Extended-wear Contact Research Articles

Incidence, risk factors, and patient characteristics in severe contact lens-related microbial keratitis.

The aim of the present study was to determine the incidence, patient characteristics, and risk factors for severe, contact lens-related keratitis in patients in need of hospitalization. Keratitis was defined as severe when the disease required hospitalization. All patients with contact lens-related keratitis hospitalized at our department between 1 January 2018 and 31 December 2020 were interviewed with a questionnaire, about their use of contact lenses and knowledge of complications. Clinical information was collected from the medical records. A total of 41 patients (42 eyes) were hospitalized with severe keratitis during the 3-year period. The yearly incidence was 2.52 per 10 000 contact lens users over the age of 15 for extended-wear lenses used overnight, and 0.52 per 10 000 for users of daily disposable contact lenses. Pseudomonas aeruginosa was the most frequently isolated microbe. The median age was 50 years (range 15-66 years). Twenty-three patients (56%) were female, 28 patients (66%) used extended-wear contact lenses and 12 patients (29%) used daily disposable lenses. Nineteen patients (45%) admitted improper use. The median duration of contact lens use was 11.5 years. Only 15 patients (37%) had knowledge of keratitis as a potential complication. Most patients were experienced contact lens users. Users of extended-wear contact lenses worn overnight had a significantly higher risk of severe microbial keratitis. More focus on information and education of the risk of keratitis in contact lens users is needed.

Retrospective analysis on the outcomes of contact lens-associated keratitis in a tertiary centre: an evidence-based management protocol to optimise resource allocation

Background/aimsContact lens-associated keratitis (CLAK) is a common sight-threatening complication of contact lens use. Current management protocols in the UK are based on historical practice and necessitate a review for every...

Prevalence of Bacterial Keratitis in Contact Lens Wearing Female Medical Students in Sana'a, Yemen

Bacterial keratitis is bacterial infection of the cornea of eye and it is the fifth leading cause of blindness. Contact lens wearing is the most critical risk factor for microbial keratitis in developed countries and developing countries.In Yemen, females wear contact lens mainly for cosmetic purposes and there are no reliable statistics documenting the prevalence of Bacterial keratitis among contact lens wear especially among females. Amis: To find the prevalence of Bacterial keratitis and associated risk factors among female medical students at the National University who wear Contact Lenses in Sana'a city, Yemen. Methods: A cross-sectional structured questionnaire survey of 50 elements conducted to evaluate the behavioral and socio-demographic data.Corneal specimens were collected and cultured to isolate bacteria that cause keratitis. Results: the results revealed that, the prevalence rate of bacterial keratitis among participants was 72%. Staphylococcus aurous and coagulase negative staphylococci were the most common agents of bacterial keratitis.There were statistically significant differences between bacterial keratitis and age, extended wear contact lens wear, sharing contact lens with others, cleaning of contact lens and use eye drops. Conclusion: The major risk factors for bacterial keratitis include prolonged wear of contact lenses, sharing of lenses with others and poor hygiene practices when handling contact lenses. Female students aged 38–42 are the most at-risk group. Bacterial keratitis is preventable diseases.

Thymosin beta 4: A potential novel adjunct treatment for bacterial keratitis.

Microbial keratitis is a rapidly progressing, visually debilitating infection of the cornea that can lead to corneal scarring, endophthalmitis, and perforation. Corneal opacification or scarring, a complication of keratitis, is among the leading causes of legal blindness worldwide, second to cataracts.Pseudomonas aeruginosaandStaphylococcus aureusare the two bacteria most commonly associated with this type of infection. Risk factors include patients who are immunocompromised, those who have undergone refractive corneal surgery, and those with prior penetrating keratoplasty, as well as extended wear contact lens users. Current treatment of microbial keratitis primarily addresses the pathogen using antibiotics. Bacterial clearance is of utmost importance yet does not guarantee good visual outcome. Clinicians are often left to rely upon the eye's innate ability to heal itself, as there are limited options beyond antibiotics and corticosteroids for treating patients with corneal infection. Beyond antibiotics, agents in use, such as lubricating ointments, artificial tears, and anti-inflammatory drops, do not fully accommodate clinical needs and have many potential harmful complications. To this end, treatments are needed that both regulate the inflammatory response and promote corneal wound healing to resolve visual disturbances and improve quality of life. Thymosin beta 4 is a small, naturally occurring 43-amino-acid protein that promotes wound healing and reduces corneal inflammation and is currently in Phase 3 human clinical trials for dry eye disease. Our previous work has shown that topical Tβ4 as an adjunct to ciprofloxacin treatment reduces inflammatory mediators and inflammatory cell infiltrates (neutrophils/PMN and macrophages) while enhancing bacterial killing and wound healing pathway activation in an experimental model ofP. aeruginosa-induced keratitis. Adjunctive thymosin beta 4 treatment holds novel therapeutic potential to regulate and, optimally, resolve disease pathogenesis in the cornea and perhaps other infectious and immune-based inflammatory disease. We plan to establish the importance of thymosin beta 4 as a therapeutic agent in conjunction with antibiotics with high impact for immediate clinical development.

