Intraoperative Image Guidance in Orbital and Lacrimal Surgery: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the efficacy and safety of the use of intraoperative image guidance (IIG) in orbital and lacrimal surgery. METHODS: A literature search of the PubMed database was last conducted in November 2023 for English-language original research that assessed the use of any image guidance system in orbital and lacrimal surgery that included at least 5 patients. The search identified 524 articles; 94 were selected for full-text analysis by the panel. A total of 32 studies met inclusion criteria. The panel methodologist assigned a level II rating to 2 studies and a level III rating to 30 studies. No study met the criteria for level I evidence. RESULTS: Procedures reported on were as follows: fracture repair (n = 14), neoplasm and infiltrate biopsy or excision (n = 6), orbital decompression for Graves ophthalmopathy (n = 3), dacryocystorhinostomy (n = 1), and mixed etiology and procedures (n = 8). Four studies used more than one IIG system. One study that met level II evidence criteria compared the outcomes of orbital fracture repair with IIG (n = 29) and without IIG (n = 29). Borderline better outcomes were reported in the IIG group: 2% versus 10% with diplopia (P = 0.039) and 3% versus 10% with enophthalmos (P = 0.065). The other level II study compared the repair of fractures with navigation (n = 20) and without (n = 20). The group in which navigation was used had a measured mean volume reduction of 3.82 cm3 compared with 3.33 cm3 (P = 0.02), and there was a greater measured reduction in enophthalmos in the navigation group of 0.72 mm (P = 0.001). Although the remaining 30 assessed articles failed to meet level II criteria, all alleged a benefit from IIG. No complications were reported. CONCLUSIONS: A small number of comparative studies suggest that there are improved outcomes when IIG is used in orbital fracture repair, but each study suffers from various limitations. No high-quality comparative studies exist for the management of lacrimal surgery, neoplastic disease, or decompression. Complications attributable to the use of IIG have not been identified, and IIG has not been analyzed for cost savings. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

A phase II study of post-remission therapy with pembrolizumab in older patients with acute myeloid leukemia.

Not available.

Primary Canalicular MALT Lymphoma Masquerading as Chronic Canaliculitis.

A 67-year-old female presented with chronic canaliculitis and underwent canalicular marsupialization. During the procedure, a fleshy mass was found in the canaliculus, which was excised completely and sent to pathology. Histology confirmed the diagnosis of extranodal marginal zone mucosa-associated lymphoid tissue lymphoma. The patient underwent staging with positron emission tomography/CT scan, which did not show any hypermetabolic foci elsewhere in the body, so the patient elected to undergo close observation without further treatment. At 12 months of follow-up, the patient has remained disease-free.

Oculoplastic Management of an Eyelid Zipper Injury.

We present a case of a zipper injury to an upper eyelid in a pediatric patient. The zipper was successfully removed in the operating room by using a double-action bone cutter to cut the median footplate of the zipper and release the entrapped tissue. Zipper injuries are well-described in urology literature, however, limited case reports exist in ophthalmology literature. We review several methods for zipper removal and present special considerations for eyelid injuries.

Orbital Richter Transformation With Subsequent Orbital MALT-type Lymphoma in a Patient With Chronic Lymphocytic Leukemia.

A 74-year-old man with a history of chronic lymphocytic leukemia (CLL) presented with large salmon-colored patch lesions along the inferior fornix and superotemporal conjunctiva of the OS. The patient underwent an incisional biopsy of the lesions, which showed a CLL with areas of large B-cell lymphoma, consistent with Richter transformation. Following medical and radiation-based therapy of these lesions, the patient returned 3 months later with inferomedial preseptal swelling in the contralateral eye, which biopsy proved to be recurrent/resistant low-grade CLL with a posttreatment extranodal marginal zone B-cell lymphoma pattern. This case exemplifies a rare presentation of CLL with Richter transformation and a recurrent/resistant posttreatment orbital CLL with a marginal zone B-cell lymphoma-like pattern.

Recurrence following ptosis repair surgery: a multivariate analysis of risk factors.

