry eye and corneal epithelial lesions in both eyes, and were treated with sodium hyaluronate, calf blood deproteinized extract ophthalmic gel, pranoprofen and other drugs, but no significant improvement was seen. Full body physical examination: TGFBI genetic test negative. Eye examination: visual acuity was 0.1 for the right eye (1.0 after correction) and 0.1 for the left eye (0.8 after correction); IOP was 13 mmHg (1 mmHg =0.133 kPa) in the right eye and 14 mmHg in the left eye; Punctate and fingerprint-like corneal opacity in both eyes, obvious in the left eye (Quintessence Picture 1）。 Clinical diagnosis: corneal epithelial basement membrane dystrophy in both eyes; Refractive error in both eyes. (The picture in this article won the Excellence Award of TOPCON Cup Photo Exhibition of the 24th National Ophthalmology Academic Conference in 2019)

This article was published first on the official website of Chinese Journal of Ophthalmology on February 23, 2020. During the 2019 novel coronavirus (2019-nCoV) pandemic, the question of the possibility of virus transmission through the eye has attracted widespread concern among ophthalmologists. At present, although there is still a lack of direct evidence of ocular infection of 2019-nCoV, there are still various signs suggesting the possibility of ocular infection. In view of the strong infectiousness of 2019-nCoV, in line with the principle of "prevention is greater than cure", reducing the disease from the "eye" is of great significance to reduce hospital cross-infection, reduce the incidence and prevent and control the epidemic. This article summarizes and analyzes the infection mechanism, transmission route and its relationship with the ocular surface of 2019-nCoV, and presents the speculative basis that the virus may be infected through the eye for readers' analysis and reference, in order to provide a reference for ocular prevention and control in this epidemic and ophthalmologists to carry out clinical work.(Chinese Journal of Ophthalmology, 2020, 56:477-480)