Risk factors for corneal abrasions in Nepal: a community-based study

BACKGROUND

South Asia is experiencing rapid urbanization, which may be changing the risk factor profile for ocular trauma. The objective of this study was to compare risk factors for traumatic corneal abrasions in rural versus urban Nepal, and to assess if any risk factors were associated with a poor outcome.

METHODS

In a prospective, cross-sectional, community-based study performed as part of a cluster-randomized trial, community health workers from Nepal were trained to diagnose and treat traumatic corneal abrasions. Participants with an abrasion were invited to complete a risk factor survey. The main exposure variable was the object of eye injury, stratified by rural-urban residence. The main outcome measure was a lack of corneal healing after a three-day course of antimicrobials.

RESULTS

Of 3657 participants diagnosed with a corneal abrasion, 2265 completed a survey. Eye trauma occurred most frequently during agricultural activities. The most common object of injury was vegetative matter, accounting for approximately 40% of injuries in rural, peri-urban, and urban communities. Wood injuries were more common in rural communities (24%) compared with urban or peri-urban communities (13%). Eye injury from an animal was more likely to result in a non-healing corneal abrasion after 3 days of treatment compared with other types of trauma (prevalence ratio 2.59, 95%CI 1.16-5.76).

CONCLUSIONS

Health promotion activities for prevention of corneal ulcers in Nepal should focus on agricultural trauma in both rural and urban areas. Community members experiencing eye trauma from an animal may benefit from early referral to an eye clinic.

Seasonal and Temporal Trends of Infectious Keratitis in Northern Vietnam

The epidemiology of corneal ulcers in Vietnam has not been well characterized. In this report, we reviewed retrospectively the microbiological data of patients with a clinical diagnosis of corneal ulcer at the microbiology laboratory of Vietnam National Eye Hospital from January 1, 2010 to March 31, 2023. We observed a seasonal pattern for fungal and microsporidial keratitis, with an annual peak in November, and an inverse relationship between fungal keratitis and inclement weather. The November peak coincided with one of the major harvesting seasons in Vietnam. We also observed increasing numbers of microsporidial and Acanthamoeba keratitis cases in recent years. Knowledge of these trends are helpful in guiding empirical treatment of corneal infections and preventing corneal blindness.

Risk factors for corneal ulcers: a population-based matched case-control study in Nepal

BACKGROUND/AIMS

We aimed to examine risk factors for corneal ulcer in a rural and peri-urban setting in Nepal.

METHODS

This population-based matched case-control study was nested in a cluster randomised trial in 24 village development committees in Nepal. Incidence density sampling was used to match incident corneal opacity cases to controls, matching on time of opacity, age, sex and location. Cases and controls were invited to participate in a survey of risk factors for corneal ulcer. Risk factors were evaluated using conditional logistic regression to account for matching.

RESULTS

Of the 540 participants with incident opacities identified in the trial, 433 were willing to participate in this substudy and matched to a control. Compared with controls, cases had lower odds of having any education vs no education (adjusted OR, aOR 0.60, 95% CI 0.39 to 0.94), working in non-manual labour occupations vs manual labour occupations (aOR 0.64, 95% CI 0.42 to 0.95) and preferring medical shops for ocular trauma versus eye care system centres (aOR 0.58, 95% CI 0.37 to 0.92). Cases had higher odds of protective goggle use versus no protection (aOR 3.8, 95% CI 1.3 to 11.0) and having an ocular injury vs none (aOR 7.7, 95% CI 4.3 to 13.6) compared with controls.

CONCLUSION

We found ocular injury, manual labour and lower education to be strongly associated with the development of corneal ulcer. Given the persistent burden of corneal blindness in this area, prevention efforts could target efforts to increase access to care in areas where these factors are common.

Relationship between cooking fuel and lens opacities in South India: a 15-year prospective cohort study

PURPOSE

Unclean cooking fuels such as wood and kerosene have been associated with cataract in cross-sectional studies. This study sought to determine whether exposure to unclean cooking fuels was associated with subsequent cataract progression.

DESIGN

Prospective cohort study.

METHODS

This is a secondary observational analysis of the community-based Antioxidants in Prevention of Cataracts trial (ClinicalTrials.gov ID NCT01664819). The exposure of interest was cooking fuel type, measured at baseline. Main outcome measures were baseline cataract severity and self-reported cataract surgery at a 15-year visit.

RESULTS

Baseline and 15-year follow-up data were available for 798 and 579 participants, respectively. Wood or kerosene was used by 711/798 (89.1%) baseline participants, including 539/579 (93.1%) participants with complete follow-up. Cooking fuel type was not associated with cataract severity at baseline (p=0.443). Out of 8,334 person-years of follow up, 90 cataract surgeries were observed over 15 years (1.08 surgeries per 100 person-years; 95%CI 0.87-1.32). Use of wood or kerosene was not associated with 15-year incidence of cataract surgery relative to individuals using propane (adjusted p=0.154). Cataract surgery was more common in older individuals (HR 1.1 per year, 95%CI 1.1-1.2, p<0.001), those with baseline myopia (HR 2.1, 95%CI 1.2-3.5, p=0.009) and women (HR 3.5, 95%CI 1.2 to 10.1, p=0.019).

CONCLUSIONS

This study found no association between unclean cooking fuels and cataract progression over a 15-year period. No other modifiable risk factors were associated with incident self-reported cataract surgery.

Village-integrated eye workers for prevention of corneal ulcers in Nepal (VIEW study): a cluster-randomised controlled trial

BACKGROUND

Corneal ulcers are a common cause of blindness in low-income and middle-income countries, usually resulting from traumatic corneal abrasions during agricultural work. Antimicrobial prophylaxis of corneal abrasions can help prevent corneal ulcers, but delays in the initiation of therapy are frequent. We aimed to assess whether a community-based programme for corneal ulcer prevention would reduce the incidence of corneal ulceration.

METHODS

A cluster-randomised trial was performed in village development committees (VDCs) in Nepal. VDCs in the catchment area of Bharatpur Eye Hospital, Nepal with less than 15 000 people were eligible for inclusion. We randomly assigned (1:1) VDCs to either an intervention group or a control group. In the intervention VDCs, existing female community health volunteers (FCHVs) were trained to diagnose corneal abrasions and provide a 3-day course of ophthalmic antimicrobials to their patients. In the control VDCs, FCHVs did not provide this intervention. Participants were not masked given the nature of the intervention. Both groups were followed up for 3 years for photographic evidence of corneal ulceration. The primary outcome was the incidence of corneal ulceration, determined by masked assessment of corneal photographs. The analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, NCT01969786.

