Late Spontaneous Postradial Keratotomy Corneal Perforation After Scleral Contact Lens Use-Case Report.

PURPOSE: To describe a case of late spontaneous postradial keratotomy corneal perforation after scleral contact lens (SCL) wear for optic correction. SETTING: Tertiary referral center for corneal pathology. DESIGN: Case report. RESULTS: A 64-year-old man presented the consequences of a late radial keratotomy (RK) surgery performed for myopia correction 26 years ago. His ophthalmologic history was a RK in both eyes (BE), previous Lasik surgery in BE and Lasik enhancement in the right eye (RE), and pterygium excision with conjunctival transplantation in RE. To improve visual acuity, SCL were fitted in both eyes. After 8 months of use, on a certain day, when removing the lens from the RE, the patient reported experiencing intense eye pain and reduced visual acuity. On ophthalmologic examination, the RE cornea was perforated in one of the previous RK incisions. An urgent corneal transplant was performed in the RE, followed by cataract surgery in the same eye. CONCLUSION: Corneal instability caused by RK scars and daily manipulation with the SCL use may have led to ocular perforation.

Ectatic diseases.

Ectatic corneal disease (ECD) comprises a group of disorders characterized by progressive thinning and subsequent bulging of the corneal structure. Different phenotypes have been recognized, including keratoglobus, pellucid marginal degeneration (PMD), and keratoconus (KC). Keratoconus has been widely investigated throughout the years, but the advent of laser refractive surgery boosted an immediate need for more knowledge and research about ectatic diseases. This article discusses nomenclature of ectatic disease, etiology and pathogenesis, along with treatment options, with special focus ok KC and forme fruste keratoconus.

The role of Acanthamoeba spp. in biofilm communities: a systematic review.

Acanthamoeba spp. have always caused disease in immunosuppressed patients, but since 1986, they have become a worldwide public health issue by causing infection in healthy contact lens wearers. Amoebae of the Acanthamoeba genus are broadly distributed in nature, living either freely or as parasites, and are frequently associated with biofilms throughout the environment. These biofilms provide the parasite with protection against external aggression, thus favoring its increased pathogeny. This review aims to assess observational studies on the association between Acanthamoeba spp. and biofilms, opening potential lines of research on this severe ocular infection. A systematic literature search was conducted in May 2020 in the following databases: PubMed Central®/Medline, LILACS, The Cochrane Library, and EMBASE®. The studies were selected following the inclusion and exclusion criteria specifically defined for this review. Electronic research recovered 353 publications in the literature. However, none of the studies met the inclusion criterion of biofilm-producing Acanthamoeba spp., inferring that the parasite does not produce biofilms. Nonetheless, 78 studies were classified as potentially included regarding any association of Acanthamoeba spp. and biofilms. These studies were allocated across six different locations (hospital, aquatic, ophthalmic and dental environments, biofilms produced by bacteria, and other places). Acanthamoeba species use biofilms produced by other microorganisms for their benefit, in addition to them providing protection to and facilitating the dissemination of pathogens residing in them.

Role of the corneal epithelium measurements in keratorefractive surgery.

PURPOSE OF REVIEW: Refractive surgery has stimulated considerable progress in corneal and anterior segment imaging, and optical characterization of the eye. From front surface corneal topography, we evolved to three-dimensional corneal tomography with limbus to limbus characterization of the front and back corneal surfaces and pachymetric mapping. Corneal anatomical evaluation has further evolved to layered or segmental tomography with the ability to characterize corneal epithelial thickness profile and the elevation of stromal front surface. Further characterization of even more specific structures, such as Bowman's layer and Descement's membrane, has been also demonstrated. The applications of such understanding in keratorefractive surgery are reviewed. RECENT FINDINGS: Understanding the corneal epithelial profile is of interest in many areas of ophthalmology, especially in refractive surgery. The most relevant applications include screening candidates at higher risk for complications (i.e. progressive ectasia and tear dysfunction syndrome), planning primary procedures, enhancements, and therapeutic surgery, and also postoperatively understanding the wound healing and clinical outcomes. SUMMARY: Corneal epithelial thickness was first available using digital very-high-frequency ultrasound. Advances in anterior segment optical coherence tomography enabled such fundamental evaluation, which accelerated progress. Such knowledge significantly impacts safety and efficacy of refractive surgery, and also allows for significant improvement for therapeutic procedures. VIDEO ABSTRACT.