PURPOSE: To identify and evaluate the risk factors for ptosis repair failure. METHODS: Retrospective, case-controlled study evaluating adult patients with ptosis who underwent ptosis surgery by external levator advancement/resection (ELR) or Müller muscle conjunctival resection (MMCR) with at least 3 months postoperative follow-up. Regression analyses were performed of ptosis repair outcomes comparing preoperative and perioperative risk factors for failure. RESULTS: A total of 240 patients (404 eyelids) met the inclusion criteria for the study. Surgical outcomes were measured categorically by success rate and measured quantitively over time using Kaplan-Meier survival analysis. Success was categorically achieved in 101/112 (90%) eyelids after MMCR and 231/292 (79%) eyelids after ELR (p = .0088). Success as measured over 5 years of follow-up was significantly better in eyelids following MMCR compared to ELR (p = .0469). In terms of surgical failure, the following variables were found to be predictive in order of decreasing risk: chronic topical prostaglandin use, chronic topical corticosteroid use, surgical approach, lower preoperative margin reflex distance 1, prior intraocular surgery, age, lower preoperative levator function, concomitant blepharoplasty, presence of a glaucoma filtering bleb, and female gender. CONCLUSIONS: Ptosis repair surgery is a complex and challenging procedure. This study provides the largest comparative analysis of ELR versus MMCR to date with findings suggesting MMCR to be more a successful surgery than ELR. Topical prostaglandin analogue use appears to be the highest known risk factor for MMCR and ELR ptosis repair failure.

Therapy With Allogeneic Severe Acute Respiratory Syndrome Coronavirus-2-Specific T Cells for Persistent Coronavirus Disease 2019 in Immunocompromised Patients.

We administered severe acute respiratory syndrome coronavirus-2 viral-specific T cells (VSTs) under emergency investigational new drug applications to 6 immunocompromised patients with persistent coronavirus disease 2019 (COVID-19) and characterized clinical and virologic responses. Three patients had partial responses after failing other therapies but then died. Two patients completely recovered, but the role of VSTs in recovery was unclear due to concomitant use of other antivirals. One patient had not responded to 2 courses of remdesivir and experienced sustained recovery after VST administration. The use of VSTs in immunocompromised patients with persistent COVID-19 requires further study.

Use of Mitomycin C in Dacryocystorhinostomy: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the literature on the adjuvant use of mitomycin C (MMC) during dacryocystorhinostomy (DCR) in adults with primary nasolacrimal duct obstructions (NLDOs) to determine the efficacy in improving functional and anatomic outcomes with an acceptable level of risk. METHODS: A literature search conducted in November 2020 and updated in November 2022 yielded 137 articles. Twenty-four articles met the inclusion criteria and were rated for level of evidence by the panel methodologist. Inclusion criteria required controlled studies on the effect of MMC on outcomes of external, endoscopic endonasal, or diode laser-assisted transcanalicular DCR in adults with primary acquired nasolacrimal obstruction with 6 months minimum follow-up and at least 10 participants. RESULTS: Six of the 24 articles were rated level I evidence, 15 level II , and 3 level III. In primary external DCR, MMC significantly improved functional outcomes in 3 of 9 series. In primary endoscopic endonasal DCR, MMC significantly improved functional outcomes in 1 of 9 series. In revision endoscopic endonasal DCR, MMC significantly improved functional success in 1 of 3 series. The use of MMC did not improve outcomes statistically in any diode laser-assisted transcanalicular DCR studies. Concentrations of MMC ranged from 0.05 to 1 mg/ml, with 0.2 mg/ml used most frequently in 12 series, with duration of application ranging from 2 to 30 minutes. Ostium size was significantly larger in MMC groups than in control groups at 6 months after surgery in 4 of 5 reporting studies. However, these larger ostia did not confer higher functional success rates. Reporting of adverse events related to MMC were rare, with delayed cutaneous wound healing reported in 1 of 750 patients. CONCLUSIONS: Intraoperative use of MMC in external and endoscopic endonasal DCR has been shown to improve functional and anatomic outcomes compared with controls in some series, but there is no agreement on the recommended concentration or application time for MMC in DCR. The data support that MMC use can result in a larger ostium size, decreased granulation tissue formation, and a decreased number of postoperative nasal debridements compared with controls, but this does not translate into improved functional success. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Manufacturing and validation of Good Manufacturing Practice-compliant regulatory dendritic cells for infusion into organ transplant recipients.

