The Guardian of Vision: Intelligent Bacteriophage-Based Eyedrops for Clinical Multidrug-Resistant Ocular Surface Infections.

Clinical multidrug-resistant Pseudomonas aeruginosa (MDR-PA) is the leading cause of refractory bacterial keratitis (BK). However, the reported BK treatment methods lack biosecurity and bioavailability, which usually causes irreversible visual impairment and even blindness. Herein, for BK caused by clinically isolated MDR-PA infection, armed phages are modularized with the type I photosensitizer (PS) ACR-DMT, and an intelligent phage eyedrop is developed for combined phagotherapy and photodynamic therapy (PDT). These eyedrops maximize the advantages of bacteriophages and ACR-DMT, enabling more robust and specific targeting killing of MDR-PA under low oxygen-dependence, penetrating and disrupting biofilms, and efficiently preventing biofilm reformation. Altering the biofilm and immune microenvironments alleviates inflammation noninvasively, promotes corneal healing without scar formation, protects ocular tissues, restores visual function, and prevents long-term discomfort and pain. This strategy exhibits strong scalability, enables at-home treatment of ocular surface infections with great patient compliance and a favorable prognosis, and has significant potential for clinical application.

Fusarium Keratitis: A Systematic Review (1969 to 2023).

BACKGROUND: Mycotic keratitis (MK) represents a corneal infection, with Fusarium species identified as the leading cause. Fusarium is a genus of filamentous fungi commonly found in soil and plants. While many Fusarium species are harmless, some can cause serious infections in humans and animals, particularly Fusarium keratitis, that can lead to severe ocular infections, prevalent cause of monocular blindness in tropical and subtropical regions of the world. Due to its incidence and importance in ophthalmology, we conducted a systematic analysis of clinical cases to increase our understanding of Fusarium keratitis by gathering clinical and demographic data. METHODS: To conduct an analysis of Fusarium keratitis, we looked through the literature from the databases PubMed, Embase, Lilacs, and Google Scholar and found 99 papers that, between March 1969 and September 2023, corresponded to 163 cases of Fusarium keratitis. RESULTS: Our analysis revealed the Fusarium solani species complex as the predominant isolate, with females disproportionately affected by Fusarium keratitis. Notably, contact lens usage emerged as a significant risk factor, implicated in nearly half of cases. Diagnosis primarily relied on culture, while treatment predominantly involved topical natamycin, amphotericin B, and/or voriconazole. Surprisingly, our findings demonstrated a prevalence of cases originating from the United States, suggesting potential underreporting and underestimation of this mycosis in tropical regions. This shows the imperative for heightened vigilance, particularly in underdeveloped regions with substantial agricultural activity, where Fusarium infections may be more prevalent than currently reported. CONCLUSION: Our study sheds light on the clinical complexities of Fusarium keratitis and emphasizes the need for further research and surveillance to effectively tackle this vision-threatening condition. Furthermore, a timely identification and early initiation of antifungal treatment appear to be as important as the choice of initial treatment itself.

Low-dose intravitreal injection of 4 mg preservative-free gentamicin and superficial lamellar keratectomy combined with modified Gundersen grafts to control chronic heterochromic iridocyclitis and secondary keratitis in horses.

OBJECTIVE: To describe a combined treatment approach for heterochromic iridocyclitis and secondary keratitis (HIK) in horses. ANIMAL STUDIED: A total of 15 horses (16 eyes). PROCEDURES: Sixteen eyes from 15 horses (mean age 14.1 years, range 6-26 years) received low-dose (4 mg) intravitreal preservative-free gentamicin injection (IVGI) and modified Gundersen grafts with standing sedation and local anesthesia following a clinical diagnosis of HIK. Additional therapies of suprachoroidal triamcinolone (8 mg) injection, episcleral bromfenac implants, and suprachoroidal cyclosporine implants were performed in individual cases. Leptospira titers were also reported when available. RESULTS: The most frequent ophthalmic findings were pigmented keratic precipitates (n = 15/16 eyes, 94%), corneal edema (n = 14/16 eyes, 88%), and pigmented cells suspended in the anterior chamber (n = 7/16 eyes, 44%). Postoperative treatment generally consisted of topical and systemic NSAIDs, topical antibiotics, and a topical mydriatic agent. Complications included persistent corneal edema (7/16, 44%), corneal ulceration (6/16, 38%), graft failure requiring revision (2/16, 13%), stromal abscess (1/16, 6%), surgery site infection (1/16, 6%), and suspected retinal degeneration following IVGI (1/16, 6%). One case was enucleated 6 months after treatment (1/16, 6%). Of the 12 eyes with at least 3 months of post-treatment follow-up, 10 were comfortable and visual with static or improved symptoms of HIK. CONCLUSIONS: This multimodal treatment approach aims to address both the anterior uveitis and endothelial decompensation frequently seen in horses with HIK. The surgery can be performed under standing sedation. Continued evaluation and long-term follow-up is necessary in all horses with HIK.