FINDINGS

We assessed 112 VDCs, of which 24 were enrolled. The study was performed between Feb 4, 2014, and Oct 20, 2017. 12 VDCs were randomly assigned to the intervention group and 12 to the control group. 252 539 individuals were included in the study (130 579 in the intervention group and 121 960 in the control group). FCHVs diagnosed and provided antimicrobials for 4777 corneal abrasions. The census identified 289 corneal ulcers among 246 893 person-years in the intervention group (incidence 1·21 cases [95% CI 0·85-1·74] per 1000 person-years) and 262 corneal ulcers among 239 170 person-years in the control group (incidence 1·18 cases [0·82-1·70] per 1000 person-years; incidence rate ratio 1·03 [95% CI 0·63-1·67]; p=0·93). Medication allergy was self-reported in 0·2% of participants.

INTERPRETATION

We did not detect a reduction in the incidence of corneal ulceration during the first 3 years of a community-based corneal ulcer prevention programme. Further study might be warranted in more rural areas where basic eye care facilities are not available.

FUNDING

National Eye Institute.

Village-Integrated Eye Worker trial (VIEW): rationale and design of a cluster-randomised trial to prevent corneal ulcers in resource-limited settings

INTRODUCTION

Corneal opacity is a leading cause of blindness worldwide. In resource-limited settings, untreated traumatic corneal abrasions may result in infection and ultimately, opacity. Although antimicrobial treatment of corneal ulcers may successfully cure infections, the scarring that accompanies the resolution of infection can still result in visual impairment. Prevention may be the optimal approach for reducing corneal blindness. Studies have employed community health workers to provide prompt administration of antimicrobials after corneal abrasions to prevent infections, but these studies were not designed to determine the effectiveness of such a programme.

METHODS AND ANALYSIS

The Village-Integrated Eye Worker trial (VIEW) is a cluster-randomised trial designed to assess the effectiveness of a community health worker intervention to prevent corneal ulcers. Twenty-four Village Development Committees (VDCs) in Nepal were randomised to receive a corneal ulcer prevention programme or to no intervention. Female Community Health Volunteers (FCHVs) in intervention VDCs are trained to diagnose corneal abrasions, provide antimicrobials and to refer participants when needed. An annual census is conducted over 3 years in all study VDCs to assess the incidence of corneal ulceration via corneal photography (primary outcome). Masked outcome assessors grade corneal photographs to determine the presence or absence of incident corneal opacities. The primary analysis is negative binomial regression to compare the incidence of corneal ulceration by study arm.

ETHICS AND DISSEMINATION

The University of California San Francisco Committee on Human Research, Nepal Netra Jyoti Sangh and the Nepal Health Research Council have given ethical approval for the trial. The results of this trial will be presented at local and international meetings and submitted to peer-reviewed journals for publication.

TRIAL REGISTRATION NUMBER

NCT01969786; Pre-results.

Association of Dry Eye Tests With Extraocular Signs Among 3514 Participants in the Sjögren's Syndrome International Registry

PURPOSE

To identify a screening strategy for dry eye patients with a high likelihood of having Sjogren syndrome (SS) through the evaluation of the association of ocular surface tests with the extraocular signs used for the diagnosis of SS.

DESIGN

Multicenter cross-sectional study.

METHODS

The Sjogren's International Clinical Collaborative Alliance (SICCA) registry enrolled 3514 participants with SS or possible SS from 9 international academic sites. Ocular surface evaluation included Schirmer I testing, tear breakup time (TBUT), and staining of the cornea (0-6 points) and conjunctiva (0-6 points). Multivariate logistic regression analysis was performed to identify predictive factors for (1) histopathologic changes on labial salivary gland (LSG) biopsies (positive = focus score of ≥1 focus/4 mm²) and (2) positive anti-SSA/B serology.

RESULTS

The adjusted odds of having a positive LSG biopsy were significantly higher among those with an abnormal Schirmer I test (adjusted OR = 1.26, 95% CI 1.05-1.51, P = .014) and positive conjunctival staining (for each additional unit of staining 1.46; 95% CI 1.39-1.53, P < .001) or corneal staining (for each additional unit of staining 1.14; 95% CI 1.08-1.21, P < .001). The odds of having a positive serology were significantly higher among those with an abnormal Schirmer I test (adjusted OR = 1.3; 95% CI 1.09-1.54, P = .004) and conjunctival staining (adjusted OR = 1.51; 95% CI 1.43-1.58, P < .001).

CONCLUSIONS

In addition to corneal staining, which was associated with a higher likelihood of having a positive LSG biopsy, conjunctival staining and abnormal Schirmer I testing are of critical importance to include when screening dry eye patients for possible SS, as they were associated with a higher likelihood of having a positive LSG biopsy and serology.

Inter-grader Agreement of the Ocular Staining Score in the Sjögren's International Clinical Collaborative Alliance (SICCA) Registry

PURPOSE

To determine the intra-observer and inter-observer reliability of a novel ocular staining score among trained ophthalmologists.

DESIGN

Reliability analysis within a prospective, observational, multicenter cohort study.

METHODS

Those enrolled in the National Institutes of Health-funded Sjögren's International Collaborative Clinical Alliance (SICCA) who presented for follow-up at the University of California San Francisco, Aravind Eye Hospital, Johns Hopkins University, and the University of Pennsylvania were included. Study participants were graded using the ocular staining score by at least 2 masked SICCA-trained ophthalmologists. The primary outcome for this study was the intraclass correlation coefficient (ICC) for the total ocular staining score. ICCs were also calculated for tear break-up time (TBUT) and conjunctival and corneal staining.

RESULTS

Total ocular staining score had an ICC of 0.91 for the right eye (95% confidence interval [CI] 0.85-0.96) and 0.90 for the left eye (95% CI 0.83-0.97). Corneal staining (right eye 0.86, 95% CI 0.76-0.93, left eye 0.90, 95% CI 0.81-0.95) and conjunctival staining (right eye 0.87, 95% CI 0.80-0.93, left eye 0.85, 95% CI 0.75-0.93) demonstrated excellent agreement. The ICC for TBUT was slightly lower (right eye 0.77, 95% CI 0.64-0.89; left eye 0.81, 95% CI 0.68-0.90).

CONCLUSIONS

Previous studies have shown that the ocular staining score is correlated with other diagnostic components of Sjögren syndrome. In this study, we demonstrate high reliability in grading among trained ophthalmologists, completing the validation of this test.

