Surveillance Tools Emerging From Search Engines and Social Media Data for Determining Eye Disease Patterns

IMPORTANCE

Internet-based search engine and social media data may provide a novel complementary source for better understanding the epidemiologic factors of infectious eye diseases, which could better inform eye health care and disease prevention.

OBJECTIVE

To assess whether data from internet-based social media and search engines are associated with objective clinic-based diagnoses of conjunctivitis.

DESIGN, SETTING, AND PARTICIPANTS

Data from encounters of 4143 patients diagnosed with conjunctivitis from June 3, 2012, to April 26, 2014, at the University of California San Francisco (UCSF) Medical Center, were analyzed using Spearman rank correlation of each weekly observation to compare demographics and seasonality of nonallergic conjunctivitis with allergic conjunctivitis. Data for patient encounters with diagnoses for glaucoma and influenza were also obtained for the same period and compared with conjunctivitis. Temporal patterns of Twitter and Google web search data, geolocated to the United States and associated with these clinical diagnoses, were compared with the clinical encounters. The a priori hypothesis was that weekly internet-based searches and social media posts about conjunctivitis may reflect the true weekly clinical occurrence of conjunctivitis.

MAIN OUTCOMES AND MEASURES

Weekly total clinical diagnoses at UCSF of nonallergic conjunctivitis, allergic conjunctivitis, glaucoma, and influenza were compared using Spearman rank correlation with equivalent weekly data on Tweets related to disease or disease-related keyword searches obtained from Google Trends.

RESULTS

Seasonality of clinical diagnoses of nonallergic conjunctivitis among the 4143 patients (2364 females [57.1%] and 1776 males [42.9%]) with 5816 conjunctivitis encounters at UCSF correlated strongly with results of Google searches in the United States for the term pink eye (ρ, 0.68 [95% CI, 0.52 to 0.78]; P < .001) and correlated moderately with Twitter results about pink eye (ρ, 0.38 [95% CI, 0.16 to 0.56]; P < .001) and with clinical diagnosis of influenza (ρ, 0.33 [95% CI, 0.12 to 0.49]; P < .001), but did not significantly correlate with seasonality of clinical diagnoses of allergic conjunctivitis diagnosis at UCSF (ρ, 0.21 [95% CI, -0.02 to 0.42]; P = .06) or with results of Google searches in the United States for the term eye allergy (ρ, 0.13 [95% CI, -0.06 to 0.32]; P = .19). Seasonality of clinical diagnoses of allergic conjunctivitis at UCSF correlated strongly with results of Google searches in the United States for the term eye allergy (ρ, 0.44 [95% CI, 0.24 to 0.60]; P < .001) and eye drops (ρ, 0.47 [95% CI, 0.27 to 0.62]; P < .001).

CONCLUSIONS AND RELEVANCE

Internet-based search engine and social media data may reflect the occurrence of clinically diagnosed conjunctivitis, suggesting that these data sources can be leveraged to better understand the epidemiologic factors of conjunctivitis.

Changing Azole Resistance: A Secondary Analysis of the MUTT I Randomized Clinical Trial

IMPORTANCE

The development of multiple triazole resistance in pathogenic filamentous fungi has become an increasing clinical concern and has been shown to increase the risk for treatment failure.

OBJECTIVE

To determine whether antifungal resistance increased during the Mycotic Ulcer Treatment Trial I (MUTT I), as measured by minimum inhibitory concentrations (MICs) in baseline cultures.

DESIGN, SETTING, AND PARTICIPANTS

This secondary analysis of a double-masked, multicenter, randomized clinical trial included patients with culture- or smear-positive filamentous fungal corneal ulcer and a baseline visual acuity of 20/40 to 20/400. Culture-positive samples with susceptibility testing were included in this analysis. The patients were treated at multiple locations of the Aravind Eye Care Hospital system in South India. Data were collected from April 3, 2010, to December 31, 2011, and analyzed from July 15 to September 1, 2015.

INTERVENTIONS

Corneal smears and cultures were obtained from all study participants at baseline. Susceptibility testing was performed for each culture-positive specimen.

MAIN OUTCOMES AND MEASURES

Minimum inhibitory concentration of voriconazole and natamycin in baseline cultures.