A novel liposomal formulation for ocular delivery of caspofungin: an experimental study by quality by design-based approach.

Aim: This study focuses on the development of a Caspofungin liposome for efficient ocular delivery by enhancing corneal penetration. Method: Quality by design (QbD) approach was adopted to identify critical factors that influence final liposomal formulation. The liposome developed using thin film hydration after optimization was subjected to characterization for physicochemical properties, irritation potential and corneal uptake. Results: The numerical optimization suggests an optimal formulation with a desirability value of 0.706, using CQAs as optimization goals with 95% prediction intervals. The optimized formulation showed no signs of irritation potential along with observation of significant corneal permeation. Conclusion: The liposomal formulation increased the permeability of Caspofungin, which could enhance the efficacy for the treatment of conditions, like fungal keratitis.

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Infectious Keratitis in Patients Over 65: A Review on Treatment and Preserving Eyesight.

Infectious keratitis (IK) represents a significant global health concern, ranking as the fifth leading cause of blindness worldwide despite being largely preventable and treatable. Elderly populations are particularly susceptible due to age-related changes in immune response and corneal structure. However, research on IK in this demographic remains scarce. Age-related alterations such as increased permeability and reduced endothelial cell density further compound susceptibility to infection and hinder healing mechanisms. Additionally, inflammaging, characterized by chronic inflammation that develops with advanced age, disrupts the ocular immune balance, potentially exacerbating IK and other age-related eye diseases. Understanding these mechanisms is paramount for enhancing IK management, especially in elderly patients. This review comprehensively assesses risk factors, clinical characteristics, and management strategies for bacterial, viral, fungal, and acanthamoeba keratitis in the elderly population, offering crucial insights for effective intervention.

Comparison of the Effect of Different Treatment Doses of Intrastromal Vancomycin in a Rabbit Model of Methicillin-Resistant Staphylococcus Aureus (MRSA) Keratitis.

PURPOSE: To compare the effect of different doses of vancomycin on a rabbit model of MRSA keratitis. METHODS: Twenty-four eyes of 24 New-Zealand White rabbits were included in the study. MRSA keratitis was applied to 24 left eyes of 24 New Zealand rabbits. Twenty-four hours after MRSA inoculation; 0.5 mg/0.1 mL, 1 mg/0.1 mL, and 2 mg/0.1 mL and balanced salt solution were administered to 6 rabbits in 4 groups, respectively. RESULTS: The effect of different doses of vancomycin on reducing bacterial load was found to be statistically significant when each was compared to the control group (p = 0.006). When comparing the dosages with each other, no superiority was shown (p = 0.297, p = 0.749, p = 0.262 respectively). There was a significant increase in the posttreatment total clinical score in the control and 2 mg/0.1 mL groups compared to the pretreatment score (p = 0.001, p = 0.001 respectively). CONCLUSION: It is emphasized that necessary treatment can be achieved by administering less antibiotic (0.5 mg/0.1 mL) to the corneal intrastromal area.

In Vivo Confocal Microscopy Findings of a Rare Cryptococcus neoformans Keratitis.

PURPOSE: To report a rare case of fungal keratitis caused by Cryptococcus neoformans, highlighting its unique morphological features using in vivo confocal microscopy (IVCM). METHODS: This was a retrospective case report. A 66-year-old man presented with foreign body sensation and blurred vision in his left eye for over 10 months. RESULTS: His best-corrected visual acuity was 20/20. Slit-lamp examination revealed a gray-white lesion approximately 4-5 mm in the superficial layer of the central cornea without epithelial defects. The IVCM images revealed numerous round or round-like pathogens, each with a central highly reflective body surrounded by a dark ring, ranging in size from 5 to 30 µm, and to a maximum of 85 µm, observed in the corneal epithelium and superficial stroma. No obvious inflammatory cell infiltration was observed in the lesions or endothelium. C. neoformans infection was confirmed. The round pathogens completely disappeared after 8 weeks of treatment with topical amphotericin B and voriconazole eye drops. CONCLUSION: Fungal keratitis caused by C. neoformans is rare and easily overlooked due to atypical clinical signs and symptoms. This case reports the unique morphological features of C. neoformans in the cornea using IVCM for the first time, facilitating rapid, noninvasive auxiliary diagnosis of C. neoformans keratitis and treatment follow-up.