BACKGROUND AIMS: Regulatory (or "tolerogenic") dendritic cells (DCregs) are a highly promising, innovative cell therapy for the induction or restoration of antigen-specific tolerance in immune-mediated inflammatory disorders. These conditions include organ allograft rejection, graft-versus-host disease following bone marrow transplantation and various autoimmune disorders. DCregs generated for adoptive transfer have potential to reduce patients' dependence on non-specific immunosuppressive drugs that can induce serious side effects and enhance the risk of infection and certain types of cancer. Here, our aim was to provide a detailed account of our experience manufacturing and validating comparatively large numbers of Good Manufacturing Practice-grade DCregs for systemic (intravenous) infusion into 28 organ (liver) transplant recipients and to discuss factors that influence the satisfaction of release criteria and attainment of target cell numbers. RESULTS: DCregs were generated in granulocyte-macrophage colony stimulating factor and interleukin (IL)-4 from elutriated monocyte fractions isolated from non-mobilized leukapheresis products of consenting healthy adult prospective liver transplant donors. Vitamin D3 was added on day 0 and 4 and IL-10 on day 4 during the 7-day culture period. Release and post-release criteria included cell viability, purity, phenotype, sterility and functional assessment. The overall conversion rate of monocytes to DCregs was 28 ± 8.2%, with 94 ± 5.1% product viability. The mean cell surface T-cell co-inhibitory to co-stimulatory molecule (programmed death ligand-1:CD86) mean fluorescence intensity ratio was 3.9 ± 2.2, and the mean ratio of anti-inflammatory:pro-inflammatory cytokine product (IL-10:IL-12p70) secreted upon CD40 ligation was 60 ± 63 (median = 40). The mean total number of DCregs generated from a single leukapheresis product (n = 25 donors) and from two leukapheresis products (n = 3 donors) was 489 ± 223 × 106 (n = 28). The mean total number of DCregs infused was 5.9 ± 2.8 × 106 per kg body weight. DCreg numbers within a target cell range of 2.5-10 × 106/kg were achieved for 25 of 27 (92.6%) of products generated. CONCLUSIONS: High-purity DCregs meeting a range of quality criteria were readily generated from circulating blood monocytes under Good Manufacturing Practice conditions to meet target cell numbers for infusion into prospective organ transplant recipients.

Flammability of Ocular Surface Lubricants.

PURPOSE: Surgical fires pose a substantial risk to patients and can cause significant injury, especially in oculofacial surgery. Ocular surface lubricants can potentially act as fuel for an operating room fire. We present an experimental analysis of the flammability of 9 commonly used ophthalmic lubricants under 4 ignition sources used in oculofacial surgery with and without supplemental oxygen. METHODS: The flammability of 9 ophthalmic lubricants were tested under various operating room conditions. Each lubricant was exposed to 4 different ignition sources: an open flame lighter, monopolar cautery, bipolar cautery, and hand-held high temperature cautery, and the response of the lubricant was recorded. The testing was conducted both in room air and with 6 L/minute of 100% oxygen directed at the lubricant through a nasal cannula. Any reaction in which there was ignition, sparking, smoking, or a transient or permanent change in appearance of the lubricant was deemed notable. RESULTS: Of the 9 lubricants tested, 4 displayed a reaction to the ignition source. Without supplemental oxygen, 100% petrolatum and neomycin-polysporin-bacitracin-hydrocortisone ointment produced some smoke when applied with the high temperature cautery. Notably, under both the conditions of no supplemental oxygen and with the addition of 6 L/minute of 100% oxygen, the carboxymethylcellulose drops and lidocaine jelly both conducted and sparked with the monopolar cautery leaving visible burn marks on the paper. CONCLUSIONS: The overall fire hazard posed by ocular surface lubricants is low. Some topical lubricants can conduct electricity from monopolar cautery, which could increase the risk of inadvertent electrical burns. Certain lubricants could potentially become a fuel source when used in combination with hand-held high temperature battery cautery. Bipolar cautery was not associated with either increased conductivity or flammability with any of the lubricants tested.

Bilateral Congenital Nasolacrimal Duct Obstruction in Williams-Beuren Syndrome.