Controlled Release of Multiple Therapeutics From Silicone Hydrogel Contact Lenses for Post-Cataract/Post-Refractive Surgery and Uveitis Treatment.

PurposeThis work demonstrates seven-day controlled and extended in vitro physiological flow dual release of multiple post-ocular surgery therapeutics from extended-wear contact lenses as a dropless alternative for treatment of uveitis and corneal inflammation, pain, and infection. Lens replacement each week optimizes treatment matching patient recall time with the ability to increase or decrease dosage.MethodsLenses were synthesized using molecular imprinting to create lenses with macromolecular memory for diclofenac sodium (DS) and dexamethasone sodium phosphate (DMSP), as well as bromfenac sodium (BS) and moxifloxacin (MOX). Drug uptake and release were analyzed, and physical properties were measured and compared to commercial standards.ResultsDS + DMSP–loaded lenses demonstrated seven-days-plus release of each, whereas controls released more than 85% of their payload within the first day. Lenses loaded with BS + MOX demonstrated release of BS and MOX for 11 and eight days, respectively. Structural analysis demonstrated statistically similar mesh size and average molecular weight between crosslinks between imprinted lenses and controls, suggesting that release extension was due to formation of macromolecular memory sites rather than a tighter polymer architecture.ConclusionsLenses demonstrated in this work have significant clinical applications as an eye drop alternative, possessing the ability to be worn continuously for one week while delivering a consistent amount of therapeutic for the duration of wear.Translational RelevanceIn vitro physiological flow release results demonstrate the clinical potential of therapeutic contact lenses as a dropless vehicle for ocular drug delivery.

Long-term effect of contact lens wear: A citation network study

BackgroundContact lenses can cause complications in 2/3 of the total population, but in most cases, they are mild and easy to manage. However, most of the studies are short-term. The aim of the study was to analyze the publications on the long-term effects of contact lens wear to understand the current research landscape through the analysis of dating networks as well as determining the different research areas and the most cited publications. MethodsThe Web of Science database was used to perform the publication search, looking for the terms “Long-term” AND “contact lens wear” within the period between 1977 and January 2021. The CitNetExplorer and CiteSpace software were then used to conduct the publication analysis. To obtain the graphics, the VOSviewer software was used. ResultsA total of 721 publications were found with 2999 citations generated within the network. The year 2010 was singled out as a “key year”, considering the number of publications that emerged in that year and increase in adaptations of contact lens worldwide. The most widely cited publication was “Effects of long-term extended contact lens wear on the human cornea”, an article by Holden et al., which was published in 1985. By using the clustering function, we were able to establish three clusters that encompassed the different research areas within this field: morphological changes, the loss of corneal sensitivity, tear film characteristics and longitudinal changes in ocular physiology. ConclusionsThe main research topic in this field focuses on the morphological changes that take place in the corneal endothelial cell layer.

