A hospital-based survey to explore lens rinsing habits of orthokeratology (ortho-k) patients, including the solution used for rinsing.
An anonymous survey, via an online questionnaire, was administered to ortho-k lens wearers or their parents when they attended Fudan University Eye and ENT Hospital for routine follow-up visits. Three major issues were investigated: basic demographics, lens rinsing solution used, and specific rinsing habits. Relationships between demographics and rinsing solution used and rinsing behaviours were explored.
Of the total of 541 online questionnaires delivered, 296 were completed and returned. The respondents were the person responsible for lens care, either the ortho-k users themselves, or their parents. The median age of the lens wearers was 12.0 years (range: 8-22 years), and the median period of ortho-k lens wear was 18.0 months (range: 1-109 months). The most common rinsing solutions reported were a particular brand of multidose preserved saline (28.4%), cooled boiled water (23.3%), and non-preserved multidose saline (16.2%). Overall, the main reason for choice of rinsing solution was recommendation of eye care practitioners (90.2%). The respondents with a longer lens wear history tended to use commercially available bottled water, drinking water, or cooled boiled water rather than non-preserved saline (unidose or multidose) (p ≤ 0.009) and were more likely to use the rinsing solution to soak their lenses (p = 0.009). Lens wearers who rinsed the lenses themselves tended to use tap water compared to those whose lenses were handled by parents (p = 0.040).
Inappropriate choice and usage of rinsing solution appeared to be a common issue among ortho-k lens wearers in Shanghai, China. The problem was more pronounced in long-term wearers and in those who performed rinsing themselves.

Both healthy and diseased human ocular surfaces possess their own microbiota. If allowed, opportunistic pathogens within the ocular microbiota may cause microbial keratitis (MK). However, the nonpathogenic component of the ocular microbiota has been proven to undermine the performance of culture, the gold standard of the etiological diagnosis for MK. As the conjunctival bacterial microbiota generates unique alterations with various oculopathies, this study aimed to evaluate the feasibility of distinguishing MK using machine learning based on the characteristics of the conjunctival bacterial microbiome associated with various types of MK. This study also aimed to reveal which bacterial genera constitute the core of the interaction network of the conjunctival bacterial microbiome. Conjunctival swabs collected from the diseased eyes of MK patients and the randomly chosen normal eyes of healthy volunteers were subjected for high-throughput 16S rDNA sequencing. The relative content of each bacterial genus and the composition of bacterial gene functions in every sample were used to establish identification models with the random forest algorithm. Tenfold cross validation was adopted. Accuracy was 96.25% using the bacterial microbiota structure and 93.75% using the bacterial gene functional composition. Therefore, machine learning with the conjunctival bacterial microbiome characteristics might be used for differentiation of MKs as a noninvasive supplementary approach. In addition, this study found that Actinobacteria, Lactobacillus, Clostridium, Helicobacter, and Sphingomonas constitute the core of the interaction network of the conjunctival bacterial microbiome.

It has been previously reported that the improper prescribing of antibiotic eye drops is common among orthokeratology (ortho-k) practitioners. Guidelines have since been developed and disseminated to improve their understanding and implementation of antibiotic prescriptions. This study aimed to investigate the influence of these guidelines on the knowledge, attitude, and prescribing habits of ortho-k practitioners by means of a questionnaire, which was administered nationwide via an official online account to eye care practitioners (ECPs) involved in ortho-k lens fitting, 548 of whom completed the survey. Differences in characteristics before and after the dissemination of the guidelines and between the groups were explored using χ2 tests. The relationship between prescribing habits and demographics was analyzed using stepwise logistic regression models. The implementation of the guidelines significantly improved the overall prescribing habits of ECPs (p < 0.001), especially for prophylactic antibiotic use before and after ortho-k lens wear (p < 0.001). Most ECPs who prescribed antibiotics properly displayed significantly better knowledge of correct antibiotic use, which in turn affected the compliance in their ortho-k patients (p < 0.001). The ECPs\' occupations (professionals other than ophthalmologists and optometrists, including nurses and opticians), clinical setting (distributor fitting centers), and age (younger than 25 years) were risk factors for the misuse of antibiotics. Although the implementation of the antibiotic guidelines significantly improved overall prescribing habits, some practitioners\' prescribing behavior still needs improvement. A limitation of this study was that all questions were mandatory, requiring ECPs to recall information, and therefore was subjected to selection and recall bias.