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.

Association of conjunctival bacterial infection and female sex in cicatricial trachoma

PURPOSE

Conjunctival infection with non-chlamydial bacteria may play an important role in the progression of trachoma, especially with regard to the development of corneal opacity and blindness. To further characterize the microbiological profile of bacterial conjunctival infections in cicatricial trachoma, a conjunctival swabbing of adults in rural Ethiopia was performed.

METHODS

In a cross-sectional study conducted in nine Ethiopian villages with hyperendemic trachoma, persons 40 years of age or older with signs or symptoms consistent with trichiasis were recruited and conjunctival swabbing for bacterial pathogens was performed.

RESULTS

Conjunctival examination and swabbing on 112 females and 36 males were performed. Of the 148 study participants, 101 (68.2%) were confirmed to have trichiasis, and 118 (80%) had conjunctival swabs positive for bacteria. In multivariate analyses, growth of pathogenic conjunctival bacteria was independently associated with trichiasis (odds ratio [OR] 6.93; 95% confidence interval [CI] 2.71-17.7) and female sex (OR 5.90; 95% CI 2.09-16.7). Females were more likely to have swabs positive for Streptococcus pneumoniae or Haemophilus influenzae than were males (OR 9.09; 95% CI 1.17-70.8).

CONCLUSIONS

In a region of Ethiopia with endemic trachoma, conjunctival bacterial growth was more common in females than that in males. S. pneumoniae and H. influenzae, both of which frequently colonize the nasopharynx of children, were more common in females, suggesting that the preponderance of infection in females may be attributable to close contact with children. This finding is consistent with the theory that childcare activities may preferentially expose females to ocular chlamydial infection. (ClinicalTrials.gov number, NCT00221364.).

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.

Clinical activity and polymerase chain reaction evidence of chlamydial infection after repeated mass antibiotic treatments for trachoma

It is unclear how the prevalence of clinically active trachoma correlates with the prevalence of ocular chlamydial infection at the community level. In 24 villages from a cluster-randomized clinical trial of mass azithromycin distributions in Ethiopia, the correlation between the prevalence of clinical activity (on examination) and chlamydial infection (by polymerase chain reaction) was moderately strong before mass antibiotic treatments (Pearson's correlation coefficient r = 0.75, 95% confidence interval [CI] = 0.52-0.87), but decreased at each time point during four biannual treatments (at 24 months, r = 0.15, 95% CI = -0.14-0.41). One year after the final treatment, the correlation coefficient had increased, but not to the pre-treatment level (r = 0.55, 95% CI = 0.30-0.73). In a region with hyperendemic trachoma, conjunctival examination was a useful indicator of the prevalence of chlamydial infection before treatments, less useful during mass treatments, but regained utility by one year after treatments had stopped.

A simplified quantitative method for assessing keratoconjunctivitis sicca from the Sjögren's Syndrome International Registry

PURPOSE

To describe, apply, and test a new ocular grading system for assessing keratoconjunctivitis sicca (KCS) using lissamine green and fluorescein.

DESIGN

Prospective, observational, multicenter cohort study.

METHODS

The National Institutes of Health-funded Sjögren's Syndrome International Registry (called Sjögren's International Collaborative Clinical Alliance [SICCA]) is developing standardized classification criteria for Sjögren syndrome (SS) and is creating a biospecimen bank for future research. Eight SICCA ophthalmologists developed a new quantitative ocular grading system (SICCA ocular staining score [OSS]), and we analyzed OSS distribution among the SICCA cohort and its association with other phenotypic characteristics of SS. The SICCA cohort includes participants ranging from possibly early SS to advanced disease. Procedures include sequenced unanesthetized Schirmer test, tear break-up time, ocular surface staining, and external eye examination at the slit lamp. Using statistical analyses and proportional Venn diagrams, we examined interrelationships between abnormal OSS (>or=3) and other characteristics of SS (labial salivary gland [LSG] biopsy with focal lymphocytic sialadenitis and focus score >1 positive anti-SS A antibodies, anti-SS B antibodies, or both).

RESULTS

Among 1208 participants, we found strong associations between abnormal OSS, positive serologic results, and positive LSG focus scores (P < .0001). Analysis of the overlapping relationships of these 3 measures defined a large group of participants who had KCS without other components of SS, representing a clinical entity distinct from the KCS associated with SS.

CONCLUSIONS

This new method for assessing KCS will become the means for diagnosing the ocular component of SS in future classification criteria. We find 2 forms of KCS whose causes may differ.

Antioxidants in Prevention of Cataracts in South India: Methodology and Baseline Data

PURPOSE

To describe the methodology and baseline data for the Antioxidants in Prevention of Cataracts (APC) study in South India.

METHODS

The APC study is a prospective, 5-year, randomized, triple-masked, placebo-controlled, field-based clinical trial to examine the effect of antioxidants (combination tablet of vitamins A, C, and E) on progression of cataract. The primary outcome variable is cataract progression (nuclear opalescence), evaluated with the slit-lamp biomicroscope by the Lens Opacification Classification System III method. Secondary outcome variables are progression in cortical and posterior subcapsular opacity and nuclear color, change in best corrected visual acuity, myopic shift, and treatment failure (progression to cataract surgery or best corrected vision worse than 20/400 in an eye). Inclusion criteria are age between 35 and 50 years and best-corrected visual acuity of 20/40 or better. Exclusion criteria are a diagnosis of diabetes mellitus or nonfasting blood glucose level>7.8 mmol/L, history or presence of various ocular conditions or treatment forms, or current use of vitamin supplements. Baseline ophthalmic, demographic, and potential cataract risk factor data (such as smoking, sunlight, or alcohol exposure) were compared between groups on an intent-to-treat basis.

RESULTS

Of 954 people screened, 798 were enrolled, a sample size which exceeded the required estimate. More than 80% of subjects had 20/20 or better vision in at least one eye, and baseline prevalence of significant cataract according to the LOCS III grading scale was high. The two treatment groups were comparable for all baseline measures except alcohol intake.

CONCLUSION

The sample size and group baseline characteristics will provide sufficient power to detect a change in cataract progression within 5 years.

Assessment of herd protection against trachoma due to repeated mass antibiotic distributions: a cluster-randomised trial

BACKGROUND

Trachoma-control programmes distribute oral azithromycin to treat the ocular strains of chlamydia that cause the disease and to control infection. Theoretically, elimination of infection is feasible if untreated individuals receive an indirect protective effect from living in repeatedly treated communities, which is similar to herd protection in vaccine programmes. We assessed indirect protection against trachoma with mass azithromycin distributions.