RESULTS

Of 323 participants with smear-positive specimens (183 men [56.7%]; 140 women [43.3%]; median [interquartile range] age, 47 [38-56] years), fungal-positive cultures were obtained for 256 (79.3%). The MIC data were available for 221 of 323 participants (68.4%), because 35 samples had no growth during susceptibility testing. A 2.14-fold increase per year (95% CI, 1.13-4.56; P = .02) in voriconazole MICs after controlling for the infectious organism was found. This association was not found when looking at natamycin MICs of baseline cultures after controlling for the infectious organism (1.26; 95% CI, 0.13-12.55; P = .85).

CONCLUSIONS AND RELEVANCE

Susceptibility to voriconazole appeared to decrease during the relatively short enrollment period of the clinical trial. This decrease may be more related to increased resistance of environmental fungi rather than previous treatment with azoles, because presenting with azole treatment was not a risk factor for resistance.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00996736.

Effect of pretreatment with antifungal agents on clinical outcomes in fungal keratitis

BACKGROUND

To determine if pretreatment with antifungal agents is predictive of worse clinical outcome in a fungal keratitis clinical trial.

DESIGN

Non-pre-specified subgroup analysis of a randomized controlled trial in a tertiary hospital.

PARTICIPANTS

Three hundred twenty-three fungal ulcer cases with an enrolment visual acuity of 20/40 to 20/400.

METHODS

The Mycotic Ulcer Treatment Trial I was a randomized, double-masked trial to determine the optimal treatment for filamentous fungal keratitis at the Aravind Eye Care System, India. Enrolled cases were randomized to receive topical natamycin or voriconazole. Prior antifungal medication use, dose and duration were collected at enrolment. A subgroup analysis was performed to determine if patients using natamycin or azoles at presentation have worse clinical outcomes compared with those who were not pretreated.

MAIN OUTCOME MEASURES

Three-month visual acuity (primary), 3-month infiltrate or scar size, corneal perforation and/or transplant and re-epithelialization time.

RESULTS

Of the 323 patients enrolled, 44% presented on an antifungal agent. Pretreated patients had larger mean baseline infiltrate size (P < 0.001) and epithelial defect size (P = 0.02). Multivariate regression analysis demonstrated that pretreatment was associated with significantly worse 3-month visual acuity (P = 0.006), larger 3-month scar size (P < 0.001) and increased odds of corneal perforation and/or transplant (P = 0.001).

CONCLUSIONS

Fungal keratitis that is smear-positive despite being pretreated with appropriate antifungal agents appears to be a risk factor for worse outcomes, likely a result of initial ulcer severity and treatment failure. These patients may benefit from more aggressive multimodal therapy at a tertiary centre.

Risk factors for low vision related functioning in the Mycotic Ulcer Treatment Trial: a randomised trial comparing natamycin with voriconazole

BACKGROUND/AIMS

The Mycotic Ulcer Treatment Trial I (MUTT I) was a double-masked, multicentre, randomised controlled trial, which found that topical natamycin is superior to voriconazole for the treatment of filamentous fungal corneal ulcers. In this study, we determine risk factors for low vision-related quality of life in patients with fungal keratitis.

METHODS

The Indian visual function questionnaire (IND-VFQ) was administered to MUTT I study participants at 3 months. Associations between patient and ulcer characteristics and IND-VFQ subscale score were assessed using generalised estimating equations.

RESULTS

323 patients were enrolled in the trial, and 292 (90.4%) completed the IND-VFQ at 3 months. Out of a total possible score of 100, the average VFQ score for all participants was 81.3 (range 0-100, SD 23.6). After correcting for treatment arm, each logMAR line of worse baseline visual acuity in the affected eye resulted in an average 1.2 points decrease on VFQ at 3 months (95% CI -1.8 to 0.6, p<0.001). Those who required therapeutic penetrating keratoplasty had an average of 25.2 points decrease on VFQ after correcting for treatment arm (95% CI -31.8 to -18.5, p<0.001). Study participants who were unemployed had on average 28.5 points decrease on VFQ (95% CI -46.9 to -10.2, p=0.002) after correcting for treatment arm.

CONCLUSIONS

Monocular vision loss from corneal opacity due to fungal keratitis reduced vision-related quality of life. Given the relatively high worldwide burden of corneal opacity, improving treatment outcomes of corneal infections should be a public health priority.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov Identifier: NCT00996736.

Vision-Related Quality-of-Life Outcomes in the Mycotic Ulcer Treatment Trial I: A Randomized Clinical Trial

IMPORTANCE

Given the limitations in health care resources, quality-of-life measures for interventions have gained importance.