A pilot study investigating the effect of extended contact lens wear on limbal and central corneal morphology

PurposeTo investigate the effect of long-term extended soft contact lens wear on limbal and central corneal cell morphology, and limbal architecture. MethodsEach participant attended a study visit involving in vivo confocal microscopy of central corneal and limbal epithelium. Scans were graded by five masked graders for three features: central epithelial irregularity, limbal epithelial irregularity and the prominence of palisades of Vogt. The variability of grades between different graders and the difference of grades between extended wearers and daily soft/non-contact lens wearers were assessed. ResultsNineteen participants (9 extended soft contact lens wearers and 10 daily soft/non-contact lens wearers) aged 31–65 years were enrolled in this study. Scans from 37 eyes were included in the analysis. Agreement between graders for each feature was moderate to good with inter class correlation >0.7. While there were no significant differences in central epithelial cell irregularity (p = 0.527) and the prominence of palisade of Vogt (p = 0.182) between extended or daily soft/non-contact lens wearers, limbal epithelial cell irregularity showed a trend with increased irregularity in extended soft contact lens wearers (p = 0.091). ConclusionsWhile no differences in limbal cell morphology and structureor central epithelial cell wasfound in thissubjective grading study of extended wearers compared to daily soft/non-contact lens wearers, further studies using a larger sample size or a longitudinal study design are warranted.

Effect of Antimicrobial Contact Lenses on Corneal Infiltrative Events: A Randomized Clinical Trial.

PurposeTo determine whether Mel4-coated antimicrobial contact lenses (MACLs) can reduce the incidence of corneal infiltrative events (CIEs) during extended wear.MethodsA prospective, randomized, double-masked, single-center, contralateral, extended contact lens wear clinical trial was conducted with 176 subjects. Each participant was randomly assigned to wear a MACL in one eye and an uncoated control contact lens in the contralateral eye or an extended-wear biweekly disposable modality for 3 months. The main outcome measures were the incidence of CIEs per 100 eye-months, identification of the microbial types colonizing the contact lenses or eyes at the time of the CIEs, and their susceptibility to Mel4.ResultsNine participants (5.1%) experienced unilateral CIEs; six participants had contact lens acute red eye, and three participants had infiltrative keratitis. The incidence rate for CIEs (0.4 events per 100 participant months; 1.7%) in the Mel4-coated lenses (test) was 69% less than that of the control lenses (1.3 events per 100 participant months; 3.4%; P = 0.29). All Gram-negative bacteria isolated from lenses and lids of participants with CIEs (Citrobacter diversus, Acinetobacter haemolyticus, and Acinetobacter lwoffii) were susceptible to Mel4 peptide; minimum inhibitory concentrations ranged from 15.6 to 62.5 µg/mL. Reduction of adhesion of these bacteria by Mel4-coated lenses ranged from 2.1 to 2.2 log10 colony-forming units/lens.ConclusionsMACLs had the capacity to reduce CIEs by at least 50% compared with uncoated control lenses during extended wear over 3 months; however, due to the relatively low rates of CIEs, the reduction was not statistically different compared with control lenses.Translational RelevanceThis study provides evidence that antimicrobial contact lenses have the potential to reduce the incidence of corneal infiltrative events during extended wear.

Bilateral Pseudomonas aeruginosa Keratitis in 7 Patients.

To report 7 patients (14 eyes) with bilateral Pseudomonas aeruginosa keratitis (PAK). Case records of patients with bilateral PAK were reviewed at a single academic medical center from April 2009 to December 2020. Seven patients aged 29 to 94 years presented with bilateral P. aeruginosa corneal ulcers. All patients were soft contact lens wearers except one elderly patient with a complex ocular history. Three patients wore specialty contact lens, including one cosmetic contact lens wearer, one multifocal contact lens wearer, and one extended-wear contact lens wearer. The remaining three patients were not overnight contact lens wearer but regularly showered in contact lens or used tap water for contact lens case cleaning. All patients presented with asymmetric disease, with visual acuity ranging from 20/20 to light perception. Ulcers were located centrally in 5 eyes (35.7%), diffusely over the entire cornea in 5 eyes (35.7%), temporally in 2 eyes (14.2%), and nasally in 1 eye (7.14%), and in 1 eye (8.3%), the ulcer location was not recorded. Corneal thinning was noted in 7 eyes (50%). Hypopyon was also noted in 7 eyes (50%). Two patients required procedures because of progressive stromal necrosis. All other patients were treated nonsurgically, with antibiotic drops, which resulted in ulcer resolution. Final visual acuity on last recorded follow-up ranged from 20/20 to no light perception. This is the largest case series of bilateral PAK, which occurred primarily in contact lens wearer. This case series reiterates the risk of contact lens infection related to poor hygiene.

Three-year outcomes of alcohol delamination of corneal epithelium for recurrent corneal erosions of traumatic etiology.