A 23-year-old patient with Williams-Beuren syndrome presented with ocular irritation and bilateral persistent tearing. Despite probing as an infant which showed bilateral nasolacrimal duct obstruction, dacryocystorhinostomy had been avoided due to the patient's syndromic supravalvular stenosis and related anesthesia risk. As the known diminished production of elastin in Williams-Beuren syndrome causes an array of associated vascular diseases, this case report hypothesizes that the lacrimal duct becomes obstructed through a similar mechanism. This case presents the unique findings of bilateral congenital nasolacrimal duct stenosis in a Williams-Beuren syndrome patient.

Orbital Dermoid Cysts in Monozygotic Twins.

Two healthy 12-year-old monozygotic twin sisters presented with strikingly similar, painless orbital masses along their frontozygomatic suture line that had been slowly enlarging since birth. The masses were clinically consistent with orbital dermoid cysts and the patients underwent excision of their lesions, with the diagnosis confirmed by histological analysis. There are prior case reports of both nasal and ovarian dermoid cysts in twins, however, no prior case of orbital dermoid cysts in twins have been described. These dermoid cysts are generally thought to be a sporadic disorder of embryogenesis, yet the authors' case suggests genetics may play a role in the underlying etiology of dermoid cysts.

Trends in Residency Academic Productivity of Ophthalmic Plastic and Reconstructive Surgery Fellows Between 2012 and 2019.

PURPOSE: To characterize research productivity of ophthalmic plastic and reconstructive surgery (OPRS) fellows during residency. METHODS: A database was compiled of OPRS fellows listed on the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) Annual Fall Scientific Symposium program books who began their fellowship between 2012 and 2019. PubMed was searched for all publications published between July 1st of the year they began residency and September 30th of the year they began fellowship training. Bibliometric variables captured for each fellow included: the number of publications, first-author publications, and ophthalmology-related publications. RESULTS: A total of 197 OPRS fellows who began their fellowship training between 2012 and 2019 published a mean (± SD) of 2.42 ± 2.80 publications, 1.43 ± 1.85 first-author publications, and 2.33 ± 2.74 ophthalmology-related publications during residency. Linear regression revealed that the number of publications ( P < 0.001), first-author publications ( P < 0.001), and ophthalmology-related publications ( P < 0.001) that OPRS fellows published during residency have all significantly increased over the time assessed. CONCLUSIONS: The academic productivity of OPRS fellows during residency was quantified through bibliometric analysis to establish a national benchmark for the benefit of both prospective applicants and program directors. Residency research output of OPRS fellows has significantly increased between 2012 and 2019. Since ASOPRS program requirements necessitate academic productivity and thesis completion, publication records and involvement in research become valuable considerations when evaluating fellowship applicants. The knowledge of what accepted fellows have published provides the opportunity to make historical comparisons and may prove useful in the evaluation of the competitiveness of a given year's applicant pool.

Quantitative assessment of botulinum toxin injection on blink rate in blepharospasm.

PURPOSE: To objectively measure the blink rate in patients with blepharospasm managed by botulinum toxin type-A injections. METHODS: In this prospective, non-interventional case series, the complete blink rates of subjects were measured before incobotulinumtoxina injection and at follow-up within 4 weeks using slow-motion video-taping. Additionally, subjects graded the frequency of blinking, the severity of light-sensitivity, and the severity and frequency of dry eye symptoms on a categorical visual analog scale. The results are reported as median (range). RESULTS: Ten subjects were enrolled, with nine females. The total duration of treatment was 70 (5-116) months with total of 27.5 (2-51) injections. The subjects were grouped as short-time (<52w) or long-time (>52w) treatments. The median age, follow-up time, and injected doses were 73.5 (49-81) years, 21 (14-28) days, and 38 (8-47) units, respectively, with no significant difference between groups. The total complete blinks per minute before incobotulinumtoxina injection was 39 (23-64) which decreased to 18.5 (1-60) at follow-up (p = 0.004). The average change in complete blink rate was -67.4 ± 23.7% in long-time and -45.2 ± 31.2% in short-time groups (mean ± SD, p = 0.01). The total self-graded frequency of blinking and light-sensitivity decreased significantly at follow-up (p = 0.004, p = 0.047, respectively). Similar patterns of subject reported grades were seen in both groups. CONCLUSION: Videotaping is a low-cost method for objective measurement of blink rate in blepharospasm patients after incobotulinumtoxina injection. There was a significant reduction in blink rate after incobotulinumtoxina injections with higher percentage of change in the long-time treatment group. Incobotulinumtoxina injection also significantly improves subjective photophobia.