METHODS

In a cluster randomised trial, 24 subkebeles (government-defined units) in Amhara, Ethiopia, were randomised, with use of a simple random sample, to distribution four times per year of single-dose oral azithromycin to children aged 1-10 years (12 subkebeles, 4764 children), or to delayed treatment until after the study (control; 12 subkebeles, 6014 children). We compared the prevalence of ocular chlamydial infection in untreated individuals 11 years and older between baseline and 12 months in the treated subkebeles, and at 12 months between the treated and control subkebeles. Health-care and laboratory personnel were blinded to study group. Analysis was intention to treat. The study is registered with clinicaltrials.gov, number NCT00322972.

FINDINGS

At 12 months, 637 children aged 1-10 years and 561 adults and children aged 11 years and older were analysed in the children-treated group, and 618 and 550, respectively, in the control group. The mean prevalence of infection in children decreased from 48.4% (95% CI 42.9-53.9) to 3.6% (0.8-6.4) after four mass treatments. At 12 months, the mean prevalence of infection in the untreated age group (>/=11 years) was 47% (95% CI 33-57) less than baseline (p=0.002), and 35% (95% CI 1-57) less than that in untreated communities (p=0.04).

INTERPRETATION

Frequent treatment of children, who are a core group for transmission of trachoma, could eventually eliminate infection from the entire community. Herd protection is offered by repeated mass antibiotic treatments, providing a strategy for elimination of a bacterial disease when an effective vaccine is unavailable.

FUNDING

National Institutes of Health.

Reduction and return of infectious trachoma in severely affected communities in Ethiopia

Background

Antibiotics are a major tool in the WHO's trachoma control program. Even a single mass distribution reduces the prevalence of the ocular chlamydia that causes trachoma. Unfortunately, infection returns after a single treatment, at least in severely affected areas. Here, we test whether additional scheduled treatments further reduce infection, and whether infection returns after distributions are discontinued.

Methods

Sixteen communities in Ethiopia were randomly selected. Ocular chlamydial infection in 1- to 5-year-old children was monitored over four biannual azithromycin distributions and for 24 months after the last treatment.

Findings

The average prevalence of infection in 1- to 5-year-old children was reduced from 63.5% pre-treatment to 11.5% six months after the first distribution (P<0.0001). It further decreased to 2.6% six months after the fourth and final treatment (P = 0.0004). In the next 18 months, infection returned to 25.2%, a significant increase from six months after the last treatment (P = 0.008), but still far lower than baseline (P<0.0001). Although the prevalence of infection in any particular village fluctuated, the mean prevalence of the 16 villages steadily decreased with each treatment and steadily returned after treatments were discontinued.

Conclusion

In some of the most severely affected communities ever studied, we demonstrate that repeated mass oral azithromycin distributions progressively reduce ocular chlamydial infection in a community, as long as these distributions are given frequently enough and at a high enough coverage. However, infection returns into the communities after the last treatment. Sustainable changes or complete local elimination of infection will be necessary.

Trial Registration

ClinicalTrials.gov NCT00221364

Trachoma is one of the leading causes of blindness in the developing world. The World Health Organization has a multi-pronged approach to controlling the ocular chlamydial infection that causes the disease, including distributing antibiotics to entire communities. Even a single community treatment dramatically reduces the prevalence of the infection. Unfortunately, infection returns back into communities after treatment, at least in severely affected areas such as rural Ethiopia. Here, we assess whether additional scheduled treatments in 16 communities in the Gurage area of Ethiopia further reduce infection, and whether the disease returns after distributions are stopped. In communities with the highest levels of trachoma ever studied, we find that repeated mass oral azithromycin distributions gradually reduce the prevalence of trachoma infection in a community, as long as these treatments are given frequently enough and to enough people in the community. Unfortunately, infection returns into the communities after the last treatment. Sustainable changes or complete local elimination of infection will be necessary to stop the return of ocular chlamydial in communities with very high prevalence of the disease.

Prospective comparison of microbial culture and polymerase chain reaction in the diagnosis of corneal ulcer

PURPOSE

To compare polymerase chain reaction (PCR) to microbial culture for the detection and identification of bacterial and fungal pathogens in microbial keratitis.

DESIGN

Prospective cohort study.

METHODS

A total of 108 consecutive corneal ulcers were cultured and analyzed by PCR using pan-bacterial and pan-fungal primers. PCR products were cloned, sequenced, and compared to culture results using standard bioinformatics tools.

RESULTS

Of the 108 samples, 56 were culture-positive, 25 for bacteria and 31 for fungi; 52 were culture-negative. After eliminating false-positive PCR products, 94 of 108 were positive by PCR, 37 for bacteria and 57 for fungi. Nineteen of 25 bacterial culture-positive samples were positive by PCR, and 29 of 31 samples culture-positive for fungi were positive by PCR. The majority of sequenced PCR products matched the positive culture results. Of the 52 culture-negative samples, 46 (88%) yielded pathogen deoxyribonucleic acid (DNA) PCR products, 18 bacterial and 28 fungal. These represented a variety of species, including at least three novel previously uncultured microbes.

CONCLUSIONS

PCR detects microbial DNA in the majority of bacterial and fungal corneal ulcers, and identifies potentially pathogenic organisms in a high proportion of culture-negative cases. Yield and concordance with culture are higher for fungal than bacterial ulcers. Practical use of the technique is limited by artefactual amplification of nonpathogenic organisms. PCR may be used as an adjunct to culture to identify potential pathogens in microbial keratitis.

Corticosteroids for bacterial corneal ulcers

AIMS

The aim of the study was to conduct a preliminary clinical trial to assess whether adjunctive topical corticosteroids improve outcomes in bacterial keratitis and, if no difference was found, to determine the feasibility and sample size necessary for conducting a larger trial to answer this question.

METHODS

In this single centre, double-masked clinical trial, 42 patients with culture-confirmed bacterial keratitis at Aravind Eye Hospital in India were randomised to receive either topical prednisolone phosphate or placebo. All patients received topical moxifloxacin. The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months, adjusting for enrolment BSCVA and arm. Other pre-specified outcomes included re-epithelialisation time, infiltrate/scar size and adverse events.

RESULTS

Compared with placebo, patients in the steroid group re-epithelialised more slowly (hazard ratio 0.47, 95% CI 0.23 to 0.94). There was no significant difference in BSCVA or infiltrate/scar size at 3 weeks or 3 months. To have 80% power to detect a two-line difference in acuity, 360 cases would be required.