Favorable outcome of Lasiodiplodia theobromae keratomycosis : a clinical case and systematic review.

BACKROUD: Keratitis caused by Lasiodiplodia theobromae is rare and typically associated with a poor prognosis. Current literature lacks sufficient evidence on effective management of patients with this condition. CASE PRESENTATION: A 74-year-old former agricultural worker presented with a red right eye, discomfort, and decreased visual acuity, progressing over three days without treatment. Examination revealed type 2 diabetes and a non-perforating, spiculated corneal abscess with a hypopyon in the right eye. Initial treatment included a triple antibiotic therapy and supportive care. Direct mycological examination identified numerous septate mycelial filaments. Antifungal treatment with natamycin and voriconazole, both topically and orally, was initiated. Cultures confirmed Lasiodiplodia theobromae. The patient showed significant improvement. Treatment continued for eight weeks, with a final visual acuity of 20/50 due to a stromal scar. CONCLUSION: An extensive literature review conducted in November 2023, using databases such as PubMed and Google Scholar with the keywords "lasiodiplodia" and "keratitis" yielded no previous cases of this specific condition being managed solely with the combined use of natamycin and voriconazole. This antifungal combination is commonly included in most management protocols for fungal keratitis. Factors such as the use of corticosteroids and delayed diagnosis were noted to adversely affect the prognosis. This case and this systematic review underscores the potential for non-surgical management options in severe fungal keratitis.

Perspectives on the incidence of Acanthamoeba Keratitis: A Systematic Review and Meta-Analysis.

TOPIC: To provide an overview on the incidence of Acanthamoeba Keratitis (AK). CLINICAL RELEVANCE: Although being a major and sight-threatening cause of infectious keratitis in the population, a comprehensive assessment of the incidence of this condition is lacking. METHODS: Incidence of AK was computed as the number of AK eyes, per healthcare center, per year (annualized-center-incidence, or ACI). Two meta-analytical ratios were also calculated: a) the ratio of AK eyes to the count of non-viral microbial keratitis (MK) eyes; b) the ratio of AK eyes to the overall population (i.e., the total number of subjects of a nation or region, as indicated by the authors in each study). Center was defined as the healthcare facility (e.g., Hospital, Private Practice, Clinic) where the study took place. Actual and projected estimates of the number of AK eyes in years were calculated multiplying the ratio of AK to the total population and the corresponding present and projected population estimates (age range: 15 to 70), sourced from the United Nations (UN) Population Prospects. RESULTS: Overall, 105 articles were included, published between 1987 and 2022. The total number of eyes identified was 91,951, with 5,660 affected by AK and 86,291 by non-viral MK. The median ACI was 1.9 new AK eyes per healthcare center per year (95%CI of the median: 1.5 to 2.6), with no statistically significant differences observed among continents. The ratio of AK eyes to the total number of MK eyes was 1.52% (95%CI: 1.02% to 2.24%), while the ratio of AK in relation to the entire population was estimated at 0.0002% (95%CI: 0.0001 to 0.0006), or 2.34 eyes per 1,000,000 subjects (95%CI: 0.98 to 5.55 per 1.000.000 subjects). The projected increase in the numbers of AK eyes indicates a rise of +18.5% (15,356 AK eyes) in 2053 and +25.5% (16,253 AK eyes) in 2073, compared to the baseline of 2023 (12,954 AK eyes) CONCLUSION: AK emerged as a relatively low-incident disorder, and no significant differences in terms of its incidence were found among different continents.

Novel treatment of infectious keratitis in canine corneas using ultraviolet C (UV-C) light.