Homeopathic Agents or Vitamins in Reducing Ecchymosis after Oculofacial Surgery: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the published literature to determine the efficacy and safety of homeopathic agents or vitamins in reducing ecchymosis after oculofacial surgery or laser surgery. METHODS: A literature search was conducted in the PubMed database initially in December 2019 and updated in March 2020 to identify all studies in the English language literature on the use of homeopathic agents or vitamins in oculofacial procedures, including laser surgery. The search yielded 124 citations, and 11 articles met all inclusion criteria for this assessment. A panel methodologist then assigned a level of evidence rating for each study. Eleven studies met inclusion criteria; 9 were rated level I, and 2 were rated level III. RESULTS: The agents studied in the articles identified included oral or topical Arnica montana (AM), oral Melilotus extract, topical vitamin K oxide, and topical AM combined with Rhododendron tomentosum. Metrics to describe ecchymosis varied. In 7 controlled studies, perioperative AM provided no or negligible benefit versus placebo. In 2 studies, vitamin K cream was equivalent to placebo. One study of oral Melilotus extract had less ecchymosis compared with controls in paranasal and eyelid ecchymosis at postoperative day (POD) 7, but not at PODs 1 and 4. A lone cohort study of combined topical AM and R. tomentosum lacked objective metrics and adequate controls. No serious side effects from administration of homeopathic agents or vitamins were identified. CONCLUSIONS: The current literature does not support the use of AM, vitamin K oxide, R. tomentosum, or Melilotus extract for reducing ecchymosis after oculofacial surgery or pulsed dye laser surgery.

Orbital Radiation for Thyroid Eye Disease: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the current literature on the safety and efficacy of orbital radiation for the management of thyroid eye disease (TED). METHODS: A literature search was conducted last in February 2021 of the PubMed database to identify all articles published in the English language on original research that assessed the effect of orbital radiation on TED. The search identified 55 articles, and 18 met the inclusion criteria for this assessment. A panel methodologist then assigned a level of evidence rating for each study, and all of them were rated level III. RESULTS: Two large retrospective studies demonstrated the efficacy of radiation treatment, with or without corticosteroid use, in preventing or treating compressive optic neuropathy (CON). Three studies highlighted the role of orbital radiation therapy (RT) to facilitate the tapering of corticosteroids. Several other studies showed a possible role for RT to improve diplopia and soft tissue signs. CONCLUSIONS: Although no level I or level II evidence exists, the best available evidence suggests that orbital radiation, used with or without corticosteroids, is efficacious in preventing CON, improving motility restriction, and decreasing clinical activity in TED. Orbital radiation also may facilitate a corticosteroid taper. Together, these studies show that RT seems to modify the active phase of TED. Short-term risks of orbital radiation are minor, but long-term outcome data are lacking.

How do I: Evaluate the safety and legitimacy of unproven cellular therapies?

BACKGROUND: Unproven cellular therapies are being offered to patients for a variety of conditions and diseases for which other treatments have failed. The use of untested cellular therapies is a worldwide problem. Practitioners (e.g., physicians, scientists, QA/QI facility managers, and policy advocates) are perhaps unaware of the risks involved with such therapies. Therefore, a critical need exists to bring attention to the potential limitations and adverse effects of these therapies to inform and limit misinformation. STUDY DESIGN AND METHODS: We describe the extent of the unproven cellular therapy problem through a search of scientific literature and social media coverage. We also describe the regulatory framework that can be used by the practitioner to review and evaluate both proven and unproven cellular therapies. RESULTS: We report on the current state of unproven cellular therapies across the globe. A workflow to facilitate an understanding of the regulatory processes involved in the approval of cellular therapies is provided as well as a list of warnings required by regulatory agencies on various products. It is hoped that this article will serve as a tool kit to educate the practitioner on navigating the field of unproven cellular therapy products. DISCUSSION: Increasing awareness of the issues associated with unproven therapies through education is important to help in reducing misinformation and risks to patients.

CARD9 facilitates microbe-elicited production of reactive oxygen species by regulating the LyGDI-Rac1 complex.