CONCLUSIONS

Although corticosteroid treatment resulted in a statistically significant delay in re-epithelialisation, this did not translate to a significant difference in visual acuity, infiltrate/scar size or adverse events. To assess the effect of steroids on acuity, a larger trial is warranted and feasible.

Mooren''s ulcer following extracapsular cataract extraction

PURPOSE

Prior cataract surgery is a recognized risk factor for the development of Mooren''s ulcer, but the demographic and clinical features of a large cohort of such patients have not been described.

METHODS

The authors performed a retrospective review of demographic and clinical data from 14 eyes in 13 patients who developed Mooren's ulcer following extracapsular cataract extraction at Aravind Eye Hospital in Madurai, South India.

RESULTS

Eight (62%) of the 13 patients were men and 5 (39%) were women. The median age in our population was 65 years, with a range of 45 to 85 years. The median number of months from surgery to the onset of Mooren's ulcer was 19, with a range of 4 to 156 months. Of the 14 eyes with prior cataract surgery, the location of the ulcer was at or contiguous with the wound in 10 eyes (71%), which was 2.5 times more likely than other circumlimbal locations, and only one patient (8%) had bilateral disease.

CONCLUSIONS

Mooren''s ulcer may occur following extracapsular cataract extraction and when it does it is most likely to be unilateral and contiguous with the wound. These findings support the notion that exposure of normally concealed corneal antigens may contribute to the pathogenesis of Mooren''s ulcer in some patients.

Does in vitro susceptibility predict clinical outcome in bacterial keratitis?

PURPOSE

To determine whether clinical outcomes in bacterial keratitis are associated with antibiotic susceptibility.

DESIGN

Retrospective, ancillary study using data and samples from a completed randomized clinical trial.

METHODS

Forty-two patients were enrolled with culture-confirmed bacterial keratitis at Aravind Eye Hospital in South India. All patients received topical moxifloxacin and were randomized to receive either topical prednisolone phosphate or placebo. Outcomes included time to epithelialization, best spectacle-corrected visual acuity (BSCVA), and infiltrate/scar size at three months. Bacterial isolates were cultured, and minimum inhibitory concentration (MIC) to moxifloxacin was measured using Etests. Multiple linear regression was used to assess the effect of MIC on outcome, adjusting for enrollment characteristics.

RESULTS

MIC was associated with three-month infiltrate/scar size: each two-fold increase in MIC was associated with a 0.33-mm average diameter increase in scar size (P=.01). MIC was not associated with three-month BSCVA (P=.71) or time to epithelialization (P=.35).

CONCLUSIONS

MIC was associated with infiltrate/scar size in bacterial keratitis. An ongoing larger, multicenter trial should provide further information on whether this association is maintained across subgroups of organisms.

Comparison of annual and biannual mass antibiotic administration for elimination of infectious trachoma

CONTEXT

Treatment recommendations assume that repeated mass antibiotic distributions can control, but not eradicate or even locally eliminate, the ocular strains of chlamydia that cause trachoma. Elimination may be an important end point because of concern that infection will return to communities that have lost immunity to chlamydia after antibiotics are discontinued.

OBJECTIVE

To determine whether biannual treatment can eliminate ocular chlamydial infection from preschool children and to compare results with the World Health Organization-recommended annual treatment.

DESIGN, SETTING, AND PARTICIPANTS

A cluster-randomized clinical trial of biannual vs annual mass azithromycin administrations to all residents of 16 rural villages in the Gurage Zone, Ethiopia, from March 2003 to April 2005.

INTERVENTIONS

At scheduled treatments, all individuals aged 1 year or older were offered a single dose of oral azithromycin either annually or biannually.

MAIN OUTCOME MEASURE

Village prevalence of ocular chlamydial infection and presence of elimination at 24 months in preschool children determined by polymerase chain reaction, correcting for baseline prevalence. Antibiotic treatments were performed after sample collections.

RESULTS

Overall, 14,897 of 16,403 eligible individuals (90.8%) received their scheduled treatment. In the villages in which residents were treated annually, the prevalence of infection in preschool children was reduced from a mean of 42.6% (range, 14.7%-56.4%) to 6.8% (range, 0.0%-22.0%) at 24 months. In the villages in which residents were treated biannually, infection was reduced from 31.6% pretreatment (range, 6.1%-48.6%) to 0.9% (range, 0.0%-4.8%) at 24 months. Biannual treatment was associated with a lower prevalence at 24 months (P = .03, adjusting for baseline prevalence). At 24 months, no infection could be identified in 6 of 8 of those treated biannually and in 1 of 8 of those treated annually (P = .049, adjusting for baseline prevalence).

CONCLUSION

Local elimination of ocular chlamydial infection appears feasible even in the most severely affected areas, although it may require biannual mass antibiotic distributions at a high coverage level.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00221364.

Complete elimination is a difficult goal for trachoma programs in severely affected communities

The World Health Organization has distributed millions of doses of azithromycin to control the ocular chlamydial infection that causes trachoma. Theoretically, a loftier goal of elimination is feasible. Here, we demonstrate that, although local elimination of infection in the most severely affected communities is difficult, it is possible with biannual antibiotic distributions.

A rationale for continuing mass antibiotic distributions for trachoma

Background

The World Health Organization recommends periodic mass antibiotic distributions to reduce the ocular strains of chlamydia that cause trachoma, the world's leading cause of infectious blindness. Their stated goal is to control infection, not to completely eliminate it. A single mass distribution can dramatically reduce the prevalence of infection. However, if infection is not eliminated in every individual in the community, it may gradually return back into the community, so often repeated treatments are necessary. Since public health groups are reluctant to distribute antibiotics indefinitely, we are still in need of a proven long-term rationale. Here we use mathematical models to demonstrate that repeated antibiotic distributions can eliminate infection in a reasonable time period.

Methods

We fit parameters of a stochastic epidemiological transmission model to data collected before and 6 months after a mass antibiotic distribution in a region of Ethiopia that is one of the most severely affected areas in the world. We validate the model by comparing our predicted results to Ethiopian data which was collected biannually for two years past the initial mass antibiotic distribution. We use the model to simulate the effect of different treatment programs in terms of local elimination of infection.

Results

Simulations show that the average prevalence of infection across all villages progressively decreases after each treatment, as long as the frequency and coverage of antibiotics are high enough. Infection can be eliminated in more villages with each round of treatment. However, in the communities where infection is not eliminated, it returns to the same average level, forming the same stationary distribution. This phenomenon is also seen in subsequent epidemiological data from Ethiopia. Simulations suggest that a biannual treatment plan implemented for 5 years will lead to elimination in 95% of all villages.