OBJECTIVE

To determine whether vision-related quality-of-life outcomes were different between the natamycin and voriconazole treatment arms in the Mycotic Ulcer Treatment Trial I, as measured by an Indian Vision Function Questionnaire.

DESIGN, SETTING, AND PARTICIPANTS

Secondary analysis (performed October 11-25, 2014) of a double-masked, multicenter, randomized, active comparator-controlled, clinical trial at multiple locations of the Aravind Eye Care System in South India that enrolled patients with culture- or smear-positive filamentous fungal corneal ulcers who had a baseline visual acuity of 20/40 to 20/400 (logMAR of 0.3-1.3).

INTERVENTIONS

Study participants were randomly assigned to topical voriconazole, 1%, or topical natamycin, 5%.

MAIN OUTCOMES AND MEASURES

Subscale score on the Indian Vision Function Questionnaire from each of the 4 subscales (mobility, activity limitation, psychosocial impact, and visual function) at 3 months.

RESULTS

A total of 323 patients were enrolled in the trial, and 292 (90.4%) completed the Indian Vision Function Questionnaire at 3 months. The majority of study participants had subscale scores consistent with excellent function. After adjusting for baseline visual acuity and organism, we found that study participants in the natamycin-treated group scored, on average, 4.3 points (95% CI, 0.1-8.5) higher than study participants in the voriconazole-treated group (P = .046). In subgroup analyses looking at ulcers caused by Fusarium species and adjusting for baseline best spectacle-corrected visual acuity, the natamycin-treated group scored 8.4 points (95% CI, 1.9-14.9) higher than the voriconazole-treated group (P = .01). Differences in quality of life were not detected for patients with Aspergillus or other non-Fusarium species as the causative organism (1.5 points [95% CI, -3.9 to 6.9]; P = .52).

CONCLUSIONS AND RELEVANCE

We found evidence of improvement in vision-related quality of life among patients with fungal ulcers who were randomly assigned to natamycin compared with those randomly assigned to voriconazole, and especially among patients with Fusarium species as the causative organism. Incorporation of quality-of-life measures in clinical trials is important to fully evaluate the effect of the studied interventions.

TRIAL REGISTRATION

clinicaltrials.gov Identifier:NCT00996736.

Early addition of topical corticosteroids in the treatment of bacterial keratitis

IMPORTANCE

Scarring from bacterial keratitis remains a leading cause of visual loss.

OBJECTIVE

To determine whether topical corticosteroids are beneficial as an adjunctive therapy for bacterial keratitis if given early in the course of infection.

DESIGN, SETTING, AND PARTICIPANTS

The Steroids for Corneal Ulcers Trial (SCUT) was a randomized, double-masked, placebo-controlled trial that overall found no effect of adding topical corticosteroids to topical moxifloxacin hydrochloride in bacterial keratitis. Here, we assess the timing of administration of corticosteroids in a subgroup analysis of the SCUT. We define earlier administration of corticosteroids (vs placebo) as addition after 2 to 3 days of topical antibiotics and later as addition after 4 or more days of topical antibiotics.

MAIN OUTCOMES AND MEASURES

We assess the effect of topical corticosteroids (vs placebo) on 3-month best spectacle-corrected visual acuity in patients who received corticosteroids or placebo earlier vs later. Further analyses were performed for subgroups of patients with non-Nocardia keratitis and those with no topical antibiotic use before enrollment.

RESULTS

Patients treated with topical corticosteroids as adjunctive therapy within 2 to 3 days of antibiotic therapy had approximately 1-line better visual acuity at 3 months than did those given placebo (-0.11 logMAR; 95% CI, -0.20 to -0.02 logMAR; P = .01). In patients who had 4 or more days of antibiotic therapy before corticosteroid treatment, the effect was not significant; patients given corticosteroids had 1-line worse visual acuity at 3 months compared with those in the placebo group (0.10 logMAR; 95% CI, -0.02 to 0.23 logMAR; P = .14). Patients with non-Nocardia keratitis and those having no topical antibiotic use before the SCUT enrollment showed significant improvement in best spectacle-corrected visual acuity at 3 months if corticosteroids were administered earlier rather than later.

CONCLUSIONS AND RELEVANCE

There may be a benefit with adjunctive topical corticosteroids if application occurs earlier in the course of bacterial corneal ulcers.