Purpose:Alcohol delamination of the corneal epithelium (ADCE) is a therapeutic option for patients with recurrent corneal erosion (RCE) who do not respond to nonsurgical management of lubricants and extended wear contact lens. The aim of the study is to report on three-year efficacy and safety of ADCE for RCE of traumatic etiology.Methods:This is a retrospective review of consecutive patients who underwent ADCE for traumatic RCE in a local hospital between January 2010 and January 2020. The outcomes at a 3-year follow-up review are included. Nonsurgical therapy used; intra- and postoperative complications were recorded. ADCE was only offered to those who remained symptomatic despite maximum topical lubrications and/or extended wear contact lens. Success was defined as the absence of recurrence of corneal erosion.Results:Twenty-six eyes of 26 patients with RCE caused by trauma underwent ADCE. The mean age of patients was 39 years. The follow-up period was a minimum of 36 months. Three eyes (11.5%) had recurrence of corneal erosion after ADCE at the 3-year follow-up. Recurrence was noted at months 2, 23, and 36 postoperatively in these patients. All patients reported significant improvement in symptoms associated with recurrent erosion. Ten eyes (38.5%) stopped all topical lubricants postoperatively. No intra- or postoperative complications were noted in our study.Conclusion:This study documents the long-term safety and efficacy of alcohol delamination of corneal epithelium at 3 years for patients with RCE of traumatic origin.

Extended Contact Lens Wear Promotes Corneal Norepinephrine Secretion and Pseudomonas aeruginosa Infection in Mice.

PurposeExtended contact lens (CL) wear predisposes the wearer to Pseudomonas aeruginosa infection of the cornea, but the mechanism involved remains incompletely understood. The purpose of this study was to investigate the role of the stress hormone norepinephrine (NE) in the pathogenesis of CL-induced P. aeruginosa keratitis.MethodsA total 195 adult C57BL/6 mice were used in this study. Corneal NE content was measured after 48 hours of sterile CL wear in mice. The effect of NE on P. aeruginosa adhesion and biofilm formation on the CL surface was examined in vitro. Moreover, mouse eyes were covered with P. aeruginosa-contaminated CLs, and either 500-µM NE was topically applied or the eyes were subconjunctivally injected with 100 µg of N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) to deplete local NE. Clinical scores, neutrophil infiltration, proinflammatory cytokine levels, and bacterial load on the corneas and CLs were evaluated.ResultsCorneal NE content was elevated with extended CL wear in mice. In vitro, NE promoted the adhesion and biofilm formation of P. aeruginosa on the CL surface. In mice, topical application of NE aggravated P. aeruginosa infection, accompanied with increased clinical scores, neutrophil infiltration, proinflammatory cytokine expression, and bacterial burden on the corneas and CLs. However, pre-depletion of local NE with DSP-4 significantly alleviated the severity of P. aeruginosa keratitis.ConclusionsExtended CL wear elevates corneal NE content, which promotes the pathogenesis of CL-induced P. aeruginosa keratitis in mice. Targeting NE may provide a potential strategy for the treatment of CL-related corneal infection caused by P. aeruginosa.

Effect of Soft Contact Lens Wear on Tear Film Break up Time

Purpose: To see the effect of soft contact lens wears on tear breakup time.
 Study Design: Descriptive Observational study.
 Place and Duration of Study: College of Ophthalmology and Allied Vision Sciences, King Edward Medical University, Mayo Hospital, Lahore. From January to March 2016.
 Material and Methods: Students of King Edward Medical University Lahore wearing soft contact lens for more than 3 months with no known ocular pathology were selected by non-probability convenient sampling technique. Subjects with history of using any eye drops, history of oral drugs, which could cause dry eye and individuals any ocular disease, were excluded from the study. Tear film BUT was tested by using Fluorescein sodium dye and examinig under cobalt blue filter of slit lamp.SPSS version 20 is used to analyze the data.
 Results: There were 30 participants with mean age of 24.5 ± 5 years. All were females. Sixty percent were wearing corrective lenses, and 40% were wearing cosmetic lenses. Out of 30 patients wearing contact lenses, only 6.67% had marginal tear film BUT and none of the patients has shown dry eyes. Individuals using contact lenses for 9 – 12 years had decreased BUT as compared to subjects using lenses for 3 – 6 months. 33.33% of extended lens wearers had reduced BUT as compared to disposable and daily wearers of contact lenses. Discomfort with contact lenses was observed in only 4 patients.
 Conclusion: As the duration of contact lens wear increases, the tear film break up time decreases. Individuals using extended wear contact lenses are more prone to develop decreased TFBUT.