Conclusion

Local elimination from a community is theoretically possible, even in the most severely infected communities. However, elimination from larger areas may require repeated biannual treatments and prevention of re-introduction from outside to treated areas.

Spectrum of eye disease caused by methicillin-resistant Staphylococcus aureus

PURPOSE

To compare the clinical features and antibiotic susceptibility of ocular methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA).

DESIGN

Cross-sectional study.

METHODS

The Proctor clinical laboratory database was reviewed to identify all ocular isolates of S. aureus collected between July 1, 1998 and July 31, 2006.

RESULTS

Of 915 S. aureus isolates, there were 88 MRSA isolates in 41 different patients. The proportion MRSA increased from 4.1% in 1998 to 1999 to 16.7% in 2005 to 2006. A total of 78.0% of patients with MRSA had blepharoconjunctivitis, 2.4% had cellulitis, 2.4% had dacryocystitis, 14.6% had keratitis, and 2.4% had endophthalmitis. The diagnoses associated with MSSA were not statistically different. A total of 63.6% of MRSA isolates were sensitive to bacitracin, 100% to vancomycin, 14.8% to ciprofloxacin, 14.8% to erythromycin, 97.7% to sulfisoxazole, and 93.2% to tetracycline.

CONCLUSIONS

MRSA has become a more common ocular pathogen but, as with MSSA, causes mild disease. MRSA should be treated with vancomycin.

Clinical characteristics of Mooren's ulcer in South India

AIM

To describe the clinical characteristics at presentation of a large cohort of patients with Mooren's ulcer in South India.

METHODS

The medical records of patients with Mooren's ulcer examined in the cornea clinic at Aravind Eye Hospital Madurai, Tamil Nadu, India, over a 10-year period were reviewed in this retrospective observational case series.

RESULTS

The cohort contained 242 eyes of 166 patients. All patients were from South India, and men outnumbered women by a ratio of 4.7:1. The median and mean ages at presentation were 65 and 61 years, respectively, with a range of 13-95 years. One eye was affected in 90 of 166 (54%) patients. Visual acuity in the affected eye at presentation ranged from 6/6 to light perception, and was 6/12 or better in 34 of 242 (14%) eyes, between 6/12 and 3/60 in 168 (69%) eyes, and worse than 3/60 in 40 (17%) eyes. Partial peripheral corneal ulceration was observed in 222 (92%) eyes, complete peripheral corneal ulceration was observed in 15 (6%) eyes and total corneal ulceration was observed in 5 (2%) eyes. For those 222 eyes with partial peripheral ulceration, 152 (68%) showed temporal involvement, 129 (58%) showed nasal involvement, 116 (52%) showed inferior involvement and 30 (14%) showed superior involvement. Perforation was observed in 26 (11%) eyes, and was more common in eyes with peripheral as compared with total ulceration (p<0.001). Identified risk factors in the cohort included evidence of prior corneal surgery (22%), corneal trauma (17%) and corneal infection (2%).

CONCLUSIONS

Mooren's ulcer is a rare and potentially blinding eye condition observed not infrequently in the cornea clinic at Aravind Eye Hospital. Men are affected more often than women and may present with either unilateral or bilateral disease. Perforation is observed in approximately 1 in 10 affected eyes at presentation and occurs most often in the setting of peripheral ulceration. The occurrence of prior corneal surgery, trauma or infection in nearly one third of patients supports theories of exposure to corneal antigen in the pathogenesis of this disorder.

Hookworm Infestation as a Risk Factor for Mooren’s Ulcer in South India

OBJECTIVE

To investigate the association between Mooren's ulcer and intestinal hookworm infestation in South India.

DESIGN

Prospective observational case-control study.

PARTICIPANTS

Fifteen patients with Mooren's ulcer and 30 age- and gender-matched controls seen at Aravind Eye Hospital.

METHODS

Stool samples from the Mooren's ulcer patients and controls were collected and analyzed for presence of hookworm infestation.

MAIN OUTCOME MEASURE

Prevalence of hookworm infestation in Mooren's ulcer patients and controls.

RESULTS

There was a statistically significant correlation between intestinal hookworm infestation and the occurrence of Mooren's ulcer (P = 0.009). Retrospective exploratory subgroup analyses suggested that the correlation between intestinal hookworm infestation and the occurrence of Mooren's ulcer in men (P<0.0001) was stronger than the correlation in women, with no statistically significant difference being observed in the prevalence of hookworm infestation between women with Mooren's ulcer and female control subjects (P>0.99). Similarly, when both the Mooren's ulcer and the control subject groups were analyzed retrospectively by age > 50 years or age < 50, subjects with an age over 50 demonstrated a stronger correlation between hookworm infestation and Mooren's ulcer than controls (P = 0.017), whereas there was no statistically significant difference in the prevalence of hookworm infection between Mooren's ulcer subjects and control subjects < or = 50 (P = 0.31).

CONCLUSION

Intestinal hookworm infestation appears to be associated with the development of Mooren's ulcer in South India. Although the power of our retrospective exploratory subgroup analyses was limited by multiple testing and small sample sizes, these data suggest further that the correlation between intestinal hookworm infestation and the development of Mooren's ulcer may be greatest in male patients with more advanced age.

Chlamydia on children and flies after mass antibiotic treatment for trachoma

There are various approaches to control trachoma. These include the elimination of the ocular strains of Chlamydia trachomatis that cause the disease and to decrease the spread of infection by other measures such as fly control. Here, we examined how these two are related (i.e., how treating children with antibiotics affects carriage of Chlamydia by flies). Flies were collected in villages that had received mass oral azithromycin distribution and were compared with flies in untreated villages. Polymerase chain reaction (PCR) was performed to detect chlamydial DNA on the flies. Conjunctival swabs were also taken to assay for chlamydial prevalence in the children. Chlamydia was found on 23% of the flies in the untreated villages but only 0.3% in treated villages. Prevalence of trachoma in children proved to be an excellent predictor of the prevalence on flies (correlation coefficient, 0.89). Thus, treating children with antibiotics may drastically reduce the role of flies as a vector.

Corneal ulceration in south-east Asia III: prevention of fungal keratitis at the village level in south India using topical antibiotics

AIM

To determine whether topical antifungal prophylaxis distributed by paid village health workers (VHWs) in south India is necessary after corneal abrasion to prevent fungal keratitis in a population where half of the ulcers are fungal.