Absence of bacterial or fungal growth in vials of reconstituted botulinum toxin type A after storage.

BACKGROUND: Botulinum toxin type A (BTX-A; Botox) is supplied as individual freeze-dried preparations that should be administered within 24 hours after reconstitution. To avoid wasting this expensive drug, some physicians have resorted to storing vials of reconstituted BTX-A beyond the recommended duration. However, there is insufficient evidence to indicate that the sterility of previously reconstituted BTX-A is maintained during storage. OBJECTIVES: The authors sought to determine whether bacterial and/or fungal proliferation occurred in vials of reconstituted BTX-A and subsequent storage of the remaining solution under refrigeration for 4 weeks. METHODS: A portion of the contents of 88 consecutive 100-U vials of BTX-A was administered aseptically to 108 patients for essential blepharospasm, hemifacial spasm, or facial rejuvenation. The vials were then stored for 4 weeks in a refrigerator, after which the contents were transferred to various media (blood agar, chocolate agar, Sabouraud agar, brain-heart infusion medium, and thioglycolate broth) and assessed for bacterial and/or fungal growth by standard methods. RESULTS: None of the BTX-A vials contained detectable bacterial or fungal contamination after 4 weeks of storage. CONCLUSIONS: Storing vials of reconstituted BTX-A for 4 weeks after administration to patients was not associated with detectable growth of bacteria or fungi.

Characterization of ocular methicillin-resistant Staphylococcus epidermidis isolates belonging predominantly to clonal complex 2 subcluster II.

Staphylococcus epidermidis is an abundant member of the microbiota of the human skin and wet mucosa, which is commonly associated with sight-threatening infections in eyes with predisposing factors. Ocular S. epidermidis has become notorious because of its capability to form biofilms on different ocular devices and due to the evolving rates of antimicrobial resistance. In this study, the molecular epidemiology of 30 ocular methicillin-resistant S. epidermidis (MRSE) isolates was assessed using multilocus sequence typing (MLST). Antimicrobial resistance, accessory gene-regulator and staphylococcal cassette chromosome mec (SCCmec) types, biofilm formation, and the occurrence of biofilm-associated genes were correlated with MLST clonal complexes. Sequence types (STs) frequently found in the hospital setting were rarely found in our collection. Overall, 12 different STs were detected with a predominance of ST59 (30%), ST5 and ST6 (13.3% each). Most of the isolates (93.3%) belonged to the clonal complex 2 (CC2) and grouped mainly within subcluster CC2-II (92.9%). Isolates grouped within this subcluster were frequently biofilm producers (92.3%) with a higher occurrence of the aap (84.5%) and bhp (46.1%) genes compared to icaA (19.2%). SCCmec type IV (53.8%) was predominant within CC2-II strains, while 38.4% were nontypeable. In addition, CC2-II strains were frequently multidrug resistant (80.7%) and demonstrated to be particularly resistant to ciprofloxacin (80.8%), ofloxacin (77%), azithromycin (61.5%), and gentamicin (57.7%). Our findings demonstrate the predominance of a particular MRSE cluster causing ocular infections, which was associated with high rates of antimicrobial resistance and particularly the carriage of biofilm-related genes coding for proteinaceous factors implicated in biofilm accumulation.

Comparison of culture media for ex vivo cultivation of limbal epithelial progenitor cells.