OBJECTIVE: To investigate the therapeutic effect of 275 nm wavelength ultraviolet C (UV-C) light for treatment of bacterial keratitis in canine corneas using an affordable, broadly available modified handheld device. METHODS: UV-C therapy (UVCT) was evaluated in two experiments: in vitro using triplicates of three bacterial genera (Staphylococcus, Streptococcus, Pseudomonas spp., and a mix of all species) where the UVCT was performed at a distance of 10, 15, and 20 mm with 1 or 2 doses (4 h apart) for 5, 15, or 30 s; ex vivo model where healthy canine corneal buttons were inoculated superficially and deep (330 µm) with the same bacterial isolates and treated at a 10 mm distance for 15 s with one dose of 22.5 mJ/cm2. Fluorescent marker (STYO9-PI) was used to label (green = live bacteria, red = dead bacteria), and confocal microscopy was used to image the bacteria. RESULTS: In vitro results showed all plates treated with UVCT had 100% bactericidal effect for all isolates with single dose of 15 s at 10 mm distance or two doses, 4 h apart at 15 mm and was ineffective with single dose at 15-20 mm. The ex vivo results confirmed a significant decrease in bacterial load for all isolates on samples inoculated superficially but were inconclusive for intrastromal ones. CONCLUSIONS: UVCT confirmed the therapeutic potential for all tested isolates, for both in vitro and ex vivo experiments using a single exposure of 15 s. While safety studies are underway, clinical trials are warranted.

Coexistence of severe peripheral ulcerative keratitis and lichen planus: case report.

Introduction and importance: Ocular involvement in lichen planus is highly uncommon, primarily affecting the eyelids, conjunctiva, and less frequently, the cornea. Peripheral ulcerative keratitis (PUK), a rare subtype form of corneal lichen planus, has been reported only once in the literature. Case presentation: The authors report details of a 34-year-old man with confirmed cutaneous lichen planus who developed severe PUK, a rare ocular manifestation of lichen planus. Despite initial worsening with corticosteroids, successful resolution of PUK was achieved with topical Cyclosporin and azathioprine over 2 months but with a final visual acuity limited to light perception. Clinical discussion: To the best of our knowledge, very rare cases have been reported of the coexistence of severe PUK and lichen planus. Lichen planus should be considered in any case of PUKs associated with cutaneous-mucosal manifestations cyclosporin and azathioprine are crucial for effective management and favorable outcomes in such cases. Conclusion: This case aims to show the importance of dermatological examination in the presence of any peripheral ulcerative keratitis. It also sheds light on the therapeutic difficulties and the prognosis of this rare form of ocular lichen planus.

Utilization of multiplex polymerase chain reaction for simultaneous and rapid detection of viral infections from different ocular structures.

The impact of viral keratitis (VK) on individuals and society is notable. Early diagnosis and treatment are crucial in managing viral keratitis effectively. Timely intervention with antiviral medications and supportive care can help mitigate the severity of the infection and improve visual outcomes. We examined the prevalence of varicella-zoster virus (VZV), herpes simplex virus type 1 (HSV-1), adenovirus (AdV) and herpes simplex virus type 2 (HSV-2) in patients suspected for ocular infections. Patients included in the study exhibited various clinical manifestations indicative of ocular pathology, such as infectious keratitis, corneal scar, endogenous endophthalmitis, panuveitis, endothelitis, stromal edema, and other relevant conditions. Four different types of tear fluid, corneal samples epithelium, aqueous humor and vitreous humor were taken. After genome extraction, multiplex real-time PCR was used for diagnosis of viruses. 48 (29.6%) out of the total of 162 (100%) eye specimen were positive. The dominant prevalence was VZV (12.3%) and HSV-1 (11.7%) followed by AdV (4.9%) and HSV-2 (0.6%). There were 4 (8.3%) coinfections within the samples (HSV-1 and VZV). Aqueous humor samples demonstrated superior virus detection ability and our only HSV-2 positive sample was from aqueous humor. The utilization of multiplex real-time PCR assays in differential diagnosis of VK holds promise for expeditious diagnoses while also preventing unwarranted antibiotic prescriptions. Moreover, the aqueous humor appears to be a more sensitive site for detecting viral keratitis.

A double-masked, sham-controlled trial of rose bengal photodynamic therapy for the treatment of fungal and acanthamoeba keratitis: Rose Bengal Electromagnetic Activation with Green Light for Infection Reduction (REAGIR) study.