Association between in vitro susceptibility to natamycin and voriconazole and clinical outcomes in fungal keratitis

PURPOSE

To assess the association between minimum inhibitory concentration (MIC) and clinical outcomes in a fungal keratitis clinical trial.

DESIGN

Experimental study using data from a randomized comparative trial.

PARTICIPANTS

Of the 323 patients enrolled in the trial, we were able to obtain MIC values from 221 patients with monocular fungal keratitis.

METHODS

The Mycotic Ulcer Treatment Trial I was a randomized, double-masked clinical trial comparing clinical outcomes of monotherapy with topical natamycin versus voriconazole for the treatment of fungal keratitis. Speciation and determination of MIC to natamycin and voriconazole were performed according to Clinical and Laboratory Standards Institute guidelines. The relationship between MIC and clinical outcome was assessed.

MAIN OUTCOME MEASURES

The primary outcome was 3-month best spectacle-corrected visual acuity. Secondary outcomes included 3-month infiltrate or scar size; corneal perforation and/or therapeutic penetrating keratoplasty; and time to re-epithelialization.

RESULTS

A 2-fold increase in MIC was associated with a larger 3-month infiltrate or scar size (0.21 mm; 95% confidence interval [CI], 0.10-0.31; P < 0.001) and increased odds of perforation (odds ratio, 1.32; 95% CI, 1.04-1.69; P = 0.02). No correlation was found between MIC and 3-month visual acuity. For natamycin-treated cases, an association was found between higher natamycin MIC with larger 3-month infiltrate or scar size (0.29 mm; 95% CI, 0.15-0.43; P < 0.001) and increased perforations (odds ratio, 2.41; 95% CI, 1.46-3.97; P < 0.001). Among voriconazole-treated cases, the voriconazole MIC did not correlate with any of the measured outcomes in the study.

CONCLUSIONS

Decreased susceptibility to natamycin was associated with increased infiltrate or scar size and increased odds of perforation. There was no association between susceptibility to voriconazole and outcome.

The steroids for corneal ulcers trial (SCUT): secondary 12-month clinical outcomes of a randomized controlled trial

PURPOSE

To determine whether topical corticosteroids as adjunctive therapy for bacterial keratitis improves long-term clinical outcomes.

DESIGN

Randomized, placebo-controlled, double-masked clinical trial.

METHODS

This multicenter trial compared 1.0% prednisolone sodium phosphate to placebo in the treatment of bacterial keratitis among 500 patients with culture-positive ulcers receiving 48 hours of moxifloxacin before randomization. The primary endpoint was 3 months from enrollment, and 399 patients were evaluated at 12 months. The outcomes examined were best spectacle-corrected visual acuity (BSCVA) and scar size at 12 months. Based on previous results, regression models with adjustments for baseline status and/or causative organism were used for analysis.

RESULTS

No significant differences in clinical outcomes by treatment group were seen with the prespecified regression models (BSCVA: -0.04 logMAR, 95% CI, -0.12 to 0.05, P = .39; scar size: 0.03 mm, 95% CI, -0.12 to 0.18, P = .69). A regression model including a Nocardia-treatment arm interaction found corticosteroid use associated with a mean 1-line improvement in BSCVA at 12 months among patients with non-Nocardia ulcers (-0.10 logMAR, 95% CI, -0.19 to -0.02, P = .02). No significant difference was observed in 12-month BSCVA for Nocardia ulcers (0.18 logMAR, 95% CI, -0.04 to 0.41, P = .16). Corticosteroids were associated with larger mean scar size at 12 months among Nocardia ulcers (0.47 mm, 95% CI, 0.06-0.88, P = .02) and no significant difference was identified by treatment for scar size for non-Nocardia ulcers (-0.06 mm, 95% CI, -0.21 to 0.10, P = .46).

CONCLUSIONS

Adjunctive topical corticosteroid therapy may be associated with improved long-term clinical outcomes in bacterial corneal ulcers not caused by Nocardia species.

In vitro susceptibility of filamentous fungal isolates from a corneal ulcer clinical trial

PURPOSE

To describe the minimum inhibitory concentration (MIC) of fungal isolates to natamycin and voriconazole, and to compare these MICs to previous ocular susceptibility studies.

DESIGN

Experimental laboratory study using isolates from a randomized clinical trial.

METHODS

The Mycotic Ulcer Treatment Trial I was a randomized, double-masked, multicenter trial comparing topical natamycin and voriconazole for fungal keratitis treatment. Susceptibility testing to natamycin and voriconazole were performed according to Clinical and Laboratory Standards Institute methods. The relationship between organism and MIC was assessed. A literature review was performed to compare results to previous ocular susceptibility studies.