PURPOSE: To compare the effectiveness of three culture media for growth, proliferation, differentiation, and viability of ex vivo cultured limbal epithelial progenitor cells. METHODS: Limbal epithelial progenitor cell cultures were established from ten human corneal rims and grew on plastic wells in three culture media: supplemental hormonal epithelial medium (SHEM), keratinocyte serum-free medium (KSFM), and Epilife. The performance of culturing limbal epithelial progenitor cells in each medium was evaluated according to the following parameters: growth area of epithelial migration; immunocytochemistry for adenosine 5'-triphosphate-binding cassette member 2 (ABCG2), p63, Ki67, cytokeratin 3 (CK3), and vimentin (VMT) and real-time reverse transcription polymerase chain reaction (RT-PCR) for CK3, ABCG2, and p63, and cell viability using Hoechst staining. RESULTS: Limbal epithelial progenitor cells cultivated in SHEM showed a tendency to faster migration, compared to KSFM and Epilife. Immunocytochemical analysis showed that proliferated cells in the SHEM had lower expression for markers related to progenitor epithelial cells (ABCG2) and putative progenitor cells (p63), and a higher percentage of positive cells for differentiated epithelium (CK3) when compared to KSFM and Epilife. In PCR analysis, ABCG2 expression was statistically higher for Epilife compared to SHEM. Expression of p63 was statistically higher for Epilife compared to SHEM and KSFM. However, CK3 expression was statistically lower for KSFM compared to SHEM. CONCLUSIONS: Based on our findings, we concluded that cells cultured in KSFM and Epilife media presented a higher percentage of limbal epithelial progenitor cells, compared to SHEM.

Bilateral interstitial keratitis in a patient with presumed brain tuberculoma.

Interstitial keratitis is an inflammation of the corneal stroma without epithelium or endothelium involvement. The underlying causes are mostly infectious or immune mediated. Brazil has one of the highest incidence rates of tuberculosis in the world. Tuberculosis is considered one of the causes of interstitial keratitis. Malnutrition and anemia are risk factors of the disseminated disease. This is a case report of a 10-year-old child who presented with decreased visual acuity and a clinical diagnosis of bilateral interstitial keratitis and sclero-uveitis. The patient had been treated with topical steroids with partial improvement. Examinations revealed severe iron deficiency anemia, negative serologies for human immunodeficiency virus and syphilis, positivity for cytomegalovirus- and herpes simplex-specific IgG, and purified protein derivative of 17 mm. During the follow-up, the patient presented with tonic-clonic seizures, and magnetic resonance imaging findings suggested a central nervous system tuberculoma. Interstitial keratitis improvement was observed after specific tuberculosis treatment. This is the first case report describing the association of interstitial keratitis and central nervous system tuberculoma.

Microbial keratitis in Sao Paulo, Brazil: a 10-year review of laboratory results, epidemiological features, and risk factors.

PURPOSE: To study epidemiological data, laboratory results, and risk factors associated with microbial keratitis. METHODS: We conducted a retrospective study of corneal sample cultures from patients with microbial keratitis from January 2010 to December 2019. Results were analyzed according to the etiological diagnosis of bacterial, mycotic, or parasitic infection and were associated with related risk factors. RESULTS: We analyzed 4810 corneal samples from 4047 patients (mean age 47.79 ± 20.68 years; male 53.27%). The prevalence of bacterial, fungal, and Acanthamoeba infections were 69.80%, 7.31%, and 3.51%, respectively. The most frequently isolated bacteria were coagulase-negative Staphylococcus (CoNS) (45.14%), S. aureus (10.02%), Pseudomonas spp. (8.80%), and Corynebacterium spp. (6.21%). Among CoNS, the main agent was S. epidermidis (n=665). For mycotic keratitis, Fusarium spp. (35.42%) and Candida parapsilosis (16.07%) were the most common agents among filamentous and yeasts isolates, respectively. Contact lens use was associated with a positive culture for Acanthamoeba spp. (OR = 19.04; p < 0.001) and Pseudomonas spp. (OR = 3.20; p < 0.001). Previous ocular trauma was associated with positive fungal cultures (OR = 1.80; p = 0.007), while older age was associated with positive bacterial culture (OR = 1.76; p = 0.001). CONCLUSIONS: Our findings demonstrated a higher positivity of corneal sample cultures for bacteria. Among those, CoNS was the most frequently identified, with S. epidermidis as the main agent. In fungal keratitis, Fusarium spp. was the most commonly isolated. Contact lens wearers had higher risks of positive cultures for Acanthamoeba spp. and Pseudomonas spp. Ocular trauma increased the risk of fungal infection, while older age increased the risk of bacterial infection.