BACKGROUND: Infectious keratitis secondary to fungus or acanthamoeba often has a poor outcome despite receiving the best available medical therapy. In vitro rose bengal photodynamic therapy (RB-PDT) appears to be effective against fungal and acanthamoeba isolates (Atalay HT et al., Curr Eye Res 43:1322-5, 2018, Arboleda A et al. Am J Ophthalmol 158:64-70, 2014). In one published series, RB-PDT reduced the need for therapeutic penetrating keratoplasty in severe bacterial, fungal, and acanthamoeba keratitis not responsive to medical therapy. METHODS: This international, randomized, sham and placebo controlled 2-arm clinical trial randomizes patients with smear positive fungal and acanthamoeba and smear negative corneal ulcers in a 1:1 fashion to one of two treatment arms: 1) topical antimicrobial plus sham RB-PDT or 2) topical antimicrobial plus RB-PDT. DISCUSSION: We anticipate that RB-PDT will improve best spectacle-corrected visual acuity and also reduce complications such as corneal perforation and the need for therapeutic penetrating keratoplasty. This study will comply with the NIH Data Sharing Policy and Policy on the Dissemination of NIH-Funded Clinical Trial Information and the Clinical Trials Registration and Results Information Submission rule. Our results will be disseminated via ClinicalTrials.gov website, meetings, and journal publications. Our data will also be available upon reasonable request. TRIAL REGISTRATION: NCT, NCT05110001 , Registered on November 5, 2021.

Two-stage deep neural network for diagnosing fungal keratitis via in vivo confocal microscopy images.

Timely and effective diagnosis of fungal keratitis (FK) is necessary for suitable treatment and avoiding irreversible vision loss for patients. In vivo confocal microscopy (IVCM) has been widely adopted to guide the FK diagnosis. We present a deep learning framework for diagnosing fungal keratitis using IVCM images to assist ophthalmologists. Inspired by the real diagnostic process, our method employs a two-stage deep architecture for diagnostic predictions based on both image-level and sequence-level information. To the best of our knowledge, we collected the largest dataset with 96,632 IVCM images in total with expert labeling to train and evaluate our method. The specificity and sensitivity of our method in diagnosing FK on the unseen test set achieved 96.65% and 97.57%, comparable or better than experienced ophthalmologists. The network can provide image-level, sequence-level and patient-level diagnostic suggestions to physicians. The results show great promise for assisting ophthalmologists in FK diagnosis.

Nocardia keratitis: A clinical diagnosis with successful outcome.

Nocardia keratitis is mostly seen in patients with alcoholism, malnutrition, or HIV. Its chronic waxing-and-waning course makes it difficult to diagnose. A 53-year-old male presented with pain and redness in his right eye for the past 3 weeks. The cornea had paracentral ulcer with stromal infiltrates and multiple satellite lesions giving wreath-like appearance suggestive of Nocardia. After corneal scraping, fortified amikacin, moxifloxacin, and cycloplegics were started. Gram stain revealed filamentous, branching Gram-positive bacteria and acid-fast on Ziehl-Neelsen stain confirming our clinical diagnosis. Ulcer completely resolved over 6 weeks. Thus, a high index of clinical suspicion which was further backed by microbiological confirmation aided in expedient management ensuring a successful outcome.

Clinical Features and Visual Outcome of Infectious Keratitis Associated with Orthokeratology Lens in Korean Pediatric Patients.

Purpose: To investigate the clinical features and visual outcome of infectious keratitis associated with Orthokeratology (Ortho-K) lens in Korean pediatric patients. Methods: We retrospectively reviewed medical records of patients diagnosed with Ortho-K lens-associated infectious keratitis from June 2005 to April 2020 at a tertiary referral hospital. Patients' demographics, clinical features, microbiological evaluation, and treatment methods were assessed and factors related to final visual outcomes were analyzed. Results: The study included 26 eyes of 26 patients (19 female, 7 male; mean age: 11.9 years), with an average Ortho-K lens wear duration of 33.7 ± 21.2 months. The highest number of cases occurred in summer (42.3%, 11/26). Central or paracentral corneal lesions were observed in 96.2% (25/26) of cases, with a mean corneal epithelial defect size of 5.13 mm². Pseudomonas aeruginosa was the most commonly isolated organism (n = 5), followed by Serratia marcescens (n = 4). All patients responded to medical treatment without needing surgical intervention. 72% of cases achieved favorable visual outcomes (Snellen BCVA > 6/12), while 8% experienced severe visual impairment (Snellen BCVA ≤ 6/60) due to residual central corneal opacities. Multivariable analysis showed that non-summer seasons, duration from symptom onset to presentation, and corneal epithelial defect size were significantly associated with final logMAR BCVA (p = 0.043, p = 0.040, and p = 0.002, respectively). Failed autorefraction at presentation due to an Ortho-K-related infectious keratitis lesion was a significant predictor of poor final visual outcome (Snellen BCVA ≤ 6/12) (OR = 38.995, p = 0.030). Conclusions: Ortho-K lens-related infectious keratitis can lead to permanent corneal opacities and potentially devastating visual outcomes in children. Delayed time to presentation, large corneal lesions, failure of autorefraction, and non-summer seasons were associated with poorer outcomes. Proper education and early detection would be key to safe use of orthokeratology lenses in pediatric patients.