RESULTS

Of the 323 patients enrolled in the trial, MICs were available for 221 (68%). Fusarium (n = 126) and Aspergillus species (n = 52) were the most commonly isolated organisms. MICs to natamycin and voriconazole were significantly different across all genera (P < .001). The MIC median (MIC50) and 90th percentile (MIC90) for natamycin were equal to or higher than voriconazole for all organisms except Curvularia species. Compared to other organisms, Fusarium species isolates had the highest MICs to voriconazole and Aspergillus flavus isolates had the highest MICs to natamycin. Our results were similar to previous reports except that the voriconazole MIC90 against Aspergillus species was 2-fold higher and the natamycin MIC90 against Aspergillus fumigatus was 4-fold higher in our study.

CONCLUSION

In this large susceptibility study, Fusarium isolates were least susceptible to voriconazole and A flavus isolates were least susceptible to natamycin when compared to other filamentous fungi. In the future, susceptibility testing may help guide therapy if performed in a timely manner.

Expert prior elicitation and Bayesian analysis of the Mycotic Ulcer Treatment Trial I

PURPOSE

To perform a Bayesian analysis of the Mycotic Ulcer Treatment Trial I (MUTT I) using expert opinion as a prior belief.

METHODS

MUTT I was a randomized clinical trial comparing topical natamycin or voriconazole for treating filamentous fungal keratitis. A questionnaire elicited expert opinion on the best treatment of fungal keratitis before MUTT I results were available. A Bayesian analysis was performed using the questionnaire data as a prior belief and the MUTT I primary outcome (3-month visual acuity) by frequentist analysis as a likelihood.

RESULTS

Corneal experts had a 41.1% prior belief that natamycin improved 3-month visual acuity compared with voriconazole. The Bayesian analysis found a 98.4% belief for natamycin treatment compared with voriconazole treatment for filamentous cases as a group (mean improvement 1.1 Snellen lines, 95% credible interval 0.1-2.1). The Bayesian analysis estimated a smaller treatment effect than the MUTT I frequentist analysis result of 1.8-line improvement with natamycin versus voriconazole (95% confidence interval 0.5-3.0, P = 0.006). For Fusarium cases, the posterior demonstrated a 99.7% belief for natamycin treatment, whereas non-Fusarium cases had a 57.3% belief.

CONCLUSIONS

The Bayesian analysis suggests that natamycin is superior to voriconazole when filamentous cases are analyzed as a group. Subgroup analysis of Fusarium cases found improvement with natamycin compared with voriconazole, whereas there was almost no difference between treatments for non-Fusarium cases. These results were consistent with, though smaller in effect size than, the MUTT I primary outcome by frequentist analysis. The accordance between analyses further validates the trial results. (ClinicalTrials.gov number, NCT00996736.).

The effect of procedure room temperature and humidity on LASIK outcomes

OBJECTIVE

To determine whether procedure room temperature or humidity during LASIK affect refractive outcomes in a large patient sample.

DESIGN

Retrospective cohort study.

PARTICIPANTS

A total of 202 394 eyes of 105 712 patients aged 18 to 75 years who underwent LASIK at an Optical Express, Inc., location in their United Kingdom and Ireland centers from January 1, 2008, to June 30, 2011, who met inclusion criteria.

METHODS

Patient age, gender, flap creation technique, pre- and 1-month post-LASIK manifest refraction, and ambient temperature and humidity during LASIK were recorded. Effect size determination and univariate and multivariate analyses were performed to characterize the relationships between LASIK procedure room temperature and humidity and postoperative refractive outcome.

MAIN OUTCOME MEASURES

One month post-LASIK manifest refraction.

RESULTS

No clinically significant effect of procedure room temperature or humidity was found on LASIK refractive outcomes. When considering all eyes in our population, an increase of 1°C during LASIK was associated with a 0.003 diopter (D) more hyperopic refraction 1 month postoperatively, and an increase in 1% humidity was associated with a 0.0004 more myopic refraction. These effect sizes were the same or similar when considering only myopic eyes, only hyperopic eyes, and subgroups of eyes stratified by age and preoperative refractive error.

CONCLUSIONS

Neither procedure room temperature nor humidity during LASIK were found to have a clinically significant relationship with postoperative manifest refraction in our population.

