Objective

To assess the trends in microbiological organisms identified from corneal scrapings from patients with infectious keratitis at a tertiary care medical centre in South India.

Methods

We reviewed the records of the microbiology laboratory at Aravind Eye Hospital in Madurai, India, from 2002 until 2012. We identified the microbiological causes of all corneal ulcers from the culture and smear results, and assessed for trends in bacterial and fungal keratitis over time.

Results

Of 23 897 corneal patients with ulcer with a corneal smear from 2002 to 2012 a fungal organism was identified in 34.3%, a bacterial organism in 24.7% and no organism in 38.3%. During this period, the annual number of keratitis cases due to bacteria decreased from 677 to 412, and the annual number due to fungus increased from 609 to 863. In analyses accounting for the total number of outpatients seen each year, the decline in number of smears positive for bacteria was statistically significant (p<0.001) but the increase in the number positive for fungus was not (p=0.73). The relative frequency of individual bacterial or fungal organisms remained relatively stable over this time.

Conclusions

At a tertiary eye care centre in South India, there has been a reduction in the numbers of smear-positive bacterial keratitis over the past 11 years. This decline likely reflects economic development in India and increased access to antibiotics.

Aims

To report trends in antibiotic resistance in cases of bacterial keratitis from a large eye hospital in South India.

Methods

In this retrospective cross-sectional study, the microbiology laboratory records of patients with infectious keratitis diagnosed at an eye hospital in South India from 2002 to 2013 were reviewed to determine the proportion with antibiotic non-susceptibility.

Results

3685 bacterial isolates had susceptibility testing performed over the 12-year period. The two most common organisms with resistance were Streptococcus pneumoniae (n=1204) and Pseudomonas aeruginosa (n=894). Antibiotic non-susceptibility was generally uncommon for these two organisms and no significant trends were detected over the course of the study. In contrast, Staphylococcus aureus (N=211) isolates demonstrated a significant increase in fluoroquinolone non-susceptibility over the 12-year study period. This coincided with a significant increase in methicillin-resistant S. aureus (MRSA) during the study period, though the increase in fluoroquinolone resistance was likewise seen in methicillin-sensitive S. aureus (MSSA). For example, ofloxacin resistance in MSSA increased from 11.1% in 2002 to 66.7% in 2013 (p=0.002). No trends were apparent for the aminoglycosides, cefazolin or vancomycin, for which in vitro non-susceptibility generally appeared to be low.

Conclusion

Resistance to antibiotics was generally stable for infectious keratitis isolates from a large eye hospital in South India, except for S. aureus, which experienced a significant increase in fluoroquinolone resistance from 2002 to 2013. Fluoroquinolone antibiotics currently have poor in vitro activity against both MRSA and MSSA in South India and are therefore not the ideal therapy for Staphylococcal corneal ulcers.

Purpose

To determine risk factors and clinical signs that may differentiate between bacterial, fungal, and acanthamoeba keratitis among patients presenting with presumed infectious keratitis.

Design

Hospital-based cross-sectional study.

Methods

We examined the medical records of 115 patients with laboratory-proven bacterial keratitis, 115 patients with laboratory-proven fungal keratitis, and 115 patients with laboratory-proven acanthamoeba keratitis seen at Aravind Eye Hospital, Madurai, India, from 2006-2011. Risk factors and clinical features of the 3 organisms were compared using multinomial logistic regression.

Results

Of 95 patients with bacterial keratitis, 103 patients with fungal keratitis, and 93 patients with acanthamoeba keratitis who had medical records available for review, 287 (99%) did not wear contact lenses. Differentiating features were more common for acanthamoeba keratitis than for bacterial or fungal keratitis. Compared to patients with bacterial or fungal keratitis, patients with acanthamoeba keratitis were more likely to be younger and to have a longer duration of symptoms, and to have a ring infiltrate or disease confined to the epithelium.

Conclusions

Risk factors and clinical examination findings can be useful for differentiating acanthamoeba keratitis from bacterial and fungal keratitis.

Objective

To compare oral voriconazole with placebo in addition to topical antifungals in the treatment of filamentous fungal keratitis.

Design, setting, and participants

The Mycotic Ulcer Treatment Trial II (MUTT II), a multicenter, double-masked, placebo-controlled, randomized clinical trial, was conducted in India and Nepal, with 2133 individuals screened for inclusion. Patients with smear-positive filamentous fungal ulcers and visual acuity of 20/400 (logMAR 1.3) or worse were randomized to receive oral voriconazole vs oral placebo; all participants received topical antifungal eyedrops. The study was conducted from May 24, 2010, to November 23, 2015. All trial end points were analyzed on an intent-to-treat basis.

Interventions

Study participants were randomized to receive oral voriconazole vs oral placebo; a voriconazole loading dose of 400 mg was administered twice daily for 24 hours, followed by a maintenance dose of 200 mg twice daily for 20 days, with dosing altered to weight based during the trial. All participants received topical voriconazole, 1%, and natamycin, 5%.

Main outcomes and measures

The primary outcome of the trial was rate of corneal perforation or the need for therapeutic penetrating keratoplasty (TPK) within 3 months. Secondary outcomes included microbiologic cure at 6 days, rate of re-epithelialization, best-corrected visual acuity and infiltrate and/or scar size at 3 weeks and 3 months, and complication rates associated with voriconazole use.