Corneal ectasia detection by epithelial pattern standard deviation from OCT.

PURPOSE: To test the ability of the corneal epithelial pattern standard deviation (PSD) to distinguish between normal and cases with corneal ectatic condition. SETTING: Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil. DESIGN: Cross-sectional retrospective study. METHODS: Patients were stratified into 4 groups based on clinical data and corneal tomography. Groups 1 and 2 comprised 1 eye randomly selected from 105 patients with normal corneas (N) and 86 patients with bilateral keratoconus (KC). Groups 3 and 4, respectively, comprised 11 ectatic eyes with no surgical treatment for KC (very asymmetric ectasia [VAE]-E) from patients whose fellow eyes (61) presented with normal topographic patterns (VAE-NT). Corneas were scanned using an OCT system (RT Vue) and Scheimpflug corneal tomography (Pentacam) and also had biomechanical assessment through the Corvis ST. Corneal epithelial thickness maps were analyzed, and the PSD value was calculated. The area under the receiver operating characteristic curve analysis was used to evaluate the diagnostic accuracy of the indices. RESULTS: A total of 105 normal eyes, 86 keratoconic eyes, and 11 ectatic eyes whose fellow eyes (61) presented normal topographic patterns were evaluated. Epithelial PSD was significantly different across the 4 groups ( P < .0001). The pairwise comparison revealed that the normal group presented significantly lower values than both ectasia groups (KC and VAE-E, P < .0001) and the VAE-NT group ( P = .0008). There was no statistical significant difference between KC and VAE-E ( P = .4284), while they were significantly higher than the VAE-NT group ( P < .0001 and P = .0004). CONCLUSIONS: Epithelial PSD can be used to detect abnormal epithelial thickness patterns. Corneal epithelial thickness changes could be detected accurately in patients with KC, even in the form fruste of the disease.

In Vitro Evaluation of Rose Bengal Photoactivated by Custom-Built Green Light-Emitting Diode Source for Bacteria and Rapidly Growing Mycobacteria Inhibition.

Purpose: In vitro evaluation of rose bengal (RB) photoactivated by our custom-built green light-emitting diode (LED) source for the growth inhibition of bacterial strains and rapidly growing mycobacterial (RGM) isolates in infectious keratitis. Methods: Six corneal clinical bacteria isolates were included in this study: two Gram-positive bacteria (methicillin-resistant Staphylococcus aureus [MRSA] and Staphylococcus epidermidis), two Gram-negative bacteria (Pseudomonas aeruginosa and Serratia marcescens), and two RGM (Mycobacterium chelonae and Mycobacterium abscessus). Microorganisms were cultured and incubated at specific conditions and prepared in suspensions to adjust their concentration to 104 cells/mL. Different treatments were conducted in triplicates: Group I, no treatment; Group II, treated with 0.1% rose bengal alone (exposed to dark for 30 minutes); Group III, exposed to custom green LED for 30 minutes (12.87 J/cm2); and Group IV, treated with 0.1% rose bengal and exposed to custom green LED for 30 minutes. Agar plates were incubated at specific conditions and photographed after growth for pixel analyses. Results: Complete growth inhibition of all bacteria and RGM was observed in Group IV. MRSA and S. epidermidis in Group II also showed complete growth inhibition. Conclusions: The custom-built green LED presented good activity by photoactivating RB and inhibiting micro-organism growth. For the first time, we demonstrated the expressive growth inhibition effect of RB against S. epidermidis, RGM, and S. marcescens. Clinical treatment with RB may offer an alternate adjunct therapy for corneal surface infections. Translational Relevance: Validating in vitro the custom-built green LED encourages the clinical application for the treatment of infectious keratitis.