Emerging moxifloxacin resistance in Pseudomonas aeruginosa keratitis isolates in South India

PURPOSE

To describe temporal trends in Pseudomonas aeruginosa resistance to moxifloxacin in keratitis isolates from South India.

METHODS

The Steroids for Corneal Ulcers Trial (SCUT) was a randomized, double-masked, placebo-controlled trial assessing outcomes in patients with culture positive bacterial corneal ulcers randomized to receive prednisolone phosphate or placebo. All patients received moxifloxacin, and susceptibility to moxifloxacin was measured at baseline using Etest. We investigated trends in moxifloxacin susceptibility of P. aeruginosa during 2007, 2008, and 2009 isolated in SCUT in South India.

RESULTS

There were 89 P. aeruginosa isolates during 2007, 2008, and 2009 in SCUT that were eligible for this study. There was an increase in the proportion of resistant isolates from 19% in 2007 to 52% in 2009 (p = 0.02, χ(2) test for trend). Logistic regression showed that there was a 2-fold increase in odds of resistance per 1 year increase during the study period (odds ratio 2.16, 95% confidence interval 1.09-4.26, p = 0.027).

CONCLUSIONS

We found a sharp increase in the proportion of isolates that were resistant to moxifloxacin from 2007 to 2009. Further work needs to be done to characterize the nature of this increase.

Fluoroquinolone treatment and susceptibility of isolates from bacterial keratitis

OBJECTIVE

To analyze the relationship between fluoroquinolone use at presentation and minimum inhibitory concentration in bacterial keratitis.

METHODS

The Steroids for Corneal Ulcers Trial was a randomized, double-masked, placebo-controlled trial assessing the effect of adjunctive topical corticosteroid treatment on outcomes in bacterial keratitis. After presentation, all patients were treated with moxifloxacin hydrochloride, 0.5%. We compare antibiotic use at presentation with minimum inhibitory concentration against moxifloxacin for all isolates. Separate analyses accounted for organism species and fluoroquinolone generation.

RESULTS

Topical fluoroquinolone use at presentation was reported in 92 of 480 cases (19.2%). Causative organisms in the 480 cases included Streptococcus pneumoniae (247 cases [51.5%]), Pseudomonas aeruginosa (109 cases [22.7%]), and Nocardia species (55 cases [11.5%]). Isolates from patients who reported fluoroquinolone use at presentation had a 2.01-fold-higher minimum inhibitory concentration (95% CI, 1.39-fold to 2.91-fold; P < .001). Fourth-generation fluoroquinolones were associated with a 3.48-fold-higher minimum inhibitory concentration than those isolates that were not exposed to pretreatment at enrollment (95% CI, 1.99-fold to 6.06-fold; P < .001).

CONCLUSION

This study provides evidence that prior use of fluoroquinolones is associated with antibiotic resistance.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00324168.

Association between cytotoxic and invasive Pseudomonas aeruginosa and clinical outcomes in bacterial keratitis

OBJECTIVES

To determine whether cytotoxic and invasive Pseudomonas aeruginosa strains differentially influence clinical presentation, outcomes, or therapeutic response in bacterial keratitis.

METHODS

Pseudomonas aeruginosa isolates from the National Eye Institute-funded Steroids for Corneal Ulcers Trial were subtyped as cytotoxic or invasive strains. The main outcome measure compared between the 2 subtypes was change in visual acuity at 3 months using Huber robust regression, adjusting for topical corticosteroid treatment.

RESULTS

Of 101 confirmed P aeruginosa isolates from the Steroids for Corneal Ulcers Trial, 74 had a classically cytotoxic or invasive genotype. While corneal ulcers caused by genotypically invasive P aeruginosa strains were associated at presentation with significantly better visual acuity than corneal ulcers caused by genotypically cytotoxic P aeruginosa strains when adjusting for the effect of ulcer location (P= .008), invasive ulcers had improved significantly less than cytotoxic ulcers at 3 months (0.35; 95% CI, 0.04-0.66 logMAR; P= .03 [3.5-line difference]). Compared with topical moxifloxacin alone, adjunctive treatment with topical corticosteroids was associated with significantly more improvement in visual acuity in the invasive subgroup (P= .04) but was associated with less improvement in visual acuity in the cytotoxic subgroup (P= .07).

CONCLUSIONS

Rational profiling of differentially expressed virulence determinants (eg, cytotoxicity and invasiveness for P aeruginosa) could be used as a tool for decision making in the management of infections to optimize outcomes.