METHODS

Two panchayaths (village administrative units in Madurai district with a combined population of 48 039 were followed prospectively for 18 months by 15 VHWs who were trained to identify post-traumatic corneal abrasions. Patients fulfilling the eligibility criteria were randomised into two groups and treated with either 1% chloramphenicol and 1% clotrimazole ointment or 1% chloramphenicol and a placebo ointment three times a day for 3 days. Patients, doctors and VHWs were blinded to treatment.

RESULTS

During the 18-month period, 1365 people reported to VHWs with ocular injuries, of whom 374 with corneal abrasions were eligible for treatment. Of these, 368 (98.5%) abrasions healed without complications. Two patients had mild localised allergic reactions to the ointment, two dropped out and two patients in the placebo group developed microscopic culture-negative corneal stromal infiltrates that healed in 1 week with natamycin drops.

CONCLUSIONS

Both fungal and bacterial ulcers that occur after traumatic corneal abrasions seem to be effectively prevented in a village setting using only antibiotic prophylaxis.

The Antioxidants in Prevention of Cataracts Study: effects of antioxidant supplements on cataract progression in South India

AIM

To determine if antioxidant supplements (beta carotene and vitamins C and E) can decrease the progression of cataract in rural South India.

METHODS

The Antioxidants in Prevention of Cataracts (APC) Study was a 5 year, randomised, triple masked, placebo controlled, field based clinical trial to assess the ability of interventional antioxidant supplements to slow cataract progression. The primary outcome variable was change in nuclear opalescence over time. Secondary outcome variables were cortical and posterior subcapsular opacities and nuclear colour changes; best corrected visual acuity change; myopic shift; and failure of treatment. Annual examinations were performed for each subject by three examiners, in a masked fashion. Multivariate modelling using a general estimating equation was used for analysis of results, correcting for multiple measurements over time.

RESULTS

Initial enrolment was 798 subjects. Treatment groups were comparable at baseline. There was high compliance with follow up and study medications. There was progression in cataracts. There was no significant difference between placebo and active treatment groups for either the primary or secondary outcome variables.

CONCLUSION

Antioxidant supplementation with beta carotene, vitamins C and E did not affect cataract progression in a population with a high prevalence of cataract whose diet is generally deficient in antioxidants.

Corneal ulceration in South East Asia. II: a strategy for the prevention of fungal keratitis at the village level in Burma

AIM

To prove that topical antifungal and antibiotic prophylaxis distributed by grass roots village health workers (VHWs) in Burma is an effective public health intervention for the prevention of post-traumatic microbial keratitis in a population where the majority of ulcers are fungal.

METHODS

Three villages in Bago District with a combined population of 16,987 were selected for the study. This defined population was followed prospectively for 12 months by 15 VHWs who were trained to identify post-traumatic corneal abrasions with fluorescein dye and a blue torch and to administer 1% chloramphenicol and 1% clotrimazole ointment three times a day for 3 days to the eyes of individuals who fulfilled the eligibility criteria.

RESULTS

During the 12 month period 273 individuals reported to VHWs with an ocular injury and 126 were found to have a corneal abrasion. All 126 were treated with 1% chloramphenicol and 1% clotrimazole ointment three times a day for 3 days, and all healed without sequelae.

CONCLUSIONS

Both fungal and bacterial ulcers that occur following traumatic corneal abrasions can be effectively prevented in a village setting by using relatively simple measures that local volunteer public health workers can easily be taught to employ.

Corneal ulceration in South East Asia. I: a model for the prevention of bacterial ulcers at the village level in rural Bhutan

AIM

To prove that antibiotic distribution by grassroots volunteer village health workers (VVHWs) in Bhutan is an effective and efficient public health intervention for the prevention of post-traumatic corneal ulceration.

METHODS

55 villages in two districts in Bhutan were selected for the study. A defined population of 10 139 individuals was followed prospectively for 18 months by 31 VVHWs who were trained to identify post-traumatic corneal abrasions with fluorescein dye and a blue torch and to administer 1% chloramphenicol ointment three times a day for 3 days to the eyes of individuals who fulfilled the eligibility criteria.

RESULTS

During the 18 month period 135 individuals reported to VVHWs with an ocular injury and 115 were found to have a corneal abrasion. All 115 were treated with 1% chloramphenicol ointment three times a day for 3 days and all healed without sequelae

CONCLUSIONS

Corneal ulcers that occur following traumatic corneal abrasions can be effectively prevented, even in the setting of isolated rural conditions such as those that exist in villages in Bhutan, by using relatively simple preventative measures that local VVHWs can easily be taught to employ.

Effect of a single mass antibiotic distribution on the prevalence of infectious trachoma

CONTEXT

The World Health Organization recommends mass antibiotic distributions in its strategy to eliminate blinding trachoma as a public health concern. Some hypothesize that a single distribution is sufficient to control the ocular strains of chlamydia that cause trachoma. Others believe infection will inevitably return and periodic treatments or other measures are essential.

OBJECTIVE

To determine whether ocular chlamydial infection returns to the community up to 24 months after a single mass antibiotic distribution in a hyperendemic region of Ethiopia.

DESIGN, SETTING, AND PARTICIPANTS

Longitudinal cohort study conducted March 2003 to March 2005 in the Gurage Zone of Ethiopia. Eight randomly selected villages were assessed for ocular chlamydial infection. Fifteen untreated villages were randomly chosen at 12 months to allow assessment of a secular trend.

INTERVENTION

A single dose of oral azithromycin was offered to all residents of the 8 selected villages who were aged 1 year or older.

MAIN OUTCOME MEASURE

Prevalence of ocular chlamydial infection in all children aged 1 to 5 years from each intervention village prior to treatment and 2, 6, 12, 18, and 24 months after mass antibiotic treatment, and also in untreated villages enrolled at 12 months.

RESULTS

Five hundred fifteen children were examined for ocular chlamydial infection at baseline. For the follow-up examinations, the mean participation rate was 83%. The mean prevalence of infection in children aged 1 to 5 years decreased from 43.5% (95% confidence interval [CI], 35.0%-52.0%) to 5.1% (95% CI, 1.1%-9.2%) after treatment. On average, infection returned gradually over 24 months to 11.3% (95% CI, 4.5%-18.1%; P = .001). In 7 of 8 villages, infection was higher at 24 months than at 2 months. In the remaining village, no infection could be identified at any point after treatment. Villages enrolled at 12 months had significantly fewer infections than those enrolled 12 months earlier, suggesting a secular trend (P<.001).