Candida species causing fungal keratitis: molecular identification, antifungal susceptibility, biofilm formation, and clinical aspects.

The study aimed to evaluate the clinical aspects, molecular identification, biofilm formation, and antifungal susceptibility profile of Candida species isolated from fungal keratitis. Thirteen Candida isolates from 13 patients diagnosed with Candida keratitis were retrieved and grown in pure culture. Species identification was performed by micromorphology analysis and ITS-rDNA sequencing. The broth microdilution method tested the minimum inhibitory concentration (MIC) of four antifungal drugs (fluconazole, amphotericin B, voriconazole, and anidulafungin). The biofilms were cultured and incubated with antifungal drugs for 24 h. The XTT reduction assay measured the biofilm activity. Biofilm MICs were calculated based on a 50% reduction in metabolic activity compared with the activity of the drug-free control. Among isolates, two were C. albicans, 10 were C. parapsilosis (sensu stricto), and one was C. orthopsilosis. All isolates were classified as susceptible or intermediate to all four antifungal drugs. Four isolates were very low biofilm producers (30%). Nine isolates were biofilm producers, and all biofilm samples were unsusceptible to all drugs tested. Previous ocular surgery was the most common underlying condition for fungal keratitis (84.6%), and C. parapsilosis was the most frequent Candida species (76.9%). Four patients (30.7%) needed keratoplasty, whereas two (15.3%) required evisceration. The biofilm formation ability of Candida isolates decreased antifungal susceptibility compared with planktonic cells. Despite in vitro antifungal susceptibility, almost half of the patients were unresponsive to clinical treatment and needed surgery.

Standardized clinical photography: the role of flash.

Medical photographic documentation is important for professional, research, and ethical concerns. This study analyzed the possible interference that the flash could cause on evaluation of lower eyelid cosmetic results. Standardized photographs with and without flash were taken of 10 patients with dermatochalasis. The photographs were evaluated by 3 independent observers, as before (without flash) and after (with flash) an alternative esthetic treatment of the lower eyelid. The observers rated the overall cosmetic improvement of the lower eyelid photographs on a visual analog scale. The 3 surgeons believed that there was improvement in cosmetic outcome from the first (without flash) to the second (with flash) picture. The results indicate that a simple flash addition in one of 2 consecutive photographs, taken seconds apart, could influence the impression of experienced surgeons on the final outcome of oculoplastic surgeries and may constitute a bias in observer-dependent studies.

Evaluation of the Pathogenic Potential of Escherichia coli Strains Isolated from Eye Infections.

While primarily Gram-positive bacteria cause bacterial eye infections, several Gram-negative species also pose eye health risks. Currently, few studies have tried to understand the pathogenic mechanisms involved in E. coli eye infections. Therefore, this study aimed to establish the pathogenic potential of E. coli strains isolated from eye infections. Twenty-two strains isolated between 2005 and 2019 from patients with keratitis or conjunctivitis were included and submitted to traditional polymerase chain reactions (PCR) to define their virulence profile, phylogeny, clonal relationship, and sequence type (ST). Phenotypic assays were employed to determine hemolytic activity, antimicrobial susceptibility, and adhesion to human primary corneal epithelial cells (PCS-700-010). The phylogenetic results indicated that groups B2 and ST131 were the most frequent. Twenty-five virulence genes were found among our strains, with ecp, sitA, fimA, and fyuA being the most prevalent. Two strains presented a hemolytic phenotype, and resistance to ciprofloxacin and ertapenem was found in six strains and one strain, respectively. Regarding adherence, all but one strains adhered in vitro to corneal cells. Our results indicate significant genetic and virulence variation among ocular strains and point to an ocular pathogenic potential related to multiple virulence mechanisms.

The Impact of the COVID-19 Pandemic on Corneal Transplantation in Brazil.