The mycotic ulcer treatment trial: a randomized trial comparing natamycin vs voriconazole

OBJECTIVE

To compare topical natamycin vs voriconazole in the treatment of filamentous fungal keratitis.

METHODS

This phase 3, double-masked, multicenter trial was designed to randomize 368 patients to voriconazole (1%) or natamycin (5%), applied topically every hour while awake until reepithelialization, then 4 times daily for at least 3 weeks. Eligibility included smear-positive filamentous fungal ulcer and visual acuity of 20/40 to 20/400.

MAIN OUTCOME MEASURES

The primary outcome was best spectacle-corrected visual acuity at 3 months; secondary outcomes included corneal perforation and/or therapeutic penetrating keratoplasty.

RESULTS

A total of 940 patients were screened and 323 were enrolled. Causative organisms included Fusarium (128 patients [40%]), Aspergillus (54 patients [17%]), and other filamentous fungi (141 patients [43%]). Natamycintreated cases had significantly better 3-month best spectacle-corrected visual acuity than voriconazole-treated cases (regression coefficient=0.18 logMAR; 95% CI, 0.30 to 0.05; P=.006). Natamycin-treated cases were less likely to have perforation or require therapeutic penetrating keratoplasty (odds ratio=0.42; 95% CI, 0.22 to 0.80; P=.009). Fusarium cases fared better with natamycin than with voriconazole (regression coefficient=0.41 logMAR; 95% CI,0.61 to 0.20; P<.001; odds ratio for perforation=0.06; 95% CI, 0.01 to 0.28; P<.001), while non-Fusarium cases fared similarly (regression coefficient=0.02 logMAR; 95% CI, 0.17 to 0.13; P=.81; odds ratio for perforation=1.08; 95% CI, 0.48 to 2.43; P=.86).

CONCLUSIONS

Natamycin treatment was associated with significantly better clinical and microbiological outcomes than voriconazole treatment for smear-positive filamentous fungal keratitis, with much of the difference attributable to improved results in Fusarium cases.

APPLICATION TO CLINICAL PRACTICE

Voriconazole should not be used as monotherapy in filamentous keratitis.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00996736

Prior elicitation and Bayesian analysis of the Steroids for Corneal Ulcers Trial

PURPOSE

To elicit expert opinion on the use of adjunctive corticosteroid therapy in bacterial corneal ulcers. To perform a Bayesian analysis of the Steroids for Corneal Ulcers Trial (SCUT), using expert opinion as a prior probability.

METHODS

The SCUT was a placebo-controlled trial assessing visual outcomes in patients receiving topical corticosteroids or placebo as adjunctive therapy for bacterial keratitis. Questionnaires were conducted at scientific meetings in India and North America to gauge expert consensus on the perceived benefit of corticosteroids as adjunct treatment. Bayesian analysis, using the questionnaire data as a prior probability and the primary outcome of SCUT as a likelihood, was performed. For comparison, an additional Bayesian analysis was performed using the results of the SCUT pilot study as a prior distribution.

RESULTS

Indian respondents believed there to be a 1.21 Snellen line improvement, and North American respondents believed there to be a 1.24 line improvement with corticosteroid therapy. The SCUT primary outcome found a non-significant 0.09 Snellen line benefit with corticosteroid treatment. The results of the Bayesian analysis estimated a slightly greater benefit than did the SCUT primary analysis (0.19 lines verses 0.09 lines).

CONCLUSION

Indian and North American experts had similar expectations on the effectiveness of corticosteroids in bacterial corneal ulcers; that corticosteroids would markedly improve visual outcomes. Bayesian analysis produced results very similar to those produced by the SCUT primary analysis. The similarity in result is likely due to the large sample size of SCUT and helps validate the results of SCUT.

Nocardia keratitis: clinical course and effect of corticosteroids

PURPOSE

To compare the clinical course of Nocardia species keratitis with keratitis resulting from other bacterial organisms and to assess the effect of corticosteroids as adjunctive therapy using data collected from the Steroids for Corneal Ulcers Trial.

DESIGN

Subgroup analysis of a randomized controlled trial.

METHODS

setting: Multicenter randomized controlled trial. study population: Five hundred patients with bacterial keratitis randomized 1:1 to topical corticosteroid or placebo who had received at least 48 hours of topical moxifloxacin. intervention/observation procedure: Topical prednisolone phosphate 1% or placebo and clinical course of Nocardia keratitis. main outcome measures: Best spectacle-corrected visual acuity and infiltrate or scar size at 3 months from enrollment.