Hydrogel dressings on neurotrophic keratitis in an experimental animal model.

AIM: To investigate the therapeutic effects of hydrogel dressings on neurotrophic keratitis in rats. METHODS: Male Wistar rats, aged 42-56d, were randomly divided into control, experimental, and treatment groups, each consisting of five rats. The experimental and treatment groups underwent neurotrophic keratitis modeling in both eyes. After successful modeling, biomedical hydrogels formed with polyvinyl alcohol and polyvinyl pyrrolidone were used in treatment group for 7d. Ocular irritation response and keratitis index scores, Schirmer's test, tear film break-up time (BUT), sodium fluorescein staining, and hematoxylin and eosin (HE) staining were used to evaluate the effectiveness of the treatment. RESULTS: The neurotrophic keratitis model was successfully established in rats with severe ophthalmic nerve injury, characterized by keratitis, ocular irritation, reduced tear secretion measured by decreased BUT and Schirmer test values, corneal epithelial loss, and disorganized collagen fibers in the stromal layer. Following treatment with hydrogel dressings, significant improvements were observed in keratitis scores and ocular irritation symptoms in model eyes. Although the recovery of tear secretion, as measured by the Schirmer's test, did not show statistical differences, BUT was significantly prolonged. Fluorescein staining confirmed a reduction in the extent of corneal epithelial loss after treatment. HE staining revealed the restoration of the structural disorder in both the epithelial and stromal layers to a certain extent. CONCLUSION: Hydrogel dressing reduces ocular surface irritation, improves tear film stability, and promotes the repair and restoration of damaged epithelial cells by maintaining a moist and clean environment on the ocular surface in the rat model.

A surgical alternative of fusiform penetrating keratoplasty for the management of severe infectious keratitis.

AIM: To describe the surgical procedure of fusiform penetrating keratoplasty (FPK) using multiple trephines of different sizes for treating patients with severe infectious keratitis. METHODS: Fourteen eyes underwent FPK, and 15 eyes received conventional penetrating keratoplasty (PK) were included in the study. The best-corrected visual acuity (BCVA), refractive outcomes, endothelial cell density, and postoperative complications were recorded. RESULTS: The FPK group was followed for an average of 15.3±2.1mo, whereas the PK group was followed for 16.1±1.9mo. The corneal ulcers were elliptical-shaped in all 14 eyes in the FPK group. The mean BCVA (logMAR, 0.26±0.13) showed no statistically significant differences from that in the PK group (logMAR, 0.21±0.12, P>0.05) at 1y after surgery. But the mean curvature, mean astigmatism, and mean spherical equivalent in the FPK group were lower than those in the PK group (P<0.05). Peripheral anterior synechia was observed in one patient in the FPK group, whereas 6 patients in the PK group. Suture loosening and neovascularization were observed in 4 and 5 eyes in the PK group, respectively. No graft immune rejection or elevation of intraocular pressure was observed in the two groups. CONCLUSION: For patients with elliptical-shaped corneas or corneal ulcers, FPK can avoid disrupting of corneal limbus, reduce the risk of postoperative complications, and can result in satisfactory visual quality.

Rational design of antibiotic-free antimicrobial contact lenses: Trade-offs between antimicrobial performance and biocompatibility.

Microbial keratitis associated with contact lenses (CLs) wear remains a significant clinical concern. Antibiotic therapy is the current standard of care. However, the emergence of multidrug-resistant pathogens necessitates the investigation of alternative strategies. Antibiotic-free antimicrobial contact lenses (AFAMCLs) represent a promising approach in this regard. The effectiveness of CLs constructed with a variety of antibiotic-free antimicrobial strategies against microorganisms has been demonstrated. However, the impact of these antimicrobial strategies on CLs biocompatibility remains unclear. In the design and development of AFAMCLs, striking a balance between robust antimicrobial performance and optimal biocompatibility, including safety and wearing comfort, is a key issue. This review provides a comprehensive overview of recent advancements in AFAMCLs technology. The focus is on the antimicrobial efficacy and safety of various strategies employed in AFAMCLs construction. Furthermore, this review investigates the potential impact of these strategies on CLs parameters related to wearer comfort. This review aims to contribute to the continuous improvement of AFAMCLs and provide a reference for the trade-off between resistance to microorganisms and wearing comfort. In addition, it is hoped that this review can also provide a reference for the antimicrobial design of other medical devices.