The frequency of non-pathologically thin corneas in young healthy adults.

Purpose: Measurement of normal corneal thickness and corneal epithelial thickness is important in keratorefractive surgery, glaucoma, following extended contact lens wear, and in patients with corneal disease. Clinically, a central corneal thickness less than 500 µm is considered to be moderately-to-extremely thin. The purpose of this study was to compare biological differences in patients with clinically thin compared to normal corneal thickness values in healthy young adults using Fourier domain optical coherence tomography.Patients and methods: In total, 168 eyes from 84 patients aged 19–38 years were scanned using an Avanti optical coherence tomographer. To eliminate circadian effects on corneal thickness, all patients were scanned within a 4-hour window. Corneal thickness was measured across the central 6 mm of the cornea. Total central corneal thickness, corneal epithelial thickness, and corneal stromal thickness were compared between males and females and tested for correlations with age, use of systemic hormones, degree of myopia, and corneal curvature.Results: The average central corneal thickness for males and females was 540.5±32.0 μm and 525.2±33.0 μm, respectively (P=0.020). Thirty-eight eyes had corneal thickness measurements below 500 µm; 12% (6 eyes) from males and 28% (16 eyes) from females (P=0.008). All women with corneas below 500 μm were bilaterally thin. This finding differed for men. Corneal thinning was not associated with age, use of systemic hormones, or degree of myopia. Females had steeper keratometry (K) readings (P=0.01 for flat K, P=0.002 for steep K) than males. No differences in layer offset values between normal thickness corneas and thin corneas were evident, suggesting that the reduced thickness was not pathological.Conclusion: The results of this study indicate that a subpopulation of healthy young adults have non-pathologically thin corneas, well below 500 μm; and that these thinner corneas are more frequent in females. This underscores the importance of accurate corneal thickness measurements prior to keratorefractive surgery and when evaluating intraocular pressure in glaucoma.

Understanding the Role of Pro-resolving Lipid Mediators in Infectious Keratitis.

Keratitis is a sight-threatening inflammatory condition of the cornea that can be caused by both infectious and non-infectious agents. Physical or chemical trauma are typically related to non-infectious keratitis, which may then become secondarily infected or remain non-infected. Etiology of infectious keratitis is most often associated with bacteria; but viruses, fungi, and parasites are common causative pathogens as well. As a global concern, common risk factors include: systemic immunosuppression (secondary to malnutrition, alcoholism, diabetes, steroid use), previous corneal surgery (refractive corneal surgery, penetrating keratoplasty), extended wear contact lens use, pre-existing ocular surface diseases (dry eye, epithelial defect) and ocular trauma (agriculture- or farm-related) [1-8]. Annual rates of incidence include nearly one million clinical visits due to keratitis in the United States, while it has been reported that roughly two million people develop corneal ulcers in India. Clinically, patients may show signs of eye pain (ranging from mild to severe), blurred vision, photophobia, chemosis and redness. Pathogenesis is generally characterized by rapid progression, focal white infiltrates with underlying stromal inflammation, corneal thinning, stromal edema, mucopurulent discharge and hypopyon, which can lead to corneal scarring, endophthalmitis, and perforation. In fact, corneal opacity is not only a complication of keratitis, but among the leading causes of legal blindness worldwide. Despite that empirical treatment effectively controls most of the pathogens implicated in infectious keratitis, improved clinical outcomes are not guaranteed. Further, if treatment is not initiated in a timely manner, good visual outcome is reduced to approximately 50% of keratitis patients [9]. Moreover, resultant structural alterations, loss of tissue and an unresolved host response remain unaddressed through current clinical management of this condition.