The introduction of various drugs onto commercial soft contact lenses (CLs) has emerged as a potentially effective strategy for treating microbial keratitis (MK) because drug-loaded CLs can maintain a controlled drug concentration which leaded to enhanced drug bioavailability and reduced side effects in ocular tissues. In this study, silver nanoparticles modified with zwitterionic poly (carboxybetaine-co-dopamine methacrylamide) copolymer (PCBDA@AgNPs) as novel anti-infective therapeutics were prepared and firmly immobilized onto soft CLs through mussel-inspired surface chemistry. The obtained PCBDA@AgNPs coated CL (PCBDA@AgNPs-CL) remained the excellent transparency of commercial CLs and exhibited strong and broad-spectrum antimicrobial activities. We systematically explored the mechanism and found that the functional CLs can effectively inhibit the growth of microbial biofilms via a synergic \"resist-kill-remove\" strategy due to the zwitterionic surface and sustained release of silver ions. Significantly, in vitro cell cytotoxicity and in vivo subcutaneous implantation experiments proved the significant biosafety of PCBDA@AgNPs-CL. Furthermore, PCBDA@AgNPs-CL was successfully employed for the in vivo treatment of MK rabbit models, demonstrating excellent abilities to eradicate microbe-induced ocular infections and to prevent the destruction and irreversible structural alterations of corneal tissues. Collectively, PCBDA@AgNPs-CL is therefore a highly promising therapeutic device to significantly boost the efficacy for MK treatment.

OBJECTIVE: Understanding the spectrum of ocular pathogens in a given geographic region is important for devising appropriate practical treatment. Therefore, we examined the pathogen spectrum and antibiotic resistance of microbial keratitis in northeast China.
METHODS: In this retrospective observational study, we reviewed the microbiology laboratory records of patients diagnosed with microbial keratitis in a tertiary eye hospital in Harbin, northeast China, between 2017 and 2019, and analysed the pathogen spectrum and antibiotic susceptibility.
RESULTS: We collected 462 specimens, of which 282 exhibited positive cultures. Among these cultures, 257 were bacterial and 25 were fungal. Of the 257 bacterial isolates, 214 (83.27%) were gram positive whereas 43 (16.73%) were gram negative. The most prevalent gram-positive pathogen was coagulase-negative staphylococcus (CoNS; 58.37%), followed by Staphylococcus aureus (S. aureus; 20.62%) and Streptococcus pneumoniae (2.33%). Of the gram-negative bacterial isolates, 10 were Pseudomonas aeruginosa (3.89%). The most frequently detected ocular pathogens from fungal isolates were Fusarium species (40%). We also found more culture-positive cases of bacterial keratitis in summer. Overall, 16.98% S. aureus and 64.00% CoNS isolates were methicillin resistant. These methicillin-resistant bacteria were also more likely to be resistant to other antibiotics, with multidrug resistance found in 77.78% methicillin-resistant S. aureus and 90.63% methicillin-resistant CoNS. However, all gram-positive isolates were sensitive to vancomycin and linezolid.
CONCLUSIONS: Coagulase-negative staphylococcus are the most common ocular pathogens in northeast China. We also show the prevalence of methicillin resistance and concurrent multidrug resistance among staphylococcal isolates. Monitoring the patterns of antimicrobial resistance could help in the management selection.

OBJECTIVE: To investigate antibiotic eye drops prescribing patterns of contact lens practitioners in Mainland China for orthokeratology (ortho-k) patients and to develop guidelines for their use.
METHODS: A questionnaire on their antibiotic prescribing habits was administered to eye care practitioners (ECP) involved in ortho-k lens fitting nationwide via an official online account. Multiple logistic regression models were used to assess the relationships between prescribing habits and demographics.
RESULTS: A total of 555 ECP completed the survey, of whom 50.5 % were optometrists (non-medical degree). About 30 % of the respondents routinely prescribed antibiotic eye drops for prophylactic use before and/or after commencement of ortho-k treatment. Forty one percent of the respondents dispensed antibiotics to patients for emergency use without giving written instructions, 48.5 % used antibiotic eye drops to wet fluorescein strips during ortho-k lens fitting, and 44.9 % considered treating corneal infiltrate(s) with antibiotics to be appropriate. A set of guidelines, including when to use antibiotic eye drops during ortho-k lens treatment and their proper use, stratified by different corneal conditions, was developed.
CONCLUSIONS: Inappropriate use of antibiotic eye drops appeared to be common among ortho-k practitioners in Mainland China. Taking into account deficiencies and errors identified from the survey, a set of guidelines based on best practice was developed and can serve to provide advice for proper use of antibiotics in ortho-k practice.