RESULTS

Of 500 patients enrolled in the trial, 55 (11%) had a Nocardia corneal ulcer. Patients with Nocardia ulcers had better presentation visual acuity compared with non-Nocardia ulcers (median Snellen visual acuity, 20/45, compared with 20/145; P < .001) and comparable 3-month visual acuity (median, 20/25, vs 20/40; P = .25). Nocardia ulcers had approximately 2 lines less of improvement in visual acuity compared with non-Nocardia ulcers (0.21 logarithm of the minimal angle of resolution; 95% confidence interval, 0.09 to 0.33 logarithm of the minimal angle of resolution; P = .001). This difference may reflect the better starting visual acuity in patients with Nocardia ulcers. In Nocardia ulcers, corticosteroids were associated with an average 0.4-mm increase in 3-month infiltrate or scar size (95% confidence interval, 0.03 to 0.77 mm; P = .03).

CONCLUSIONS

Nocardia ulcers responded well to treatment. They showed less overall improvement in visual acuity than non-Nocardia ulcers, but had better presentation acuity. Corticosteroids may be associated with worse outcomes.

The clinical differentiation of bacterial and fungal keratitis: a photographic survey

PURPOSE

The purpose of this study was to determine whether clinical signs of infectious keratitis can be used to identify the causative organism.

METHODS

Eighty photographs of eyes with culture-proven bacterial keratitis or smear-proven fungal keratitis were randomly selected from 2 clinical trials. Fifteen cornea specialists from the F. I. Proctor Foundation and the Aravind Eye Care System assessed the photographs for prespecified clinical signs of keratitis, and they identified the most likely causative organism.

RESULTS

Clinicians were able to correctly distinguish bacterial from fungal etiology 66% of the time (P < 0.001). The Gram stain, genus, and species were accurately predicted 46%, 25%, and 10% of the time, respectively. The presence of an irregular/feathery border was associated with fungal keratitis, whereas a wreath infiltrate or an epithelial plaque was associated with bacterial keratitis.

CONCLUSIONS

Cornea specialists correctly differentiated bacterial from fungal keratitis more often than chance, but in fewer than 70% of cases. More specific categorization led to less successful clinical distinction. Although certain clinical signs of infectious keratitis may be associated with a bacterial or fungal etiology, this study highlights the importance of obtaining appropriate microbiological testing during the initial clinical encounter.

Relationship of in vitro susceptibility to moxifloxacin and in vivo clinical outcome in bacterial keratitis

BACKGROUND

For bacterial infections, the susceptibility to antibiotics in vitro has been associated with clinical outcomes in vivo, although the importance of minimum inhibitory concentration (MIC) has been debated. In this study, we analyzed the association of MIC on clinical outcomes in bacterial corneal ulcers, while controlling for organism and severity of disease at presentation.

METHODS

Data were collected as part of a National Eye Institute-funded, randomized, controlled trial (the Steroids for Corneal Ulcers Trial [SCUT]). All cases enrolled in SCUT had a culture-positive bacterial corneal ulcer and received moxifloxacin. The MIC to moxifloxacin was measured by E test. Outcomes included best spectacle-corrected visual acuity, infiltrate/scar size, time to re-epithelialization, and corneal perforation.

RESULTS

Five hundred patients with corneal ulcers were enrolled in the trial, and 480 were included in this analysis. The most commonly isolated organisms were Streptococcus pneumoniae and Pseudomonas aeruginosa. A 2-fold increase in MIC was associated with an approximately 0.02 logMAR decrease in visual acuity at 3 weeks, approximately 1 letter of vision loss on a Snellen chart (0.019 logMAR; 95% confidence interval [CI], .0040-.033; P = .01). A 2-fold increase in MIC was associated with an approximately 0.04-mm larger infiltrate/scar size at 3 weeks (0.036 mm; 95% CI, .010-.061; P = .006). After controlling for organism, a higher MIC was associated with slower time to re-epithelialization (hazards ratio, 0.92; 95% CI, .86-.97; P = .005).

CONCLUSIONS

In bacterial keratitis, a higher MIC to the treating antibiotic is significantly associated with worse clinical outcomes, with approximately 1 line of vision loss per 32-fold increase in MIC.

CLINICAL TRIALS REGISTRATION

NCT00324168.