Relationship between climate, disease severity, and causative organism for contact lens-associated microbial keratitis in Australia
ABSTRACT To evaluate associations between disease severity, causative organism, and climatic variation in contact lens-related microbial keratitis in Australia.
Prospective, observational case series.
Contact lens wearing patients (n = 236) with presumed microbial keratitis presenting to private and hospital ophthalmologists in Australia between October 1, 2003 and September 30, 2004 were identified prospectively. Clinical details, management information, and microbiology data were collected and cases were graded for severity based on lesion size and location criteria. Causative organisms were assigned to "environmental" or "endogenous" groups. Climate zone and daytime temperature and humidity were determined for the geographic location of each event. The main outcome measures were disease severity, causative organism, and climate zone.
Severe contact lens-related microbial keratitis was more likely to occur in warmer, humid regions of the country (P < .001), compared with smaller, increasingly peripheral corneal lesions that were more common in cooler conditions (P < .001). Culture-proven keratitis was predominantly caused by environmental organisms with Pseudomonas aeruginosa being recovered most frequently. Environmental organisms were isolated more commonly from tropical regions of the country and also accounted for nearly all cases of vision loss that occurred during the study period. Humidity did not have a significant effect on causative organism.
Climatic conditions play a role in disease severity and causative organism in contact lens-related microbial keratitis and therefore have implications for practitioners involved in contact lens care and contact lens wearers who live in or travel to the tropics.
- SourceAvailable from: etd.ohiolink.edu
- [Show abstract] [Hide abstract]
ABSTRACT: Contact lens-associated microbial keratitis is a severe condition with sight-threatening potential and increasing incidence. Information regarding the etiological agents is essential in guiding management and may vary geographically. The aim of this study was to analyze the microbiological results of corneal scrapings collected from patients presenting with contact lens-associated microbial keratitis. Retrospective analysis of the records of all patients who were clinically diagnosed with contact lens-associated microbial keratitis and had corneal scrapings sent to the Laboratory of Ocular Microbiology, UNIFESP/EPM during a 5-year period from January 2002 to December 2007. The etiological agent was identified in 239 patients. Bacterial isolates accounted for 166 (69.46%) cases, Acanthamoeba for 95 (39.75%) cases and fungi for 4 (1.67%) cases. Among the bacterial infections, coagulase-negative Staphylococcus was demonstrated in 74 cases, while Pseudomonas spp was found in 32 patients. All coagulase negative Staphylococcus and Pseudomonas were susceptible to ciprofloxacin and ofloxacin. Resistance to gentamicin was documented in a single case of Pseudomonas. Fourth-generation flouoroquinolone resistance was not observed among Pseudomonas cases. Coagulase-negative Staphylococcus was the most frequent isolate, and such data must be considered when determining empiric treatment. Second-generation fluoroquinolones ciprofloxacin and ofloxacin and fourth-generation fluoroquinolones moxifloxacin and gatifloxacin showed a good antibacterial profile and therefore could be good options for initial management.Arquivos brasileiros de oftalmologia 01/2008; 71(6 Suppl):32-6. DOI:10.1590/S0004-27492008000700007 · 0.44 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: We examine the referral pathways and treatment for contact lens-related microbial keratitis in Australia and New Zealand. Cases were reported in May 2003-September 2004; data on presentation, referral and treatment collected from practitioners and via patient interview. Severity was graded, 1-week cure rate estimated, delays in treatment and medications documented. Hospital and private clinic managements were compared. A total of 297 eligible cases were reported; detailed information on treatment and referral pathways was available on a subset of these cases. Presentation was to optometrists (81/200, 41%), general practitioners (GPs) (69/200, 34%) or emergency departments (46/200, 23%). Optometrists referred to private ophthalmologists (47/79, 60%) more often than hospitals (27/79, 34%). GPs initiated treatment (39/68, 57%) but also referred to hospitals (22/68, 32%) and to private ophthalmologists (7/68, 10%). Of all cases, 67% (195/297) were managed in hospitals (29% admitted, 87/297). Hospitalized cases were predominantly managed with fortified aminoglycoside/cephalosporin (66/81, 82%) and others fluoroquinolones (168/195, 86%). Steroids were used in 36% (98/276) commencing on day 5 (median, interquartile range = 3-7). One-week cure rate was 60% (49/82) in private clinics, 72% (62/86) for hospital outpatient cases and 37% (25/67, P < 0.001) for inpatient cases, which were more severe diseases (47%, 52% and 0% mild, respectively). Delays (>/=12 h) receiving therapy were experienced by 33% (55/168) because of initial inappropriate treatment (48/55), time delays (7/55) but not remoteness (P = 0.6). The majority of treatment is via hospital clinics, but milder disease is managed in private clinics. The referral process via optometrists, GPs and emergency departments is generally efficient; however, one-third of cases experienced some delays before receiving appropriate therapy highlighting the need for timely diagnosis.Clinical and Experimental Ophthalmology 05/2008; 36(3):209-16. DOI:10.1111/j.1442-9071.2008.01722.x · 1.95 Impact Factor