Results

A total of 2133 patients in India and Nepal with smear-positive ulcers were screened; of the 787 who were eligible, 240 (30.5%) were enrolled. Of the 119 patients (49.6%) in the oral voriconazole treatment group, 65 were male (54.6%), and the median age was 54 years (interquartile range, 42-62 years). Overall, no difference in the rate of corneal perforation or the need for TPK was determined for oral voriconazole vs placebo (hazard ratio, 0.82; 95% CI, 0.57-1.18; P = .29). In prespecified subgroup analyses comparing treatment effects among organism subgroups, there was some suggestion that Fusarium species might have a decreased rate of perforation or TPK in the oral voriconazole-treated arm; however, this was not a statistically significant finding after Holms-Šidák correction for multiple comparisons (effect coefficient, 0.49; 95% CI, 0.26-0.92; P = .03). Patients receiving oral voriconazole experienced a total of 58 adverse events (48.7%) compared with 28 adverse events (23.1%) in the placebo group (P < .001 after Holms-Šidák correction for multiple comparisons).

Conclusions and relevance

There appears to be no benefit to adding oral voriconazole to topical antifungal agents in the treatment of severe filamentous fungal ulcers. All patients in this study were enrolled in India and Nepal; therefore, it is possible that organisms in this region may exhibit characteristics different from those in other regions of the world.

Trial registration

clinicaltrials.gov Identifier: NCT00996736.

PURPOSE:To identify fungal keratitis patients who are at risk of a poor outcome and may benefit from closer follow-up or more aggressive treatment. DESIGN:Secondary analysis of randomized clinical trial data. METHODS:We compared the clinical outcomes of patients who had positive 6-day fungal cultures with those who did not, using backward stepwise regression with covariates for all baseline clinical characteristics. SUBJECTS:Patients presenting with a smear-positive filamentous fungal ulcer and visual acuity of 20/400 or worse, and who subsequently had a 6-day fungal culture performed at the Aravind Eye Care system (India), Lumbini Eye Hospital (Nepal), or Bharatpur Eye Hospital (Nepal). MAIN OUTCOME MEASURES:The primary outcome is rate of corneal perforation and/or the need for therapeutic penetrating keratoplasty. Secondary outcomes include 3-month best spectacle-corrected visual acuity (BSCVA), 3-month infiltrate and/or scar size, and rate of re-epithelialization. RESULTS:Patients who tested positive at their 6-day culture had twice the hazard of experiencing a corneal perforation or the need for therapeutic penetrating keratoplasty (P = .002) than those who tested negative, even after controlling for baseline ulcer characteristics. These patients also had on average 0.26 logMAR lines worse BSCVA at 3 months (P = .001). Culture positivity at day 6 was not a statistically significant predictor of 3-month infiltrate/scar-size (-0.24 mm1; P = .45) or time to re-epithelialization (hazard ratio = .81; P = .31). CONCLUSIONS:Here we identify a uniquely valuable clinical tool, day 6 culture results, for the treatment of severe fungal keratitis. Risk stratification based on repeat culture positivity is an objective way to assess response to medical therapy and identify patients who are at high risk of a poor clinical outcome. This establishes a new standard of care for severe fungal keratitis management.

Importance

Identifying patients with infectious keratitis who are at risk of experiencing a poor outcome may be useful to allocate resources toward high-risk patients, particularly in resource-poor settings.

Objective

To determine baseline patient and ulcer characteristics that predict a high risk of developing corneal perforation and/or the need to undergo therapeutic penetrating keratoplasty (TPK).

Design, setting, and participants

This is a secondary analysis of Mycotic Ulcer Treatment Trial II, a multicenter, double-masked, placebo-controlled randomized clinical trial that enrolled 240 patients with smear-positive filamentous fungal corneal ulcers who enrolled between May 2010 and August 2015. Participants had a baseline visual acuity of 20/400 or worse and were randomized to receive oral voriconazole or a placebo (all participants received topical voriconazole, 1%). After 39 participants (16.3%) were enrolled, topical natamycin, 5%, was also added.

Main outcomes and measures

The primary outcome of this secondary analysis was the rate of corneal perforation or the need to undergo TPK.

Results

The mean (SD) age at enrollment was 49 (13) years, 104 participants (43.3%) were women, and all were of Southeast Asian descent. The presence of hypopyon at baseline indicated 2.28 times the odds of the patient developing corneal perforation and/or needing TPK (95% CI, 1.18-4.40; P = .01). Study participants whose infiltrate involved the posterior one-third had a 71.4% risk of developing corneal perforation and/or needing TPK. For each 1-mm increase in the geometric mean of the infiltrate, there was 1.37 (95% CI, 1.12-1.67; P = .002) increased odds of developing perforation and/or needing TPK. Other clinical features such as visual acuity, baseline culture positivity, type of filamentous fungal organism and duration of symptoms, and demographic characteristics, such as sex and occupation, were not significant predictors in the multivariable regression analysis.

Conclusions and relevance

These results suggest that risk stratification from baseline ulcer characteristics can identify those at highest risk for developing corneal perforation and/or needing TPK.

Trial registration

clinicaltrials.gov Identifier: NCT00996736.