PURPOSE: The purpose of this study was to evaluate the impact of the coronavirus disease 2019 pandemic on corneal transplantation (CT) in Brazil. METHODS: Data from patients who underwent CT at the Hospital Oftalmológico de Sorocaba (HOS), Brazil, were analyzed. National and state numbers of keratoplasties, patients added to the CT waiting list, and total patients on the waiting list were also obtained. Baseline prepandemic (from January 1, 2019, to March 31, 2020) data were compared with 2 time frames of the coronavirus disease 2019 pandemic: elective CT suspension period (between April 1, 2020, and September 31, 2020) and after elective CT resumption (between October 1, 2020, and April 30, 2021). RESULTS: Despite elective CT resumption after the moratorium, the monthly CT rates did not return to baseline at HOS (-14.7%, P = 0.007), São Paulo state (-19.1%, P = 0.001), or Brazil (-30.1%, P < 0.001). The waiting list increased significantly regionally (P < 0.001) and nationally (P < 0.001). Among optical keratoplasties performed at HOS after resuming elective CTs, the proportion of endothelial keratoplasties declined from 38.2% to 30.0% (P < 0.001), whereas penetrating keratoplasties increased from 33.2% to 39.5% (P < 0.001) when comparing with prepandemic data. CONCLUSIONS: Keratoplasty numbers dropped significantly locally, regionally, and nationally. Hence, the CT waiting lists had a progressive increase, with significant long-term implications. An estimated increment on monthly CT rates of approximately 34% in São Paulo state, and 91% in Brazil, is required for the CT waiting list to get back to prepandemic numbers over the next 2 years.

Trends in Corneal Transplantation in a Tertiary Hospital in Brazil.

PURPOSE: The purpose of this study was to analyze the evolving trends of surgical techniques and indications of corneal transplantation (CT) at a tertiary hospital in Brazil. METHODS: The medical records of all patients who underwent CT at the Hospital Oftalmológico de Sorocaba (Sorocaba Eye Hospital) from the Banco de Olhos de Sorocaba (Sorocaba Eye Bank) group in Sorocaba, Brazil, from January 1, 2012, to December 31, 2019, were analyzed. Data regarding age, sex, transplant indication, and surgical technique were collected. RESULTS: A total of 16,250 CTs were performed. There was a statistically significant decreasing trend of keratoconus-related CT ( P < 0.0001), with rates dropping from 41.7% among all CTs in 2012 to 25.5% in 2019. Penetrating keratoplasty, anterior lamellar keratoplasty, and endothelial keratoplasty (EK) accounted for 59.3%, 27.1%, and 7.8% of the CTs performed in 2012 and 33.3%, 16.4%, and 39.9% in 2019, respectively. A statistically significant decreasing trend was observed for penetrating keratoplasty ( P < 0.0001) and anterior lamellar keratoplasty ( P < 0.0001), whereas EK showed a statistically significant increasing trend during the period ( P < 0.0001). Among EKs, Descemet membrane EK increased statistically significantly from 12.8% in 2012 to 74.4% in 2019 ( P < 0.0001). CONCLUSIONS: This study shows relevant evolving trends in indications and preferred CT techniques in a tertiary hospital in Brazil.

Impact of COVID-19 on corneal esthesiometry.

Individuals with suspected COVID-19 symptoms (n=202) were tested using nasopharyngeal RT-qPCR. All individuals underwent corneal esthesiometry measurements using the Cochet-Bonnet esthesiometer during their first visit; 50 participants underwent an additional measurement at a mean interval of 32.5 (17.8) days. COVID-19 was confirmed in 101 subjects (50%) using nasopharyngeal PCR. The mean time from symptom onset to disease diagnosis and corneal esthesiometry was 4.2 (2.1) days. Mean corneal esthesiometry findings based on the positive and negative PCR status indicated no statistical difference. This study demonstrated that COVID-19 had no effect on corneal esthesiometry in individuals with acute-phase COVID-19.

Pseudomonas aeruginosa endophthalmitis after penetrating keratoplasty transmitted from the same donor to two recipients confirmed by pulsed-field gel electrophoresis.

Two devastating cases of multidrug-resistant Pseudomonas aeruginosa endophthalmitis after keratoplasty as the result of transmission from the same donor were confirmed by pulsed-field gel electrophoresis. Strategies for preventing donor-to-host transmission, such as the use of antimicrobial agents of greater efficacy and better methods for detecting microorganisms in preservation medium, could minimize this type of transmission.