In response to invading microorganisms, macrophages engage in phagocytosis and rapidly release reactive oxygen species (ROS), which serve an important microbicidal function. However, how phagocytosis induces ROS production remains largely unknown. CARD9, a caspase-recruitment domain (CARD)-containing protein, is important for resistance to fungal and bacterial infection. The mechanism of CARD9-mediated bacterial clearance is still mostly unknown. Here we show that CARD9 is required for killing intracellular bacteria in macrophages. CARD9 associated with the GDP-dissociation inhibitor LyGDI in phagosomes after bacterial and fungal infection and binding of CARD9 suppressed LyGDI-mediated inhibition of the GTPase Rac1, thereby leading to ROS production and bacterial killing in macrophages. Thus, our studies identify a key pathway that leads to microbe-elicited ROS production.

Interventions for Indirect Traumatic Optic Neuropathy: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the literature on the efficacy and safety of medical and surgical interventions for indirect traumatic optic neuropathy (TON), defined as injury to the nerve that occurs distal to the optic nerve head. METHODS: A literature search was conducted on October 22, 2019, and updated on April 8, 2020, in the PubMed database for English language original research that assessed the effect of various interventions for indirect TON. One hundred seventy-two articles were identified; 41 met the inclusion criteria outlined for assessment and were selected for full-text review and abstraction. On full-text review, a total of 32 studies met all of the study criteria and were included in the analysis. RESULTS: No study met criteria for level I evidence. Seven studies (1 level II study and 6 level III studies) explored corticosteroid therapy that did not have uniformly better outcomes than observation. Twenty studies (3 level II studies and 17 level III studies) assessed optic canal decompression and the use of corticosteroids. Although visual improvement was noted after decompression, studies that directly compared surgery with medical therapy did not report uniformly improved outcomes after decompression. Four studies (1 level II study and 3 level III studies) evaluated the use of erythropoietin. Although initial studies demonstrated benefit, a direct comparison of its use with observation and corticosteroids failed to confirm the usefulness of this medication. One study (level II) documented visual improvement with levodopa plus carbidopa. Complication rates were variable with all of these interventions. Pharmacologic interventions generally were associated with few complications, whereas optical canal decompression carried risks of serious side effects, including hemorrhages and cerebrospinal fluid leakage. CONCLUSIONS: Despite reports of visual improvement with corticosteroids, optic canal decompression, and medical therapy for indirect TON, the weight of published evidence does not demonstrate a consistent benefit for any of these interventions. In summary, no consensus exists from studies published to date on a preferred treatment for TON. Treatment strategies should be customized for each individual patient. More definitive treatment trials will be needed to identify optimal treatment strategies for indirect TON.

Rapid identification and discrimination of methicillin-resistant Staphylococcus aureus strains via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

RATIONALE: Methicillin-resistant Staphylococcus aureus (MRSA) is one of major clinical pathogens responsible for both hospital- and community-acquired infections worldwide. A delay in targeted antibiotic treatment contributes to longer hospitalization stay, higher costs, and increasing in-hospital mortality. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been integrated into the routine workflow for microbial identification over the past decade, and it has also shown promising functions in the detection of bacterial resistance. Therefore, we describe a rapid MALDI-TOF MS-based methodology for MRSA screening with machine-learning algorithms. METHODS: A total of 452 clinical S. aureus isolates were included in this study, of which 194 were MRSA and 258 were methicillin-sensitive S. aureus (MSSA). The mass-to-charge ratio (m/z) features from MRSA and MSSA strains were binned and selected through Lasso regression. These features were then used to train a non-linear support vector machine (SVM) with radial basis function (RBF) kernels to evaluate the discrimination performance. The classifiers' accuracy, sensitivity, specificity, and the area under the receiver operating characteristic (ROC) curve (AUC) were evaluated and compared with those from the random forest (RF) model. RESULTS: A total of 2601 unique spectral peaks of all isolates were identified and 38 m/z features were selected for the classifying model. The AUCs of the non-linear RBF-SVM model and the RF model were 0.89 and 0.87, respectively, and the accuracy ranged between 0.86 (RBF-SVM) and 0.82 (RF). CONCLUSIONS: Our study demonstrates that MALDI-TOF MS coupled with machine-learning algorithms could be used to develop a rapid and easy-to-use method to discriminate MRSA from MSSA. Considering that this method is easy to implement in routine microbiology laboratories, it suggests a cost-effective and time-efficient alternative to conventional resistance detection in the future to improve clinical treatment.