Awareness and Compliance in Contact Lens Wearers: Case Study

Purpose: To assess the contact lens compliance rate by using a self-administrated validated questionnaire, the level of awareness, compliance & detectable behavioral changes, patterns or trends in contact lens users. Methods: A questionnaire ,Cross sectional prospective study to understand the compliance in contact lens wearers, the questionnaires were distributed randomly among the users at various clinical & optical outlets. Based on various studies, and taking into account time constraints the sample size of 40 was taken. The mean age of 24 years was taken without any ocular pathology and systemic disease affecting the ocular health. Result: The majority of 87% of the subjects studied, preferred the monthly modality and 13 % preferred conventional yearly replacement lenses.Considering average duration of wear 64% of the subjects showed non- compliance and prolonged their wearing schedules beyond 8 hours. 38% of the contact lens users were not taking optimum care of the lens cases. A majority of 50% of the subjects rated better cosmetic appearance the most important factor, while 25% of them rated cosmetic & better vision equally important. 68% knew the availability of extended wear contact lenses that can be worn during sleep. Optical outlets are the places where the patient is more motivated for soft contact lens. Conclusion: Cost and convenience are two factors that must be considered when educating patients about proper lens care regimens. In addition, compliance is more likely if the patient is satisfied with the medical visit.

Case series: Extended wear of rigid gas permeable scleral contact lenses for the treatment of persistent corneal epithelial defects

To report the successful treatment of persistent corneal epithelial defects that failed to respond to alternative treatment methods using extended wear of three different rigid gas-permeable scleral lenses. Eight eyes of eight patients with persistent corneal epithelial defects were treated with Blanchard Onefit 2.0 Scleral lens, BostonSight Scleral lens, and BostonSight PROSE device and were observed for defect resolution and improvement in best-corrected visual acuity over the duration of treatment. All eyes observed complete re-epithelialization with a mean time of 11.1 ± 5.5 days. At the conclusion of the treatment, visual acuity improved in all but one patient. No complications were observed during treatment. Scleral lenses provide the corneal epithelium with hydration, oxygen permeation, and protection from mechanical forces; thereby facilitating healing of persistent corneal epithelial defects. This case series demonstrates the successful use of continuous wear scleral lenses in a number of patients for the treatment of persistent epithelial defects refractory to other interventions.

A diagnosis of Stevens-Johnson Syndrome (SJS) in a patient presenting with superficial keratitis

PurposeTo describe a case of Stevens-Johnson syndrome (SJS) diagnosed in a patient presenting with primarily ocular findings where SJS had not been initially suspected. ObservationsA 23-year-old female presented with a 2 day history of bilateral eye pain, conjunctival injection, decreased visual acuity, and photophobia in the context of a 4 day history of fever, headache, and sore throat. She was found to have bilateral superficial keratitis and treated for suspected early infectious keratitis secondary to extended contact lens wear. She returned the next day with worsening visual symptoms, a new macular rash over her upper torso, and new ulcerating lesions over her buccal and perioral tissue. The patient was diagnosed with SJS. She was successfully treated using systemic cyclosporine with antibiotics and steroid eye drops. Conclusions and importanceOphthalmologists may be the first physicians to diagnose SJS, a life-threatening condition that can initially present with non-specific viral prodromal symptoms and ocular signs alone. This case emphasizes the importance of considering a patient's entire clinical history, especially when the presentation is atypical and the diagnosis is not obviously apparent.

Using Nanoparticle Drug Delivery Mechanisms to Improve Eye Moisture Over Extended Periods of Contact Lens Wear

Millions of people around the world suffer from dry eye symptoms as a result of extended contact lens wear. The objective of this design document is to engineer a solution for chronic dry eyes. The solution must be safe, effective, easy to use, and affordable. The goal of the treatment is to decrease tear film osmolarity by 20 mOsmol/L. Three types of nanotechnologies were considered for this task. The candidate solutions were 1) hydrogel contact lenses infused with lubricant-loaded liposomes, 2) lubricant-loaded microemulsions applied as eye drops, and 3) lubricant-loaded niosomes applied as eye drops. All solutions use polyethylene glycol 400 as the primary active ingredient in the lubricant. The three solutions provide a safe treatment option that allows increased bioavailability of drug and increased retention time, as well as controlled release of drug. A combination of candidates 1 and 3 – namely, hydrogel contact lenses infused with lubricant-loaded niosomes – seems to be the best solution because of excellent drug delivery kinetics and minimal safety concerns. The success of this project would encourage further research in niosome-based and contact lens-based drug delivery. It would also allow this company to expand research and development and further specialize in ocular drug delivery.