Microbial keratitis at a referral center in Brazil.

To describe the epidemiological and laboratory characteristics of microbial keratitis at a referral center in Brazil. Charts of all patients referred to the Ocular Microbiology Laboratory at Federal University of São Paulo (UNIFESP) from July 1975 to September 2007 were retrospectively reviewed. The following data were recorded: age, gender, involved eye, use of ocular medication, previous trauma or surgery, contact lens wear and the results of laboratory cultures. The study included 6,804 corneal cultures. The mean age was 42.1 ± 21.4 years. The male-to-female ratio was 1.5:1. Positive cultures were obtained in 3,309 (48.6%) cases. Of these, bacteria were isolated in 2,699 (39.7%), fungi in 364 (5.3%) and Acanthamoeba in 246 (3.6%) samples. Positive bacterial cultures were 2.7-fold more frequent in patients with previous use of steroids (P < 0.01), and a 30% reduction in positive bacterial cultures was observed in patients with previous use of antibiotics (P < 0.01). A total of 1,524 patients (22.4%) had a past history of ocular surgery. Contact lens wearers showed a 1.7 times greater chance of having an Acanthamoeba-positive culture (P < 0.01). Previous ocular trauma was present in 1,118 (16.4%) cases and injury caused by plants showed a 3.8 times greater chance of a positive fungal culture (P < 0.01). Bacterial organisms were identified as the most frequent agent followed by fungi and Acanthamoeba. Prescription of steroids and antibiotics prior to corneal scrapings may modify the laboratory test results. Previous corneal surgery, contact lens wear and ocular trauma have been shown to be risk factors for bacterial, Acanthamoeba and fungal keratitis, respectively.

Three Decades of Contact Lens-associated Microbial Keratitis in a Referral Hospital in São Paulo, Brazil.

PURPOSE: The aim of this study was to analyze patient data and the laboratory results of corneal samples collected from patients followed at the Ophthalmology Department, Hospital São Paulo, Brazil over a 30-year period, and correlate the analize with contact lens wearing. METHODS: Corneal samples from patients diagnosed clinically with microbial keratitis between January 1987 and December 2016 were included in this study. Cultures that were positive for bacteria, fungi, and Acanthamoeba spp. were analyzed retrospectively. To ascertain if the number of patients with contact-lens-associated microbial keratitis (as a risk factor for microbial infection) changed over time, the analysis was divided into three decades: 1987-1996, 1997-2006, and 2007-2016. Information pertaining to patient gender and age, as well as type of organism isolated, were compared among these periods. RESULTS: The corneal samples of 10.562 patients with a clinical diagnosis of microbial keratitis were included in the study, among which 1.848 cases were related to the use of contact lenses. The results revealed that the frequency of contact-lens-associated microbial keratitis increased over the last two decades. Overall, females had contact-lens-associated microbial keratitis more frequently (59.5%). Patients aged 19-40 years also had contact-lens-associated microbial keratitis more frequently in all study periods. Staphylococcus spp. and Pseudomonas spp. were the most frequent Gram-positive and Gram-negative bacteria, respectively, in the microbial keratitis groups. Among the fungal cases of microbial keratitis, filamentous fungi were the most frequent fungi over the entire study period, with Fusarium spp. being the most frequent fungi in the group with microbial keratitis not associated with contact lens wearing (p<0.001). Samples positive for Acanthamoeba spp. and Pseudomonas spp. were significantly correlated with contact-lens-associated microbial keratitis (p<0.001). CONCLUSIONS: Females and young adults aged 19-40 years exhibited the highest frequency of contact-lens-associated microbial keratitis in our study. Staphylococcus spp. and Fusarium spp. were the predominant bacteria and fungi, respectively, isolated from corneal samples. Pseudomonas spp. and Acanthamoeba spp. were significantly correlated with contact-lens-associated microbial keratitis in this study.