CONCLUSIONS

Ocular chlamydial infection was not eliminated in children aged 1 to 5 years after a single mass azithromycin distribution; it slowly returned over 24 months, although not to baseline levels. Repeated treatments or other effective measures will be necessary for elimination.

Correlation between clinical suspicion and polymerase chain reaction verification of infectious vitritis

PURPOSE

To compare polymerase chain reaction (PCR) results to presumptive clinical diagnosis in patients with vitritis.

DESIGN

Retrospective review of PCR laboratory records from vitreous samples.

METHODS

Fifty consecutive laboratory records of vitreous samples sent for PCR testing were reviewed. Three reviewers with uveitis training ranked the clinical suspicion of a specific diagnosis using a classification system (scale of 1 to 4) and were masked to the PCR results.

RESULTS

The degree of clinical suspicion of a particular diagnosis was significantly associated with a positive PCR result (P = .048). Higher clinical suspicion was significantly more associated with a positive PCR result compared with cases with lower clinical suspicion (P = .01).

CONCLUSIONS

If the clinical suspicion of a specific diagnosis is low, the PCR for any infectious etiology is unlikely to be positive.

Reliability of transport medium in the laboratory evaluation of corneal ulcers

PURPOSE

To compare the microbiological yield of corneal ulcer cultures established by direct inoculation of culture media vs indirect inoculation by means of transport medium (Amies without charcoal).

DESIGN

Single masked, prospective clinical trial.

METHODS

Scrapings were obtained for Gram and potassium hydroxide (KOH) stains from eyes with presumed infectious keratitis and cultured by direct plating onto standard media. Samples were also held in transport media (Amies without charcoal) at room temperature and then plated after 4 and 24 hours. Yields from direct plating vs cultures by means of transport media were compared.

RESULTS

Of 100 consecutive eyes examined with presumed infectious keratitis, Gram or KOH stain revealed a bacterial or fungal agent in 69 cases (69%). Of these, 26 were bacterial and 43 fungal. Twenty-two bacterial infections produced positive cultures by direct plating, and all produced the same organism with Amies medium after 4 and 24 hours, respectively. For 43 fungal infections identified by KOH stain, 29 (67%) yielded a positive result after 4 hours in Amies transport medium and 27 (63%) after 24 hours in Amies medium. A total of three cases (7%) that showed fungal infection on KOH stain but did not yield organisms by direct plating did so after inoculation with Amies transport medium. For all comparisons, there was no difference in recovery rates by means of transport medium compared with direct plating (McNemar exact P > .05).

CONCLUSIONS

In the clinical setting, Amies transport medium may be a useful alternative to direct inoculation onto blood agar for the laboratory evaluation of infectious keratitis.

Topical ocular antibiotics induce bacterial resistance at extraocular sites

AIM

To compare the prevalence of antibiotic resistance found in nasopharyngeal Streptococcus pneumoniae between villages treated with topical tetracycline or systemic azithromycin as part of a trachoma control programme.

METHODS

All children aged 1-10 years were offered either single dose oral azithromycin treatment (20 mg/kg) or a course of topical 1% tetracycline ointment, depending on the area. Treatment was given annually for 3 years. Six months after the third annual treatment in each village, children were surveyed for nasopharyngeal carriage of S pneumoniae and resistance was determined using broth dilution MIC technique. Children in two additional villages, which had not yet been treated, were also surveyed.

RESULTS

Nasopharyngeal carriage of S pneumoniae was similar in the tetracycline treated, azithromycin treated, and untreated areas (p=0.57). However, resistance to tetracycline and azithromycin was distributed differently between the three areas (p=0.004). The village treated with topical tetracycline had a higher prevalence of tetracycline resistance than the other villages (p=0.010), while the oral azithromycin treated village had a higher prevalence of macrolide resistance than the other villages (p=0.014).

CONCLUSIONS

Annual mass treatment with oral azithromycin may alter the prevalence of drug resistant S pneumoniae in a community. Surprisingly, topical tetracycline may also increase nasopharyngeal pneumococcal resistance. Topical antibiotics may have an effect on extraocular bacterial resistance.

Trachoma decline and widespread use of antimicrobial drugs

Widespread use of antimicrobial drugs may be contributing to trachoma decline.

Trachoma is disappearing in many parts of the world, even in the absence of specific control programs. Following mass antimicrobial drug treatments for trachoma in western Nepal, the prevalence of trachoma declined far more rapidly than could be attributed to the control program alone. Pharmacy surveys in the same region found that children received more antichlamydial drugs from sources outside the trachoma program than they did from the program itself. We demonstrate that high background antimicrobial drug use may be responsible for much of the observed decline in trachoma and discuss its potential role in eliminating this infectious disease.

Lamivudine is not effective in primary Sjögren's syndrome

BACKGROUND

Retroviral infection has been implicated in the pathogenesis of primary Sjögren's syndrome.

OBJECTIVE

To examine the efficacy of the reverse transcriptase inhibitor lamivudine in patients with this syndrome.

METHODS

16 patients with primary Sjögren's syndrome were randomised to receive either lamivudine 150 mg twice daily or placebo for three months. Measures of lacrimal and salivary function, including minor salivary gland biopsies, were obtained before and after treatment.

RESULTS

Treatment with lamivudine did not result in significant improvement in the primary outcome measure of unstimulated whole salivary flow or other secondary measures, including minor salivary gland biopsy focus scores.

CONCLUSION

Lamivudine is not effective in patients with primary Sjögren's syndrome, suggesting either that a retroviral aetiology is not present or that it may be important only in early disease.

How reliable is the clinical exam in detecting ocular chlamydial infection?

PURPOSE

To describe the relationship between the clinical exam for trachoma and the polymerase chain reaction (PCR) for ocular chlamydia.

METHODS

One hundred children in a trachoma-endemic area of Ethiopia were examined three times and swabbed twice for PCR analysis. The assays were compared, and an analysis of the variance between exam and PCR was performed.

RESULTS

Inter-examiner agreement was 0.57 (Cohen's kappa), inter-PCR agreement 0.98, and agreement between examiner and PCR, 0.26-0.34. The positive predictive value of the exam in identifying infection was 66%. Inter-examiner variance accounted for 30% of the total variance between the exam and PCR, with the remainder presumably due to an underlying difference in what the exam and PCR measure.

CONCLUSIONS

Despite modest inter-grader reliability and correlation with evidence of infection, the clinical exam is widely used due to its convenience and low cost. Efforts to make laboratory tests for ocular Chlamydia trachomatis more affordable would be useful.