Contact lens-related keratitis and purulent corneal ulcers

To analyze cases of severe infectious keratitis and corneal ulcers associated with contact lenses (CL), to develop the optimum treatment strategy for these patients, and to identify areas for improvement in prevention, diagnosis and treatment methods. The study included 97 patients (103 eyes) with infectious keratitis and corneal ulcers associated with usage of contact lenses (CL) who were followed up from 2009 to 2016. Medical history of the patients was thoroughly analyzed. Scraping was taken from the cornea and conjunctiva of 61 patients for seeding. A three-step treatment strategy using 2-4 types of antimicrobial agents was developed. In 77 cases (79.3%) the occurrence of infection was associated with violation of the recommended rules of CL wearing and maintenance. Extended-wear CL had higher complication rate (62 patients) compared with daily-wear CL (17 patients) and orthokeratology (8 patients). Rigid CL was used in 1 case. In 9 patients CL type was unknown. Visual acuity upon admission varied from 1.0 to irregular perception of light projections; in 71 cases visual acuity was 0.3 or lower. According to microbiological examination, growth of microflora was observed in 20 cases (informational content 32.8%): Pseudomonas aeruginosa (9 eyes); Staphylococcus epidermidis, Acinetobacter species and mold fungi (3 eyes); Cryptococcus laurentii, Serratia marcescens, Burkholderia cepacia, Staphylococcus hominis, Candida (1 eye). In 10% of patients, non-bacterial infections (fungi and Acanthamoeba) were found. The average hospital stay duration was 15.2±8.9 days. Surgical treatment was required in 15 patients (15.5%) including 5 cases of penetrating keratoplasty. Visual acuity outcome was 0.3-1.0 in 67 cases; 3 patients had light perception with correct projection, and 2 - light perception with irregular projection. An effective treatment strategy for patients with CL-related keratitis and purulent corneal ulcers was developed. It is necessary to improve microbiological research methods. Creating a unified national database of such CL-related complications is advisable.

Bacterial Interactions among Soft Contact Lens Users and Lens Care Solutions with Antibiotic Susceptibility Pattern

PURPOSE: To evaluate the bacterial contamination associated with contact lenses and lens care solutions used by a group of soft contact lens (CL) users (daily & extended wear CL) and the susceptibility pattern of the isolated organisms to antibiotics for 12 months duration. METHODS: This prospective case controlled, non randomized study included 50 participants of contact lens (CL) wearers from Outpatient Clinics at Al-Azhar University Hospitals, International Eye Hospital New Damietta and available special clinics, (between 2013 and 2014). The sample population was divided into two groups: a Case group: 30 contact lens users (60 eyes) were suffering from symptoms and signs of conjunctivitis in one or both eyes; a Control group: 20 CL users were not suffering from conjunctivitis. Samples were takenfromsolution in contact lens storage cases; daily wear CL, extended wear CL, andconjunctiva were cultured on different media. Microbiological identification of the organisms and their antimicrobial susceptibility were done in accordance to standard protocols. RESULTS: In the case group, positive growth was found in 85% of the lens care solution, 65% of the contact lenses, and 56.7% of the conjunctiva of participants. While in the control group, it was found in 10% , 20% and 15% respectively, with a statistically significant difference between both groups (P<0.001). There was no statistically significant differences between the two usage schedules (daily wear and extended wear) regarding results of solution and contact lens cultures (p =0.599) and (p=0.694) respectively, but there was a significant higher growth in the conjunctival cultures of extended wear contact lenses (p =0.014). The isolated organisms in case group were; Staphylococcus epidermidis (36.3%), followed by Pseudomonas aeruginosa (34.7%), Staphylococcus aureus (15.3%), Anthracoid (5.6%), Escherichia coli (4.1%), Diphtheroid (1.6%), Non haemolytic streptreptococci (1.6 %) and least was found to be Mycoplasma (0.8%). Antibiotic susceptibility tests revealed that all isolates are sensitive to gatifloxacin, Impenem and ciprofloxacin which are commercially ophthalmological antibiotics. CONCLUSION: Prevention of bacterial contamination of contact lens can reduce the risk of developing ocular infections. Lens care practices amongst the participants were not optimum which resulted into high contamination level. Hence, creating awareness among the users about the lens care practices and regular cleaning and replacements of lens cases are required.